GSTM1 Research Articles

Single-cell analysis of cellular heterogeneity and interactions in the ischemia-reperfusion injured mouse intestine

Nine major cell populations among 46,716 cells were identified in mouse intestinal ischemia‒reperfusion (II/R) injury by single-cell RNA sequencing. For enterocyte cells, 11 subclusters were found, in which enterocyte cluster 1 (EC1), enterocyte cluster 3 (EC3), and enterocyte cluster 8 (EC8) were newly discovered cells in ischemia 45 min/reperfusion 720 min (I 45 min/R 720 min) group. EC1 and EC3 played roles in digestion and absorption, and EC8 played a role in cell junctions. For TA cells, after ischemia 45 min/reperfusion 90 min (I 45 min/R 90 min), many TA cells at the stage of proliferation were identified. For Paneth cells, Paneth cluster 3 was observed in the resting state of normal jejunum. After I 45 min/R 90 min, three new subsets were found, in which Paneth cluster 1 had good antigen presentation activity. The main functions of goblet cells were to synthesize and secrete mucus, and a novel subcluster (goblet cluster 5) with highly proliferative ability was discovered in I 45 min/R 90 min group. As a major part of immune system, the changes in T cells with important roles were clarified. Notably, enterocyte cells secreted Guca2b to interact with Gucy2c receptor on the membranes of stem cells, TA cells, Paneth cells, and goblet cells to elicit intercellular communication. One marker known as glutathione S-transferase mu 3 (GSTM3) affected intestinal mucosal barrier function by adjusting mitogen-activated protein kinases (MAPK) signaling during II/R injury. The data on the heterogeneity of intestinal cells, cellular communication and the mechanism of GSTM3 provide a cellular basis for treating II/R injury.

A Review of the GSTM1 Null Genotype Modifies the Association between Air Pollutant Exposure and Health Problems.

Air pollution is one of the significant environmental risks known as the cause of premature deaths. It has deleterious effects on human health, including deteriorating respiratory, cardiovascular, nervous, and endocrine functions. Exposure to air pollution stimulates reactive oxygen species (ROS) production in the body, which can further cause oxidative stress. Antioxidant enzymes, such as glutathione S-transferase mu 1 (GSTM1), are essential to prevent oxidative stress development by neutralizing excess oxidants. When the antioxidant enzyme function is lacking, ROS can accumulate and, thus, cause oxidative stress. Genetic variation studies from different countries show that GSTM1 null genotype dominates the GSTM1 genotype in the population. However, the impact of the GSTM1 null genotype in modifying the association between air pollution and health problem is not yet clear. This study will elaborate on GSTM1's null genotype role in modifying the relationship between air pollution and health problems.

Air pollution associated acute respiratory inflammation and modification by GSTM1 and GSTT1 gene polymorphisms: a panel study of healthy undergraduates

Epidemiological evidence has linked air pollution with adverse respiratory outcomes, but the mechanisms underlying susceptibility to air pollution remain unclear. This study aimed to investigate the role of glutathione S-transferase (GST) polymorphism in the association between air pollution and lung function levels. A total of 75 healthy young volunteers aged 18–20 years old were recruited for six follow-up visits and examinations. Spirometry was conducted to obtain lung function parameters such as forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV1). Nasal fluid concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and 8-epi-prostaglandin F2α (8-epi-PGF2a) were measured using ELISA kits. Linear mixed-effect models were used to evaluate the association of air pollutants with respiratory outcomes. Additionally, polymorphisms of glutathione S-transferase mu 1 (GSTM1) and glutathione S-transferase theta 1 (GSTT1) were estimated to explore its role in the association between air pollutants and lung function. We found that short-term exposure to atmospheric particulates such as PM2.5 and PM10 can cause an increase in nasal biomarkers of inflammation, oxidative stress, and lung function, while air gaseous pollutant exposure is linked with decreased lung function, except for CO. Stratification analyses showed that an increase in nasal inflammatory cytokines caused by exposure to atmospheric particulates is more obvious in subjects with GSTM1-sufficient (GSTM1+) than GSTM1-null (GSTM1−), while elevated lung function levels due to air particles are more significant in subjects with the genotype of GSTM1− when compared to GSTM1+. As for air gaseous pollutants, decreased lung function levels caused by O3, SO2, and NO2 exposure is more manifest in subjects with the genotype of GSTM1− compared to GSTM1+. Taken together, short-term exposure to air pollutants is associated with alterations in nasal biomarkers and lung function levels in young healthy adults, and susceptible genotypes play an important mediation role in the association between exposure to air pollutants and inflammation, oxidative stress, and lung function levels.

Functional papaya beverage increases healthy gut microbiota in Streptozotocininduced diabetic Sprague Dawley rats

Diabetes mellitus is a silent killer illness, characterized by hyperglycaemia effect and can cause many health complications. A new functional papaya beverage was produced via selected pure symbiotic culture of bacteria and yeast (SCOBY) which offers an alternative food therapy in regulating blood glucose and its efficacy was evaluated using Streptozotocin (STZ)-induced diabetic Sprague Dawley rats for one month treatment. Under moderate diabetes condition, SCOBY papaya beverage was shown able to reduce high blood glucose in diabetic rats to normal level, comparably effective with commercial drug, Metformin. Not only that, it also helped restore body weight of diabetic rats to a healthier state with a gradual increment of body weight observed weekly. In contrast, untreated diabetic rats experienced a sharp rise in blood glucose with stunted body weight. Nutrigenomic studies were conducted to identify the mechanisms that support the effectiveness of SCOBY papaya beverage as an anti-diabetic therapy. Evidence from quantitative polymerase chain reaction (qPCR) analysis disclosed significant higher expression on gene markers related to insulin receptor substrate 1 (Irs1), glucose transporter (Slc2a8) and glutathione S-transferase mu 1 (Gstm1), but lower expression of gene markers indicative of diabetes complications and inflammation e.g., tissue inhibitors of metalloproteinase 1 (Timp1), nuclear factor kappa B subunit 1 (Nfkb1) and nitric oxide 2 (NOS2) in diabetic rats treated with SCOBY papaya beverage and Metformin (p<0.05). SCOBY papaya treated diabetic rats showed an increment of short chain fatty acids content and gut microbiota enriched with some beneficial microbes particularly for Alloprevotella, Ruminococcus 1, Lachnospiraceae NK4A136, Prevotellaceae UCG-001 and Prevotellaceae NK3B31 compared to untreated diabetic rats. These data support the effectiveness of SCOBY papaya as a functional beverage in improving intestinal health by changing the environment of the microbiome of diabetic rats, in turn offering costeffective food therapies in blood glucose regulation.

Genetic Polymorphisms of GSTM1 and GPX1 Genes and Smoking Susceptibility in the Saudi Population.

Glutathione-S-transferase Mu1 (GSTM1) and glutathione peroxidase 1 (GPX1) are known antioxidant enzymes that help protect cells from the oxidative damage that occurs from smoking. This study explored the correlation between GSTM1 and GPX1 levels between a group of smokers with the GSTM1 and GPX1 genes in the Saudi population and a control group and investigated the genetic risk factors in the group of smokers. The control and smokers' group (n = 50; aged 22.3 ± 3.1 years; BMI 24.6 ± 5.9 kg/m2) were genotyped using quantitative polymerase chain reaction (qPCR). In comparison with the control group, the smokers' group displayed a different genotype disruption of GSTM1 and GPX1. Carriers of the homozygous (TT) genotype of GSTM1 had more than a twofold (OR = 2.71, 95% CI = 0.10-70.79, P = 1.000) smoking risk than the carriers of the heterozygous (CT) genotype. Those with the GPX1 gene showed no risk in the control and smokers' groups. Smokers with the TT/GG combination (homozygous for GPX1 and normal for GPX1) were identified as high risk (OR = 2.58, 95% CI = 0.096-69.341). The main outcomes showed no significant association between genetic polymorphism of the GSTM1 and GPX1 genes and cigarette smoking in the Saudi Arabian population. However, the results showed a slight decrease in the number of GSTM1 and GPX1 gene modifications among smokers.

Abstract C019: Evaluation of genes for glutathione-S-transferase genetic polymorphism in drivers exposed to air pollution

Abstract Air pollution and its possible impact on human health is attracting growing interest around the world. It remains a serious threat of premature death. Multiple source of pollution are present in the outdoor and indoor air such as exhaust gases, industry, pesticides, gasoline, fuels, incense, air fresheners, insecticides, smoke, cosmetics and maintenance products…. These sources emited pollutants such as PM, CO, NO, VOC, PAH, O3 which are responsible for headaches, dizziness, eye irritation, hepatitis, respiratory and cardiac diseases and cancers (breast, blood, cervix, prostate…). These pathologies are due to the homozygous deletion of the glutathione-S-transferase (GST) genes. GST protects the body against toxicants by neutralizing electrophiles and makes toxic metabolites more soluble. Objective: To evaluate the genes of the glutathione-S-transferase genetic polymorphism GSTM1 and GSTT1 in pollutant-exposed motorcycle drivers. Materials & methods The study group is made up of 60 motorcycle drivers, including 30 professionals and 30 non-professionals. Blood samples are taken into the EDTA tube and DNA was extracted by the phenol/chloroform method. PCR was chosen to determine the presence or absence of GSTM1 and GSTT1. Results Our results showed that the percentage of GSTM1 null genotype was a significant difference (P=0.02), while the percentage of GSTT1 null genotype was not significant (P=0.76) between the two groups. The deletion of both genes is greater in professional than non-professional drivers. Conclusion In sum, air pollution in Cotonou appears to influence GSTM1 and GSTT1 gene suppression at a higher percentage in professional motorcycle drivers. This population could be predisposed to develop cancers. We recommend the consumption of fruits, organic vegetables and plants rich in antioxidants to strengthen the immune system. Citation Format: Firmin Houénoukpo Sagbo, Mènonvè Atindehou, Boris Cachon. Evaluation of genes for glutathione-S-transferase genetic polymorphism in drivers exposed to air pollution [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C019.

Association of deletion polymorphisms of GSTM1 and GSTT1 genes with the degree of lung damage in elderly people after COVID-19

Association of deletion polymorphisms of GSTM1 and GSTT1 genes with the degree of lung damage in elderly people after COVID-19

Полиморфизм генов глутатион-S-трансфераз в формировании синдрома повышенной эпителиальной проницаемости у детей с гастроинтестинальной формой пищевой аллергии

In order to study the role of glutathione transferase genes polymorphism in the formation of increased epithelial permeability syndrome in children with food allergy, we examined 39 young children (from 1.5 months to 3 years, group I) with a gastrointestinal form of food allergy and 30 healthy children with an uncomplicated anamnesis, comparable in sex and age (control group). It was found the association of alleles — /del of the GSTM1 gene and Ile105/Ala114 of the GSTP1 gene — with the development of increased epithelial permeability syndrome in food allergies in children. The obtained associations indirectly indicate the contribution of disturbances in the glutathione transferase system in children with gastrointestinal forms of food allergy both in terms of the syndrome of increased epithelial permeability formation and the comorbid pathology development.

Relationship between glutathione S-transferase M1 gene polymorphism and gastric cancer

This experiment was designed to investigate the relationship between glutathione S-transferase M1 (GSTM1) gene polymorphism and gastric cancer (GC). For this purpose, from January 2013 to December 2014, 116 patients with GC diagnosed in the Department of Gastroenterology of our hospital and 120 healthy people in the physical examination center were selected as the research objects. 116 patients with GC served as the observation group and 120 healthy people in the physical examination center served as the control group. Collect and isolate the peripheral blood nucleated cells of the subjects, obtain the GSTM1 gene polymorphism by sequencing, analyze the differences of GSTM1 genotype between the two groups, compare the differences of clinicopathological characteristics of patients with different genotypes in the observation group, look for the survival relative risk factors of patients with GC, and analyze the risk factors of death risk of GC by multivariate Cox risk proportional regression. Results showed that the proportion of GSTM1 (-) in the observation group (62.07%) was raised compared with the control group (48.33%) (p<0.05). There was a correlation between GSTM1 gene polymorphism and smoking, TNM stage differentiation and GSTM1 gene polymorphism in the observation group. The specific analysis found that the proportion of non-smoking, stage I-III and low differentiation in the GSTM1 (-) group was raised compared with that in the GSTM1 (+) group (p<0.05). TNM stage, differentiation degree and GSTM1 gene polymorphism were correlated with the median survival time of patients with GC (p<0.05). Further multivariate Cox risk proportional regression analysis showed that TNM stage IV, low differentiation and GSTM1 (-) the relative risk coefficients of death in patients with GC were stage Ⅰ - Ⅲ, high/medium differentiation and GSTM1, respectively (+) patients were 1.75, 1.46, and 2.14 times higher. In conclusion, GSTM1 gene polymorphism is associated with susceptibility to GC, and the GSTM1 deletion genotype is an unfavourable factor for poor prognosis in patients with GC.

Nicotinamide Mononucleotide Ameliorates Silica-Induced Lung Injury through the Nrf2-Regulated Glutathione Metabolism Pathway in Mice

Nicotinamide mononucleotide (NMN) is a natural antioxidant approved as a nutritional supplement and food ingredient, but its protective role in silicosis characterized by oxidative damage remains unknown. In this study, we generated a silicosis model by intratracheal instillation of silica, and then performed histopathological, biochemical, and transcriptomic analysis to evaluate the role of NMN in silicosis. We found that NMN mitigated lung damage at 7 and 28 days, manifested as a decreasing coefficient of lung weight and histological changes, and alleviated oxidative damage by reducing levels of reactive oxygen species and increasing glutathione. Meanwhile, NMN treatment also reduced the recruitment of inflammatory cells and inflammatory infiltration in lung tissue. Transcriptomic analysis showed that NMN treatment mainly regulated immune response and glutathione metabolism pathways. Additionally, NMN upregulated the expression of antioxidant genes Gstm1, Gstm2, and Mgst1 by promoting the expression and nuclear translocation of nuclear factor-erythroid 2 related factor 2 (Nrf2). Gene interaction analysis showed that Nrf2 interacted with Gstm1 and Mgst1 through Gtsm2. Promisingly, oxidative damage mediated by these genes occurred mainly in fibroblasts. In summary, NMN alleviates silica-induced oxidative stress and lung injury by regulating the endogenous glutathione metabolism pathways. This study reveals that NMN supplementation might be a promising strategy for mitigating oxidative stress and inflammation in silicosis.

Contribution of the GSTM1, GSTP1 and GSTT1 genes polymorphisms from glutationtransferases family to formation of predisposition for cervical cancer in women of Kyrgyz nationality

Цель работы ― провести оценку вклада вариантов генов семейства глутатионтрансфераз (GSTM1, GSTP1, GSTT1), а также их межгенных взаимодействий в формирование предрасположенности к раку шейки матки (РШМ) у женщин кыргызской национальности. Материалы и методы. Всего в исследование была включена 191 женщина кыргызской национальности, из них 95 женщин с гистологически верифицированным диагнозом рака шейки матки (РШМ), и 96 женщин ― без онкопатологии в индивидуальном анамнезе. Генотипирование по полиморфным локусам проводили с использованием методов полиморфизма длин рестрикционных фрагментов (ПЦР-ПДРФ) и аллель-специфической ПЦР (АС-ПЦР). Межгенные взаимодействия оценивали с использованием программы MDR 3.0.2. Результаты. Среди обследованных женщин делеция участка гена GSTM1 оказалась генетическим маркером, ассоциированным с повышенной вероятностью развития РШМ ― отношение шансов (ОШ)=2,02, 95% ДИ (1,28–3,20), p=0,002. Аналогичные результаты были получены для GSTT1 ― делеция участка гена также служила генетическим маркером, ассоциированным с повышенной вероятностью развития РШМ ― ОШ=3,04, 95% ДИ (2,00–4,64), p&lt;0,0001. Анализ варианта p.Ile105Val (ген GSTP1) не выявил статистически значимых различий в распределении частот генотипов или аллелей между больными РШМ и женщинами из группы сравнения. Выводы. Результаты настоящего исследования свидетельствуют о том, что сочетанное носительство конкретных вариантов генов GSTM1 и GSTT1 ассоциировано с повышенной вероятностью развития РШМ у женщин кыргызской национальности.

The combined effects of GSTM1/GSTT1 and MTHFR C677T polymorphisms on the systemic arterial hypertension susceptibility: A genetic association study in Brazilian diabetic patients

This genetic association study included 150 hypertensive diabetic patients and 150 normotensives non-diabetic subjects. Glutathione S-transferases M1 and T1 (GSTM1/GSTT1) deletion polymorphisms and methylenetetrahydrofolate reductase (MTHFR) C677T SNP (rs1801133) genotyping were performed by SYBR Green multiplex real-time and RFLP-PCR, respectively. Both GSTM1 and GSTT1 null (OR = 4.52, p = 0.04, and OR = 4.27, p = 0.01) and mutant (677TT) genotypes (OR = 2.95, p = 0.02) conferred risk to hypertension susceptibility. The combined genotypes (MTHFR:GSTT1:GSTM1) revealed a significant association: W/−/+, W/+/−, H/−/−, H/−/+, M/+/−, and M/+/+. These findings suggesting a probable oxidative hypothesis for hypertensive diabetic patients from the interaction of the detoxification mechanism and the homocysteine metabolism. The imbalance in antioxidant enzymes contributes to the establishment of oxidative stress in conjunction with hyperhomocysteinemia and reactive oxygen species production. We concluded that these findings suggest that both polymorphisms may contribute to hypertension susceptibility in diabetic patients.

Comprehensive analysis of the correlation between GSTM1 and tumor immunity in colon cancer

Glutathione S-transferase mu 1 (GSTM1) is one of the major glutathione conjugation enzymes. Its expression and activity have been suggested to correlate with the occurrence of colon cancer; however, the role of GSTM1 in tumor immunity remains unclear. Relevant data downloaded from The Cancer Genome Atlas (TCGA), Clinical Proteomic Tumor Analysis Consortium (CPTAC), and Human Protein Atlas (HPA) was used to perform a multi-dimensional expression analysis of GSTM1 in colon adenocarcinoma (COAD). The correlation between GSTM1 and tumor immunity was analyzed with multiple online tools. Then protein-protein interaction (PPI) network and functional enrichment analyses of GSTM1-associated immunomodulators were performed. Further, we developed the Cox regression model based on the GSTM1-related immunomodulators. Finally, a GSTM1-based clinical nomogram and a calibration curve was established to predict the probability and accuracy of long-term survival. GSTM1 was significantly downregulated in COAD versus normal tissues. Infiltration levels of B cells, CD8+ T cells, and dendritic cells were closely correlated to GSTM1 gene copy number deletion, and GSTM1 expression levels in COAD positively correlated with dendritic cell, B cell, neutrophil, and macrophage infiltration. Functional enrichment analysis indicated 36 GSTM1-related immunomodulators are involved in immune-related pathways of regulating T cell activation and lymphocytic activation. A 2-gene prognostic risk signature based on the 36 GSTM1-related immunomodulators was built using the Cox regression model, and the risk signature in combination with stage had an area under the curve (AUC) value of 0.747 by the receiver operating characteristic method. patients with higher risk scores-calculated based on 2 gene prognostic risk characteristics and further identified as an independent prognostic factor-were associated with worse survival using the Kaplan-Meier analysis. Together, the clinical nomogram and calibration curve based on GSTM1 suggested a good prediction accuracy for long-term survival probability. Our study provided evidence supporting the significant role of GSTM1 in COAD immunity and suggests GSTM1 as a potential novel target for COAD immunotherapy.

Prediction of recurrent course of respiratory infections in premature infants

The problem of prevention of frequent respiratory diseases for children remains relevant. Among premature infants, the most vulnerable group are children with very low and extremely low birth weight. Therefore, the development of a clinical prognostic model for the development of respiratory recurrent infections in premature infants may be the basis for creating a preventive program of early intervention. Purpose - to determine the clinical and genetic determinants of the development of recurrent respiratory infections for children born with a body weight less than 1500 g and to develop an algorithm for early prediction of adverse effects. Materials and methods. A cohort prospective study was conducted, which involved 155 children with very low and extremely low body weight. Prediction of the development of recurrent respiratory diseases was performed using simple and step-by-step multiple logistic regression analysis. Genetic methods included polymorphism studies of the GSTP1, GSTT1, GSTM1, ACE, AGT2R1 and eNOS genes. Results. Important predictors of increased morbidity of the examined children in a simple logistic regression analysis were: body weight at 12 months &lt;10 percentile, rickets in the first year of life and artificial feeding at discharge from the neonatal hospital. The study showed no effect of genes polymorphism of the glutathione-S-transferase family and genes of the renin-angiotensin system on the development of recurrent respiratory infections in children with born weight less than 1500 g. Conclusions. The developed model for predicting the recurrent course of respiratory infections for children born with a body weight less than 1500 g has a high specificity (95.35%) and moderate sensitivity (76.90%), which indicates the possibility of its use for a personalized approach to prevention adverse effects. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

Implications of Glutathione-S-transferases in Mitogen-activated protein kinase pathway: Risk associated with anticancer drug resistance

Anticancer drug resistance is a perilous glitch to accomplish alleviation of disease in patients with cancer. The setback of drug resistance in chemotherapy is a weighty snag of present time. Hassle of carcinoma has ability to develop resistance that arises due to certain alterations in drug targets. In the course of anticancer administrations, development of targeted therapies anticipates a new arena to subdue the drug resistance. Exalted levels of certain glutathione transferase isozymes have been identified with malign transformations as well as with anticancer drug resistance. Glutathione-S-transferases are a large group of phase-II detoxification enzymes which catalyse the conjugation of reduced glutathione to a broad range of exogenous as well as endogenous compounds. The enzymes of this family are divided into two distinct subgroups namely: cytosolic enzymes and membrane bound microsomal enzymes. Human cytosolic glutathione-S-transferases are extremely polymorphic in nature and exist in many forms such as mu, pi, alpha, theta, omega and zeta. Among these enzymes, mu and pi classes take part in regulation of mitogen-activated protein kinase pathway in directing cellular responses with apoptosis signal-regulating kinase and c-Jun Nterminal kinase 1 protein interactions. In normal condition, these two protein are mainly activated in response to cellular stress. The implications of glutathione S-transferase in development of anticancer drug resistance have been observed in two distinct ways. The first way is through direct detoxification mechanism while the second way deals with the action of glutathione S-transferase (mu and pi forms) as inhibitor to mitogen-activated protein kinase pathway.

Sinomenine attenuates lipopolysaccharide-induced inflammation and apoptosis of WI-38 cells by reducing glutathione S-transferase M1 expression.

Pediatric pneumonia is an infectious lung disease with high morbidity and mortality. Sinomenine, an alkaloid extracted from Caulis Sinomenii, exerts anti-inflammatory and anti-apoptotic activities. Lipopolysaccharide (LPS) is widely used for the establishment of an inflammatory model. This research aimed to explore the influences of sinomenine on LPS-caused inflammatory injuries in fetal lung WI-38 cells. WI-38 cells were treated with LPS to establish a cellular model of pediatric pneumonia. Cell viability was evaluated using CCK-8 assay. Apoptosis was evaluated using TUNEL staining and caspase-3 activity assays. Inflammatory cytokines and NF-κB p65 phosphorylation levels were measured by Enzyme-Linked Immunosorbent Assay. Glutathione S-transferase M1 (GSTM1) expression was detected by western blotting. Results showed that LPS reduced WI-38 cell viability, and sinomenine protected cells against LPS-induced viability reduction. Sinomenine concentration-dependently attenuated LPS-induced inflammation by reducing TNF-α, IL-1β and MCP-1, and increasing IL-10 levels. Sinomenine mitigated LPS-induced apoptosis. GSTM1 was screened by matching the targets of sinomenine and pediatric pneumonia. GSTM1 was upregulated in LPS-treated WI-38 cells, and this effect was attenuated after sinomenine treatment. GSTM1 was upstream of NF-κB pathway. Overexpression of GSTM1 reversed the suppressive functions of sinomenine on LPS-stimulated inflammation and apoptosis. Overall, sinomenine attenuates inflammation and apoptosis in WI-38 cells stimulated by LPS via inhibiting GSTM1 expression, indicating the therapeutic potential of sinomenine in pediatric pneumonia.

IQUB deficiency causes male infertility by affecting the activity of p-ERK1/2/RSPH3.

Can new genetic factors responsible for male infertility be identified, especially for those characterized by asthenospermia despite normal sperm morphology? We identified the novel pathogenetic gene IQ motif and ubiquitin-like domain-containing (IQUB) as responsible for male infertility characterized by asthenospermia, involving sperm radial spoke defects. To date, only a few genes have been found to be responsible for asthenospermia with normal sperm morphology. Iqub, encoding the IQUB protein, is highly and specifically expressed in murine testes and interacts with the proteins radial spoke head 3 (RSPH3), CEP295 N-terminal like (CEP295NL or DDC8), glutathione S-transferase mu 1 (GSTM1) and outer dense fiber of sperm tails 1 (ODF1) in the yeast two-hybrid system. The IQUB variant was identified by whole-exome sequencing in a cohort of 126 male infertility patients with typical asthenospermia recruited between 2015 and 2020. Knockout (KO) and knockin (KI) mouse models, scanning and transmission electron microscopy (TEM), and other functional assays were performed, between 2019 and 2021. The IQUB variant was identified by whole-exome sequencing and confirmed by Sanger sequencing. Iqub KO and KI mice were constructed to mimic the phenotype of the affected individual. After recapitulating the phenotype of human male infertility, scanning and TEM were performed to check the ultrastructure of the sperm. Western blot and co-immunoprecipitation were performed to clarify the pathological mechanism of the IQUB variant. We identified a homozygous nonsense IQUB variant (NM_001282855.2:c.942T> G(p.Tyr314*)) from an infertile male. Iqub KO and KI mice mimicked the infertility phenotype and confirmed IQUB to be the pathogenetic gene. Scanning and TEM showed that sperm of both the mouse models and the affected individual had radial spoke defects. The functional assay suggested that IQUB may recruit calmodulin in lower Ca2+ environments to facilitate the normal assembly of radial spokes by inhibiting the activity of RSPH3/p-ERK1/2 (a nontypical AKAP (A-Kinase Anchoring Protein) forming by RSPH3 and phosphorylation of extracellular signal-regulated kinase 1 and 2 (p-ERK1/2)). Additional cases are needed to confirm the genetic contribution of IQUB variants to male infertility. In addition, because no IQUB antibody is available for immunofluorescence and the polyclonal antibody we generated was only effective in western blotting, immunostaining for IQUB was not performed in this study. Therefore, this study lacks direct in vivo proof to confirm the effect of the variant on IQUB protein level. Our results suggest a causal relation between IQUB variants and male infertility owing to asthenospermia, and partly clarify the pathological mechanism of IQUB variants. This expands our knowledge of the genes involved in human sperm asthenospermia and potentially provides a new genetic marker for male infertility. This work was supported by the National Key Research and Development Program of China (2021YFC2700100), the National Natural Science Foundation of China (32130029, 82171643, 81971450, 82001538, and 81971382) and the Guangdong Science and Technology Department Guangdong-Hong Kong-Macao Joint Innovation Project (2020A0505140003). There are no competing interests to declare. N/A.

IPSCs derived from esophageal atresia patients reveal SOX2 dysregulation at the anterior foregut stage.

A series of well-regulated cellular and molecular events result in the compartmentalization of the anterior foregut into the esophagus and trachea. Disruption of the compartmentalization process leads to esophageal atresia/tracheoesophageal fistula (EA/TEF). The cause of EA/TEF remains largely unknown. Therefore, to mimic the early development of the esophagus and trachea, we differentiated induced pluripotent stem cells (iPSCs) from EA/TEF patients, and iPSCs and embryonic stem cells from healthy individuals into mature three-dimensional esophageal organoids. CXCR4, SOX17 and GATA4 expression was similar in both patient-derived and healthy endodermal cells. The expression of the key transcription factor SOX2 was significantly lower in the patient-derived anterior foregut. We also observed an abnormal expression of NKX2.1 (or NKX2-1) in the patient-derived mature esophageal organoids. At the anterior foregut stage, RNA sequencing revealed the critical genes GSTM1 and RAB37 to be significantly lower in the patient-derived anterior foregut. We therefore hypothesize that a transient dysregulation of SOX2 and the abnormal expression of NKX2.1 in patient-derived cells could be responsible for the abnormal foregut compartmentalization.

Association of glutathione S-transferase M1 and T1 polymorphisms on the susceptibility of diabetic retinopathy in the Bangladeshi population.

This study investigated the role of glutathione-S-transferase gene (GSTM1 and GSTT1) polymorphisms in the predisposition of type 2 diabetes mellitus (T2DM) with or without diabetic retinopathy (DR). Thecase-control study included188 subjects: 50 T2DMwith DR, 63T2DM without DR, and 75 healthy individuals' presenting no clinical signs or evidence of diabetes mellitus. Zinc and magnesium levels were measured using a flame atomic absorption spectrophotometer, and the lipid profile was evaluated using standard methods. The gene polymorphism of GSTs was performed by the multiplex-PCR method. Compared to the control, DR and T2DM had considerably greater total cholesterol, LDL-C, and decreased HDL-C levels. Magnesium levels were significantly lower in DR and T2DM than in control. Total cholesterol, LDL, TG, and magnesium levels didn't differ significantly between DR and T2DM groups. In DR, the GSTT1-null genotype was more prevalent than in T2DM subjects and controls (26.0%, 12.7%, and 10.7%, respectively). GSTT1-null genotype was considerably more common in DR than in controls and associated with 2.94-folds enhancing the chance of developing DR (OR = 2.94; 95% CI = 1.12-7.75;p = 0.02). However, the recurrence of GSTM1-null genotype was not clearly distinguishable among these three populations (28.0%, 38.1% and 29.3%, respectively) and not particularly prone to the risk of DR compared to T2DM subjects and controls (OR = 0.63; 95% CI = 0.28-1.41; p = 0.26; OR = 0.94; 95% CI = 0.42-2.07; p = 0.87, respectively). Taken together, these findings suggest the potential role of GSTT1 deletion mutation as a risk factor for the vulnerability of DR among T2DM patients in the Bangladeshi population.

Glutathione S-transferase genetic polymorphisms and fluoride-induced reproductive toxicity in men with idiopathic infertility.

Male infertility caused by idiopathic oligoasthenospermia (OAT) is known as idiopathic male infertility. Glutathione S-transferase (GST) and fluoride may play important roles in idiopathic male infertility, but their effects are still unknown. Our study examined the relationship between GST polymorphisms and fluoride-induced toxicity in idiopathic male infertility and determined the underlying mechanism. Sperm, blood, and urine samples were collected from 560 males. Fluoride levels were measured by a highly selective electrode method, and GST genotypes were identified using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP). Semen parameters, DNA fragmentation index (DFI), mitochondrial membrane potential (MMP), and oxidative stress (OS) biomarkers were statistically assessed at the P < 0.05 level. Compared with healthy fertile group, semen parameters, fluoride levels, OS biomarkers, sex hormone levels, and MMP and DFI levels were lower in the idiopathic male infertility group. For glutathione S-transferase M1 (GSTM1[-]) and glutathione S-transferase T1 (GSTT1[-]) or glutathione S-transferase P1 (GSTP1) mutant genotypes, levels of semen fluoride, OS, MMP, and DFI were considerably higher, and the mean levels of sperm parameters and testosterone were statistically significant in GSTM1(+), GSTT1(+), and GSTP1 wild-type genotypes. Both semen and blood fluoride levels were associated with oxidative stress in idiopathic male infertility patients. Elevated fluoride in semen with the genotypes listed above was linked to reproductive quality in idiopathic male infertility patients. In conclusion, GST polymorphisms and fluorine may have an indicative relationship between reproductive quality and sex hormone levels, and OS participates in the development of idiopathic male infertility.