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Frontiers in Endocrinology 2023Hypertension (HTN) is a multifactorial chronic disease that poses a significant global health burden and is associated with increased mortality rates. It often coexists...
BACKGROUND AND PURPOSE
Hypertension (HTN) is a multifactorial chronic disease that poses a significant global health burden and is associated with increased mortality rates. It often coexists with other conditions, such as cardiovascular, liver, and renal diseases, and has a strong association with diabetes mellitus. Insulin resistance and endothelial dysfunction commonly occur in individuals with both HTN and type 2 diabetes mellitus (T2DM). Genetic factors, along with environmental and pathological factors, play a role in the development of HTN. Recent studies have revealed the influence of single nucleotide polymorphisms (SNPs) in various genes on HTN. In this study, we aimed to investigate the genetic polymorphism of angiotensinogen (AGT) T174M (rs4762) and its association with HTN in diabetic patients.
METHODS
A total of 300 participants were enrolled in this study and divided into three groups: control, hypertensive, and hypertensive diabetic. Blood samples were collected, and predetermined biochemical parameters were assessed. Genotyping of the AGT T174M (rs4762) gene was conducted using Tetra ARMS PCR with specific primers.
RESULTS
The study findings revealed a significant association between AGT T174M (rs4762) genotype and HTN in diabetic patients within the Pakistani population. The C/T genotype of AGT T174M (rs4762) was found to be significant in both the hypertensive and hypertensive diabetic participants compared to the control group. This genotype was identified as a risk factor for developing HTN in both the hypertensive and hypertensive diabetic participants.
CONCLUSION
This study demonstrates a significant association between AGT T174M (rs4762) genetic polymorphism and HTN in diabetic patients. The C/T genotype of AGT T174M (rs4762) may serve as a potential marker for identifying individuals at risk of developing HTN, specifically in the hypertensive and hypertensive diabetic populations. Further research is warranted to elucidate the underlying mechanisms and validate these findings in larger cohorts.
Topics: Humans; Diabetes Mellitus, Type 2; Angiotensinogen; Polymorphism, Single Nucleotide; Hypertension; Insulin Resistance
PubMed: 37693342
DOI: 10.3389/fendo.2023.1240291 -
Heliyon Jul 2023Upregulation of Ca/calmodulin-dependent protein kinase II (CaMKII) contributes to the pathogenesis of cardiovascular disease, including hypertension. Transgenic rats...
AIMS
Upregulation of Ca/calmodulin-dependent protein kinase II (CaMKII) contributes to the pathogenesis of cardiovascular disease, including hypertension. Transgenic rats expressing the human angiotensinogen gene [TGR (hAGT)L1623] are a new novel humanized model of hypertension that associates with declines in cardiac contractile function and β-adrenergic receptor (AR) reserve. The molecular mechanisms are unclear. We tested the hypothesis that in TGR (hAGT)L1623 rats, left ventricular (LV) myocyte CaMKIIδ and β-AR are upregulated, but β-AR is down-regulated, which are important causes of cardiac dysfunction and β-AR desensitization.
MAIN METHODS
We compared LV myocyte CaMKIIδ, CaMKIIδ phosphorylation (at Thr287) (pCaMKIIδ), and β-and β-AR expressions and determined myocyte functional and [Ca] transient ([Ca]) responses to β-AR stimulation with and without pretreatment of myocytes using an inhibitor of CaMKII, KN-93 (10 M, 30 min) in male Sprague Dawley (SD; N = 10) control and TGR (hAGT)L1623 (N = 10) adult rats.
KEY FINDINGS
Hypertension in TGR (hAGT)L1623 rats was accompanied by significantly increased LV myocyte β-AR protein levels and reduced β-AR protein levels. CaMKIIδ phosphorylation (at Thr287), pCaMKIIδ was significantly increased by 35%. These changes were followed by significantly reduced basal cell contraction (dL/dt), relaxation (dR/dt) and [Ca]. Isoproterenol (10 M) produced significantly smaller increases in dL/dt, dR/dt and [Ca]. Moreover, only in TGR (hAGT)L1623 rats, pretreatment of LV myocytes with KN-93 (10 M, 30 min) fully restored normal basal and isoproterenol-stimulated myocyte contraction, relaxation, and [Ca].
SIGNIFICANCE
LV myocyte CaMKIIδ overactivation with associated contrast changes in β-AR and β-AR may be the key molecular mechanism for the abnormal contractile phenotype and β-AR desensitization in this humanized model of hypertension.
PubMed: 37456012
DOI: 10.1016/j.heliyon.2023.e17851 -
International Journal of Molecular... Jan 2024Increased body weight (BW) induces inappropriate renin-angiotensin system (RAS) activation. The activation of the intrarenal RAS is associated with increased urinary...
Increased body weight (BW) induces inappropriate renin-angiotensin system (RAS) activation. The activation of the intrarenal RAS is associated with increased urinary angiotensinogen (uAGT), blood pressure (BP), and kidney damage. Here, we examined uAGT excretion levels in young non-diabetic human subjects with overweight (OW) and non-diabetic mice with high-fat diet (HFD)-induced OW. Human subjects (women and men; 20-28 years old) included two groups: (a) overweight (OW, = 17, BMI ≥ 25); and (b) controls (normal weight (NW; = 26, BMI ≤ 25). In these subjects, we measured BP, albuminuria, and protein levels of uAGT by ELISA adjusted by urinary creatinine (expressed by uAGT/uCrea). Mice (female and male C57BL/6J mice, 8 ± 2 weeks of age) also included two groups: HFD or normal fat diet (NFD) fed for 8 weeks. We measured BW, fasting blood glucose (FBG), BP by telemetry, albuminuria, and uAGT by ELISA. In humans: (i) no significant changes were observed in BP, albuminuria, and FBG when comparing NW and OW subjects; (ii) multivariate logistic regression analysis of independent predictors related to uAGT/uCrea levels demonstrated a strong association between uAGT and overweight; (iii) urinary reactive oxygen species (ROS) were augmented in men and women with OW; (iv) the uAGT/uCrea ratio was higher in men with OW. However, the uAGT/uCrea values were lower in women even with OW. In mice: (i) males fed an HFD for 8 weeks became OW while females did not; (ii) no changes were observed either in FBG, BP, or albuminuria; (iii) kidney ROS were augmented in OW male mice after 28 weeks but not in females; (iv) OW male mice showed augmented excretion of uAGT but this was undetectable in females fed either NFD or HFD. In humans and mice who are OW, the urinary excretion of AGT differs between males and females and overcomes overt albuminuria.
Topics: Adult; Animals; Female; Humans; Male; Mice; Young Adult; Albuminuria; Angiotensinogen; Mice, Inbred C57BL; Overweight; Reactive Oxygen Species; Sex Characteristics; Renin-Angiotensin System
PubMed: 38203807
DOI: 10.3390/ijms25010635 -
Pain Jul 2024Visceral pain is a leading cause of morbidity in inflammatory bowel disease (IBD), contributing significantly to reduced quality of life. Currently available analgesics...
Visceral pain is a leading cause of morbidity in inflammatory bowel disease (IBD), contributing significantly to reduced quality of life. Currently available analgesics often lack efficacy or have intolerable side effects, driving the need for a more complete understanding of the mechanisms causing pain. Whole transcriptome gene expression analysis was performed by bulk RNA sequencing of colonic biopsies from patients with ulcerative colitis (UC) and Crohn's disease (CD) reporting abdominal pain and compared with noninflamed control biopsies. Potential pronociceptive mediators were identified based on gene upregulation in IBD biopsy tissue and cognate receptor expression in murine colonic sensory neurons. Pronociceptive activity of identified mediators was assessed in assays of sensory neuron and colonic afferent activity. RNA sequencing analysis highlighted a 7.6-fold increase in the expression of angiotensinogen transcripts, Agt , which encode the precursor to angiotensin II (Ang II), in samples from UC patients ( P = 3.2 × 10 -8 ). Consistent with the marked expression of the angiotensin AT 1 receptor in colonic sensory neurons, Ang II elicited an increase in intracellular Ca 2+ in capsaicin-sensitive, voltage-gated sodium channel subtype Na V 1.8-positive sensory neurons. Ang II also evoked action potential discharge in high-threshold colonic nociceptors. These effects were inhibited by the AT 1 receptor antagonist valsartan. Findings from our study identify AT 1 receptor-mediated colonic nociceptor activation as a novel pathway of visceral nociception in patients with UC. This work highlights the potential utility of angiotensin receptor blockers, such as valsartan, as treatments for pain in IBD.
Topics: Humans; Animals; Inflammatory Bowel Diseases; Angiotensin II; Mice; Male; Gene Expression Profiling; Female; Colon; Sensory Receptor Cells; Adult; Middle Aged; Mice, Inbred C57BL; Nociceptors; Transcriptome
PubMed: 38293826
DOI: 10.1097/j.pain.0000000000003159 -
Arteriosclerosis, Thrombosis, and... Apr 2024Hypertension is a prevalent public health problem, contributing to >10 million deaths annually. Though multiple therapeutics exist, many patients suffer from... (Review)
Review
Hypertension is a prevalent public health problem, contributing to >10 million deaths annually. Though multiple therapeutics exist, many patients suffer from treatment-resistant hypertension or try several medications before achieving blood pressure control. Genomic advances offer mechanistic understanding of blood pressure variability, therapeutic targets, therapeutic response, and promise a stratified approach to treatment of primary hypertension. Cyclic guanosine monophosphate augmentation, aldosterone synthase inhibitors, and angiotensinogen blockade with silencing RNA and antisense therapies are among the promising novel approaches. Pharmacogenomic studies have also been done to explore the genetic bases underpinning interindividual variability in response to existing therapeutics. A polygenic approach using risk scores is likely to be the next frontier in stratifying responses to existing therapeutics.
Topics: Humans; Hypertension; Blood Pressure; Multifactorial Inheritance; Genomics; Pharmacogenetics
PubMed: 38385287
DOI: 10.1161/ATVBAHA.123.319220 -
Function (Oxford, England) 2023Non-enzymatic activation of renin via its interaction with prorenin receptor (PRR) has been proposed as a key mechanism of local renin-angiotensin system (RAS)...
Non-enzymatic activation of renin via its interaction with prorenin receptor (PRR) has been proposed as a key mechanism of local renin-angiotensin system (RAS) activation. The presence of renin and angiotensinogen has been reported in the rostral ventrolateral medulla (RVLM). Overactivation of bulbospinal neurons in the RVLM is linked to hypertension (HTN). Previous studies have shown that the brain RAS plays a role in the pathogenesis of the deoxycorticosterone (DOCA)-salt HTN model. Thus, we hypothesized that PRR in the RVLM is involved in the local activation of the RAS, facilitating the development of DOCA-salt HTN. Selective PRR ablation targeting the RVLM (PRR mice) resulted in an unexpected sex-dependent and biphasic phenotype in DOCA-salt HTN. That is, PRR females (but not males) exhibited a significant delay in achieving maximal pressor responses during the initial stage of DOCA-salt HTN. Female PRR subsequently showed exacerbated DOCA-salt-induced pressor responses during the "maintenance" phase with a maximal peak at 13 d on DOCA-salt. This exacerbated response was associated with an increased sympathetic drive to the resistance arterioles and the kidney, exacerbated fluid and sodium intake and output in response to DOCA-salt, and induced mobilization of fluids from the intracellular to extracellular space concomitant with elevated vasopressin. Ablation of PRR suppressed genes involved in RAS activation and catecholamine synthesis in the RVLM but also induced expression of genes involved in inflammatory responses. This study illustrates complex and sex-dependent roles of PRR in the neural control of BP and hydromineral balance through autonomic and neuroendocrine systems. Graphical abstract.
Topics: Animals; Female; Mice; Blood Pressure; Desoxycorticosterone Acetate; Hypertension; Prorenin Receptor; Receptors, Cell Surface; Renin; Sodium Chloride; Vasoconstrictor Agents
PubMed: 37609445
DOI: 10.1093/function/zqad043 -
Kidney International Feb 2024Renin, an aspartate protease, regulates the renin-angiotensin system by cleaving its only known substrate angiotensinogen to angiotensin. Recent studies have suggested...
Renin, an aspartate protease, regulates the renin-angiotensin system by cleaving its only known substrate angiotensinogen to angiotensin. Recent studies have suggested that renin may also cleave complement component C3 to activate complement or contribute to its dysregulation. Typically, C3 is cleaved by C3 convertase, a serine protease that uses the hydroxyl group of a serine residue as a nucleophile. Here, we provide seven lines of evidence to show that renin does not cleave C3. First, there is no association between renin plasma levels and C3 levels in patients with C3 Glomerulopathies (C3G) and atypical Hemolytic Uremic Syndrome (aHUS), implying that serum C3 consumption is not increased in the presence of high renin. Second, in vitro tests of C3 conversion to C3b do not detect differences when sera from patients with high renin levels are compared to sera from patients with normal/low renin levels. Third, aliskiren, a renin inhibitor, does not block abnormal complement activity introduced by nephritic factors in the fluid phase. Fourth, aliskiren does not block dysregulated complement activity on cell surfaces. Fifth, recombinant renin from different sources does not cleave C3 even after 24 hours of incubation at 37 °C. Sixth, direct spiking of recombinant renin into sera samples of patients with C3G and aHUS does not enhance complement activity in either the fluid phase or on cell surfaces. And seventh, molecular modeling and docking place C3 in the active site of renin in a position that is not consistent with a productive ground state complex for catalytic hydrolysis. Thus, our study does not support a role for renin in the activation of complement.
Topics: Humans; Amides; Atypical Hemolytic Uremic Syndrome; Complement Activation; Complement C3; Complement C3-C5 Convertases; Complement Pathway, Alternative; Fumarates; Kidney Diseases; Renin
PubMed: 38008161
DOI: 10.1016/j.kint.2023.11.005 -
Kidney International Apr 2024Some patients diagnosed with benign IgA nephropathy (IgAN) develop a progressive clinical course, not predictable by known clinical or histopathological parameters. To...
Some patients diagnosed with benign IgA nephropathy (IgAN) develop a progressive clinical course, not predictable by known clinical or histopathological parameters. To assess if gene expression can differentiate between progressors and non-progressors with assumed benign IgAN, we tested microdissected glomeruli from archival kidney biopsy sections from adult patients with stable clinical remission (21 non-progressors) or from 15 patients that had undergone clinical progression within a 25-year time frame. Based on 1 240 differentially expressed genes from patients with suitable sequencing results, we identified eight IgAN progressor and nine non-progressor genes using a two-component classifier. These genes, including APOL5 and ZXDC, predicted disease progression with 88% accuracy, 75% sensitivity and 100% specificity on average 21.6 years before progressive disease was clinically documented. APOL lipoproteins are associated with inflammation, autophagy and kidney disease while ZXDC is a zinc-finger transcription factor modulating adaptive immunity. Ten genes from our transcriptomics data overlapped with an external genome wide association study dataset, although the gene set enrichment test was not statistically significant. We also identified 45 drug targets in the DrugBank database, including angiotensinogen, a target of sparsentan (dual antagonist of the endothelin type A receptor and the angiotensin II type 1 receptor) currently investigated for IgAN treatment. Two validation cohorts were used for substantiating key results, one by immunohistochemistry and the other by nCounter technology. Thus, glomerular mRNA sequencing from diagnostic kidney biopsies from patients with assumed benign IgAN can differentiate between future progressors and non-progressors at the time of diagnosis.
Topics: Adult; Humans; Glomerulonephritis, IGA; Genome-Wide Association Study; Kidney Glomerulus; Gene Expression Profiling; Gene Expression Regulation
PubMed: 38154557
DOI: 10.1016/j.kint.2023.12.010 -
Inflammation and Regeneration Sep 2023Pancreatic adenocarcinoma (PAAD) is one of the most fatal human cancers, but effective therapies remain to be established. Cancer stem cells (CSCs) are highly resistant...
BACKGROUND
Pancreatic adenocarcinoma (PAAD) is one of the most fatal human cancers, but effective therapies remain to be established. Cancer stem cells (CSCs) are highly resistant to anti-cancer drugs and a deeper understanding of their microenvironmental niche has been considered important to provide understanding and solutions to cancer eradication. However, as the CSC niche is composed of a wide variety of biological and physicochemical factors, the development of multidisciplinary tools that recapitulate their complex features is indispensable. Synthetic polymers have been studied as attractive biomaterials due to their tunable biofunctionalities, while hydrogelation technique further renders upon them a diversity of physical properties, making them an attractive tool for analysis of the CSC niche.
METHODS
To develop innovative materials that recapitulate the CSC niche in pancreatic cancers, we performed polymer microarray analysis to identify niche-mimicking scaffolds that preferentially supported the growth of CSCs. The niche-mimicking activity of the identified polymers was further optimized by polyethylene glycol (PEG)-based hydrogelation. To reveal the biological mechanisms behind the activity of the optimized hydrogels towards CSCs, proteins binding onto the hydrogel were analyzed by liquid chromatography with tandem mass spectrometry (LC-MS/MS), and the potential therapeutic targets were validated by looking at gene expression and patients' outcome in the TCGA database.
RESULTS
PA531, a heteropolymer composed of 2-methoxyethyl methacrylate (MEMA) and 2-(diethylamino)ethyl methacrylate (DEAEMA) (5.5:4.5) that specifically supports the growth and maintenance of CSCs was identified by polymer microarray screening using the human PAAD cell line KLM1. The polymer PA531 was converted into five hydrogels (PA531-HG1 to HG5) and developed to give an optimized scaffold with the highest CSC niche-mimicking activities. From this polymer that recapitulated CSC binding and control, the proteins fetuin-B and angiotensinogen were identified as candidate target molecules with clinical significance due to the correlation between gene expression levels and prognosis in PAAD patients and the proteins associated with the niche-mimicking polymer.
CONCLUSION
This study screened for biofunctional polymers suitable for recapitulation of the pancreatic CSC niche and one hydrogel with high niche-mimicking abilities was successfully fabricated. Two soluble factors with clinical significance were identified as potential candidates for biomarkers and therapeutic targets in pancreatic cancers. Such a biomaterial-based approach could be a new platform in drug discovery and therapy development against CSCs, via targeting of their niche.
PubMed: 37759310
DOI: 10.1186/s41232-023-00296-0 -
Clinical and Experimental Nephrology Jul 2023Astragalus root is a commonly used herb in traditional Chinese medicine. Although renoprotective effects have been reported in some clinical and experimental studies,...
BACKGROUND
Astragalus root is a commonly used herb in traditional Chinese medicine. Although renoprotective effects have been reported in some clinical and experimental studies, the details remain unknown.
METHODS
We used 5/6 nephrectomized rats as chronic kidney disease (CKD) models. At 10 weeks, they were divided into four groups, namely, CKD, low-dose astragalus (AR400), high-dose astragalus (AR800), and sham groups. At 14 weeks, they were sacrificed for the evaluation of blood, urine, mRNA expression in the kidney, and renal histopathology.
RESULTS
Kidney dysfunction was significantly improved following astragalus administration (creatinine clearance: sham group; 3.8 ± 0.3 mL/min, CKD group; 1.5 ± 0.1 mL/min, AR400 group; 2.5 ± 0.3 mL/min, AR800 group; 2.7 ± 0.1 mL/min). Blood pressure, urinary albumin, and urinary NGAL levels were significantly lower in the astragalus-treated groups than those in the CKD group. Excretion of urinary 8-OHdG, an oxidative stress marker, and intrarenal oxidative stress were lower in the astragalus-treated groups than those in the CKD group. Furthermore, the mRNA expression of NADPH p22 phox, NADPH p47 phox, Nox4, renin, angiotensin II type 1 receptor, and angiotensinogen in the kidney was lower in the astragalus-treated groups compared with the CKD group.
CONCLUSION
This study suggests that astragalus root slowed CKD progression, possibly through the suppression of oxidative stress and the renin-angiotensin system.
Topics: Rats; Animals; NADP; Kidney; Renal Insufficiency, Chronic; Renin; Renin-Angiotensin System; RNA, Messenger
PubMed: 37140734
DOI: 10.1007/s10157-023-02356-8