Wild-type Group Research Articles

Impact of peridiagnostic genetic counseling and germline testing on treatment decisions for patients with triple negative breast cancer undergoing pembrolizumab-chemotherapy neoadjuvant approach.

e12633 Background: Triple negative breast cancer (TNBC) has been globally associated with a high risk of carrying pathogenic or likely pathogenic (P/LP) variants in germline breast cancer (BC) susceptibility genes (BCSG). Immunotherapy- based Neoadjuvant (pembro-NA) treatment is the preferred approach for localized, T2 or node positive TNBC. To the best of our knowledge, information about peridiagnostic genetic counseling (PGC), germline status and their impact on patients (pts) undergoing this treatment approach has not been reported yet. Our aim was to describe the feasibility and impact of PGC in TNBC pts treated with pembro-NA and to compare clinical benefits between carriers and wild type (WT) pts in a real- world (RW) setting. Methods: Consecutive, localized TNBC pts who received pembro-NA were enrolled, between March 2022 and August 2023 in a private Argentinian institution. Informed consent was obtained, and medical information collected from medical records and an institutional GC registry. Clinical benefit in terms of pathological complete response (pCR) was analyzed according to BCSG status. Univariate analyses, including chi-square, Fisher and Wilcoxon tests were performed when appropriate. p<0.05 was considered for statistical significance. Results: 47 pts were ascertained. 36.5% (15/41) tested positive for BCSG: 93% (14/15) for BRCA1-2 genes (gBRCA+). No differences were observed in pts ages, with medians of 45 years [IQR 40-50.5] vs 40 [IQR 35-48] among non-carriers versus carriers, respectively (p=0.56). Also, stage at presentation was similar for both subgroups (II: 77.8% vs 60%, III: 14.8% vs 33.3; p=0.37). PGC outcomes: 1/47 (2%) was previously diagnosed as BRCA1 positive (gBRCA+), 1/47 (2%) died before PGC assessment; 85% (40/47) were assessed locally; 64% (30/47) revealed a positive cancer family history; 93% (38/41) were tested through multi-gene panel testing. Median time from diagnosis to first GC appointment was 11.4 weeks (wk) and to disclosure of genetic results by a geneticist or oncologist was 13 wk. Treatment outcomes: 81% (38/47) had completed pembro-NA; one (2%) progressed in the WT group. pCR was achieved in 78.9% (30/38), with no differences between groups (p=0.46). Olaparib or capecitabine were added in pts that did not achieve pCR according to gBRCA status. Notably, 73% carriers versus 37.5% WT pts underwent risk-reducing bilateral mastectomy (p=0.0304). Conclusions: PGC is feasible in a RW scenario of limited resources such as in Argentina. We found a high rate of carriers, mostly gBRCA+, in which surgical decisions and post-NA treatments were determined considering germline status findings. Although efficacy differences between gBRCA+ and WT were not found, further research and data on long-terms outcomes are needed to assess comparative results.

The pan-cancer landscape of SMARCA4 and SMARCB1 alterations in a large cohort of Chinese patients.

e14636 Background: Alterations of SMARCA4 or SMARCB1 (SMARCA4/B1) proteins have been identified in various aggressive cancers. Recent studies show that tumors harboring deleterious SMARCA4/B1 alterations express PD-L1 and respond to immune checkpoint inhibitor (ICI) therapies. Current ongoing immunotherapy-based clinical trials for cancers deficient in SMARCA4/B1 include combinations of atezolizumab and the TIGIT antibody tiragolumab (Phase II), as well as nivolumab and the CTLA-4 antibody ipilimumab (Phases II & III). Here we present a comprehensive analysis of the pan-cancer landscape of SMARCA4/B1 alterations, based on real-world data from a large cohort of Chinese patients. Methods: From 2021 to 2023, we collected genomic information from 16,113 cancer patients, spanning more than 40 different cancer types. These patients had undergone targeted next-generation sequencing (NGS) through the Med1CDx panel, which targets 601 cancer-associated genes. After excluding 1,034 samples of unidentified tumor origins, 15,079 samples were analyzed further. The analysis included somatic and germline pathogenic/likely pathogenic (P/LP) single-nucleotide variants, insertions/deletions, and copy number alteration in SMARCA4/B1. Results: We identified 421/15079 (2.8%) patients with SMARCA4/B1 alterations, with a median age of 63 years (range 13-90). Cancer types with a higher frequency of SMARCA4/CB1 mutations include: endometrial cancer (9.8%), thyroid cancer (6.9%), gastric cancer (6.2%), cholangiocarcinoma (5.7%), and lung cancer (4.4%). The predominant mutation type is variants of uncertain significance (VUS) gene mutations, constituting 72% (302/421) of the spectrum, with nearly all being missense mutations. These are mainly observed in lung cancer, thyroid cancer, and colorectal cancer. The frequency of pathogenic/likely pathogenic mutations is 28% (119/421), mainly distributed in lung cancer and liver cancer. Q201L, P222L, and E1364del are the most common mutations in SMARCA4, with a mutation rate of approximately 4.1%, occurring across over five cancer types. The most common co-mutations of SMARCA4/B1 were TP53 (47.3%), EGFR (25.4%), KRAS (15.9%), STK11 (7.1%) and CDKN2A (7.4%). Clinicopathological feature of age showed no significant differences between SMARCA4/B1 mutant and wild-type groups. Tissues with SMARCA4/B1 mutations exhibited a higher tumor mutational burden (TMB) (median=8.3) than wild-type tissues (median=4.2) (P < 0.001). Conclusions: Elevated TMB levels in patients with SMARCA4/B1 mutations suggest a significant potential benefit from immunotherapy. The presence of co-mutations may also aid in predicting the efficacy of combination immunotherapy treatments. Furthermore, the high prevalence of VUS emphasizes the need for additional research to determine their clinical relevance.

Single-cell sequencing to elucidate the disparities in the immune microenvironment between PIK3CA mutants and wild types.

e17524 Background: In patients with cervical cancer, PIK3CA exhibits the highest mutation rate, with the predominant oncogenic alteration reported to occur in 40% of cases. Recent studies in cervical cancer have indicated that the mutation status of PIK3CA is prominently associated with a diminished overall survival. Nevertheless, in our preceding study entitled 'Efficacy and Safety of Sintilimab Plus Anlotinib for PD-L1–Positive Recurrent or Metastatic Cervical Cancer: A Multicenter, Single-Arm, Prospective Phase II Trial', the prognosis for the mutant group surpassed that of the non-mutant group. Therefore, distinguishing the differences in the immune microenvironment between PIK3CA mutant and wild-type cervical cancer patients is of great significance. Methods: We used Single-cell RNA sequencing (scRNA-seq) to analyze the tissue samples of 7 cervical cancer patients with PIK3CA mutations and 9 with wild-type. Results: We partitioned cells from both the mutated and wild-type forms of cervical cancer into nine distinct clusters. To better understand the transcriptional heterogeneity of tumor-infiltrating T lymphocytes, we re-clustered 45,574 NK/T cells into 9 clusters. A specific cell cluster, designated as CD8+ ISG15, exhibited a significant enrichment in interferon-induced genes, including ISG15, IFIT3, IFIT1, RSAD2, and IFI6. To explore intergroup differences, we performed differential analysis on the proportions of mutations and non-mutations in different subgroups. We found significant differences in CD8+ ISG15 between the mutant group and the widegroup. ISG15 plays a pivotal role in antiviral responses, and as research advances, it has been identified as a potential prognostic biomarker and therapeutic target for cancer, beyond its antiviral function. A growing body of studies indicates that ISG15 is overexpressed in the majority of tumors, however, the influence of high ISG15 expression on the overall survival of cancer patients is dependent on the cancer type. In our single-cell analysis of cervical cancer, we observed that the CD8+ ISG15 subgroup specifically expresses ISG15, and the prevalence of this subgroup is significantly greater in the PIK3CA wild-type group compared to the mutant group. Consequently, the CD8+ ISG15 subgroup is perceived as a significant subset within the cervical cancer immune microenvironment for regulating anti-tumor responses. Conclusions: We defined the CD8+ ISG15 cell cluster present in the cervical cancer immune microenvironment using scRNA-seq, and found that its proportion is significantly lower in the PIK3CA mutant group than in the wild-type group. Combined with existing research, this suggests that this subgroup plays an important role in immune regulation within the cervical cancer immune microenvironment.

Association of homologous recombination repair mutation defined with a 15-gene panel with the prognosis of epithelial ovarian cancer: A Chinese multicenter retrospective study.

e17556 Background: There was no consensus regarding the optimal homologous recombination repair (HRR) gene panel to predict prognosis of epithelial ovarian cancer (EOC). Methods: The genetic testing results in a 15-gene panel from 308 EOC patients diagnosed between 2014 and 2022 from six centres were collected. The association of clinicopathologic characteristics, the use of poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors and progression-free survival (PFS) with 15-gene panel mutation status was assessed. Results: 43.2% (133/308) of patients were determined to carry 144 deleterious HRR mutations (HRRm), among which 68.1% (98/144) were germline mutations and 32.8% (101/308) were BRCA1/2 gene lethal mutations. Patients who received PARP inhibitors (PARPis) were 29.1% (37/127) and 50.5% (46/91) in the HRR wild-type (HRRwt) group and HRRm group at IIIC-IV stages, respectively. A prognostic difference was observed only between the BRCA mutation group and the HRRwt group, not between the non-BRCA HRRm group and the HRRwt group. In univariate analysis, significant predictors of relapse included nonresidual status (HR, 0.62; 95% CI, 0.39-0.98; P = 0.0287), 15-gene panel mutation (HR, 0.42; 95% CI, 0.28-0.64; P = 0.0001), platinum sensitivity (HR, 0.07; 95% CI, 0.02-0.22; P < 0.001) and maintenance therapy (PARPi) (HR, 0.48; 95% CI, 0.31-0.74; P = 0.0028) (Figure 5). In multivariate Cox analysis, nonresidual (HR, 0.63; 95% CI, 0.40-0.99; P = 0.046), 15-gene panel mutation (HR, 0.49; 95% CI, 0.28-0.88; P = 0.016) and platinum sensitivity (HR, 0.02; 95% CI, 0.01-0.05; P < 0.001) remained independent prognostic factors. Conclusions: This study provides evidence that HRRm with a 15-gene panel can predict the prognosis of EOC, among which only BRCA1/2 mutations contribute to prognosis prediction. [Table: see text]

Analyzing Differences in Hematological and Immunological Characteristics Related to Common Gene Mutations in Myelodysplastic Syndromes.

Genetic mutations play a crucial role in the development and progression of myelodysplastic syndromes (MDS), impacting the immune microenvironment and influencing the choice of treatment regimen, as well as the efficacy and prognosis of patients. The objective of this study was to examine variations in hematological and immunological characteristics associated with common gene mutations in MDS patients and establish a foundation for the precise treatment of MDS. The hematological, immunological, and other clinical features of 71 recently diagnosed MDS patients from January 1, 2019, to July 31, 2023, were retrospectively analyzed. These patients were categorized based on their gene mutations, and the variances in hematological and immunological characteristics among distinct groups were compared. Hematological variances were observed among different gene mutation groups. Specifically, platelet counts in the splicing factor 3B subunit 1 (SF3B1) mutation group were notably higher compared to the wild-type group (p = 0.009). Conversely, in the additional sex combs like 1 (ASXL1) mutation groups, monocyte ratios were significantly elevated in comparison to the wild-type group (p = 0.046), and in the ten-eleven translocation 2 (TET2) mutation group, lymphocyte ratios were significantly lower (p = 0.022). Additionally, the leukocyte (p = 0.005), neutrophil ratio (p = 0.002), and lymphocyte ratio (p = 0.001) were significantly higher in the Runt-related transcription factor 1 (RUNX1) mutation group. Regarding immunological distinctions, the Natural Killer (NK) cell ratio demonstrated a significant increase in the SF3B1 mutation group (p = 0.005). Moreover, the TET2 mutation group exhibited a significantly higher Interleukin-8 (IL-8) level (p = 0.017). In contrast, the U2 small nuclear RNA auxiliary factor 1 (U2AF1) group displayed significantly lower levels of IL-1β (p = 0.033), IL-10 (p = 0.033), and Tumour Necrosis Factor-α (TNF-α) (p = 0.009). Distinct variations exist in the immune microenvironment of MDS associated with different genetic mutations. Further studies are imperative to delve into the underlying mechanisms that drive these differences.

Genetic Profiling and Survival Outcomes in Romanian Colorectal Cancer Patients.

The increasing incidence of colorectal cancer is one of the most frequently addressed medical topics worldwide. It represents the third most commonly diagnosed cancer in both men and women globally, with significant implications for public health. Mortality for this type of malignancy remains high, second only to lung cancer. Given their clinical relevance, the identification and understanding of KRAS and BRAF mutations have become crucial components of personalized medicine approaches in colorectal cancer. Hence, our desire is to carry out a research that analyzes the impact of these mutations in terms of survival and mortality on patients diagnosed with colorectal cancer. We conducted a retrospective study spanning from 2018 to 2022, which involved 118 patients diagnosed with colorectal cancer. The patients were selected from the databases of the Oradea County Emergency Clinical Hospital and Pelican Oradea Hospital. Genetic testing was performed at the "Resident Laboratory" clinic. Subsequently, patients were divided into two groups of equal size based on the presence or absence of mutations. The survival rate one year after the diagnosis of colorectal cancer is 84.74% (N=50/59) for the mutant group versus 67.96% (N=40/59) for the wild-type group. The survival rate at five years from the diagnosis of colorectal cancer is 25.93% (N=15/59) for patients with wild-type tumors compared to 33.54% (N=20/59) for patients with tumors with mutant status (p=0.483, HR=1.153, CI 95% 0.7661-1.735). The five-year survival rate, depending on the mutation present, highlights the fact that the average overall survival for those with the KRAS mutation is 38.6 months (CI 95% 35.22-41.97) and for those with the BRAF mutation is 8.3 months (CI 95% 5.42-11.17) (p=0.039). The mortality rate for mutant KRAS is 44.89% (N=22/50), while for those with mutant BRAF, it is 100% (N=6/6). We observed no statistically significant difference in overall survival rate and disease-free interval between the two studied groups, but the overall survival was better for those with mutations present (38.64 months versus 31.07 months for wild-type tumors). The mortality rate is higher among tumors with wild-type status (p=0.005), in the first year after the diagnosis of colorectal cancer. The BRAF mutation confers a much worse prognosis than the KRAS mutation, from both the survival analysis and the mortality rate.

Real-world outcomes in patients with biomarker-selected early-stage non-small cell lung cancer.

11156 Background: Extensive literature has assessed the prognostic value of Lung driver mutations (LDMs) in advanced non-small cell lung cancer (aNSCLC). However, their role in predicting outcomes in early-stage cases (eNSCLC) is less defined due to limited data on biomarker-selected eNSCLC. Study variations have led to diverse findings on the prognostic value of individual LDMs in eNSCLC. Methods: We retrospectively analyzed patients with resected stage I-IIIa NSCLC diagnosed between 2011-2023 using the nationwide (US-based) de-identified Flatiron Health-Foundation Medicine lung clinico-genomic database, which consolidates data from approximately 280 US cancer clinics (~800 sites of care). We allocated patients to five cohorts classified by early-stage LDM status: ALK+, EGFR+, KRAS G12C+, KRAS non-G12C+ and wild-type (WT - negative for the listed biomarkers). The clinical attributes and treatment patterns for this cohort were described by our group in a previous abstract; here we analyze recurrence-free and overall survival (RFS and OS) by cohort, using the Kaplan-Meier method. We used Cox regression for multivariate analysis, controlling for demographic and clinical characteristics including age, race, insurance status, stage, histology, and smoking status. Results: The sample contained 1,595 stage I-IIIa patients with known LDM status. Of these, 2.8%, 20.4%, 10.7%, 19.3%, and 46.8% were ALK+, EGFR+, KRAS G12C+, KRAS non-G12C+, and WT. Median OS and RFS were shorter in the WT group compared to any LDM group; results can be found in the table. These differences in OS and RFS persisted in multivariate analysis; hazard ratios (HR) were all statistically significant (p<0.05) and can be found in the table below. Conclusions: In this real-world analysis, patients with eNSCLC LDM-positive tumors had improved OS and RFS relative to WT patients. Differences in OS between WT and LDM+ patients are likely due to frequent receipt of targeted therapy (TT) following progression to advanced disease. However, the small fraction of patients that received adjuvant TT within 6 months of surgery (described in our previous abstract) is not likely to explain observed differences in RFS; thus the differences may be due to innate characteristics of these LDMs. [Table: see text]

Exploratory biomarker analysis for predicting treatment effects of aflibercept in the VELOUR trial.

3592 Background: Second-line treatment with aflibercept and FOLFIRI in patients with metastatic colorectal carcinoma (mCRC) previously treated with oxaliplatin improved overall survival (OS) versus placebo [Hazard ratio (HR), 0.81; 95% CI, 0.71–0.93; P=0.003]1. However, colorectal cancer (CRC) is a heterogenous disease and the new intrinsic consensus molecular (iCMS) allows for tumours to be subtyped into unique genetic and transcriptional features2. We present a post hoc analysis of VELOUR patient data, to assess the impact of KRAS or BRAF mutation status and iCMS on efficacy parameters. Methods: Patient samples were classified as either KRAS or BRAF mutant or wild-type (WT) via a targeted mutation panel1. Gene expression data was used to classify samples as either iCMS2 or iCMS3 using a modified classifier based on iCMS signatures which are specifically up-regulated in tumour samples2. Results: Of the 439 patients with available RNA data, 54.9% (241/439) were classified as iCMS2; 45.1% (198/439) as iCMS3; 48.3% (212/439) as RAS mutant and 8.4% (37/439) as RAF mutant. A favourable aflibercept treatment effect was observed for patients within the KRAS WT group (Median OS from 11 to 17.7 months; HR 0.87; 95% CI 0.79-0.96, P=0.005), particularly for patients with KRAS WT iCMS2 tumours (Median OS from 15.5 to 30.4 months; HR 0.81; 95% CI 0.70-0.94, P=0.004). This is in comparison to the KRAS WT iCMS3 patients where no treatment benefit was seen (HR 0.97; 95% CI 0.82-1.14, P=0.683). In addition, no treatment benefit was seen in the KRAS mutant group (OS HR 1.03; 95% CI 0.96-1.12, P=0.405). Progression-free survival (PFS) data followed the same trend. Aflibercept seemed to also strongly benefit the 37 patients with BRAF-mutated tumours, (PFS HR 0.46, 95% CI 0.20-1.09; OS HR 0.65, 95% CI 0.29-1.48), although differences were not statistically significant. Irrespective of treatment, improved OS (HR 0.60; 95% CI 0.48-0.75, P< 0.001) and PFS (HR 0.75; 95% CI 0.60-0.94, P=0.011) were observed in all patients with iCMS2 versus iCMS3 tumours, as expected. Treatment-by-mutation status interaction tests (OS P=0.40, PFS P=0.33) indicated that the aflibercept benefit was not statistically different among the mutation sub-groups, although the small sample size limited the analysis. Conclusions: In the VELOUR study, the benefit of the addition of aflibercept to FOLFIRI appears to be primarily in patients with KRAS WT tumours, especially those with KRAS WT iCMS2. The improved OS and PFS seen in all patients with iCMS2 tumours in comparison to iCMS3 is prognostic but not predictive of aflibercept treatment response in addition to FOLFIRI. On the contrary, the addition of aflibercept to FOLFIRI provided a numerical benefit in BRAF-mutated tumours, however the P-values were not statistically significant.

Real-world impact of KRAS mutations on clinical outcomes in metastatic colorectal cancer treated with trifluridine-tipiracil in the USA.

e15566 Background: Defining the impact of KRAS mutation status on outcomes to standard of care treatments in metastatic colorectal cancer (mCRC) is of increasing clinical relevance. We interrogated a large real-world genomic database to further explore the association between KRAS mutations and benefit to trifluridine-tipiracil (FTD-TPI) in patients with mCRC. Methods: 19,364 patients with mCRC and known KRAS mutation status were analyzed by next-generation sequencing (NextSeq, 592 Genes; NovaSeq, whole exome sequencing (WES)) at Caris Life Sciences. Real-world overall survival (rwOS) and time on treatment (ToT) was inferred from insurance claims data and calculated from time of start of treatment with FTD-TPI to last contact and time from first to last treatment with FTD-TPI with comparison done by the Kaplan-Meier test, respectively. Chi-square test was applied where appropriate, with p-value adjusted for multiple comparisons (p < 0.05). Results: 764 of 10,571 (7.2%) patients with wild-type (WT) KRAS, 768 of 6,984 (11%) with KRAS G12 mutation, and 170 of 1,809 (9.4%) with KRAS G13 mutation received FTD-TPI. Age distribution was similar among groups. Sidedness of primary site was reported in 692 (40.3%) patients; an increased proportion of right-sided tumors was observed in KRAS G12 (53.4% vs. 28.3%, p < 0.0001) and G13 (56% vs 28.3%, p < 0.0001) groups compared to KRAS WT. An increased proportion of TP53 mutations in KRAS WT was observed compared to KRAS G12 mutation (87% vs. 70%, p < 0.0001) and KRAS G13 mutation groups (87% vs. 75%, p < 0.0001). KRAS G12 mutation was associated with shorter median rwOS compared to KRAS WT (7.33 vs. 8.43 months (mo), HR 1.13 (95% CI 1.11-1.42), p = 0.041). KRAS G13 mutation was associated with similar rwOS to KRAS WT. Median ToT was shorter in patients with KRAS G12 mutations than KRAS WT (1.8 vs. 2 mo, HR of 1.22 (95% CI 1.11-1.42), p < 0.001). Median ToT was longer in patients with KRAS G13 versus KRAS G12 (2.3 vs. 1.8 mo, HR 0.82 (95% CI 0.68-0.98), p = 0.032). Conclusions: To our knowledge, this is the largest primarily US-based cohort of mCRC treated with FTD-TPI to be reported. KRAS G12 mutation, but not KRAS G13 mutation, was associated with shorter rwOS and ToT compared to KRAS WT, despite enrichment of TP53 and BRAF mutations in the KRAS WT group. This finding is consistent with previously published analyses of large randomized prospective trials of FTD-TPI in mCRC and further support KRAS mutation status as a predictive biomarker in this setting. [Table: see text]

Effect of SlSAHH2 on metabolites in over-expressed and wild-type tomato fruit.

Tomato (Solanum lycopersicum) is an annual or perennial herb that occupies an important position in daily agricultural production. It is an essential food crop for humans and its ripening process is regulated by a number of genes. S-adenosyl-l-homocysteine hydrolase (AdoHcyase, EC 3.3.1.1) is widespread in organisms and plays an important role in regulating biological methylation reactions. Previous studies have revealed that transgenic tomato that over-express SlSAHH2 ripen earlier than the wild-type (WT). However, the differences in metabolites and the mechanisms driving how these differences affect the ripening cycle are unclear. To investigate the effects of SlSAHH2 on metabolites in over-expressed tomato and WT tomato. SlSAHH2 over-expressed tomato fruit (OE-5# and OE-6#) and WT tomato fruit at the breaker stage (Br) were selected for non-targeted metabolome analysis. A total of 733 metabolites were identified by mass spectrometry using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database and the Human Metabolome database (HMDB). The metabolites were divided into 12 categories based on the superclass results and a comparison with the HMDB. The differences between the two databases were analyzed by PLS-DA. Based on a variable important in projection value >1 and P < 0.05, 103 differential metabolites were found between tomato variety OE-5# and WT and 63 differential metabolites were found between OE-6# and WT. These included dehydrotomatine, L-serine, and gallic acid amongst others. Many metabolites are associated with fruit ripening and eight common metabolites were found between the OE-5# vs. WT and OE-6# vs. WT comparison groups. The low L-tryptophan expression in OE-5# and OE-6# is consistent with previous reports that its content decreases with fruit ripening. A KEGG pathway enrichment analysis of the significantly different metabolites revealed that in the OE-5# and WT groups, up-regulated metabolites were enriched in 23 metabolic pathways and down-regulated metabolites were enriched in 11 metabolic pathways. In the OE-6# and WT groups, up-regulated metabolites were enriched in 29 pathways and down-regulated metabolites were enriched in six metabolic pathways. In addition, the differential metabolite changes in the L-serine to flavonoid transformation metabolic pathway also provide evidence that there is a phenotypic explanation for the changes in transgenic tomato. The metabolomic mechanism controlling SlSAHH2 promotion of tomato fruit ripening has been further elucidated.

Zebrafish dspb-/- mutant as model for arrhythmogenic cardiomyopathy - impact of physical activity

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Instituto de Salud Carlos III Background Zebrafish has been reported as a model to study the Arrythmogenic cardiomyopathy, which is generally associated with desmosomal gene mutations. We have identified a founder non-sense human variant in patients from our region (DSP p.Q447*) associated with left ventricle Arrythmogenic cardiomyopathy and we have selected it for modelling in zebra fish by CRISPR/Cas9 method, choosing exon 10 as the region of homology to be mutated and obtaining the p.T449fs* variant that determines a premature stop codon. Purpose Our aim was the characterization of dspb-/- mutants, studying the impact of physical activity in development of the disease. Methods The characterization of phenotype was performed through viability assays, cardiac function measurements and gene expression assays in larvae (3 days post fertilization) and adult (8 months old) individuals. The impact of physical activity was determined through moderated training periods (1 month) and endurance assays using a swimming tunnel. Results Viability assays showed that dspb mutants suffer a premature death, with significant higher mortality rates than the wildtype group (survival WT 89.7% vs dspb-/- 61.3%, p&amp;lt;0.01). Larvae cardiac function showed dspb mutants had a higher heart rate (WT 106.8 ± 26.8 vs dspb-/- 141.0 ± 7.2, p&amp;lt;0.01) while echocardiography showed differences in heart rate (WT 127.2 ± 49,8 vs dspb-/- 219.2 ± 26.8, p&amp;lt;0.05), systolic (WT 26.9 ± 5.3 vs dspb-/- 18.5 ± 5.2, p&amp;lt;0.05) and diastolic (WT 37.6 ± 8.4 vs dspb-/- 23.7 ± 5.4, p&amp;lt;0.05) areas. Gene expression analysis in adult heart showed dspb expression drastically decreased (WT 0.9 ± 0.1 vs dspb-/- 0.4 ± 0.01, p&amp;lt;0.01), whilst pkp2 expression increased (WT 0.9 ± 0.1 vs dspb-/- 2.59 ±0.22, p&amp;lt;0.001) as well as dspa gene expression (wt 0.9 ± 0.1 vs dspb-/- 4.41 ± 0.18, p&amp;lt; 0.001) as a compensation mechanism. Moderated long term physical activity had a positive impact in heart rate (dspb-/-pre 219.2 ± 26.8 vs dspb-/-post 138 ± 7.5, p&amp;lt;0.01) and diastolic area (dspb-/-pre 24 ± 5 vs dspb-/-post 32 ± 2.1, p&amp;lt;0.05). Adult mutants showed a better endurance showing improvement in immobile cumulative duration (dspb-/-pre 849.3 ± 29.3 vs dspb-/-post 179.8 ± 29.7, p&amp;lt;0.01) and immobile frequency (dspb-/-pre 5399.5 ± 1127.8 vs dspb-/-post 1310 ± 481.9, p&amp;lt;0.01). Conclusion The dspb-/- zebrafish presented pathological cardiac phenotype at larvae and adult stages, and less endurance in intensity exercises. The moderate exercise has turned out to be a beneficial modulator of the phenotype.

A novel gain-of-function mutation in transient receptor potential C6 that causes podocytes injury.

Podocyte injury plays a vital role in focal segmental glomerulosclerosis (FSGS), and apoptosis is one of its mechanisms. The transient receptor potential channel 6 (TRPC6) is highly expressed in podocytes and mutations mediate podocyte injury. We found TRPC6 gene mutation (N110S) was a new mutation and pathogenic in the preliminary clinical work. The purpose of this study was to investigate the potential mechanism of mutation in TRPC6 (TRPC6-N110S) in the knock-in gene mouse model and in immortalized mouse podocytes (MPC5). Transmission electron microscopy was used to evaluate renal injury morphology. We measured 24-hour urinary albumin-to-creatinine ratios and major biochemical parameters such as serum albumin, urea nitrogen, and total cholesterol. The results of CCK-8 assay and apoptosis experiments showed that the TRPC6-N110S overexpression group had slower proliferative activity and increased apoptosis than the control group. FluO-3 assay revealed increased calcium influx in the TRPC6-N110S overexpression group. Podocin level was decreased in TRPC6-N110S group, while TRPC6 and desmin levels were increased in TRPC6-N110S group. The 24 h uACR at 6 weeks was significantly higher in the pure-zygotes group than in the WT and heterozygotes groups, and this difference was found at 8 and 10 weeks.TRPC6 levels showed no significant difference between homozygote and WT mice. Compared to homozygote group, expression of podocin and nephrin were increased in WT, but levels of desmin was decreased in WT. Our results suggest that this new mutation causes podocyte injury probably by enhancing calcium influx and podocyte apoptosis, accompanied by increased proteinuria and decreased expression of nephrin and podocin.

Focused Ultrasound-Mediated Disruption of the Blood-Brain Barrier for AAV9 Delivery in a Mouse Model of Huntington's Disease.

Huntington's disease (HD) is a monogenic neurodegenerative disorder caused by a cytosine-adenine-guanine (CAG) trinucleotide repeat expansion in the HTT gene. There are no cures for HD, but the genetic basis of this disorder makes gene therapy a viable approach. Adeno-associated virus (AAV)-miRNA-based therapies have been demonstrated to be effective in lowering HTT mRNA; however, the blood-brain barrier (BBB) poses a significant challenge for gene delivery to the brain. Delivery strategies include direct injections into the central nervous system, which are invasive and can result in poor diffusion of viral particles through the brain parenchyma. Focused ultrasound (FUS) is an alternative approach that can be used to non-invasively deliver AAVs by temporarily disrupting the BBB. Here, we investigate FUS-mediated delivery of a single-stranded AAV9 bearing a cDNA for GFP in 2-month-old wild-type mice and the zQ175 HD mouse model at 2-, 6-, and 12-months. FUS treatment improved AAV9 delivery for all mouse groups. The delivery efficacy was similar for all WT and HD groups, with the exception of the zQ175 12-month cohort, where we observed decreased GFP expression. Astrocytosis did not increase after FUS treatment, even within the zQ175 12-month group exhibiting higher baseline levels of GFAP expression. These findings demonstrate that FUS can be used to non-invasively deliver an AAV9-based gene therapy to targeted brain regions in a mouse model of Huntington's disease.

Associations between genetic mutations in different SARS-CoV-2 strains and negative conversion time of viral RNA among imported cases in Hangzhou: A cross-sectional study

PurposePrevious studies on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have focused on factors that influence the achievement of negative conversion of viral RNA. This study aimed to investigate the effects of the genetic mutations in different SARS-CoV-2 strains on the negative conversion time (NCT) among imported cases in Hangzhou, Zhejiang Province, China, in order to provide valuable insights for developing targeted epidemic prevention guidelines. MethodsThis retrospective study involved 146 imported SARS-CoV-2 cases in Hangzhou from 8 April 2021 to 11 June 2022. We compared the SARS-CoV-2-specific indicators, clinical indexes, and NCT among the wild-type (WT), Delta, and Omicron groups. Spearman correlation analysis was used to identify the correlations of NCT with mutation types/frequencies. ResultsThe mean age of the imported cases was 35.3 (SD: 12.3) years, with 71.92 % males and 28.08 % females. The mean cycle threshold (Ct) values of open reading frame 1ab (ORF1ab) and nucleocapsid (N) RNA were 25.17 (SD: 6.44) and 23.4 (SD: 6.76), respectively. The mutations of SARS-CoV-2 strains were mainly located in N, membrane (M), spike (S), ORF1a, ORF1b, ORF3a, ORF6, and ORF9b genes among the WT, Delta, and Omicron groups. NCT was significantly prolonged in the WT and Delta groups compared to the Omicron group. T lymphocyte, white blood cell, eosinophil, and basophil counts were dramatically higher in the WT group than the Delta group. White blood cell, red blood cell, and basophil counts were significantly lower in the Delta group than the Omicron group. Spearman correlation analysis revealed a significant correlation between the NCT of viral RNA and mutation types of viral genes of WT and Omicron strains. Additionally, NCT was markedly negatively correlated with the frequencies of five mutations in Omicron strains (ORF1b:P1223L, ORF1b:R1315C, ORF1b:T2163I, ORF3a:T223I, and ORF6:D61L). ConclusionsThis study indicates that five mutations in Omicron strains (ORF1b:P1223L/R1315C/T2163I, ORF3a:T223I and ORF6:D61L) shortened NCT in imported SARS-CoV-2 cases.

Association between Aquaporin 7 Expression and Myocardial Protection with Nicorandil or Del Nido Cardioplegia: An Experimental Study

Background: Aquaporin 7 (AQP7), a member the aquaglyceroporin subgroup of the AQP family, is a water channel that controls transport of glycerol and water in heart tissues. It facilitates the uptake of glycerol, a substrate for cardiac energy production, in cardiomyocytes. St. Thomas' Hospital cardioplegic solution No. 2 has cardio-protective effect even in AQP7-deficient hearts. Here, we aimed to determine whether nicorandil or del Nido cardioplegia (DNC) solution can protect AQP7-deficient hearts. Methods: The hearts of male AQP7 knockout (KO) and wild-type (WT) C57/B6N mice (age &gt;15 weeks) were aerobically perfused using the Langendorff technique, and cardiac function was measured as left ventricular diastolic pressure (LVDP) throughout the study. Troponin T was measured as an indicator of myocardial damage after reperfusion for 60 min. We compared WT and KO controls subjected to 25 min of global ischemia as well as WT and KO groups infused with nicorandil (100 µM) for 10 min followed by 25 min of global ischemia. We also compared WT-DNC and KO-DNC hearts administered with DNC for 2 min followed by 23 min of global ischemia (Study 2). Results: The final recovery rates of LVDP were 20.8 ± 7.0%, 28.1 ± 7.6%, 40.0 ± 8.4%, and 38.7 ± 4.7% in the WT control, KO control, WT nicorandil, and KO nicorandil groups, respectively. The LVDP recovered faster in the hearts treated with DNC and reached a significantly higher plateau in the KO than in the WT hearts. Troponin T values were 2144 ± 493 and 1313 ± 717 in the WT and KO groups, respectively (p = 0.041). Conclusion: The Langendorff perfusion model revealed similar myocardial protective effects of nicorandil in AQP7-deficient mice as in WT mice. AQP7 deficiency did not impair the cardioprotective effects of DNC solution.

Determinants of plasma levels of proglucagon and the metabolic impact of glucagon receptor signalling: a UK Biobank study

Aims/hypothesesGlucagon and glucagon-like peptide-1 (GLP-1) are derived from the same precursor; proglucagon, and dual agonists of their receptors are currently being explored for the treatment of obesity and metabolic dysfunction-associated steatotic liver disease (MASLD). Elevated levels of endogenous glucagon (hyperglucagonaemia) have been linked with hyperglycaemia in individuals with type 2 diabetes but are also observed in individuals with obesity and MASLD. GLP-1 levels have been reported to be largely unaffected or even reduced in similar conditions. We investigated potential determinants of plasma proglucagon and associations of glucagon receptor signalling with metabolic diseases based on data from the UK Biobank.MethodsWe used exome sequencing data from the UK Biobank for ~410,000 white participants to identify glucagon receptor variants and grouped them based on their known or predicted signalling. Data on plasma levels of proglucagon estimated using Olink technology were available for a subset of the cohort (~40,000). We determined associations of glucagon receptor variants and proglucagon with BMI, type 2 diabetes and liver fat (quantified by liver MRI) and performed survival analyses to investigate if elevated proglucagon predicts type 2 diabetes development.ResultsObesity, MASLD and type 2 diabetes were associated with elevated plasma levels of proglucagon independently of each other. Baseline proglucagon levels were associated with the risk of type 2 diabetes development over a 14 year follow-up period (HR 1.13; 95% CI 1.09, 1.17; n=1562; p=1.3×10−12). This association was of the same magnitude across strata of BMI. Carriers of glucagon receptor variants with reduced cAMP signalling had elevated levels of proglucagon (β 0.847; 95% CI 0.04, 1.66; n=17; p=0.04), and carriers of variants with a predicted frameshift mutation had higher levels of liver fat compared with the wild-type reference group (β 0.504; 95% CI 0.03, 0.98; n=11; p=0.04).Conclusions/interpretationOur findings support the suggestion that glucagon receptor signalling is involved in MASLD, that plasma levels of proglucagon are linked to the risk of type 2 diabetes development, and that proglucagon levels are influenced by genetic variation in the glucagon receptor, obesity, type 2 diabetes and MASLD. Determining the molecular signalling pathways downstream of glucagon receptor activation may guide the development of biased GLP-1/glucagon co-agonist with improved metabolic benefits.Data availabilityAll coding is available through https://github.com/nicwin98/UK-Biobank-GCGGraphical

The Recombinant Profilin from Free-Living Amoebae Induced Allergic Immune Responses via TLR2.

Repeated exposure to recombinant profilin from Acanthamoeba (rAc-PF) induces allergic airway responses in vitro and in vivo. Based on the role of toll-like receptors (TLRs) in allergic airway diseases, TLRs play a central role in innate immune responses and the adaptive immune system and regulate responses against antigens through antigen-specific receptors. In this study, we attempted to determine the molecular mechanisms underlying rAc-PF-induced allergic inflammatory responses. We determined the correlation between rAc-PF and TLRs and analyzed changes in allergic immune responses after blocking multiple TLR signaling under rAc-PF treatment conditions in vitro. We also compared allergic inflammatory responses in TLR2 knockout (KO) and wild-type (WT) mice. To investigate the effect of TLR2 on antigen prototyping and T cell activation in the inflammatory response induced by rAc-PF, we assessed maturation of BMDCs and polarization of naïve T cells by rAc-PF stimulation. Additionally, we compared changes in inflammation-related gene expression by rAc-PF treatment in primary lung epithelial cells isolated from TLR2 KO and WT mice. The rAc-PF treatment was increased the expression level of TLR2 and 9 in vitro. But, there were not significantly differ the others TLRs expression by rAc-PF treated group. And then, the mRNA expression levels of inflammation-related genes were reduced in the TLR2 or TLR9 antagonist-treated groups compared to those in the rAc-PF alone, were no difference the treated with the other TLRs (TLR4, 6, and 7/8) antagonist. The difference was higher in the TLR2 antagonist group. Additionally, the levels of airway inflammatory disease indicators were lower in the TLR2 KO group than in the WT group after rAc-PF treatment. Furthermore, the expression of bone marrow-derived dendritic cell (BMDC) surface molecular markers following rAc-PF stimulation was lower in TLR2 KO mice than in WT mice, and TLR2 KO in BMDCs resulted in a remarkable decline in Th2/17-related cytokine production and Th2/17 subset differentiation. In addition, the expression levels of rAc-PF-induced inflammatory genes were reduced inTLR2 KO primary lung cells compared to those in normal primary lung cells. These results suggest that the rAc-PF-induced airway inflammatory response is regulated by TLR2 signaling.

Abstract 145: Chronic Electronic Cigarette Exposure Accelerates SMC Phenotypic Modulation And Activates The NMDA-type Glutamate Receptor (NMDAR) Pathway In Mediating Vascular Calcification

Introduction: Electronic cigarettes pose a serious emerging threat to cardiovascular health. The use of electronic nicotine delivery systems (ENDS) such as electronic cigarettes (e-cigs) have increased exponentially, especially among adolescents. Emerging data suggest e-cig use has been implicated in promoting atherosclerosis. This work explores the mechanism of e-cig exposure accelerated the atherosclerotic lesion development and vascular remodeling. Methods: SMC-lineage tracing mice (n=16) on a ApoE null hyperlipidemic background were put on high fat diet for 12 weeks and exposed to pod-based e-cigs (Juul) three times a week for 12 weeks in a whole-body chamber (inExpose, Scireq) and compared to WT mice exposed to air (n=16). The aortic sinus was dissected and digested, FACS was performed to sort for live single cells, then single-cell RNA-Seq (sc-RNAseq) and ATAC-seq were performed on the 10X Genomics platform. Analyses were completed with Seurat and Signac tools. The osteogenic load was assessed by histology with alkaline phosphatase (AP) enzymatic assay using the Ferangi Blue Chromogen kit. Results: scRNA-Seq analysis revealed that e-cig accelerated the SMC transition to a chondrogenic phenotype (CMC). We found a significantly increased proportion of chondromyocytes (CMC) expressing specific markers such as Col2a1 and Acan in the e-cig exposed mice compared to control. The scATAC-seq profiles showed that e-cig exposed mice develop a cell cluster that enriched for markers related to nicotine, glutamatergic and dopaminergic pathways. The genes highly enriched for chromatin accessibility in this cluster included Grin2a , a gene that encodes a N-methyl-D-aspartate receptor (NMDAR) GluN2A, which was found to be expressed in the fibromyocyte and CMC population of the scRNA-seq. Consistent with our finding from the scRNA-Seq data showing a greater CMC proportion in the e-cig exposed mice, we found the relative AP-stained area to be larger in the exposed group than in the WT group. Conclusion: Overall, these data indicate that e-cig exposure can promote atherosclerosis through adverse SMC phenotypic modulation. Moreover, e-cig exposure induces NMDAR activation that may be implicated in SMC modulation to a chondrogenic phenotype.

C-Jun N-Terminal Kinase-2 (JNK2) Plays a Crucial Role in Alcohol and Corticosterone-Induced Dysbiosis of Gut Microbiota and Tissue Injury at the Gut-Liver Axis

Introduction: About 15% of heavy drinkers develop liver disease, suggesting the “Multiple hit hypothesis” of Alcohol-Associated Liver Diseases (AALD). Chronic stress is a potential second hit in AALD pathogenesis. Our recent study showed that alcohol-induced gut and liver injury is exacerbated by chronic restraint stress or corticosterone. JNK2 plays an essential role in stress-induced cell injury. In this study, we investigated the role of JNK2 in ethanol (EtOH) and corticosterone-induced gut and liver injury and microbiota dysbiosis in mice. Methods: Wildtype (WT) and JNK2 knockout (JNK2-KO) mice (male and female; 8-10 wks) were fed a Lieber-DiCarli liquid diet with or without EtOH (0% 2d, 1% 2d, 2% 2d, 4% 1wk, 5% 1wk, &amp; 6% 1wk). Control groups were pair-fed isocaloric EtOH-free diet. One group of pair-fed and EtOH-fed WT and JNK2-KO mice were administered corticosterone (CORT, 25 mg/kg/day; s.c.). Intestinal permeability was measured by vascular-to-luminal flux of FITC-inulin in vivo, tight junction (TJ) and adherens junction (AJ) integrity was assessed by confocal microscopy for occludin, ZO-1, E-cadherin, and β-catenin, and mucosal inflammation by RT-PCR for cytokines/chemokines. Plasma lipopolysaccharide (LPS) and cytokines were measured to evaluate endotoxemia and systemic inflammation. Liver damage was assessed by measuring plasma AST/ALT, liver triglyceride, and cytokine/chemokine mRNA. Gut microbiota was analyzed by 16S rRNA sequencing of colonic flushing followed by bioinformatics analyses. Results and conclusion: In WT mice, EtOH feeding increased intestinal permeability, disrupted epithelial TJ and AJ, and elevated mucosal cytokine expression, indicating epithelial barrier dysfunction and mucosal inflammation. EtOH increased plasma LPS and cytokine/chemokine levels, indicating endotoxemia and systemic inflammation. Plasma AST/ALT and liver triglyceride levels were increased, indicating EtOH-induced liver damage. CORT significantly elevated EtOH-induced intestinal permeability, TJ/AJ disruption, endotoxemia, systemic inflammation, and liver damage in WT mice. These effects of EtOH and CORT were absent in JNK2-KO mice. Microbiota α-diversity was higher in JNK2-KO mice than in WT mice, and β-diversity analysis showed that the microbiota composition in WT mice differed from that of KO mice. Microbiota α- and β-diversities were altered by EtOH and CORT in WT mice but not in JNK2-KO mice. The relative abundance of Nocardiaceae and Verrucomicrobiaceae was high, and Ruminococcaceae and Bacillaceae were low in KO mice. CORT decreased the abundance of Caulobacteriaceae and Ruminococcaceae and increased Verrucomicrobiaceae and Lactobacillaceae in WT but not KO mice. EtOH increased Ruminococcaceae and Bacillaceae and decreased Lactobacillaceae in WT mice but not KO mice. CORT-induced modulation of EtOH-induced microbiota dysbiosis was observed in WT mice but not KO mice. In conclusion, these data demonstrate that JNK2 regulates gut microbiota in mice, and JNK2 deficiency confers resistance to alcohol and corticosterone-induced tissue injury and microbiota dysbiosis. Acknowledgements: NIH/NIAAA - R01AA012307, AA029270; VA - IO1BX003014. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Locally produced nerve growth factor is a novel regulator of (juxta)glomerular and collecting duct functions in the kidney

The dense network of sympathetic efferent and sensory afferent nerves innervating the kidney is well recognized, however the elements and the functional importance of neurotrophin signaling in renal tissues are much less known. Peripherally innervated tissues are known to produce and release nerve growth factor (NGF) which belongs to the neurotrophin family of neuronal signaling proteins and is essential for the growth and survival of peripheral sensory and sympathetic nerves. This study aimed to characterize the expression and role of NGF in the kidney. We hypothesized that NGF is produced by multiple renal tubular and vascular cell types and helps to maintain hemodynamic and tubular transport functions. Local NGF expression was studied using histological sections of kidneys harvested from NGF-GFP reporter mice. To address the functional importance of NGF signaling, a new mouse model was generated by crossing Ren1d-Cre and NGF-floxed mice and Cre/lox-mediated knockout of NGF from cells of the renin lineage co-labeled with the multicolor reporter Confetti (Ren1d-Confetti-NGF KO). WT and NGF KO mice were placed in metabolic cages for urine collections and analysis, and systolic blood pressure (SBP) was measured with tail-cuff pletysmography. Intercalated cells of the collecting duct (CD) showed by far the highest NGF expression among all renal cell types based on the reporter signal in NGF-GFP mice, in addition to select cells in the renal interstitium including juxtaglomerular (JG) renin cells. Since both CD cells and JG cells are part of the renin lineage, the applied genetic strategy using Ren1d-Confetti-NGF KO mice was ideal, and showed diminished NGF expression compared to WT. Urine excretion rate and albuminuria were 3-fold increased in Ren1d-Confetti-NGF KO vs. WT mice, while there was no difference in SBP between WT and KO groups. Immunohistochemistry showed aberrant CD structure with multiple small, undifferentiated cells with apparently lost polarity and reduced AQP2 labeling in CD principal cells in Ren1d-Confetti-NGF KO mice compared to WT. In addition, the characteristic strong apical membrane AQP2 (in principal cells) and H+-ATPase (in intercalated cells) labeling in WT mice was diminished in Ren1d-Confetti-NGF KO mice. JG renin cell number per nephron was significantly reduced in Ren1d-Confetti-NGF KO (2.5±1.0) vs. WT mice (6.2±1.5, n=4 mice each). In summary, our results suggest high level of NGF expression in the adult kidney that plays important physiological functional roles in maintaining collecting duct water and electrolyte reabsorption and acid secretion, and intrarenal renin production. Deficient intrarenal NGF production may cause kidney disease, suggesting the importance of altered renal neurotrophin signaling in pathology development. DK064234, DK123564, DK135290. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.