Evaluation of Transforming Growth Factor Beta-1 Gene 869T/C Polymorphism with Hypertension: A Meta-Analysis

The identification of key genes and pathways in polycystic ovary syndrome by bioinformatics analysis of next-generation sequencing data

Background

Polycystic ovary syndrome (PCOS) is a reproductive endocrine disorder. The specific molecular mechanism of PCOS remains unclear. The aim of this study was to apply a bioinformatics approach to reveal related pathways or genes involved in the development of PCOS.

Methods

The next-generation sequencing (NGS) dataset GSE199225 was downloaded from the gene expression omnibus (GEO) database and NGS dataset analyzed is obtained from in vitro culture of PCOS patients’ muscle cells and muscle cells of healthy lean control women. Differentially expressed gene (DEG) analysis was performed using DESeq2. The g:Profiler was utilized to analyze the gene ontology (GO) and REACTOME pathways of the differentially expressed genes. A protein–protein interaction (PPI) network was constructed and module analysis was performed using HiPPIE and cytoscape. The miRNA-hub gene regulatory network and TF-hub gene regulatory network were constructed. The hub genes were validated by using receiver operating characteristic (ROC) curve analysis.

Results

We have identified 957 DEG in total, including 478 upregulated genes and 479 downregulated gene. GO terms and REACTOME pathways illustrated that DEG were significantly enriched in regulation of molecular function, developmental process, interferon signaling and platelet activation, signaling, and aggregation. The top 5 upregulated hub genes including HSPA5, PLK1, RIN3, DBN1, and CCDC85B and top 5 downregulated hub genes including DISC1, AR, MTUS2, LYN, and TCF4 might be associated with PCOS. The hub gens of HSPA5 and KMT2A, together with corresponding predicted miRNAs (e.g., hsa-mir-34b-5p and hsa-mir-378a-5p), and HSPA5 and TCF4 together with corresponding predicted TF (e.g., RCOR3 and TEAD4) were found to be significantly correlated with PCOS.

Conclusions

These study uses of bioinformatics analysis of NGS data to obtain hub genes and key signaling pathways related to PCOS and its associated complications. Also provides novel ideas for finding biomarkers and treatment methods for PCOS and its associated complications.

Association of serum level of TGF-B1 and its genetic polymorphisms (C509T and T869C) with Ischemic heart disease in Iraqi population

Transforming growth factor beta 1 (TGF-β1) is considered a pleotropic cytokine involved in the progression of cardiovascular disease. The purpose of the current study was to identify the relationship between serum levels of TGF-β1, the genetic variations (C509T rs1800469, T869C rs1800470) and their constructed haplotypes with the susceptibility of ischemic heart disease (IHD) in the Iraqi population.The case-control study enrolled 200 participants, including 100 patients with IHD and 100 healthy controls. Genotypes of (TGF-β1) polymorphisms were performed by TaqMan allele-specific probes detected by real-time PCR (RT-PCR). The serum level of TGF-β1 was measured by an ELISA assay. The obtained results showed that the two minor alleles of C509T rs1800469 and T869C rs1800470 were associated with a decreased risk of IHD, preventive fraction (PF%) = 11.6 %; 23.9 %, respectively. Genotype distribution was significantly noted in the TT genotype of C509T rs1800469 (p = 0.033) and in the TC genotype of T869C rs1800470 (p = 0.006) between patients and control groups. A significant distribution was seen in the C allele of T869C rs1800470 (p = 0.002) between the studied groups. The carriers of the TT genotype in the C509T rs1800469 and the TC; CC genotypes in the T869C rs1800470 decreased the chance of having IHD, (hazard ratio HR<1). Furthermore, the haplotype analysis observed that H1 (C-T) was significantly associated with the development of IHD (HR=1.66; 95 % CI=1.10-2.51; p = 0.021) and the inverse effect of H4 (T-C), (HR=0.36; 95 % CI=0.20-0.65; p = 0.001). The TGF-β1 alleles of both SNPs, TT genotype of C509T rs1800469, TC, CC of T869C rs1800470 and H4 locus of haplotypes were suggested to be protective biomarkers against IHD in Iraqi population.

Positive genetic effect of hypertension family history on stroke: A cross Mendelian randomization study

BACKGROUND

Clinical observational study demonstrated that hypertension is an independent risk factor for stroke. Furthermore, both hypertension and stroke exhibit genetic predispositions. However, the genetic relationship between hypertension and stroke in first-degree relatives remains unclear.

METHOD

The Genetic effects were validated using an across-Mendelian randomization (MR) approach. The Genome-Wide Association Study summary data used in this study were obtained from a publicly available platform. The primary MR effect employed was inverse-variance weighted (IVW), and the other analysis methods included MR-Egger, weighted median, simple mode, and weighted mode. Prior to MR analysis, tests for MR_PRESSO, pleiotropy, and heterogeneity were conducted.

RESULT

The presence of family history of hypertension significantly contributed to the genetic predisposition to various types of stroke, including ischemic stroke, subarachnoid hemorrhage, lacunar stroke, cardioembolic ischemic stroke, small vessel ischemic stroke, and large artery atherosclerosis-related ischemic stroke.

CONCLUSION

Briefly, hypertension in first-degree relatives has a genetic impact on the risk of stroke development. Shared genetic factors may exist between hypertension and stroke.

Glutathione S-Transferase Omega-2 and Transforming Growth Factor-β1 Polymorphisms in Iranian Glaucoma Patients

Background

To investigate the association of glutathione s-transferase omega 2 (GSTO2) (142N > D) and transforming growth factor-β1 (TGF-β1) (869T > C) gene polymorphisms on the pathogenesis of two common types of glaucoma (including primary open-angle glaucoma (POAG) and chronic angle-closure glaucoma (CACG)) in the Iranian population.

Methods

A total of 100 glaucoma patients (60% males and 40% females with an age mean ± SD of 34.66 ± 14.25 years; 56 cases of POAG and 44 cases of CACG) were enrolled in this study. GSTO2 (142N > D) and TGF-β1 (869T > C) polymorphisms were evaluated by PCR-based methods in patients and controls.

Results

At locus GSTO2 (142N > D), the odds of ND genotype with respect to DD and NN genotypes were 1.55 and 2.08 times higher in POAG and CACG patients compared to those of patients in the control group (95% CI₁: 0.80–2.98; 95% CI₂: 1.00–4.33) which was statistically significant in CACG patients. However, the odds of DD and NN genotypes against the reference genotype in two patients group were not statistically significant as compared to those of patients in the control group. There was a significant association between the ND genotype and male patients (OR = 2.28, 95% CI: 1.06–4.92). The analysis of TGF-β1 (869T > C) polymorphisms showed no significant difference between the genotypes of TGF-β1 (869T > C) polymorphisms in patients and control groups; however, the CT genotype of TGF-β1 significantly differed between female controls and patients (OR = 0.42, 95% CI: 0.18–0.96).

Conclusion

The presented results revealed that there was a significant association between the ND genotype of GSTO2 and the pathogenesis of glaucoma. Furthermore, this genotype can be considered as a sex-dependent genetic risk factor for the development of glaucoma. In contrast, the CT genotype of TGF-β1 is suggested to be a protective genetic factor against the pathogenesis of glaucoma.

Role of activin receptor-like kinase 1 in vascular development and cerebrovascular diseases

Activin receptor-like kinase 1 (ALK1) is a transmembrane serine/threonine receptor kinase of the transforming growth factor beta (TGFβ) receptor superfamily. ALK1 is specifically expressed in vascular endothelial cells, and its dynamic changes are closely related to the proliferation of endothelial cells, the recruitment of pericytes to blood vessels, and functional differentiation during embryonic vascular development. The pathophysiology of many cerebrovascular diseases is today understood as a disorder of endothelial cell function and an imbalance in the proportion of vascular cells. Indeed, mutations in ALK1 and its co-receptor endoglin are major genetic risk factors for vascular arteriovenous malformation. Many studies have shown that ALK1 is closely related to the development of cerebral aneurysms, arteriovenous malformations, and cerebral atherosclerosis. In this review, we describe the various roles of ALK1 in the regulation of angiogenesis and in the maintenance of cerebral vascular homeostasis, and we discuss its relationship to functional dysregulation in cerebrovascular diseases. This review should provide new perspectives for basic research on cerebrovascular diseases and offer more effective targets and strategies for clinical diagnosis, treatment, and prevention.

Mouse Models of Primary Aldosteronism: From Physiology to Pathophysiology

Primary aldosteronism (PA) is a common form of endocrine hypertension that is characterized by the excessive production of aldosterone relative to suppressed plasma renin levels. PA is usually caused by either a unilateral aldosterone-producing adenoma or bilateral adrenal hyperplasia. Somatic mutations have been identified in several genes that encode ion pumps and channels that may explain the aldosterone excess in over half of aldosterone-producing adenomas, whereas the pathophysiology of bilateral adrenal hyperplasia is largely unknown. A number of mouse models of hyperaldosteronism have been described that recreate some features of the human disorder, although none replicate the genetic basis of human PA. Animal models that reproduce the genotype-phenotype associations of human PA are required to establish the functional mechanisms that underlie the endocrine autonomy and deregulated cell growth of the affected adrenal and for preclinical studies of novel therapeutics. Herein, we discuss the differences in adrenal physiology across species and describe the genetically modified mouse models of PA that have been developed to date.

Transforming growth factor beta1 and aldosterone

PURPOSE OF REVIEW

It is well established that blocking the renin-angiotensin-aldosterone system (RAAS) is effective for the treatment of cardiovascular and renal complications in hypertension and diabetes mellitus. Although the induction of transforming growth factor beta1 (TGFbeta1) by components of the RAAS mediates the hypertrophic and fibrogenic changes in cardiovascular-renal complications, it is still controversial as to whether TGFbeta1 can be a target to prevent such complications. Here, we review recent findings on the role of TGFbeta1 in fluid homeostasis, focusing on the relationship with aldosterone.

RECENT FINDINGS

TGFbeta1 suppresses the adrenal production of aldosterone and renal tubular sodium reabsorption. We have generated mice with TGFbeta1 mRNA expression graded in five steps, from 10 to 300% of normal, and found that blood pressure and plasma volume are negatively regulated by TGFbeta1. Notably, the 10% hypomorph exhibits primary aldosteronism and sodium and water retention due to markedly impaired urinary excretion of water and electrolytes.

SUMMARY

These results identify TGFbeta signalling as an important counterregulatory system against aldosterone. Understanding the molecular mechanisms for the suppressive effects of TGFbeta1 on adrenocortical and renal function may further our understanding of primary aldosteronism, as well as assist in the development of novel therapeutic strategies for hypertension.

Novel alleles of the transforming growth factor β-1 regulatory region and exon 1

Transforming growth factor β-1, encoded by the TGFB1 gene, is a cytokine that plays a central role in many physiologic and pathogenic processes with pleiotropic effects. Regulatory activity for this gene has been shown for 3.0 kb between positions -2665 and +423 from its translational start site. At least 17 TGFB1 regulatory region and exon 1 alleles have been defined on the basis of 18 polymorphic sites. Polymorphisms in TGFB1's regulatory region have been associated with differential levels of expression of this cytokine and to genetic risk in cancer and transplantation. In this report, we present 19 novel TGFB1 regulatory region and exon 1 alleles: p018-p036. Amplification of TGFB1's regulatory region was performed with an in-house protocol, and novel alleles were defined by either allele-specific amplification and/or molecular cloning of the amplicons, followed by sequencing in isolation. Three of these novel alleles (p018, p019, and p020) are shown to be formed by novel combinations of the aforementioned known polymorphic positions. Another 16 novel alleles are shown to carry additional known and unknown single-nucleotide polymorphisms. Polymorphism in TGFB1's regulatory region could have an impact on important processes, including embryogenesis, hematopoiesis, carcinogenesis, angiogenesis, fibrosis, immune responses, and transplantation, making its characterization necessary.

The role of transforming growth factor β1 in the regulation of blood pressure

Although human association studies suggest a link between polymorphisms in the gene encoding transforming growth factor (TGF) β1 and differing blood pressure levels, a causative mechanism for this correlation remains elusive. Recently we have generated a series of mice with graded expression of TGFβ1, ranging from approximately 10% to 300% compared to normal. We have found that blood pressure and plasma volume are negatively regulated by TGFβ1. Of note, the 10% hypomorph exhibits primary aldosteronism and markedly impaired urinary excretion of water and electrolytes. We here review previous literature highlighting the importance of TGFβ signaling as a natriuretic system, which we postulate is a causative mechanism explaining how polymorphisms in TGFβ1 could influence blood pressure levels.

Blood pressure homeostasis is maintained by a P311-TGF-β axis

P311 is an 8-kDa intracellular protein that is highly conserved across species and is expressed in the nervous system as well as in vascular and visceral smooth muscle cells. P311-null (P311-/-) mice display learning and memory defects, but alterations in their vasculature have not been previously described. Here we report that P311-/- mice are markedly hypotensive with accompanying defects in vascular tone and VSMC contractility. Functional abnormalities in P311-/- mice resulted from decreased total and active levels of TGF-β1, TGF-β2, and TGF-β3 that arise as a specific consequence of decreased translation. Vascular hypofunctionality was fully rescued in vitro and in vivo by exogenous TGF-β1-TGF-β3. Conversely, P311-transgenic (P311(TG)) mice had elevated levels of TGF-β1-TGF-β3 and subsequent hypertension. Consistent with findings attained in mouse models, arteries recovered from hypertensive human patients displayed increased P311 expression. Thus, we identified P311 as the first protein known to modulate TGF-β translation and the first pan-regulator of TGF-β expression under steady-state conditions. Together, our findings point to P311 as a critical blood pressure regulator and establish a potential link between P311 expression and the development of hypertensive disease.

Primary aldosteronism and impaired natriuresis in mice underexpressing TGFβ1

To uncover the potential cardiovascular effects of human polymorphisms influencing transforming growth factor β1 (TGFβ1) expression, we generated mice with Tgfb1 mRNA expression graded in five steps from 10% to 300% normal. Adrenal expression of the genes for mineralocorticoid-producing enzymes ranged from 50% normal in the hypermorphs at age 12 wk to 400% normal in the hypomorphs accompanied with proportionate changes in plasma aldosterone levels, whereas plasma volumes ranged from 50% to 150% normal accompanied by marked compensatory changes in plasma angiotensin II and renin levels. The aldosterone/renin ratio ranged from 0.3 times normal in the 300% hypermorphs to six times in the 10% hypomorphs, which have elevated blood pressure. Urinary output of water and electrolytes are markedly decreased in the 10% hypomorphs without significant change in the glomerular filtration rate. Renal activities for the Na(+), K(+)-ATPase, and epithelial sodium channel are markedly increased in the 10% hypomorphs. The hypertension in the 10% hypomorphs is corrected by spironolactone or amiloride at doses that do not change blood pressure in wild-type mice. Thus, changes in Tgfb1 expression cause marked progressive changes in multiple systems that regulate blood pressure and fluid homeostasis, with the major effects being mediated by changes in adrenocortical function.

Transforming growth factor-β1 gene +869T/C, but not +915G/C polymorphism is associated with essential hypertension in a Chinese patient cohort

Many studies have suggested that transforming growth factor-β1 (TGF-β1) gene might be involved in the development of hypertension. However, results have been inconsistent. In this study, the authors performed a meta-analysis to investigate the associations of +869T/C and +915G/C polymorphisms in TGF-β1 gene with hypertension risk in Chinese. Published literature from PubMed, EMBASE, CNKI, CBM, and Wanfang Data were searched. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using fixed or random-effects model. Nine studies (1,995 cases/1,840 controls) for +869T/C polymorphism and seven studies (1,547 cases/1,577 controls) for +915G/C polymorphism were included in the meta-analysis. The overall result showed that there was a statistically significant association between +869T/C polymorphism and hypertension risk (CC vs. TT: OR = 1.80, 95% CI 1.34-2.44). Similar results were found among two geographic locations and two subgroups with different sample size. However, no significant association was found for +915G/C polymorphism with the risk of hypertension (CC vs. GG: OR = 1.66, 95% CI 0.74-3.74). The meta-analysis indicated the significant association of +869T/C, but not +915G/C polymorphism with hypertension susceptibility. However, given the limited sample size, the associations warrant further investigation.