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

The acidic microenvironment in the perisinusoidal space critically determines bile salt-induced activation of hepatic stellate cells

Cholestatic liver diseases, accompanied by the hepatic accumulation of bile salts, frequently lead to liver fibrosis, while underlying profibrogenic mechanisms remain incompletely understood. Here, we evaluated the role of extracellular pH (pHe) on bile salt entry and hepatic stellate cell (HSC) activation and proliferation. As modulators of intracellular pH (pHi), various proton pump inhibitors (PPI) were tested for their ability to prevent bile salt entry and HSC activation. Lastly, the PPI pantoprazole was employed in the 3,5-Diethoxycarbonyl-1,4-Dihydrocollidine (DDC)-diet model of cholestatic liver fibrosis. We found in vitro, that slightly acidic pHe (7.2-7.3) enhanced bile salt accumulation in HSC and was a prerequisite to bile salt-induced HSC activation. Pantoprazole in the DDC model exhibited antifibrotic effects. We conclude that bile salt-induced activation of HSC may depend on the slightly acidic microenvironment present in the perisinusoidal space and modulation of pHi in HSC may offer a novel pharmacological target in cholestatic disease.

How PPAR-alpha mediated inflammation may affect the pathophysiology of chronic kidney disease

Chronic kidney disease (CKD) is a major risk factor for death in adults. Inflammation plays a role in the pathogenesis of CKD, but the mechanisms are poorly understood. Peroxisome proliferator-activated receptor alpha (PPAR-α) is a nuclear receptor and one of the three members (PPARα, PPARβ/δ, and PPARγ) of the PPARs that plays an important role in ameliorating pathological processes that accelerate acute and chronic kidney disease. Although other PPARs members are well studied, the role of PPAR-α is not well described and its role in inflammation-mediated chronic disease is not clear. Herein, we review the role of PPAR-α in chronic kidney disease with implications for the immune system.

TGF-β Isoforms and GDF-15 in the Development and Progression of Atherosclerosis

The effect of oxidised lipoproteins on the endothelium, monocytes, platelets, and macrophages is a key factor in the initiation and development of atherosclerosis. Antioxidant action, lipoprotein metabolism, and chronic inflammation are the fields of research interest for better understanding the development of the disease. All the fields are related to inflammation and hence to the secretion of cytokines, which are being investigated as potential diagnostic markers for the onset of atherosclerosis. Pathways of vascular damage are crucial for the development of new laboratory readouts. The very early detection of endothelial cell damage associated with the onset of atherosclerosis, allowing the initiation of therapy, remains a major research goal. This article summarises the latest results on the relationship of tumour growth factor beta (TGF-β) isoforms and growth differentiation factor 15 (GDF-15) to the pathogenesis of atherosclerosis: which cells involved in atherosclerosis produce them, which effectors stimulate their synthesis and secretion, how they influence atherosclerosis development, and the relationship between the levels of TGF-β and GDF-15 in the blood and the development and extent of atherosclerosis.

Fibroblasts under pressure: cardiac fibroblast responses to hypertension and antihypertensive therapies

Approximately 50% of Americans have hypertension, which significantly increases the risk of heart failure. In response to increased peripheral resistance in hypertension, intensified mechanical stretch in the myocardium induces cardiomyocyte hypertrophy and fibroblast activation to withstand increased pressure overload. This changes the structure and function of the heart, leading to pathological cardiac remodeling and eventual progression to heart failure. In the presence of hypertensive stimuli, cardiac fibroblasts activate and differentiate to myofibroblast phenotype capable of enhanced extracellular matrix secretion in coordination with other cell types, mainly cardiomyocytes. Both systemic and local renin-angiotensin-aldosterone system activation lead to increased angiotensin II stimulation of fibroblasts. Angiotensin II directly activates fibrotic signaling such as transforming growth factor β/SMAD and mitogen-activated protein kinase (MAPK) signaling to produce extracellular matrix comprised of collagens and matricellular proteins. With the advent of single-cell RNA sequencing techniques, heterogeneity in fibroblast populations has been identified in the left ventricle in models of hypertension and pressure overload. The various clusters of fibroblasts reveal a range of phenotypes and activation states. Select antihypertensive therapies have been shown to be effective in limiting fibrosis, with some having direct actions on cardiac fibroblasts. The present review focuses on the fibroblast-specific changes that occur in response to hypertension and pressure overload, the knowledge gained from single-cell analyses, and the effect of antihypertensive therapies. Understanding the dynamics of hypertensive fibroblast populations and their similarities and differences by sex is crucial for the advent of new targets and personalized medicine.

Summary of Known Genetic and Epigenetic Modification Contributed to Hypertension

Hypertension is a multifactorial disease due to a complex interaction among genetic, epigenetic, and environmental factors. Characterized by raised blood pressure (BP), it is responsible for more than 7 million deaths per annum by acting as a leading preventable risk factor for cardiovascular disease. Reports suggest that genetic factors are estimated to be involved in approximately 30 to 50% of BP variation, and epigenetic marks are known to contribute to the initiation of the disease by influencing gene expression. Consequently, elucidating the genetic and epigenetic mediators associated with hypertension is essential for better discernment of its pathophysiology. By deciphering the unprecedented molecular hypertension basis, it could help to unravel an individual's inclination towards hypertension which eventually could result in an arrangement of potential strategies for prevention and therapy. In the present review, we discuss known genetic and epigenetic drivers that contributed to the hypertension development and summarize the novel variants that have currently been identified. The effect of these molecular alterations on endothelial function was also presented.

Involvement of AGE and Its Receptors in the Pathogenesis of Hypertension in Elderly People and Its Treatment

Both systolic and diastolic blood pressures increase with age up to 50 to 60 years of age. After 60 years of age systolic pressure rises to 84 years of age but diastolic pressure remains stable or even decreases. In the oldest age group (85-99 years), the systolic blood pressure (SBP) is high and diastolic pressure (DBP) is the lowest. Seventy percent of people older than 65 years are hypertensive. This paper deals with the role of advanced glycation end products (AGE) and its cell receptor (RAGE) and soluble receptor (sRAGE) in the development of hypertension in the elderly population. Plasma/serum levels of AGE are higher in older people as compared with younger people. Serum levels of AGE are positively correlated with age, arterial stiffness, and hypertension. Low serum levels of sRAGE are associated with arterial stiffness and hypertension. Levels of sRAGE are negatively correlated with age and blood pressure. Levels of sRAGE are lower in patients with arterial stiffness and hypertension than patients with high levels of sRAGE. AGE could induce hypertension through numerous mechanisms including, cross-linking with collagen, reduction of nitric oxide, increased expression of endothelin-1, and transforming growth factor-β (TGF-β). Interaction of AGE with RAGE could produce hypertension through the generation of reactive oxygen species, increased sympathetic activity, activation of nuclear factor-kB, and increased expression of cytokines, cell adhesion molecules, and TGF- β. In conclusion, the AGE-RAGE axis could be involved in hypertension in elderly people. Treatment for hypertension in elderly people should be targeted at reduction of AGE levels in the body, prevention of AGE formation, degradation of AGE in vivo, downregulation of RAGE expression, blockade of AGE-RAGE interaction, upregulation of sRAGE expression, and use of antioxidants.

Transforming Growth Factor-β1, Arterial Stiffness and Vascular Age in Patients With Uncontrolled Arterial Hypertension

BACKGROUND

Lack of blood pressure control leads to a higher incidence of hypertension-mediated target organ damage (HMOD). One of the markers of HMOD is an increased arterial stiffness, an independent predictor of cardiovascular complications. However, abstract numbers showing the level of arterial stiffness do not give patients a clear understanding of the risk of their condition. In order to increase patient compliance, the term "vascular age" (VA) was introduced. Arteriosclerosis plays the main role in increasing VA. The greatest interest, according to the literature, in the study of this issue is in arteriosclerosis caused by transforming growth factor β1 (TGF-β1)-the effect of TGF-β1 on the culture of smooth muscle cells leads to their proliferation and growth; also, TGF-β1 increases the amount of collagen and accelerates the degradation of elastin.

METHODS

We included 140 people in the study: 80 patients with controlled arterial hypertension (CAH), 30 with uncontrolled arterial hypertension (UAH), and 30 patients who formed the control group. All patients underwent a determination of arterial stiffness and VA using the cardio-ankle vascular index (CAVI), a corrected (blood-pressure independent) cardio-ankle vascular index (CAVI₀) and the concentration of TGF-β1 was measured.

RESULTS

The TGF-β1 value in the UAH group was 22.6 (25th percentile=20.6; 75th percentile=25.6) ng/mL, and in the control group it was 17.4 (25th percentile=11.8; 75th percentile=19.3) ng/mL. In the CAH group, an intermediate value was noted-19.2 (25th percentile=17.2; 75th percentile=24.7) ng/mL. The CAVI in the UAH group was 9.2 (25th percentile=8.5; 75th percentile=9.9), in the control group-7 (25th percentile=6.5; 75th percentile=7.5). In the CAH group, the average CAVI was 7.8 (25th percentile=7.0; 75th percentile=8.5). The CAVI 0 in the UAH group was 14.8 (25th percentile=12.0; 75th percentile=15.6), in the control group - 9.7 (25th percentile=8.8; 75th percentile=9.7). In the CAH group, the average CAVI was 11.1 (25th percentile=10.1; 75th percentile=13.6). Vascular age in the UAH group was 71.5 (25th percentile=64; 75th percentile=74) years, in the CAH group 59 (25th percentile=49; 75th percentile=69) years, and in both groups (UAH, CAH), VA was significantly higher than the chronological age (p<0.05). In the control group, the VA did not significantly differ from the chronological age (p>0.05) and it was 54 (25th percentile=44; 75th percentile=59) years. A significant relationship was found between the TGF-β1 level and CAVI (CAH r=0.777; UAH r=0.753; p<0.05), CAVI 0 (CAH r=0.625; UAH r=0.502; p<0.05) and VA in patients with AH (CAH r=0.649; UAH r=0.753; p<0.05).

CONCLUSION

In patients in the UAH group, there was an increase in the concentration of TGF-β1, an increase in the arterial stiffness and in VA in comparison with patients in the CAH group and the control group. The relationship between TGF-β1 and the arterial stiffness and VA was revealed in patients with hypertension.

ROLE OF THE TRANSFORMING GROWTH FACTOR β1 IN THE GENESIS OF ARTERIAL HYPERTENSION AND ITS COMPLICATIONS

Transforming growth factor beta 1 (TGFβ1) is an actively studied cytokine with rather contradictory effects. The article systematizes and summarizes the scientific data on TGFβ1 and its role in the development and progression of arterial hypertension, with an emphasis on arterial stiffness.

Transforming Growth Factor-Beta 1 and Endoglin Levels in Congenital Solitary Functioning Kidney

Introduction:

Glomerular hyperfiltration leads to hypertension, microalbuminuria, and impaired renal function in children with congenital solitary functioning kidney (cSFK). The purpose of this study was to investigate the associations between serum transforming growth factor β-1 (TGF) and endoglin levels and hypertension, renal function or microalbuminuria in children with cSFK.

Materials and Methods:

63 patients and 36 controls were included in the study. Serum endoglin and TGF-β1 level was measured using ELISA commercial kits.

Results:

Serum TGF-β1 and endoglin levels were higher in patients than those of controls (P = 0.04 and P < 0.001, respectively). The prevalence of hypertension was found to be 45.6%. There was a positive association between endoglin levels and the presence of masked hypertension (odds ratio: 1.121, P = 0.04). TGF-β1 and endoglin levels were positively associated with microalbuminuria (OR: 1.17, P = 0.04; OR: 1.836, P = 0.01). ROC curve analysis showed that serum endoglin and TGF-β1 levels had predictive value for microalbuminuria (cut-off value: 4.86 ng/mL, sensitivity: 94.7%, specificity: 54.5%, area under the curve ± standard error [AUC ± SE]: 0.888 ± 0.025, P = 0.01 for endoglin; cut-off value 561.24 pg/mL, sensitivity: 89.5%, specificity: 73%, AUC ± SE: 0.995 ± 0.334, P = 0.02 for TGF-β1). There were no significant relationships between glomerular filtration rate and serum TGF-β1 or endoglin levels.

Conclusions:

Endoglin and TGF-β1 may play an important role in the pathophysiology of microalbuminuria in cSFK. Endoglin may have a role in the development of hypertension in children with cSFK.

Trans-ethnic association study of blood pressure determinants in over 750,000 individuals

In this trans-ethnic multi-omic study, we reinterpret the genetic architecture of blood pressure to identify genes, tissues, phenomes and medication contexts of blood pressure homeostasis. We discovered 208 novel common blood pressure SNPs and 53 rare variants in genome-wide association studies of systolic, diastolic and pulse pressure in up to 776,078 participants from the Million Veteran Program (MVP) and collaborating studies, with analysis of the blood pressure clinical phenome in MVP. Our transcriptome-wide association study detected 4,043 blood pressure associations with genetically predicted gene expression of 840 genes in 45 tissues, and mouse renal single-cell RNA sequencing identified upregulated blood pressure genes in kidney tubule cells.

Changes in extracellular matrix in subcutaneous small resistance arteries of patients with essential hypertension

BACKGROUND

In the development of hypertensive microvascular remodeling, a relevant role may be played by changes in extracellular matrix proteins. Aim of this study was the to evaluate some extracellular matrix components within the tunica media of subcutaneous small arteries in 9 normotensive subjects and 12 essential hypertensive patients, submitted to a biopsy of subcutaneous fat from the gluteal or the anterior abdominal region.

PATIENTS AND METHODS

Subcutaneous small resistance arteries were dissected and mounted on an isometric myograph, and the tunica media to internal lumen ratio was measured. In addition, fibronectin, laminin, transforming growth factor-beta-1 (TGF-β1) and emilin-1 contents within the tunica media were evaluated by immunofluorescence and relative immunomorphometrical analysis (immunopositivity % of area). The total collagen content and collagen subtypes within the tunica media were evaluated using both Sirius red staining (under polarized light) and immunofluorescence assay.

RESULTS

Normotensive controls had less total and type III collagen in respect with hypertensive patients. Fibronectin and TGF-β1 tunica media content was significantly greater in essential hypertensive patients, compared with normotensive controls, while laminin and emilin-1 tunica media content was lesser in essential hypertensive patients, compared with normotensive controls. A significant correlation was observed between fibronectin tunica media content and media to lumen ratio.

CONCLUSIONS

Our results indicate that, in small resistance arteries of patients with essential hypertension, a relevant fibrosis may be detected; fibronectin and TGF-β1 tunica media content is increased, while laminin and emilin-1 content is decreased; these changes might be involved in the development of small resistance artery remodeling in humans.

Activin A increases arterial pressure in the hypothalamic paraventricular nucleus in rats by angiotension II

Activin A, a member of the transforming growth factor β superfamily, plays an important role in the central nervous system as a neurotrophic and neuroprotective factor. The hypothalamic paraventricular nucleus (PVN) in the central nervous system is characterized as an important integrative site to regulate arterial pressure (AP). However, whether activin A in the PVN is involved in the regulation of AP is not well characterized. This study aimed to determine the effect of activin A on AP in the PVN in rats. The results showed that activin βA, activin type IIA and IIB receptors (ActRIIA and ActRIIB), and Smad2 and Smad3 mRNA expressions were detectable in the PVN of WKY rats by reverse-transcription PCR, and the expression of ActRIIA protein in the PVN was further confirmed by immunohistochemical staining. A microinjection of angiotensin II (AngII) (0.1 nmol/100 nl) or activin A (2 ng/100 nl) into the PVN increased AP significantly in WKY rats (P<0.05). Moreover, activin A (5 ng/ml) promoted AngII release from the primary cultured PVN neurons that can increase AP and upregulated the expressions of ActRIIA and Smad3 mRNA in the primary cultured PVN neurons (P<0.05). These data suggest that activin A can regulate AP in the PVN in an autocrine or a paracrine manner, which is related to AngII release and the ActRIIA-Smad3 signal pathway.

Bioinformatics analysis of fibroblasts exposed to TGF‑β at the early proliferation phase of wound repair

The aim of the current study was to identify gene signatures during the early proliferation stage of wound repair and the effect of TGF-β on fibroblasts and reveal their potential mechanisms. The gene expression profiles of GSE79621 and GSE27165 were obtained from GEO database. Differentially expressed genes (DEGs) were identified using Morpheus and co-expressed DEGs were selected using Venn Diagram. Gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs were performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) online tool. Protein-protein interaction (PPI) networks of the DEGs were constructed using Cytoscape software. PPI interaction network was divided into subnetworks using the MCODE algorithm and the function of the top one module was analyzed using DAVID. The results revealed that upregulated DEGs were significantly enriched in biological process, including the Arp2/3 complex-mediated actin nucleation, positive regulation of hyaluronan cable assembly, purine nucleobase biosynthetic process, de novo inosine monophosphate biosynthetic process, positive regulation of epithelial cell proliferation, whereas the downregulated DEGs were enriched in the regulation of blood pressure, negative regulation of cell proliferation, ossification, negative regulation of gene expression and type I interferon signaling pathway. KEGG pathway analysis showed that the upregulated DEGs were enriched in shigellosis, pathogenic Escherichia coli infection, the mitogen-activated protein kinase signaling pathway, Ras signaling pathway and bacterial invasion of epithelial cells. The downregulated DEGs were enriched in systemic lupus erythematosus, lysosome, arachidonic acid metabolism, thyroid cancer and allograft rejection. The top 10 hub genes were identified from the PPI network. The top module analysis revealed that the included genes were involved in ion channel, neuroactive ligand-receptor interaction pathway, purine metabolism and intestinal immune network for IgA production pathway. The functional analysis revealed that TGF-β may promote fibroblast migration and proliferation and defend against microorganisms at the early proliferation stage of wound repair. Furthermore, these results may provide references for chronic wound repair.

Regulation of Lung Epithelial Sodium Channels by Cytokines and Chemokines

Acute lung injury leading to acute respiratory distress (ARDS) is a global health concern. ARDS patients have significant pulmonary inflammation leading to flooding of the pulmonary alveoli. This prevents normal gas exchange with consequent hypoxemia and causes mortality. A thin fluid layer in the alveoli is normal. The maintenance of this thin layer results from fluid movement out of the pulmonary capillaries into the alveolar interstitium driven by vascular hydrostatic pressure and then through alveolar tight junctions. This is then balanced by fluid reabsorption from the alveolar space mediated by transepithelial salt and water transport through alveolar cells. Reabsorption is a two-step process: first, sodium enters via sodium-permeable channels in the apical membranes of alveolar type 1 and 2 cells followed by active extrusion of sodium into the interstitium by the basolateral Na⁺, K⁺-ATPase. Anions follow the cationic charge gradient and water follows the salt-induced osmotic gradient. The proximate cause of alveolar flooding is the result of a failure to reabsorb sufficient salt and water or a failure of the tight junctions to prevent excessive movement of fluid from the interstitium to alveolar lumen. Cytokine- and chemokine-induced inflammation can have a particularly profound effect on lung sodium transport since they can alter both ion channel and barrier function. Cytokines and chemokines affect alveolar amiloride-sensitive epithelial sodium channels (ENaCs), which play a crucial role in sodium transport and fluid reabsorption in the lung. This review discusses the regulation of ENaC via local and systemic cytokines during inflammatory disease and the effect on lung fluid balance.

Greater transforming growth factor-β in adult female SHR is dependent on blood pressure, but does not account for sex differences in renal T-regulatory cells

Female spontaneously hypertensive rats (SHR) have more renal regulatory T cells (Tregs) than males, and greater levels of Tregs in female SHR are dependent on blood pressure (BP). However, the molecular mechanism responsible for greater Tregs in female SHR is unknown. Transforming growth factor (TGF)-β is a pleiotropic cytokine critical in the differentiation of naïve T cells into Tregs, and female SHR have higher TGF-β excretion than male SHR. The goals of the current study were to test the hypotheses that 1) female SHR have greater renal TGF-β expression than male SHR, which is dependent on BP and 2) neutralizing TGF-β will decrease renal Tregs in female SHR. Renal cortices were isolated from 5- and 13-wk-old male and female SHR, and TGF-β levels were measured via Western blot and ELISA. Adult female SHR have more free, active TGF-β₁ than 5-wk-old female SHR (46% more) or male SHR (44% more than 5-wk-old males and 56% more than 13-wk-old male SHR). We confirmed greater TGF-β₁ in adult female SHR was due to increases in BP and not sexual maturation by measuring TGF-β₁ levels following treatment with BP-lowering drugs or ovariectomy. Separate female SHR were treated with an antibody to TGF-β_1,2,3; BP was measured, and T cells were assessed in whole blood and the kidney. Neutralizing TGF-β had no effect on BP, although circulating Tregs decreased by 32%, while Th17 cells increased by 64%. Renal Tregs were not altered by antibody treatment, although Th17 cells were decreased by 61%. In conclusion, although TGF-β promotes circulating Tregs in female SHR, it does not account for the sex difference in renal Tregs in SHR.