Isoforms In Patients Research Articles

Cardiac Autonomic Neuropathy Is Not Associated with Apolipoprotein E Gene Isoforms in the Kazakh Population: A Case-Control Study.

The absence of an early diagnosis of cardiac autonomic neuropathy might increase the risk of the disease, progressing to an irreversible stage. Therefore, this study aims to investigate the APOE gene isoforms in patients with cardiac autonomic neuropathy to identify early markers for predicting this disease in the Kazakh population. A total of 147 patients with cardiac neuropathy and 153 controls were examined in this case-control study. Patients were genotyped for two polymorphisms of the APOE gene using real-time PCR. Statistical calculations were performed using binary logistic regression. As a result of our study, we found that there was no statistically significant difference in the frequency of any APOE gene isoforms (APOE (ε2/ε2), APOE (ε2/ε3), APOE (ε2/ε4), APOE (ε3/ε3), or APOE (ε4/ε4)) between the patient group and the control group (p = 0.69, p = 0.64, p = 0.19, p = 0.22, p = 0.97, respectively). Thus, cardiac autonomic neuropathy is not associated with APOE gene isoforms in the Kazakh population.

Systemic imbalance of TGF-β isoforms in patients with various manifestations of diabetic retinopathy

Transforming growth factor-β (TGF-β) is a group of structurally similar multifunctional regulatory proteins that exhibit pleiotropy in various tissues of the body. Considering that TGF-β isoforms show tropism to various cells, and in diabetic retinopathy both a neurodegenerative process and damage to microvessels can be simultaneously realized, we believe that the study of the content of TGF-β1, TGF-β2, and TGF-β3 in patients with various manifestations of diabetic retinopathy (DR) is relevant. The aim of the study was to determine the levels of TGF-β1, TGF-β2, and TGF-β3 in the blood serum in patients with neurodegenerative and vascular manifestations of diabetic retinopathy against the background of type 2 diabetes mellitus. The study involved 80 patients diagnosed with type 2 diabetes mellitus and 30 healthy volunteers. Based on ophthalmoscopy and optical coherence tomography (OCT), patients with type 2 diabetes mellitus were divided into 4 groups: Group 1 (n = 12) – patients without vascular symptoms of fundus DR and without OCT signs of retinal neurodegeneration; Group 2 (n = 28) – patients without vascular symptoms of fundus DR and the presence of OCT signs of retinal neurodegeneration; Group 3 (n = 10) – patients with vascular symptoms of non-proliferative DR and without OCT signs of retinal neurodegeneration; and Group 4 (n = 30) – patients with vascular symptoms of non-proliferative DR and the presence of OCT signs of retinal neurodegeneration. The serum content of TGF-β1 in all groups was within the reference values throughout the study. The serum concentration of TGF-β2 in all groups was higher in comparison with the control group. The content of TGF-β3 in the blood serum of patients with neurodegenerative manifestations of diabetic retinopathy (groups 2 and 4) was significantly lower than the reference values. A more pronounced deficiency was observed in group 4, whose patients had both vascular and neurodegenerative signs of DR. The presented study showed the presence of a systemic imbalance in the levels of TGF-β1, TGF-β2, and TGF-β3 in vascular and neuronal manifestations of diabetic retinopathy. The results obtained confirm the data that changes in the production of cytokines from the TGF-β family in one pathological process can be multidirectional.

Deciphering the prognostic value of FGFR2b/2c isoform expression levels in advanced esophagogastric cancer through whole-transcriptome sequencing.

53 Background: Fibroblast growth factor receptor (FGFR) isoform switching from FGFR2b to FGFR2c has been implicated in epithelial-to-mesenchymal transition and enhanced invasive potential in various malignancies and potentially be involved in resistance mechanisms to FGFR2b targeted therapy (e.g., bemarituzumab). This study sought to investigate the potential of respective FGFR2 isoform expression evaluation utilizing whole-transcriptome sequencing (WTS) and its correlation with therapeutic efficacy and clinical outcomes in patients with advanced G/GEJ cancer. Methods: Patients with advanced G/GEJ cancer who received systemic therapy at the National Cancer Center Hospital East between May 2021 and September 2023, and were enrolled in the immunological profiling study (UMIN000019129) and MONSTAR-SCREEN-2 (UMIN000043899) were included. FGFR2 protein and RNA expression were assessed via immunohistochemistry (IHC) and WTS with Caris MI Profile, respectively. FGFR2b and FGFR2c isoforms were distinguished by the detection of their respective splice junctions using WTS data. The FGFR2b/(2b+2c) ratio was stratified into FGFR2b-dominat and -containing subtypes using the median value. The log-rank test was used to discern differences in overall survival (OS). Results: Among the 129 patients, 21 (16.3%) exhibited FGFR2-positivity by IHC (staining intensity 2+ or 3+≥1% membranous staining of tumor cells), and a significant correlation was observed between FGFR2 IHC status and RNA expression levels (TPM: transcript per million) in WTS (FGFR2-positive, median TPM=11.1; FGFR2-negative, median TPM=4.7; P=0.002). The distribution of FGFR2b/(2b+2c) ratio (median, 0.89) was: 10.9% (0≤x<0.2), 5.4% (0.2≤x<0.4), 7.0% (0.4≤x<0.6), 12.4% (0.6≤x<0.8), 43.4% (0.8≤x<1.0), and 20.9% (x=1.0). Among 58 patients treated with 1st line therapy, no significant difference in treatment response was observed between the FGFR2b-dominat (67.9%) and FGFR2c-containing subtypes (53.3%) (P=0.259). Overall, the FGFR2c-containing subtype was associated with significantly shorter OS compared to the FGFR2b-dominat subtype (median OS, 10.1 vs. 17.9 months; hazard ratio, 1.72; 95% confidence interval, 1.03-2.86; log-rank P=0.037). Conclusions: Our findings underscore the substantial concordance between IHC and WTS analysis of FGFR2, the feasibility of distinguishing FGFR2 isoforms using WTS, and the prognostic implications of FGFR2c isoform in patients with advanced G/GEJ cancer. Further analysis is warranted in patients receiving FGFR2b targeted treatment.

2206P Detection of circulating KRAS4A and KRAS4B isoforms in patients with metastatic lung adenocarcinoma treated with pembrolizumab or chemotherapy plus pembrolizumab by liquid biopsy: Clinical impact and association with circulating PD-L1

2206P Detection of circulating KRAS4A and KRAS4B isoforms in patients with metastatic lung adenocarcinoma treated with pembrolizumab or chemotherapy plus pembrolizumab by liquid biopsy: Clinical impact and association with circulating PD-L1

Differential expression of mRNA 3′-end isoforms in cervical and ovarian cancers

Early diagnosis and therapeutic targeting are continuing challenges for gynecological cancers. Here, we focus on cancer transcriptomes and describe the differential expression of 3′UTR isoforms in patients using an algorithm to detect differential poly(A) site usage. We find primarily 3′UTR shortening cases in cervical cancers compared with the normal cervix. We show differential expression of alternate 3′-end isoforms of FOXP1, VPS4B, and OGT in HPV16-positive patients who develop high-grade cervical lesions compared with the infected but non-progressing group. In contrast, in ovarian cancers, 3′UTR lengthening is more evident compared with normal ovary tissue. Nevertheless, highly malignant ovarian tumors have unique 3′UTR shortening events (e.g., CHRAC1, SLC16A1, and TOP2A), some of which correlate with upregulated protein levels in tumors. Overall, our study shows isoform level deregulation in gynecological cancers and highlights the complexity of the transcriptome. This transcript diversity could help identify novel cancer genes and provide new possibilities for diagnosis and therapy.

Posttranslational-modifications of human-serum-albumin analysis by a top-down approach validated by a comprehensive bottom-up analysis

The posttranslational modifications (PTM) of human serum albumin (HSA) can result in the development of isoforms that have been identified as potential biomarkers for advanced hepatic diseases. However, previous approaches using top-down (TD) analysis to identify isoforms based on molecular weight may have resulted in misidentifications. The nature of the identified isoforms has never been confirmed in previous works. Here, we aimed to critically evaluate TD for the characterization and determination of HSA isoforms in patients and make an inventory of HSA-PTM.Serum samples from control subjects and patients with liver dysfunctions were analyzed using both top-down (TD) and bottom-up (BU) approaches. TD analysis involved using a LC-TOF-MS system to obtain a multicharged spectrum of HSA, which was deconvoluted to identify isoforms. Spectra were then used for relative quantitation analysis of albumin isoform abundances based on trapezoidal integration. For BU analysis, serums were reduced +/- alkylated, digested with trypsin and analyzed in the Q-TOF, data-dependent acquisition (DDA) mode to generate a SWATH-MS high-resolution mass spectral library of all HSA peptides. Tryptic digests of another set of serum samples were then analyzed using data-independent acquisition (DIA) mode to confirm the presence of HSA isoforms and their modification sites.TD detected 15 isoforms corresponding to various modifications, including glycation, cysteinylation, nitrosylation, and oxidation (di- and tri-). In BU, the spectral library containing 127 peptides allowed for the characterization of the important isoforms with their modified sites, including some modifications that were only characterized in BU (carbamylation, deamidation, and amino-acid substitution). The method used for determining isoforms offered acceptable reproducibility (intra-/inter-assay CVs < 15%) for all isoforms present at relative abundances higher than 2%.Overall, the study found that several isoforms could be missed or misidentified by TD. However, all HSA isoforms identified by TD and reported to be relevant in liver dysfunctions were confirmed by BU. This critical evaluation of TD approach helped design an adequate and reliable method for the characterization of HSA isoforms in patients and offers the possibility to estimate isoform abundances within 3 min. These findings have significant implications for the diagnosis and treatment of liver dysfunctions.

The Splicing Factor PTBP1 Represses TP63 γ Isoform Production in Squamous Cell Carcinoma.

Quantifying TP63γ isoforms in patients' tumors could allow for the early detection of patients with HNSCC with an early loss in desmosomal gene expression and poor prognostic. The identification of PTBP1 as a transacting factor controlling TP63γ production may allow to control TP63γ expression.

P979: EXOSOMES IN POLYCYTHEMIA VERA: “MINI PLATELETS“ WITH THROMBOGENIC POTENTIAL

Background: Polycythemia vera (PV) is characterized by clonal proliferation of myeloid progenitor cells that is caused by activating mutation in the Janus Kinase (JAK)2 gene. Patients with PV tend to develop thrombotic complications across the vasculature tree. Yet, how PV-clonal cells induce pro-thrombotic environment is still under investigation. Secreted by all types of cells, exosomes are nano-scaled particles which carry a molecular cargo that reflects their cell of origin. Exosomes travel in blood, may reach distant sites and affect various physiological and pathological processes. These features led us to think that PV-derived exosomes (hereafter PV-exosomes) carry the mutated JAK2 oncogene and contribute to the thrombotic manifestations seen in PV. Aims: Determine whether PV-exosomes carry mutated JAK2 transcripts. Determine the prothrombotic potential of PV-exosomes and their effect on endothelium. Methods: Exosomes were isolated from eythroleukemia (HEL 92.1.7) cell line (positive for mutated JAK2) and from patients with PV by serial ultracentrifugation. To confirm the presence of exosomes, electron microscopy images were obtained and to quantify their concentration nanoscale tracking analysis was applied (Malvern). The exosomes were stained with the FM-4-11 lipophilic dye and their uptake by HUVECs and HaCaT cells was followed by flow cytometry. To determine the presence of JAK2 transcript, a 465 bp long DNA segment within exon14 of JAK2 was amplified by qRT-PCR and by Sanger sequencing JAK2 mutational status was determined. Thrombin generation assay (TGA) (Ceveron®, Alpha, Technoclone) was used to assess the thrombotic potential of PV-exosomes. Platelet activation status was assessed by the expression of PAC-1, CD-62 and CD-63 in platelets and Trans Epithelial Electric Resistance (TEER) (Electric cell substrate impedance sensing device, Applied Biophysics) was used to assay endothelial dysfunction in HUVECs. Results: We isolated exosomes from the sera of 24 healthy donors and 31 patients with PV. We found the presence of the mutated JAK2 mRNA in all samples confirming that the mutated JAK2 transcript is packaged into sera-exosomes. Yet, while healthy donors’ derived exosomes carry only the wild type JAK2 mRNA, we detected both the wild type and the mutated JAK2 isoforms in patients with PV. We showed that PV-exosomes induced thrombin generation. Then we compared PV-exosomes and healthy-individuals’ derived exosomes and found that thrombin generation potential of PV-exosomes is higher in all measured parameters (p< 0.05 in all parameters). Furthermore, using various platelet markers (CD62, CD63, PAC1) we confirmed that PV-exosomes induced platelet activation. Together, these findings suggest that PV-exosomes may promote thrombosis directly. Under physiological conditions the integrity of the vascular wall prevents uncontrolled thrombi. Therefore, we wondered whether PV-exosomes induce endothelial dysfunction, and in this way contribute indirectly to the pro-thrombotic phenotype. PV-exosomes were taken up by HUVEC endothelial cells in a dose- and time- dependent manner and TEER assay revealed that exosomal uptake by HUVECs induced endothelial dysfunction by breaking the tight junction between adjacent endothelial cells. Summary/Conclusion: Exosomes may act as “mini platelets” that promote thrombosis in patients with PV. PV-exosomes may promote thrombosis either directly by activating platelets and inducing thrombin generation or indirectly by inducing endothelial dysfunction.

Circulating levels of AGEs and soluble RAGE isoforms are associated with all-cause mortality and development of cardiovascular complications in type 2 diabetes: a retrospective cohort study

BackgroundAdvanced glycation end-products (AGEs) and their interaction with the receptor for advanced glycation end-products (RAGE) play a pivotal role in the development and progression of type 2 diabetes. In this retrospective cohort study, we explored the association of circulating levels of soluble RAGE (sRAGE) isoforms, i.e., endogenous secretory esRAGE and cleaved cRAGE, AGEs and their respective ratios with 15-year all-cause mortality in type 2 diabetes.MethodsBaseline AGEs and sRAGE isoforms concentration were measured by ELISA in 362 patients with type 2 diabetes and in 125 age- and gender-matched healthy control subjects (CTR). Independent predictors of mortality were determined using Cox proportional-hazards models and used to build and validate a nomogram for all-cause mortality prediction in type 2 diabetes.ResultsAGEs, total sRAGE, cRAGE and the AGEs/sRAGE and AGEs/esRAGE ratios were significantly increased in patients with type 2 diabetes compared to CTR (p < 0.001). In CTR subjects, but not in type 2 diabetes patients, a significant negative correlation between cRAGE and age was confirmed (p = 0.003), whereas the AGEs/sRAGE (p = 0.032) and AGEs/cRAGE (p = 0.006) ratios were positively associated with age. At an average follow-up of 15 years (4,982 person-years), 130 deaths were observed. The increase in the AGEs/cRAGE ratio was accompanied by a higher risk of all-cause mortality in patients with type 2 diabetes (HR per each SD increment = 1.30, 95% CI 1.15–1.47; p < 0.001). Moreover, sRAGE was associated with the development of major adverse cardiovascular events (MACE) in type 2 diabetes patients without previous MACE (OR for each SD increase: 1.48, 95% CI 1.11–1.89). A nomogram based on age, sex, HbA1c, systolic blood pressure, and the AGEs/cRAGE ratio was built to predict 5-, 10- and 15-year survival in type 2 diabetes. Patients were categorized into quartiles of the monogram scores and Kaplan-Meier survival curves confirmed the prognostic accuracy of the model (log-rank p = 6.5 × 10− 13).ConclusionsThe ratio between AGEs and the cRAGE isoform is predictive of 15-year survival in patients with type 2 diabetes. Our data support the assessment of circulating AGEs and soluble RAGE isoforms in patients with type 2 diabetes as predictors of MACE and all-cause mortality.

Transforming growth factors TGF- β1, TGF- β2 and TGF- β3 in the tissue of nasal polyps in different phenotypes of chronic rhinosinusitis with nasal polyps

Chronic rhinosinusitis with nasal polyps (CRSP) is a heterogenous disease. We have earlier detected differences in severity of clinical manifestations, cellular infiltration degree shown in nasal polyps, of eosinophil-to-neutrophil ratio, efficacy of intranasal glucocorticosteroid baseline therapy, and various inflammatory patterns for several cytokines on the mRNA expression level in different phenotypes with isolated CRSP cases, CRSP associated with respiratory allergy (RA), or non-allergic bronchial asthma.The purpose of this work was to study the cytokines of TGF-â family in the tissues of nasal polyps in patients with different CRSP phenotypes. The research involved 292 patients suffering from CRSP divided into 3 phenotypic groups. Group I consisted of patients with isolated CRSP free of associated BA and/or sensitization to atopic allergens. Group II included patients with CRSP combined with respiratory allergy and was further divided into two subgroups. I.e., Group 2a comprised patients with CRSP, allergic BA (aBA), and allergic rhinitis (AR), while the patients with CRSP, AR, and non-allergic BA were placed to the group 2b. The patients suffering from CRSP complicated with non-allergic BA were allocated to the group III. The patients with hypertrophic rhinitis served as control. The levels of TGF-â1, TGF-â2, and TGF-â3 proteins (pg/mg) were measured by means of multiplex immunoassay approach in supernates of tissue homogenates from nasal polyps removed by surgery, and in posterior parts of inferior nasal conchae. The total protein level was determined in tissue supernatant, with cytokine contents recalculated for the mg/ml protein concentration for standardization of measurements.In the control group, trace concentrations of all three growth factors were detected. Significant difference in protein contents was found for the studied cytokines, depending on CRSP phenotype. The levels of TGF-â1 and TGF-â2 were statistically lower in isolated CRSP than in other groups of comorbid CRSP patients. TGF-â1 and TGF-â2 concentrations were significantly lower in CRSP + allergic BA group IIa than in CRSP + nonallergic BA and CRSP + RA groups. The amount of TGF-â3 cytokine was maximal in CRSP + non-allergic BA group III compared to the patients with isolated CRSP of group I and CRSP + non-allergic BA group 2a.Conclusions.The high level of all three TGF-â isoforms in patients with CRSP compared to the control group suggested a high potential of mucous membranes of paranasal sinuses for active tissue remodeling followed by nasal polype formation.Different mechanisms were presumed for development of local pathological process in different clinical phenotypes of CRSP, depending on the comorbid pathology, especially, BA or respiratory disorders.Minimal TGF-â1 and TGF-â2 levels were detected in isolated CRSP.The highest concentrations of TGF-â1, TGF-â2, and TGF-â3 were discovered in the patients with CRSP accompanied by non-allergic BA as compared to the groups with isolated CRSP and CRSP+allergic BA.5. Determination of TGF-â1, TGF-â2, and TGF-â3 levels can serve as an additional criterion for differentiating between the mechanisms of mucous membrane damage in local pathological process in tissues of comorbid patients with different CRSP phenotypes.

The enteroendocrine-osseous axis in patients with long-term type 1 diabetes mellitus.

The relationship between the gut and skeleton is increasingly recognized as a component of the regulation of carbohydrate metabolism. The aim of our study was to assess the relationship between bone mineral density (BMD), incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), intestinotrophic peptide glucagon-like peptide-2 (GLP-2) and osteocalcin isoforms in patients with long-term type 1 diabetes (T1D) when compared to healthy controls. Eighty two patients with long term T1D, treated in the Department of Metabolic Diseases and 53 healthy controls were recruited to the study. Long term disease duration was defined as lasting for more than 10years. The control group was selected among age- and sex-matched healthy people. Fasting blood samples were collected to measure levels of incretin hormones (GLP-1, GLP-2, GIP), two forms of osteocalcin (uncarboxylated (ucOC), and carboxylated (cOC)), and additional biochemical parameters associated with glucose and bone metabolism (HbA1c, calcium, phosphorus, 25(OH)D3, PTH). Patients with T1D had higher BMI than in controls (p=0.02). There was no difference in BMD at the lumbar spine and the femoral neck between patients with long-term T1D and healthy ones. Z-score values in both groups were within normal ranges. The level of GIP was significantly higher in T1D patients (p=0.0002) in comparison to the healthy ones. The levels of GLP-1 and GLP-2 did not differ between T1D patients and controls. In the T1D group, strong, positive associations were found between serum levels of GLP-1 and cOC (r=0.546, p<0.001) and between GLP-1 and total OC (r=0.51, p<0.001), also after adjusting for BMI (p<0.001 and p<0.001, respectively). Significant positive associations were also found between serum levels of GLP-2 and cOC (r=0.27, p=0.013) and between GLP-2 and total OC (r=0.25, p=0.018), also in a multivariate regression (p=0.009, p=0,175, respectively). Moreover, in T1D patients, GLP-1 correlated positively with the femoral neck BMD (g/cm2) (r=0.265, p=0.016) and this association was statistically significant after adjusting for BMI (p=0.011). These correlations were not present in the control group. The only significant correlation observed in the control group was between OC and BMD of the neck (p=0.049 for neck BMD g/cm2, and p=0.041 for neck Z-score). Our data suggests an effect of gut hormones on bone in long-term T1D, which could be associated with OC activity, however we did not find a direct connection with glucose metabolism. GLP-1 could have a possible, protective role on bone mineral density in patients with T1D. The data from our study suggests that gut hormones could be considered as a new link in the skeleton - pancreatic endocrine loop in patients with T1D.

Effects of Remote Ischaemic Preconditioning on the Internal Thoracic Artery Nitric Oxide Synthase Isoforms in Patients Undergoing Coronary Artery Bypass Grafting.

Remote ischaemic preconditioning (RIPC) is a medical procedure that consists of repeated brief periods of transient ischaemia and reperfusion of distant organs (limbs) with the ability to provide internal organ protection from ischaemia. Even though RIPC has been successfully applied in patients with myocardial infarction during coronary revascularization (surgery/percutaneous angioplasty), the underlying molecular mechanisms are yet to be clarified. Thus, our study aimed to determine the role of nitric oxide synthase (NOS) isoforms in RIPC-induced protection (3 × 5 min of forearm ischaemia with 5 min of reperfusion) of arterial graft in patients undergoing urgent coronary artery bypass grafting (CABG). We examined RIPC effects on specific expression and immunolocalization of three NOS isoforms — endothelial (eNOS), inducible (iNOS) and neuronal (nNOS) in patients’ internal thoracic artery (ITA) used as a graft. We found that the application of RIPC protocol leads to an increased protein expression of eNOS, which was further confirmed with strong eNOS immunopositivity, especially in the endothelium and smooth muscle cells of ITA. The same analysis of two other NOS isoforms, iNOS and nNOS, showed no significant differences between patients undergoing CABG with or without RIPC. Our results demonstrate RIPC-induced upregulation of eNOS in human ITA, pointing to its significance in achieving protective phenotype on a systemic level with important implications for graft patency.

High-Sensitivity Single Molecule Array Assays for Pathological Isoforms in Parkinson's Disease.

Clinical trials for neurodegenerative diseases are increasingly utilizing measurements of post-translational modifications (PTMs) and pathological isoforms as surrogate markers of target engagement and therapeutic efficacy. These isoforms, however, tend to exist at femtomolar concentrations, well below the detection limit of conventional immunoassays. Therefore, highly sensitive and well-validated assays for these isoforms are needed. We developed a novel panel of single molecule array assays for pathological isoforms and PTMs implicated in the development and pathophysiology of Parkinson's disease. We validated this panel by measuring these analytes in the cerebrospinal fluid of a cross-sectional cohort of 100 patients with Parkinson's disease and 100 healthy controls. When comparing patients with Parkinson's disease to healthy controls, alpha synuclein, pSer129 alpha synuclein, DJ-1, and C-reactive protein were shown to be reduced in patients with Parkinson's disease while p396 tau and neurofilament light chain were shown to be increased. A random forest analysis produced an area under the curve of 0.70 for the panel. Measurement of post-translational modifications and pathological isoforms in patients with Parkinson's disease improved diagnostic accuracy above that of total protein measurements, demonstrating the potential utility of these assays for monitoring patients in clinical trials.

Distinct Uptake Kinetics of Alzheimer Disease Amyloid-β 40 and 42 at the Blood-Brain Barrier Endothelium.

Blood-brain barrier (BBB) endothelial cells lining the cerebral microvasculature maintain dynamic equilibrium between soluble amyloid-β (Aβ) levels in the brain and plasma. The BBB dysfunction prevalent in Alzheimer disease contributes to the dysregulation of plasma and brain Aβ and leads to the perturbation of the ratio between Aβ42 and Aβ40, the two most prevalent Aβ isoforms in patients with Alzheimer disease. We hypothesize that BBB endothelium distinguishes between Aβ40 and Aβ42, distinctly modulates their trafficking kinetics between plasma and brain, and thereby contributes to the maintenance of healthy Aβ42/Aβ40 ratios. To test this hypothesis, we investigated Aβ40 and Aβ42 trafficking kinetics in hCMEC/D3 monolayers (human BBB cell culture model) in vitro as well as in mice in vivo. Although the rates of uptake of fluorescein-labeled Aβ40 and Aβ42 (F-Aβ40 and F-Aβ42) were not significantly different on the abluminal side, the luminal uptake rate of F-Aβ42 was substantially higher than F-Aβ40. Since higher plasma Aβ levels were shown to aggravate BBB dysfunction and trigger cerebrovascular disease, we systematically investigated the dynamic interactions of luminal [125I]Aβ peptides and their trafficking kinetics at BBB using single-photon emission computed tomography/computed tomography imaging in mice. Quantitative modeling of the dynamic imaging data thus obtained showed that the rate of uptake of toxic [125I]Aβ42 and its subsequent BBB transcytosis is significantly higher than [125I]Aβ40. It is likely that the molecular mechanisms underlying these kinetic differences are differentially affected in Alzheimer and cerebrovascular diseases, impact plasma and brain levels of Aβ40 and Aβ42, engender shifts in the Aβ42/Aβ40 ratio, and unleash downstream toxic effects. SIGNIFICANCE STATEMENT: Dissecting the binding and uptake kinetics of Aβ40 and Aβ42 at the BBB endothelium will facilitate the estimation of Aβ40 versus Aβ42 exposure to the BBB endothelium and allow assessment of the risk of BBB dysfunction by monitoring Aβ42 and Aβ40 levels in plasma. This knowledge, in turn, will aid in elucidating the role of these predominant Aβ isoforms in aggravating BBB dysfunction and cerebrovascular disease.

Mutational analysis of Ras hotspots in patients with urothelial carcinoma of the bladder.

BACKGROUNDMutational activation of Ras genes is established as a prognostic factor for the genesis of a constitutively active RAS-mitogen activated protein kinase pathway that leads to cancer. Heterogeneity among the distribution of the most frequent mutations in Ras isoforms is reported in different patient populations with urothelial carcinoma of the bladder (UCB).AIMTo determine the presence/absence of mutations in Ras isoforms in patients with UCB in order to predict disease outcome.METHODSThis study was performed to determine the mutational spectrum at the hotspot regions of H-Ras, K-Ras and N-Ras genes by polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing followed by their clinical impact (if any) by examining the relationship of mutational spectrum with clinical histopathological variables in 87 UCB patients.RESULTSNone of the 87 UCB patients showed point mutations in codon 12 of H-Ras gene; codon 61 of N-Ras gene and codons 12, 13 of K-Ras gene by PCR-RFLP. Direct DNA sequencing of tumor and normal control bladder mucosal specimens followed by Blastn alignment with the reference wild-type sequences failed to identify even one nucleotide difference in the coding exons 1 and 2 of H-Ras, N-Ras and K-Ras genes in the tumor and control bladder mucosal specimens.CONCLUSIONOur findings on the lack of mutations in H-Ras, K-Ras and N-Ras genes could be explained on the basis of different etiological mechanisms involved in tumor development/progression, inherent genetic susceptibility, tissue specificity or alternative Ras dysfunction such as gene amplification and/or overexpression in a given cohort of patients.

Decreased Levels of Blood AMPKα1 but not AMPKα2 Isoform in Patients with Mild Cognitive Impairment and Alzheimer's Disease: A Pilot Study.

There is an urgent need to develop feasible biomarkers for diagnosis and prognosis of Alzheimer's disease (AD). Mounting evidence implicates that dysregulation of energy metabolism is a key and early event in AD pathogenesis. AMP-activated protein kinase (AMPK) is a central molecular sensor that plays a critical role in maintaining cellular energy homeostasis, and aberrant brain AMPK activities are linked to AD pathophysiology. We aimed to investigated protein levels of AMPKα isoforms, AMPKα1 and AMPKα2, in plasma samples from patients clinically diagnosed with mild cognitive impairment (MCI) or AD, along with age-matched healthy controls. 30 participants (10 MCI, 10 AD, and 10 controls) were included in our pilot study. Plasma levels of AMPKα1 and AMPKα2 were determined by ELISA. Receiver operating characteristic (ROC) analysis was used to assess sensitivity and specificity. Linear regression was used to assess the correlation between levels of AMPKα isoforms and other biomarkers. Plasma levels of AMPKα1 were decreased in MCI and AD patients, while levels of AMPKα2 were unaltered as compared to controls. ROC analysis showed relatively high sensitivity and specificity for AMPKα1 to distinguish MCI and AD from controls. Linear regression analysis showed that plasma levels of AMPKα1 were correlated with a brain imaging biomarker (AD signature cortical thicknesses). Plasma levels of AMPKα1 were decreased in MCI and AD patients. Future endeavor to explore whether blood AMPKα1 protein expression has the value as a potential biomarker for AD and MCI diagnosis shall be encouraged.

Pharmacodynamic assessment of cell-bound natalizumab on PBMC samples stored in liquid nitrogen

Natalizumab is a monoclonal IgG4 antibody used for treatment of relapsing remitting MS. Natalizumab interferes with lymphocyte migration by blocking alpha-4 integrin (CD49d). Saturation levels of alpha-4 integrin on circulating T cells by natalizumab have been associated with clinical effectiveness of therapy. However, in most cases, measurements have been carried out using freshly isolated PBMCs. The aim of this study was to set up and evaluate a method to measure relative levels of cell-bound natalizumab using frozen PBMC samples. A new method was set up to measure cell-bound natalizumab by flow cytometry on T cell subsets using fully saturated cells as a 100% reference. A comparison was made between spike samples and samples of natalizumab-treated MS patients freshly isolated and stored in liquid nitrogen. Cell-bound natalizumab could be measured (using an anti-IgG4 antibody) on cells stored in liquid nitrogen. Natalizumab was found to slowly dissociate from the cells during isolation and subsequent sample work-up. This dissociation was more pronounced for monovalent natalizumab resulting from Fab arm exchange (the predominant isoform in patients) than bivalent natalizumab straight from the vial. We established a correction factor to account for this phenomenon. The resulting method has good accuracy compared to assessing fresh cells. The inter-assay precision (%CV) is ca. 12% using frozen cells. In conclusion, we established a method to assess relative levels of cell-bound natalizumab on cells obtained from frozen PBMC samples.

CTLA-4 Expression Inversely Correlates with Kidney Function and Serum Immunoglobulin Concentration in Patients with Primary Glomerulonephritides

Major causes of chronic kidney disease are primary proliferative and nonproliferative glomerulonephritides (PGN and NPGN). However, the pathogenesis of PGN and NPGN is still not fully understood. Cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) is a T-cell membrane receptor that plays a key role in T-cell inhibition. Despite its role in autoimmunological diseases, little is known about the involvement of CTLA-4 in the pathogenesis of PGN and NPGN. The objective of this study was to determine the role of CTLA-4 in the pathogenesis of PGN and NPGN by evaluating the frequencies of T and B lymphocytes expressing CTLA-4 and the serum concentration of the sCTLA-4 isoform in patients with PGN and NPGN in relation to clinical parameters. The study included peripheral blood (PB) samples from 40 PGN and NPGN patients and 20 healthy age- and sex-matched volunteers (control group). The viable PB lymphocytes were labeled with fluorochrome-conjugated monoclonal anti-CTLA-4 antibodies and analyzed using flow cytometry. The serum concentration of sCTLA-4 was measured using ELISA. The frequencies and absolute counts of CD4+/CTLA-4+ T lymphocytes, CD8+/CTLA-4+ T lymphocytes and CD19+/CTLA-4+ B lymphocytes and the serum sCTLA-4 concentration were lower in PGN and NPGN patients that in the control group. Reduced sCTLA-4 expression was associated with a lower concentration of serum immunoglobulins. Our results indicate that deregulation of CTLA-4 expression may result in continuous activation of T cells and contribute to the pathogenesis of PGN and NPGN.

Differential expression of progesterone receptor isoforms related to PGR +331g/a polymorphism in endometriosis: A case-control study.

BackgroundEndometriosis are defined as a progesterone-resistance disease. Two progesterone receptor (PR) isoforms, namely PR-A and PR-B, mediate the special effects of progesterone. One of the most effective polymorphism in the promoter region of PGR is the +331G/A.ObjectiveThe differential expression level of PR isoforms due to +331G/A polymorphism may be able to influence the function of progesterone and reduce the susceptibility of endometriosis.Materials and MethodsThis analytic, case-control study was carried out at Royan Institute, Tehran, Iran. Whole-blood samples were collected from 98 infertile women undergoing laparoscopy for endometriosis and 102 healthy fertile women. After DNA extraction, genotype frequencies were determined by polymerase chain reaction-restriction fragment length polymorphism. Then, RNA was extracted from the selected eutopic tissue samples of endometriosis patients. Analysis of PR-A and PR-B mRNA expressions were performed using Real-time polymerase chain reaction.ResultsThe frequency distribution of GG, GA genotypes in +331G/A polymorphism was 98.04%, 1.96% in the patients and 97.96%, 2.04% in the control groups, respectively (p = 0.968). Although our data did not show any significant association with +331G/A in the patient and control groups, we were able to demonstrate significantly higher expression level of PR-B and no significant lower expression level of PR-A isoforms in patients by favoring GA to GG genotypes (p = 0.017, p = 0.731, respectively).ConclusionOur findings show that patients with GA genotypes had a higher expression level of PR-B compared to patients with GG genotypes.

Hepatic Expression of Phosphorylated Kinase Akt and Glycogen Synthase Kinase-3 Isoforms in Patients with Chronic Hepatitis C.

Some patients with chronic hepatitis C also demonstrate liver steatosis, but the mechanism remains elusive. To analyze the hepatic expression of phosphorylated kinase Akt at Thr 308 and phosphorylated GSK-3 (Glycogen synthase kinase-3) isoforms, GSK3α at Ser 21 and GSK3β at Ser 9, in chronic hepatitis C patients with normal body weight, glucose, and lipid profiles depending on homeostasis model assessment of insulin resistance (HOMA-IR) levels and histological parameters. The study group consisted of 31 patients with chronic hepatitis C. The hepatic expression of kinase Akt (Thr308), GSK3β (Ser9), and GSK3α (Ser21) was measured using Western blot assay. Liver steatosis was observed in 41.93% of patients with HCV infection, in those with increased HOMA-IR index (p = 0.02). However, the hepatic expression of Akt (Thr308), GSK3β (Ser9), and GSK3α (Ser21) was not related to progression of liver steatosis, inflammation, and fibrosis. There was no significant difference in the hepatic expression of kinase Akt (Thr308), GSK3β (Ser9), and GSK3α (Ser21) in relation to HOMA-IR. Liver steatosis was found to be positively associated with HOMA-IR levels in patients with chronic hepatitis C without metabolic disorders. However, the hepatic expression of Akt (Thr308), GSK3β (Ser9), and GSK3α (Ser21) did not correspond to progression of liver disease.