Pathological Gene Expression Research Articles

Chromatin remodeling by the histone methyltransferase SETD2 drives cardiometabolic heart failure with preserved ejection fraction

Abstract Background Cardiometabolic heart failure with preserved ejection fraction (cHFpEF) is highly prevalent and associates with a poor outcome. Pathological gene expression in heart failure is accompanied by changes in active histone marks without major alterations in DNA methylation. Histone 3 trimethylation at lysine 36 (H3k36me3) - a chromatin signature induced by the histone methyltransferase SETD2 – has shown a strong correlation with changes in gene expression in the human failing heart; however its role in cardiac disease is poorly understood. The present study investigates the role of SETD2/ H3k36me3 in cHFpEF. Purpose To investigate the role of chromatin remodelling in obese HFpEF (obHFpEF). Methods Mice with cardiomyocyte-specific deletion of SETD2 (c-SETD2-/-) were generated and subjected to high fat diet feeding and L-NAME treatment for 15 weeks to induce cHFpEF. Cardiac function and exercise tolerance were assessed by echocardiography and Treadmill exhaustion test, respectively. ChIP-Seq datasets were employed to determine the biological pathways regulated by H3k36me3, whereas chromatin immunoprecipitation assays (ChIP) were performed to investigate SETD2/H3k36me3 enrichment on gene promoters. SETD2 gain- and loss-of-function experiments were performed in cultured cardiomyocytes (CMs) exposed to metabolic stress (palmitic acid). SETD2/H3k36me3 axis was also investigated in left ventricular (LV) myocardial specimens from patients with cHFpEF and control donors. Moreover, pharmacological inhibition of SETD2 was performed in skinned CMs from cHFpEF patients. Results Bioinformatic analysis of ChIP-Seq data in mouse CMs showed a strong involvement of SETD2/H3k36me3 in lipid-related pathways. Specifically, SETD2 and H3k36me3 were upregulated in cHFpEF vs. control mouse hearts and were highly enriched on the promoter of sterol regulatory element-binding transcription factor 1 (SREBP1) gene. SETD2 activation in cHFpEF led to SREBP1 upregulation, myocardial triglyceride accumulation and lipotoxic damage. In cHFpEF mice, cardiomyocyte-specific deletion of SETD2 prevented hypertrophic remodeling, diastolic dysfunction and lung congestion while improving exercise tolerance. Mechanistically, SETD2 deletion blunted H3K36me3 enrichment on SREBP1 promoter thus preventing SREBP1-driven lipid accumulation and leading to a significant rewiring of the cardiac lipidome. These findings were associated with restoration of autophagic flux in the cHFpEF myocardium. In CMs exposed to palmitic acid, SETD2 depletion prevented SREBP1 upregulation, whereas SETD2 overexpression recapitulated lipotoxic damage. Finally, SETD2 was upregulated in LV myocardial samples from cHFpEF patients and its pharmacological inhibition attenuated CM stiffness. Conclusions SETD2 is a new molecular target implicated in the pathophysiology of cHFpEF.

Relationship between EZH2 expression and prognosis of patients with hepatocellular carcinoma using a pathomics predictive model

BackgroundEnhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) is overexpressed in hepatocellular carcinoma, promoting tumorigenesis and correlating with poor prognosis. Traditional histopathological examinations are insufficient to accurately predict hepatocellular carcinoma (HCC) survival; however, pathomics models can predict EZH2 expression and HCC prognosis. This study aimed to investigate the relationship between pathomics features and EZH2 expression for predicting overall survival of patients with HCC. MethodsWe analyzed 267 patients with HCC from the Cancer Genome Atlas database, with available pathological images and gene expression data. RNA sequencing data were divided into high and low EZH2 expression groups for prognosis and survival analysis. Pathological image features were screened using mRMR_RFE. A pathological model was constructed using a gradient boosting machine (GBM) algorithm, and efficiency evaluation and survival analysis of the model were performed. The R package “survminer” took the pathomics score (PS) cutoff value of 0.4628 to divide the patients into two groups: high and low PS expression. Survival analyses included Kaplan–Meier curve analysis, univariate and multivariate Cox regression analyses, and interaction tests. Potential pathomechanisms were explored through enrichment, differential, immune cell infiltration abundance, and gene mutation analyses. ResultEZH2 was highly expressed in tumor samples but poorly expressed in normal tissue samples. Univariate and multivariate Cox regression analyses revealed that EZH2 was an independent risk factor for HCC (hazard ratio [HR], 2.792 and 3.042, respectively). Seven imaging features were selected to construct a pathomics model to predict EZH2. Decision curve analysis showed that the model had high clinical utility. Multivariate Cox regression analysis showed that high PS expression was an independent risk factor for HCC prognosis (HR, 2.446). The Kaplan–Meier curve showed that high PS expression was a risk factor for overall survival. ConclusionEZH2 expression can affect the prognosis of patients with liver cancer. Our pathological model could predict EZH2 expression and prognosis of patients with HCC with high accuracy and robustness, making it a new and potentially valuable tool.

Assessing clinical pathological characteristics and gene expression patterns associated with hepatoid adenocarcinoma of the stomach.

The objective of this study is to assess the clinical pathological attributes of Hepatoid Adenocarcinoma of the Stomach (HAS) and to delineate the differential diagnostic considerations about it. The investigation involved analyzing 31 HAS cases using histomorphological assessment, immunohistochemical profiling, and relevant gene detection methodologies. Among the 31 HAS cases, 9 (29.0%) were of trabecular hepatoid adenocarcinoma of the stomach, 7 (22.6%) were of glandular hepatoid adenocarcinoma of the stomach, 4 (12.9%) were of nesting hepatoid adenocarcinoma of the stomach, 3 (9.7%) were of clear cell hepatoid adenocarcinoma of the stomach, and 8 (25.8%) were of diverse hepatoid adenocarcinoma of the stomach. Of these 31 cases, 24 were male, accounting for 77.4% of the cases. Serum alpha-fetoprotein (AFP) levels were notably elevated, with radioimmunoassay results reaching 1240ng/ml; 28 out of 31 cases had AFP levels below 25µg/l, accounting for 90.3%. Related genes: HER2 protein indicated positive expression on the cell membrane in 35.5% (11/31) of the cases; HER2 gene amplification detected by the FISH technique was 12.9% (4/31). Tumoral stromal lymphocytes exhibited a PD-1 positive expression rate of 58.1% (18/31). In gastric cancer tissues, the PD-L1 positive rate was 45.1% (14/31). HAS represents a distinctive subtype of gastric cancer with a propensity for mimicking other forms of tumors, underscoring the significance of discerning its unique histopathological attributes for accurate differential diagnosis and tailored therapeutic interventions.

Identification and genetic validation of leukemia inhibitory factor super-enhancers in acute respiratory distress syndrome and lung cancer.

Super-enhancers play prominent roles in driving robust pathological gene expression, but they are hidden in human genome at noncoding regions, making them difficult to explore. Leukemia inhibitory factor (LIF) is a multifunctional cytokine crucially involved in acute respiratory distress syndrome (ARDS) and lung cancer progression. However, the mechanisms governing LIF regulation in disease contexts remain largely unexplored. In this study, we observed elevated levels of LIF in the bronchoalveolar lavage fluid (BALF) of patients with sepsis-related ARDS compared to those with nonsepsis-related ARDS. Furthermore, both basal and LPS-induced LIF expression were under the control of super-enhancers. Through analysis of H3K27Ac ChIP-seq data, we pinpointed three potential super-enhancers (LIF-SE1, LIF-SE2, and LIF-SE3) located proximal to the LIF gene in cells. Notably, genetic deletion of any of these three super-enhancers using CRISPR-Cas9 technology led to a significant reduction in LIF expression. Moreover, in cells lacking these super-enhancers, both cell growth and invasion capabilities were substantially impaired. Our findings highlight the critical role of three specific super-enhancers in regulating LIF expression and offer new insights into the transcriptional regulation of LIF in ARDS and lung cancer.

Catecholamine treatment induces reversible heart injury and cardiomyocyte gene expression

BackgroundCatecholamines are commonly used as therapeutic drugs in intensive care medicine to maintain sufficient organ perfusion during shock. However, excessive or sustained adrenergic activation drives detrimental cardiac remodeling and may lead to heart failure. Whether catecholamine treatment in absence of heart failure causes persistent cardiac injury, is uncertain. In this experimental study, we assessed the course of cardiac remodeling and recovery during and after prolonged catecholamine treatment and investigated the molecular mechanisms involved.ResultsC57BL/6N wild-type mice were assigned to 14 days catecholamine treatment with isoprenaline and phenylephrine (IsoPE), treatment with IsoPE and subsequent recovery, or healthy control groups. IsoPE improved left ventricular contractility but caused substantial cardiac fibrosis and hypertrophy. However, after discontinuation of catecholamine treatment, these alterations were largely reversible. To uncover the molecular mechanisms involved, we performed RNA sequencing from isolated cardiomyocyte nuclei. IsoPE treatment resulted in a transient upregulation of genes related to extracellular matrix formation and transforming growth factor signaling. While components of adrenergic receptor signaling were downregulated during catecholamine treatment, we observed an upregulation of endothelin-1 and its receptors in cardiomyocytes, indicating crosstalk between both signaling pathways. To follow this finding, we treated mice with endothelin-1. Compared to IsoPE, treatment with endothelin-1 induced minor but longer lasting changes in cardiomyocyte gene expression. DNA methylation-guided analysis of enhancer regions identified immediate early transcription factors such as AP-1 family members Jun and Fos as key drivers of pathological gene expression following catecholamine treatment.ConclusionsThe results from this study show that prolonged catecholamine exposure induces adverse cardiac remodeling and gene expression before the onset of left ventricular dysfunction which has implications for clinical practice. The observed changes depend on the type of stimulus and are largely reversible after discontinuation of catecholamine treatment. Crosstalk with endothelin signaling and the downstream transcription factors identified in this study provide new opportunities for more targeted therapeutic approaches that may help to separate desired from undesired effects of catecholamine treatment.

The glucocorticoid receptor acts locally to protect dystrophic muscle and heart during disease.

Absence of dystrophin results in muscular weakness, chronic inflammation and cardiomyopathy in Duchenne muscular dystrophy (DMD). Pharmacological corticosteroids are the DMD standard of care; however, they have harsh side effects and unclear molecular benefits. It is uncertain whether signaling by physiological corticosteroids and their receptors plays a modifying role in the natural etiology of DMD. Here, we knocked out the glucocorticoid receptor (GR, encoded by Nr3c1) specifically in myofibers and cardiomyocytes within wild-type and mdx52 mice to dissect its role in muscular dystrophy. Double-knockout mice showed significantly worse phenotypes than mdx52 littermate controls in measures of grip strength, hang time, inflammatory pathology and gene expression. In the heart, GR deletion acted additively with dystrophin loss to exacerbate cardiomyopathy, resulting in enlarged hearts, pathological gene expression and systolic dysfunction, consistent with imbalanced mineralocorticoid signaling. The results show that physiological GR functions provide a protective role during muscular dystrophy, directly contrasting its degenerative role in other disease states. These data provide new insights into corticosteroids in disease pathophysiology and establish a new model to investigate cell-autonomous roles of nuclear receptors and mechanisms of pharmacological corticosteroids.

Improving diagnosis and outcome prediction of gastric cancer via multimodal learning using whole slide pathological images and gene expression

For the diagnosis and outcome prediction of gastric cancer (GC), machine learning methods based on whole slide pathological images (WSIs) have shown promising performance and reduced the cost of manual analysis. Nevertheless, accurate prediction of GC outcome may rely on multiple modalities with complementary information, particularly gene expression data. Thus, there is a need to develop multimodal learning methods to enhance prediction performance. In this paper, we collect a dataset from Ruijin Hospital and propose a multimodal learning method for GC diagnosis and outcome prediction, called GaCaMML, which is featured by a cross-modal attention mechanism and Per-Slide training scheme. Additionally, we perform feature attribution analysis via integrated gradient (IG) to identify important input features. The proposed method improves prediction accuracy over the single-modal learning method on three tasks, i.e., survival prediction (by 4.9% on C-index), pathological stage classification (by 11.6% on accuracy), and lymph node classification (by 12.0% on accuracy). Especially, the Per-Slide strategy addresses the issue of a high WSI-to-patient ratio and leads to much better results compared with the Per-Person training scheme. For the interpretable analysis, we find that although WSIs dominate the prediction for most samples, there is still a substantial portion of samples whose prediction highly relies on gene expression information. This study demonstrates the great potential of multimodal learning in GC-related prediction tasks and investigates the contribution of WSIs and gene expression, respectively, which not only shows how the model makes a decision but also provides insights into the association between macroscopic pathological phenotypes and microscopic molecular features.

Ca2+/calmodulin-dependent kinase IIδC-induced chronic heart failure does not depend on sarcoplasmic reticulum Ca2+ leak.

Hyperactivity of Ca2+/calmodulin-dependent protein kinase II (CaMKII) has emerged as a central cause of pathologic remodelling in heart failure. It has been suggested that CaMKII-induced hyperphosphorylation of the ryanodine receptor 2 (RyR2) and consequently increased diastolic Ca2+ leak from the sarcoplasmic reticulum (SR) is a crucial mechanism by which increased CaMKII activity leads to contractile dysfunction. We aim to evaluate the relevance of CaMKII-dependent RyR2 phosphorylation for CaMKII-induced heart failure development in vivo. We crossbred CaMKIIδC overexpressing [transgenic (TG)] mice with RyR2-S2814A knock-in mice that are resistant to CaMKII-dependent RyR2 phosphorylation. Ca2+-spark measurements on isolated ventricular myocytes confirmed the severe diastolic SR Ca2+ leak previously reported in CaMKIIδC TG [4.65±0.73 mF/F0 vs. 1.88±0.30 mF/F0 in wild type (WT)]. Crossing in the S2814A mutation completely prevented SR Ca2+-leak induction in the CaMKIIδC TG, both regarding Ca2+-spark size and frequency, demonstrating that the CaMKIIδC-induced SR Ca2+ leak entirely depends on the CaMKII-specific RyR2-S2814 phosphorylation. Yet, the RyR2-S2814A mutation did not affect the massive contractile dysfunction (ejection fraction=12.17±2.05% vs. 45.15±3.46% in WT), cardiac hypertrophy (heart weight/tibia length=24.84±3.00 vs. 9.81±0.50mg/mm in WT), or severe premature mortality (median survival of 12weeks) associated with cardiac CaMKIIδC overexpression. In the face of a prevented SR Ca2+ leak, the phosphorylation status of other critical CaMKII downstream targets that can drive heart failure, including transcriptional regulator histone deacetylase 4, as well as markers of pathological gene expression including Xirp2, Il6, and Col1a1, was equally increased in hearts from CaMKIIδC TG on a RyR WT and S2814A background. S2814 phosphoresistance of RyR2 prevents the CaMKII-dependent SR Ca2+ leak induction but does not prevent the cardiomyopathic phenotype caused by enhanced CaMKIIδC activity. Our data indicate that additional mechanisms-independent of SR Ca2+ leak-are critical for the maladaptive effects of chronically increased CaMKIIδC activity with respect to heart failure.

Pathological image profiling identifies onco-microbial, tumor immune microenvironment, and prognostic subtypes of colorectal cancer.

Histology slide, tissue microbes, and the host gene expression can be independent prognostic factors of colorectal cancer (CRC), but the underlying associations and biological significance of these multimodal omics remain unknown. Here, we comprehensively profiled the matched pathological images, intratumoral microbes, and host gene expression characteristics in 527 patients with CRC. By clustering these patients based on histology slide features, we classified the patients into two histology slide subtypes (HSS). Onco-microbial community and tumor immune microenvironment (TIME) were also significantly different between the two subtypes (HSS1 and HSS2) of patients. Furthermore, variation in intratumoral microbes-host interaction was associated with the prognostic heterogeneity between HSS1 and HSS2. This study proposes a new CRC classification based on pathological image features and elucidates the process by which tumor microbes-host interactions are reflected in pathological images through the TIME.

A phenotypic screening platform for identifying chemical modulators of astrocyte reactivity.

Disease, injury and aging induce pathological reactive astrocyte states that contribute to neurodegeneration. Modulating reactive astrocytes therefore represent an attractive therapeutic strategy. Here we describe the development of an astrocyte phenotypic screening platform for identifying chemical modulators of astrocyte reactivity. Leveraging this platform for chemical screening, we identify histone deacetylase 3 (HDAC3) inhibitors as effective suppressors of pathological astrocyte reactivity. We demonstrate that HDAC3 inhibition reduces molecular and functional characteristics of reactive astrocytes in vitro. Transcriptional and chromatin mapping studies show that HDAC3 inhibition disarms pathological astrocyte gene expression and function while promoting the expression of genes associated with beneficial astrocytes. Administration of RGFP966, a small molecule HDAC3 inhibitor, blocks reactive astrocyte formation and promotes neuroprotection in vivo in mice. Collectively, these results establish a platform for discovering modulators of reactive astrocyte states, inform the mechanisms that control astrocyte reactivity and demonstrate the therapeutic benefits of modulating astrocyte reactivity for neurodegenerative diseases.

Diagnostic Model for Alzheimer's Disease Based on PANoptosis-Related Genes.

The pathophysiology of Alzheimer's disease (AD) involves the interplay of three different processes: pyroptosis, apoptosis, and necroptosis. To explore role of PANoptosis, a novel pro-inflammatory programmed cell death pathway, in AD patients. We performed a consensus clustering analysis to identify distinct transcriptional profiles in the samples using the R package "ConsensusClusterPlus". The PANoptosis key genes were obtained by crossing the WGCNA brown module and differentially expressed PANoptosis genes. We accomplished regression analyses using the LASSO-Cox method, combined with pathological status and gene expression data. At the same time, we also constructed PANscore system. The expression of PANoptosis hub genes were validated by qRT-PCR in AD transgenic mice. Our study utilized tissue expression profile data from AD patients to construct three distinct PANoptosis patterns, each with unique molecular and clinical characteristics. We have created a risk scoring system called PANscore, which can analyze patterns specific for each AD patient. Additionally, we observed significantly lower levels of follicular helper T (Tfh) cells in the high PANscore and AD patients. Further analysis revealed a significant negative correlation of Tfh with GSDMD and MLKL. These findings provide a roadmap for personalized patient stratification, enabling clinicians to develop personalized treatment plans for AD patients and advance the field of precision medicine.

Breast cancer development coordinated by changes in microenvironment setting

Breast cancer is the most common malignancy in women worldwide, and one of the leading causes of cancer death. This disease shows a significant heterogeneity due to its genomic and histological diversity. Breast cancer is classified by pathologic features (i.e. histological subtype, tumor grade) and gene expression profiles (i.e. molecular subtypes). There are complex mechanisms implicated in its progression and the development of chemotherapy resistance. In recent times, tumor stroma is increasingly being recognized as an important factor which influences tumor pathogenesis and progression. Tumor-stromal cells interactions are involved in many phases of tumor growth, by modulating different cellular processes. Tumor-infiltrating lymphocytes are proven to be clinically significant as they correlate with good prognosis, especially in triple-negative and HER2-positive breast cancer patients. However, tumor-infiltrating lymphocytes are just one of the many components of the tumor microenvironment, which includes fibroblasts, macrophages, adipocytes, vascular cells etc., but also non-cellular components. One of the main cellular components of the tumor microenvironment are the fibroblasts which are activated and differentiated into breast cancer associated fibroblasts. They secrete many growth factors, cytokines, and chemokines which influence tumor growth and dissemination. Tumor microenvironment could be a source of new biomarkers with a potential predictive and prognostic significance. This review highlights the tumor microenvironment as an important contributor to the process of cancer development with an overview of the main components and the potential impact on the prognosis of breast cancer. It’s important to expand our understanding and knowledge of tumor-stromal signalling processes which may lead to the development of more successful and individualized therapeutic strategies.

Protein overexpression by adeno-associated virus-based gene therapy products in cardiomyocytes induces endoplasmic reticulum stress and myocardial degeneration in mice.

Gene therapy (GT) products created using adeno-associated virus (AAV) vectors tend to exhibit toxicity via immune reactions, but other mechanisms of toxicity remain incompletely understood. We examined the cardiotoxicity of an overexpressed transgenic protein. Male C57BL/6J mice were treated with a single intravenous dose of product X, an AAV-based GT product, at 2.6 × 1013 vg/kg. Necropsies were performed at 24 h, 7 days, and 14 days after dosing. Pathological examination and gene expression analysis were performed on the heart. Histopathologically, hypertrophy and vacuolar degeneration of cardiomyocytes and fibrosis were observed 14 days after dosing. Immunohistochemistry for endoplasmic reticulum (ER) stress-related proteins revealed increased positive reactions for glucose-regulated protein 78 and C/EBPR homologous protein in cardiomyocytes 7 days after dosing, without histopathological abnormalities. Fourteen days after dosing, some cardiomyocytes showed positivity for PKR-like endoplasmic reticulum kinase and activating transcription factor 4 expression. Ultrastructurally, increases in the ER and cytosol were observed in cardiomyocytes 7 days after dosing, along with an increase in the number of Golgi apparatus compartments 14 days after dosing. The tissue concentration of the transgene product protein increased 7 days after dosing. Gene expression analysis showed upregulation of ER stress-related genes 7 days after dosing, suggesting activation of the PKR-like ER kinase pathway of the unfolded protein reaction (UPR). Thus, the cardiotoxicity induced by product X was considered to involve cell damage caused by the overexpression of the product protein accompanied by UPR. Marked UPR activation may also cause toxicity of AAV-based GT products.

Effect of Eight Weeks of High Intensity Interval Training on Tissue Changes and Gene Expression of APP and Tau Indices in the Hippocampus of Rats Addicted to Methamphetamine

Introduction: The use of methamphetamine (METH) can cause neurotoxicity. The purpose of this research was to investigate the effect of high intensity interval training on tissue changes and gene expression of neurodegeneration indicators in the hippocampal tissue of methamphetamine-dependent rats.
 Methods: In this experimental research, 32 male rats were divided into four equal groups of saline, primary methamphetamine (METH-1), methamphetamine+training (METH+HIT) and secondary methamphetamine (METH-2). METH was injected at the dose of 5 mg/kg body weight for 21 days. The exercise program (5 sessions per week) included interval training (4 sets of 2 minutes with high intensity and 2 to 4 minutes of active rest between sets) on a treadmill. At the end of the injection and training period, the hippocampus tissue of the rats was extracted to evaluate the pathological changes and gene expression of related indicators. Data were analyzed using one-way ANOVA test at the significance level of (P≥0.05) by GraphPad software.
 Results: The results of gene expression in the hippocampal tissue showed that along with METH injection, the expression of α-syn, GSK-3β, CDK5, APP, Tau and p-Tau indicators increased significantly; nevertheless the exercises (HIT) decreased the expression of the genes of the current research. Pathological studies showed that METH injection caused a significant increase in the destruction of neurons in the CA1 region of the hippocampus, and performing intense intermittent exercise had significantly reduced the destruction of neurons.
 Conclusion: Methamphetamine has caused intoxication and neurodegeneration, and HIT training has been able to improve these conditions to some extent. More research is needed in this field to reach general conclusions.

Comparative study of nickel oxide and nickel oxide nanoparticles on oxidative damage, apoptosis and histopathological alterations in rat lung tissues

BackgroundNickel oxide nanoparticles (NiONPs) are used as industrial photoelectric and recording materials, catalysts, and sensors. It has been increasingly used in many industrial sectors. Lungs are the important biological barrier that comes into contact with nanomaterials in the inhaled air. This study aimed to compare the effects of nickel oxide (NiO) microparticles and NiONPs on rat lung tissues in different dose administrations, such as oral, intraperitoneal, and intravenous. MethodsThe mature male Wistar rats (n = 42) were divided into seven groups with six animals: Group I (control), Group II NiO gavage (150 mg/kg), Group III NiO intraperitoneally (20 mg/kg), Group IV NiO intravenously (1 mg/kg), Group V NiONP gavage (150 mg/kg), Group VI NiONP intraperitoneal (20 mg/kg), and Group VII NiONP intravenous (1 mg/kg) for 21 days. Oxidative stress (MDA, CAT, SOD, GPx, and GST), apoptotic marker (p53) gene expression, and histopathological changes were determined comparatively. ResultsOur data showed that NiO and NiONPs caused an exposure-related increase in the incidence of alveolar/bronchiolar pathological changes, oxidative damage, and p53 gene expression in male rats. Intravenous exposure to NiONPs produces statistically (p < 0.05) more oxidative damage and histopathological changes than exposure to NİO. It also induces higher upregulation of the pro-apoptotic p53 gene. ConclusionNiO and NiONPs induce oxidative damage, histopathological alterations and p53 gene expression in rat lungs. Thus, exposure to NiO and NiONPs, especially intravenously, may indicate more toxicity and carcinogenicity.

HIV-1 gp120-Induced Cognitive Disorder Is Concomitant with Altered Gut Microbiota

Background HIV-associated neurocognitive disorders (HAND) is an essential factor affecting the quality of life of people living with HIV (PLWH), and the prevalence of HAND in PLWH can reach 19% to 64%. More than 50% of HAND patients treated with highly active antiretroviral therapy (HAART) did not show improvement in symptoms of cognitive impairment. HIV-1 envelope protein gp120 may be a major contributor to HAND pathology. HIV-1 gp120 enters neurons by binding CXCR4 and CCR5 and can also bind neuronal tubulin to cause direct neurotoxicity and neuronal death. HIV-1 gp120 transgenic mice (Tgm) are commonly used as HAND animal models, and Tgm brain pathological changes and differential gene expression are highly consistent with HAND patients. Intestinal flora affects the progression of diseases by regulatory the intestinal barrier, and several studies have confirmed that the normalization of abnormal intestinal flora reduces the damage to the nervous system in a variety of neurodegenerative diseases. Studies reported that Akkermansia muciniphila has a downward trend in PLWH, which may cause intestinal barrier damage. There is still a lack of relevant evidence to confirm the association between abnormal changes in gut microbiota and HAND induced by HIV-1 gp120. Therefore, in this study, we examined the gut microbiota changes in 6, 9, and 12 months Tgm to explore the relationship between age-dependent significantly different bacterial genera, intestinal barrier and neuronal damage. Methods The fresh feces were collected from HIV-1 gp120 transgenic mice (Tgm) and C57BL/6J mice (wild type, WT) at ages 6, 9, and 12 months using perianal stimulation at the same time (n=5). Total bacterial DNA was extracted from each fecal sample and the V3-V4 region of 16S rRNA was sequenced by the Illumina MiSeq platform. 12 months Tg and WT mice were sacrificed, and serum was collected to detect lipopolysaccharide (LPS) concentration by ELISA, and brain tissue of mice in each group was collected for Map2 immunohistochemical staining (n=5). SPSS 20.0 software was used for statistical analysis. P &amp;lt;0.05 were considered statistically significant. Results 16S rRNA analysis showed that increased age was significantly associated with increased abundance of Blautia ( P &amp;lt;0.01) and Prevotellaceae_NK3B31_group ( P &amp;lt;0.0001) genus and decreased abundance of Akkermansia genus ( P &amp;lt;0.05) in Tgm. Notably, the increasing age of WT was associated with the opposite trend of Blautia, Prevotellaceae_NK3B31_group and Akkermansia genus abundance, indicating those genus changes with age and gp120 induced. To further explore the effect of gut microbiota on the gut barrier, serum LPS concentrations were detected for 12 months Tgm and WT. The results showed that serum LPS level was significantly higher in Tgm than in WT ( P &amp;lt;0.01), indicating that the intestinal barrier may be impaired in Tgm. Finally, we collected 12 months Tgm and WT brain tissues for Map2 immunohistochemical staining to evaluate neuronal synaptic length and integrity. Compared with WT, the expression of map2 in the hippocampus and cerebral cortex was significantly decreased ( P &amp;lt;0.05), indicating neuronal damage in Tgm. Conclusion At the genus level, the abundance of Akkermansia was negatively correlated and the Blautia and Prevotellaceae_NK3B31_group abundance was positively correlated with increasing age in Tgm but showed an opposite trend in WT. The serum LPS level increased dramatically in the 12 months Tgm, indicating Tgm with intestinal barrier damage. Map2 expression was reduced considerably hippocampus and cortex in Tgm brain, which means neuronal synaptic integrity was impaired. ( Acknowledgements: National Natural Science Foundation of China, No. 82172259 to H.C.; Corresponding author: Hong Cao, gzhcao@smu.edu.cn.)

Pathological Response and Gene Expression in Rectal Cancer Neoadjuvant Therapy

Rectal Adenocarcinoma (RA) represents more than 90% of rectal tumors, with high global incidence and mortality rates. Treatment includes neoadjuvant therapy

Effects of Fmr1 Gene Mutations on Sex Differences in Autism-Like Behavior and Dendritic Spine Development in Mice and Transcriptomic Studies

Fragile X syndrome (FXS) is the most common single gene disorder contributing to autism spectrum disorder (ASD). Although significant sex differences are observed in FXS, few studies have focused on the phenotypic characteristics as well as the differences in brain pathological changes and gene expression in FXS by sex. Therefore, we analyzed sex differences in autism-like behavior and dendritic spine development in two-month-old male and female Fmr1 KO and C57 mice and evaluated the mechanisms at transcriptome level. Results suggest that Fmr1 KO mice display sex differences in autism-like behavior and dendritic spine density. Compared to females, male had more severe effects on anxiety, repetitive stereotype-like behaviors, and socializing, with higher dendritic spine density. Furthermore, two male-biased and five female-biased expressed genes were screened based on KEGG pathway enrichment and protein–protein interaction (PPI) analyses. In conclusion, our findings show mutations in the Fmr1 gene lead to aberrant expression of related genes and affect the sex-differentiated behavioral phenotypes of Fmr1 KO mice by affecting brain development and functional architecture, and suggest future studies should focus on including female subjects to comprehensively reflect the differentiation of FXS in both sexes and develop more precise and effective therapeutic strategies.

Abstract GS.03: Functional Role Of Placental Senescence In Peripartum Cardiomyopathy

Introduction: Peripartum cardiomyopathy (PPCM) and preeclampsia (PEC) are leading causes of maternal mortality with limited therapies. Circulating factors in late pregnancy contribute to cardiac dysfunction in PPCM and PEC. We recently identified senescence-associated secretory proteins (SASP), markers of biological aging, as the most highly upregulated circulating proteins in PPCM and PEC. The mechanisms driving this paradoxical aging pathophysiology in these pregnancy-induced heart failure (HF) syndromes are unknown. Hypothesis: The placenta becomes markedly senescent by term. We hypothesized that 1) amplified placental senescence causes the increase in circulating SASP in PPCM and PEC, and 2) attenuating placental senescence might improve cardiac function in PPCM. Methods: We performed comprehensive senescence assessments in placental samples from women with preeclampsia vs . matched pregnant controls. We assessed the effects of placental senescence in human iPSC-derived cardiomyocytes (iPSC-CM) and the PGC1α-KO PPCM murine model. Results: Placentas from PEC women displayed multiple markers of amplified senescence, including increased p16 and p21 expression (2 &amp; 4 fold, p&lt;0.03), decreased DNA methylation (-1.7 fold, p&lt;0.04), and increased overall SASP expression (2 fold; p&lt;0.001). In iPSC-CM, PEC plasma induced pathologic gene expression profiles (Nppa, Nppb, Myh7) and increased Activin-A signaling (Fstl3, Serpine1, Ccn2), a key SASP factor that contributes to cardiac dysfunction in PEC and PPCM. The senolytic Fisetin attenuated placental senescence in pregnant PGC1α-KO mice, reducing placental p16 and p21 expression (-2 &amp; -3 fold, p&lt;0.01) and Activin-A levels (-2 fold, p&lt;0.03). Compared to vehicle-treated pregnant PGC1α-KO mice, Fisetin-treated animals had 35% higher left ventricular fractional shortening (31% vs . 42%; p&lt;0.001), along with reductions in cardiac Nppa expression and Activin signaling. No changes in cardiac senescence or adverse effects on fetal development were observed with Fisetin. Conclusion: We identify amplified placental senescence as part of the core pathobiology underlying PPCM and PEC, and present proof-of-concept evidence for senolytic therapeutic approaches in pregnancy-induced HF.

Abstract P1139: Remodeling Chromatin Structure To Induce And Reverse Heart Failure

Heart failure is a critical health issue that causes one in nine deaths in the United States. Despite extensive research on gene expression dynamics in the failing myocardium, the mechanisms by which the genome reorganizes itself to reconfigure transcription are poorly understood. CTCF is a crucial protein in chromatin architecture that mediates chromatin looping, acts as an enhancer insulator, and can function as either an activator or repressor of transcription. Our previous research indicates that CTCF plays a crucial role in heart failure, as cardiac-specific knockout of this protein promotes genome organization defects that result in cardiac pathology marked by reduced ejection fraction. To determine whether restoring CTCF levels could reverse this phenotype, we designed an AAV9 vector in which the cardiomyocyte-specific Troponin T promoter drives the expression of CTCF and GFP. Our results show that reintroduction of CTCF into failing CTCF-depleted mouse hearts successfully rescues the pathological phenotype of the animals, characterized by sustained improvement in ejection fraction and left ventricular chamber size in both systole and diastole. Furthermore, RNA-seq experiments reveal numerous differentially expressed genes with opposite transcriptional behavior depending on CTCF levels, including genes involved in chromatin organization (e.g., CHmgb2, Brca1, Smyd2), development of hypertrophy (e.g., Mef2a, Gata4, Mybpc3), extracellular matrix organization (e.g., Adamts5, Itgb1, Vtn) and collagen deposition (e.g., Col5a1, Col5a3). We also examined chromatin architecture through Hi-C experiments and discovered that restoration of CTCF levels remodels the global architecture of chromatin to closely resemble healthy myocyte chromatin. This finding supports the hypothesis that rescue of CTCF levels ameliorates cardiac disease by reverting the observed pathological gene expression profile through genomic reorganization. In summary, our project highlights the crucial role of CTCF in heart failure and demonstrates that structural repair of chromatin organization through modulation of CTCF levels is a novel and realistic approach to treating heart failure.