Molecular Mechanisms of Hypertensive Nephropathy: Renoprotective Effect of Losartan through Hsp70

Current perspectives and trends of the research on hypertensive nephropathy: a bibliometric analysis from 2000 to 2023

Hypertensive nephropathy continues to be a major cause of end-stage renal disease and poses a significant global health burden. Despite the staggering development of research in hypertensive nephropathy, scientists and clinicians can only seek out useful information through articles and reviews, it remains a hurdle for them to quickly track the trend in this field. This study uses the bibliometric method to identify the evolutionary development and recent hotspots of hypertensive nephropathy. The Web of Science Core Collection database was used to extract publications on hypertensive nephropathy from January 2000 to November 2023. CiteSpace was used to capture the patterns and trends from multi-perspectives, including countries/regions, institutions, keywords, and references. In total, 557 publications on hypertensive nephropathy were eligible for inclusion. China (n = 208, 37.34%) was the most influential contributor among all the countries. Veterans Health Administration (n = 19, 3.41%) was found to be the most productive institution. Keyword bursting till now are renal fibrosis, outcomes, and mechanisms which are predicted to be the potential frontiers and hotspots in the future. The top seven references were listed, and their burst strength was shown. A comprehensive overview of the current status and research frontiers of hypertensive nephropathy has been provided through the bibliometric perspective. Recent advancements and challenges in hypertensive nephropathy have been discussed. These findings can offer informative instructions for researchers and scholars.

Recent advances on quinoxalines as target-oriented chemotherapeutic anticancer agents through apoptosis

The current review outlines all possible recent synthetic platforms to quinoxaline derivatives and the potent stimulated apoptosis mechanisms targeted by anticancer therapies. The currently reported results disclosed that quinoxaline derivatives had promising anticancer potencies against a wide array of cancer cell lines, better than the reference drugs, through target inhibition. This review summarizes some potent quinoxaline derivatives with their synthesis strategies and their potential activities against various molecular targets. Quinoxalines can be considered an important scaffold for apoptosis inducers in cancer cells through inhibiting some molecular targets, so they can be further developed as target-oriented chemotherapeutics.

Higher prevalence of kidney function impairment among older people living with HIV in Uganda

Background

People living with HIV (PLWH) are at risk of kidney function impairment due to HIV-related inflammation, antiretroviral therapy (ART), diabetes mellitus, and hypertension. Older persons may experience a higher burden of chronic kidney disease (CKD) as kidney function declines with increasing age. There is a paucity of data comparing the prevalence of kidney function impairment in older PLWH to that in HIV-uninfected people in sub-Saharan Africa.

Methods

We conducted a cross-sectional study among people aged ≥ 60 years living with and without HIV in Kampala, Uganda who were matched 1:1 by community location. We collected data on sociodemographics, comorbidities, and HIV-related clinical characteristics. We defined kidney function impairment as an estimated glomerular filtration rate(eGFR) < 60mls/min/1.73m2 with or without proteinuria. We constructed multivariable logistic regression models to study associations between participant characteristics and kidney function impairment.

Results

We enrolled 278 people (median age 66 years); 50% were PLWH, and 51.8% were female. Overall, the prevalence of kidney function impairment was 23.0% (95% CI:18.4%-28.4%); 33.1% (95% CI: 25.7%-41.4%) versus 12.9% (95% CI: 8.3%-19.7%) among people living with and without HIV (p-value < 0.01). The prevalence of proteinuria among PLWH versus people without HIV was 43.9% (95% CI:35.8%-52.3%) versus 19.4% (95% CI:13.6%-26.9%) p-value < 0.01. Living with HIV (OR = 3.89(95% CI: 2.04-7.41), p-value < 0.01), older age (OR = 1.13, (95% CI:1.07-1.20), p-value < 0.01), female sex (OR = 1.95, (95% CI:1.06-3.62), p-value = 0.03) and a prior diagnosis of hypertension (OR = 2.19(95% CI:1.02-4.67), p-value = 0.04) were significantly associated with kidney function impairment.

Conclusions

HIV infection is strongly associated with kidney function impairment among older PLWH. Prioritizing routine measurements of kidney function and proteinuria in older PLWH will enable early detection and institution of measures to reduce the progression of kidney disease.

Preliminary Exploration of Potential Active Ingredients and Molecular Mechanisms of Yanggan Yishui Granules for Treating Hypertensive Nephropathy Using UPLC-Q-TOF/MS Coupled with Network Pharmacology and Molecular Docking Strategy

Hypertensive nephropathy (HN) is a prevalent complication of hypertension and stands as the second primary reason for end-stage renal disease. Research in clinical settings has revealed that Yanggan Yishui Granule (YGYSG) has significant therapeutic effects on HN. However, the material basis and action mechanisms of YGYSG against HN remain unclear. Consequently, this study utilized a comprehensive method integrating ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS), network pharmacology, and molecular docking to delineate the active ingredients and potential therapeutic mechanisms of YGYSG for treating HN. Firstly, sixty distinct components were recognized in total as potential active ingredients in YGYSG by UPLC-Q-TOF/MS. Subsequently, the mechanisms of YGYSG against HN were revealed for the first time using network pharmacology. 23 ingredients played key roles in the complete network and were the key active ingredients, which could affect the renin-angiotensin system, fluid shear stress and atherosclerosis, HIF-1 signaling pathway, and AGE-RAGE signaling pathway in diabetic complications by regulating 29 key targets such as TNF, IL6, ALB, EGFR, ACE, and MMP2. YGYSG could treat HN through the suppression of inflammatory response and oxidative stress, attenuating the proliferation of renal vascular smooth muscle cells, lessening glomerular capillary systolic pressure, and ameliorating renal dysfunction and vascular damage through the aforementioned targets and pathways. Molecular docking results revealed that most key active ingredients exhibited a high affinity for binding to the key targets. This study pioneers in clarifying the bioactive compounds and molecular mechanisms of YGYSG against HN and offers scientific reference into the clinical application.

Renal Function Improvement With Glucagon-Like Peptide-1 Receptor Agonist in a Patient With Type 2 Diabetes

Diabetic kidney disease (DKD) includes hypertensive nephrosclerosis, aging, obesity, and atherosclerosis-related renal diseases, in addition to classical diabetic nephropathy. Sodium-glucose co-transporter 2 inhibitors (SGLT2is) have been approved for diabetic and non-diabetic patients at risk of chronic kidney disease progression. As the main mechanism for SGLT2i-mediated improvement of renal function, the normalization of tubulo-glomerular feedback (TGF) has been proposed. Enhanced TGF and resulting glomerular hypertension are observed in diabetic patients, and SGLT2is normalize TGF, reducing the intraglomerular pressure, which may reduce albuminuria and improve renal function. A type 2 diabetic patient with DKD complicated with hypertensive nephrosclerosis, whose renal function was deteriorated by SGLT2i and improved by glucagon-like peptide-1 receptor agonists (GLP-1RAs), was presented. In patients with hypertensive nephrosclerosis such as this case, the normalization of TGF by SGLT2i may further reduce afferent arteriolar blood flow which may worsen glomerular ischemia, resulting in deterioration of renal function. GLP-1RAs have no effect on TGF and have multiple effects to improve vascular endothelial function, which may be associated with an improvement in renal function in this patient.

Potential implication of serum lipid levels as predictive indicators for monitoring oral lichen planus

Compelling evidence indicates that dyslipidemia is positively associated with oral lichen planus (OLP). The types and magnitude of lipid metabolism disturbance in peripheral blood of OLP patients have been investigated in different studies. Yet, consensus on how these different lipid components varied in levels for the development of OLP lesions has not been reached so far. Herein, a total of 8 eligible studies were recognized, which enrolled 533 cases of OLP and 499 healthy controls. The analysis showed that the average total triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) levels were considerably higher, and high-density lipoprotein cholesterol (HDL-C) levels were significantly lower in OLP patients compared to healthy controls. Collectively, the lipid profile panel maybe serve as the potential predictive indicator for screening OLP.

Mechanisms of inflammation modulation by different immune cells in hypertensive nephropathy

Hypertensive nephropathy (HTN) is the second leading cause of end-stage renal disease (ESRD) and a chronic inflammatory disease. Persistent hypertension leads to lesions of intrarenal arterioles and arterioles, luminal stenosis, secondary ischemic renal parenchymal damage, and glomerulosclerosis, tubular atrophy, and interstitial fibrosis. Studying the pathogenesis of hypertensive nephropathy is a prerequisite for diagnosis and treatment. The main cause of HTN is poor long-term blood pressure control, but kidney damage is often accompanied by the occurrence of immune inflammation. Some studies have found that the activation of innate immunity, inflammation and acquired immunity is closely related to the pathogenesis of HTN, which can cause damage and dysfunction of target organs. There are more articles on the mechanism of diabetic nephropathy, while there are fewer studies related to immunity in hypertensive nephropathy. This article reviews the mechanisms by which several different immune cells and inflammatory cytokines regulate blood pressure and renal damage in HTN. It mainly focuses on immune cells, cytokines, and chemokines and inhibitors. However, further comprehensive and large-scale studies are needed to determine the role of these markers and provide effective protocols for clinical intervention and treatment.

Prevalence of Biomarkers and Associated Factors for Chronic Kidney Disease in Adult Diabetic Out-patients in a Tertiary Hospital in Eastern Uganda - a Cross-sectional Study

Background

Chronic kidney disease (CKD) is one of the most common complications of Diabetes Mellitus (DM). DM contributes to about 66% of CKD cases globally. CKiiiD results in increased morbidity and mortality and advanced stages often require renal replacement therapy that is unaffordable for the majority of the patients. Developing countries have scanty data regarding CKD burden in diabetic patients.

OBJECTIVES

This study aimed at determining the prevalence of biomarkers for CKD and associated factors among diabetic patients attending the adult diabetic clinic of Mbale Regional Referral Hospital (MRRH).

Methods

A cross-sectional study was conducted at the adult diabetic clinic of Mbale Regional Referral Hospital in Eastern Uganda. 374 adult diabetic patients who consented, were recruited and interviewed. A urine sample for Urine Albumin Creatinine Ratio (UACR) determination and a venous blood sample for measurement of serum creatinine were obtained from each participant. The estimated glomerular filtration rate (eGFR) was determined using the CKD-EPI equation and CKD was staged according to the Kidney Disease Improving Global Outcomes (KDIGO) systems.

Results

A total of 318 (85%) participants had an eGFR of ≤ 60mls/min/1.72m2, significant proteinuria, or both. 6.1% were aware. Age, Duration of DM, Hypertension, and Dyslipidemia were associated with CKD biomarkers.

Conclusion

There is a high prevalence of biomarkers for CKD among DM patients, the majority of them being undiagnosed. Over half of the DM patients had an eGFR consistent with advanced CKD. Strengthening routine screening for CKD biomarkers and enhancing the DM clinics with more diagnostic resources is recommended.

Cardiovascular Consequences of Uremic Metabolites: an Overview of the Involved Signaling Pathways

The crosstalk of the heart with distant organs such as the lung, liver, gut, and kidney has been intensively approached lately. The kidney is involved in (1) the production of systemic relevant products, such as renin, as part of the most essential vasoregulatory system of the human body, and (2) in the clearance of metabolites with systemic and organ effects. Metabolic residue accumulation during kidney dysfunction is known to determine cardiovascular pathologies such as endothelial activation/dysfunction, atherosclerosis, cardiomyocyte apoptosis, cardiac fibrosis, and vascular and valvular calcification, leading to hypertension, arrhythmias, myocardial infarction, and cardiomyopathies. However, this review offers an overview of the uremic metabolites and details their signaling pathways involved in cardiorenal syndrome and the development of heart failure. A holistic view of the metabolites, but more importantly, an exhaustive crosstalk of their known signaling pathways, is important for depicting new therapeutic strategies in the cardiovascular field.

Impact of body mass index on adverse kidney events in diabetes mellitus patients: A systematic-review and meta-analysis

BACKGROUND

The incidence of chronic kidney disease among patients with diabetes mellitus (DM) remains a global concern. Long-term obesity is known to possibly influence the development of type 2 diabetes mellitus. However, no previous meta-analysis has assessed the effects of body mass index (BMI) on adverse kidney events in patients with DM.

AIM

To determine the impact of BMI on adverse kidney events in patients with DM.

METHODS

A systematic literature search was performed on the PubMed, ISI Web of Science, Scopus, Ovid, Google Scholar, EMBASE, and BMJ databases. We included trials with the following characteristics: (1) Type of study: Prospective, retrospective, randomized, and non-randomized in design; (2) participants: Restricted to patients with DM aged ≥ 18 years; (3) intervention: No intervention; and (4) kidney adverse events: Onset of diabetic kidney disease [estimated glomerular filtration rate (eGFR) of < 60 mL/min/1.73 m2 and/or microalbuminuria value of ≥ 30 mg/g Cr], serum creatinine increase of more than double the baseline or end-stage renal disease (eGFR < 15 mL/min/1.73 m2 or dialysis), or death.

RESULTS

Overall, 11 studies involving 801 patients with DM were included. High BMI (≥ 25 kg/m2) was significantly associated with higher blood pressure (BP) [systolic BP by 0.20, 95% confidence interval (CI): 0.15-0.25, P < 0.00001; diastolic BP by 0.21 mmHg, 95%CI: 0.04-0.37, P = 0.010], serum albumin, triglycerides [standard mean difference (SMD) = 0.35, 95%CI: 0.29-0.41, P < 0.00001], low-density lipoprotein (SMD = 0.12, 95%CI: 0.04-0.20, P = 0.030), and lower high-density lipoprotein (SMD = -0.36, 95%CI: -0.51 to -0.21, P < 0.00001) in patients with DM compared with those with low BMIs (< 25 kg/m2). Our analysis showed that high BMI was associated with a higher risk ratio of adverse kidney events than low BMI (RR: 1.22, 95%CI: 1.01-1.43, P = 0.036).

CONCLUSION

The present analysis suggested that high BMI was a risk factor for adverse kidney events in patients with DM.

Kidney Disease and Proteomics: A Recent Overview of a Useful Tool for Improving Early Diagnosis

Kidney disease is a critical and potentially life-threatening degenerative condition that poses a significant global public health challenge due to its elevated rates of morbidity and mortality. It manifests primarily in two distinct clinical forms: acute kidney injury (AKI) and chronic kidney disease (CKD). The development of these conditions hinges on a multitude of factors, including the etiological agents and the presence of coexisting medical conditions. Despite disparities in their underlying pathogenic mechanisms, both AKI and CKD can progress to end-stage kidney disease (ESKD). This advanced stage is characterized by organ failure and its associated complications, greatly increasing the risk of mortality. There is an urgent need to delve into the pathogenic mechanisms underlying these diseases and to identify novel biomarkers that can facilitate earlier diagnosis. Such early detection is crucial for enhancing the efficacy of therapy and impeding disease progression. In this context, proteomic approaches have emerged as invaluable tools for uncovering potential new markers of different pathological conditions, including kidney diseases. In this chapter, we overview the recent discoveries achieved through diverse proteomic techniques aimed at identifying novel molecules that may play a pivotal role in kidney diseases such as diabetic kidney disease (DKD), IgA nephropathy (IgAN), CKD of unknown origin (CKDu), autosomal dominant polycystic kidney disease (ADPKD), lupus nephritis (LN), hypertensive nephropathy (HN), and COVID-19-associated acute kidney injury (COVID-AKI).

Renal stiffness measured by shear wave elastography and its relationship with perirenal fat in patients with chronic kidney disease

PURPOSE

This study aimed to utilize shear wave elastography (SWE) to assess changes in renal stiffness and its influencing factors in patients with chronic kidney disease (CKD) across different estimated glomerular filtration rate (eGFR) categories. It also sought to determine the correlation between perirenal fat (PF) and renal stiffness at various stages of CKD.

METHODS

A total of 190 CKD patients and 50 healthy controls were evaluated. Clinical parameters, conventional renal ultrasound measurements, PF, and renal stiffness trends were assessed separately. Factors independently associated with renal stiffness and PF were further analyzed.

RESULTS

Renal parenchymal stiffness was significantly higher in the Albumin-CKD G1-2 (ALB-CKD G1-2) and CKD G3 groups than in the control group (p < 0.05). The parenchymal stiffness of the CKD G3 group was higher than that of the ALB-CKD G1-2 group (p < 0.05). The independent factors of renal parenchymal stiffness varied at different stages of disease development, with eGFR and PF being significant factors in the CKD G3 group. PF was elevated in the ALB-CKD G1-2 and CKD G3 groups compared to the control group, and the independent factors of PF varied across different stages, although waist circumference remained a common factor.

CONCLUSION

Using SWE to detect renal elastic moduli can effectively assess changes in renal stiffness in patients with CKD with varying eGFRs. PF is an independent factor of renal stiffness in patients with CKD G3, providing a foundation for early diagnosis and clinical treatment.

Endogenous stimuli-responsive drug delivery nanoplatforms for kidney disease therapy

Kidney disease is one of the most life-threatening health problems, affecting millions of people in the world. Commonly used steroids and immunosuppressants often fall exceptionally short of outcomes with inescapable systemic toxicity. With the booming research in nanobiotechnology, stimuli-responsive nanoplatform has come an appealing therapeutic strategy for kidney disease. Endogenous stimuli-responsive materials have shown profuse promise owing to their enhanced spatiotemporal control and precise to the location of the lesion. This review focuses on recent advances stimuli-responsive drug delivery nano-architectonics for kidney disease. First, a brief introduction of pathogenesis of kidney disease and pathological microenvironment were provided. Then, various endogenous stimulus involved in drug delivery nanoplatforms including pH, ROS, enzymes, and glucose were categorized based on the pathological mechanisms of kidney disease. Next, we separately summarized literature examples of endogenous stimuli-responsive nanomaterials, and outlined the design strategies and response mechanisms. Finally, the paper was concluded by discussing remaining challenges and future perspectives of endogenous stimuli-responsive drug delivery nanoplatform for expediting the speed of development and clinical applications.

Modeling the renoprotective mechanisms of SGLT2 inhibition in hypertensive chronic kidney disease

Sodium-glucose cotransporter (SGLT)-2 inhibitors have recently been approved for chronic kidney disease (CKD) based on their ability to lower proteinuria and slow CKD progression independent of diabetes status. In diabetic renal disease, modulation of tubuloglomerular feedback (TGF) leading to lower intraglomerular pressure has been postulated as one of the mechanisms of renal protection with SGLT2 inhibition; however, this mechanism has not been sufficiently explored in non-diabetic CKD. We hypothesized that SGLT2 inhibition exerts renoprotection in CKD through increasing TGF despite normoglycemia. To test this hypothesis, we used an integrative mathematical model of human physiology, HumMod. Stage 3 CKD conditions were simulated by reducing nephron mass which was associated with hypertension, low glomerular filtration rate (GFR) (55 mL/min), hyperfiltration of remnant nephrons, elevated albuminuria (500 mg/day), and minimal levels of urinary glucose (0.02 mmol/L). SGLT2 inhibition was associated with acute reductions in GFR associated with afferent arteriolar vasoconstriction due to TGF. After 12 months, glomerular pressure, nephron damage, and chronic GFR decline were reduced with SGLT2 inhibition with additional SGLT1 inhibitory effects further enhancing these effects. This model supports the use of SGLT2 inhibitors to reduce hyperfiltration in CKD and mitigate renal disease progression, even in the absence of diabetes.

Btg2 Promotes Focal Segmental Glomerulosclerosis via Smad3-Dependent Podocyte-Mesenchymal Transition

Podocyte injury plays a critical role in the progression of focal segmental glomerulosclerosis (FSGS). Here, it is reported that B-cell translocation gene 2 (Btg2) promotes Adriamycin (ADR)-induced FSGS via Smad3-dependent podocyte-mesenchymal transition. It is found that in FSGS patients and animal models, Btg2 is markedly upregulated by podocytes and correlated with progressive renal injury. Podocyte-specific deletion of Btg2 protected against the onset of proteinuria and glomerulosclerosis in ADR-treated mice along with inhibition of EMT markers such as α-SMA and vimentin while restoring epithelial marker E-cadherin. In cultured MPC5 podocytes, overexpression of Btg2 largely promoted ADR and TGF-β1-induced EMT and fibrosis, which is further enhanced by overexpressing Btg2 but blocked by disrupting Btg2. Mechanistically, Btg2 is rapidly induced by TGF-β1 and then bound Smad3 but not Smad2 to promote Smad3 signaling and podocyte EMT, which is again exacerbated by overexpressing Btg2 but blocked by deleting Btg2 in MPC5 podocytes. Interestingly, blockade of Smad3 signaling with a Smad3 inhibitor SIS3 is also capable of inhibiting Btg2 expression and Btg2-mediated podocyte EMT, revealing a TGF-β/Smad3-Btg2 circuit mechanism in Btg2-mediated podocyte injury in FSGS. In conclusion, Btg2 is pathogenic in FSGS and promotes podocyte injury via a Smad3-dependent EMT pathway.

Detection of Various Traditional Chinese Medicinal Metabolites as Angiotensin-Converting Enzyme Inhibitors: Molecular Docking, Activity Testing, and Surface Plasmon Resonance Approaches

Angiotensin-converting enzyme 1 (ACE1) is a peptide involved in fluid and blood pressure management. It regulates blood pressure by converting angiotensin I to angiotensin II, which has vasoconstrictive effects. Previous studies have shown that certain compounds of natural origin can inhibit the activity of angiotensin-converting enzymes and exert blood pressure-regulating effects. Surface Plasmon Resonance (SPR) biosensor technology is the industry standard method for observing biomolecule interactions. In our study, we used molecular simulation methods to investigate the docking energies of various herbal metabolites with ACE1 proteins, tested the real-time binding affinities between various herbal metabolites and sACE1 by SPR, and analyzed the relationship between real-time binding affinity and docking energy. In addition, to further explore the connection between inhibitor activity and real-time binding affinity, several herbal metabolites' in vitro inhibitory activities were tested using an ACE1 activity test kit. The molecular docking simulation technique's results and the real-time affinity tested by the SPR technique were found to be negatively correlated, and the virtual docking technique still has some drawbacks as a tool for forecasting proteins' affinities to the metabolites of Chinese herbal metabolites. There may be a positive correlation between the enzyme inhibitory activity and the real-time affinity detected by the SPR technique, and the results from the SPR technique may provide convincing evidence to prove the interaction between herbal metabolites and ACE1 target proteins.

Proteomics to Metabolomics: A New Insight into the Pathogenesis of Hypertensive Nephropathy

BACKGROUND

Hypertensive nephropathy (HN) is a high-burden disorder and a leading cause of end-stage renal disease. Despite huge investigations, the underlying mechanisms are yet largely unknown. Systems biology is a promising approach to providing a comprehensive insight into this complex disorder.

METHODS

Proteome profiles of kidney tubulointerstitium and outer and inner cortex from a rat model of HN were retrieved from the proteomics identification database, and the quality of the datasets was assessed. Proteins that exhibited differential expression were detected and their interactions were analyzed in the kidney sub-compartments. Furthermore, enzymes were linked to the attributed metabolites. Functional enrichment analyses were performed to identify key pathways and processes based on the differentially expressed proteins and predicted metabolites.

RESULTS

Proteasome-mediated protein degradation, actin cytoskeleton organization, and Rho GTPase signaling pathway are involved in the pathogenesis of HN. Furthermore, tissue hypoxia and dysregulated energy homeostasis are among the key underlying events. The metabolism of purine and amino acids is also affected in HN.

CONCLUSION

Although the proposed pathogenic mechanisms remain to be further validated in experimental studies, this study contributes to the understanding of the molecular mechanisms of HN through a systematic unsupervised approach. Considering the significant alterations of metabolic pathways, HN can be viewed as an "acquired error of metabolism."

GPR97 deficiency ameliorates renal interstitial fibrosis in mouse hypertensive nephropathy

Hypertensive nephropathy (HTN) ranks as the second-leading cause of end-stage renal disease (ESRD). Accumulating evidence suggests that persistent hypertension injures tubular cells, leading to tubulointerstitial fibrosis (TIF), which is involved in the pathogenesis of HTN. G protein-coupled receptors (GPCRs) are implicated in many important pathological and physiological processes and act as important drug targets. In this study, we explored the intrarenal mechanisms underlying hypertension-associated TIF, and particularly, the potential role of GPR97, a member of the adhesion GPCR subfamily, in TIF. A deoxycorticosterone acetate (DOCA)/salt-induced hypertensive mouse model was used. We revealed a significantly upregulated expression of GPR97 in the kidneys, especially in renal tubules, of the hypertensive mice and 10 patients with biopsy-proven hypertensive kidney injury. GPR97-/- mice showed markedly elevated blood pressure, which was comparable to that of wild-type mice following DOCA/salt treatment, but dramatically ameliorated renal injury and TIF. In NRK-52E cells, we demonstrated that knockdown of GPR97 suppressed the activation of TGF-β signaling by disturbing small GTPase RhoA-mediated cytoskeletal reorganization, thus inhibiting clathrin-mediated endocytosis of TGF-β receptors and subsequent Smad activation. Collectively, this study demonstrates that GPR97 contributes to hypertension-associated TIF at least in part by facilitating TGF-β signaling, suggesting that GPR97 is a pivotal intrarenal factor for TIF progression under hypertensive conditions, and therapeutic strategies targeting GPR97 may improve the outcomes of patients with HTN.

Independent Prognostic and Predictive Role of Interstitial Macrophages in Kidney Biopsies of IgA Nephropathy Patients

A relevant percentage of IgAN patients experience a progressive decline in kidney function. According to the KDIGO guidelines, proteinuria and eGFR are the only validated prognostic markers. The role of interstitial macrophages in kidney biopsies of IgAN patients and the outcome of patients treated with renin-angiotensin system inhibitors (RASBs) alone or combined with glucocorticoids were evaluated. Clinical and laboratory records (age, gender, hypertension, hematuria, proteinuria, eGFR, serum creatinine, and therapy), MEST-C parameters of the Oxford classification, C4d deposition, peritubular capillaries, and glomerular and interstitial macrophages in 47 IgAN patients undergoing kidney biopsy consecutively between 2003 and 2016 were examined. A high number of interstitial macrophages significantly correlated with peritubular capillary rarefaction and impairment of kidney function. Cox's multivariable regression analysis revealed that a value > 19.5 macrophages/HPF behaved as an independent marker of an unfavorable outcome. Patients exhibiting > 19.5 macrophages/HPF treated at the time of diagnosis with RASBs combined with methylprednisolone had an estimated probability of a favorable outcome higher than patients treated with RASBs alone. Thus, a value > 19.5 macrophages/HPF in IgAN biopsies can predict an unfavorable outcome and endorse a well-timed administration of glucocorticoids. Studies evaluating urine biomarkers associated with peritubular capillary rarefaction in patients with marked macrophage infiltration may help personalized treatment decisions.

Patchouli alcohol against renal fibrosis of spontaneously hypertensive rats via Ras/Raf-1/ERK1/2 signalling pathway

OBJECTIVES

The present study was designed to obverse the protection of patchouli alcohol (PA) ameliorates hypertensive nephropathy in spontaneously hypertensive rats (SHR) and reveals potential mechanism.

METHODS

Briefly, the adult spontaneously hypertensive rats (SHR) or Wistar-Kyoto (WKY) rats (half male and half female) were intragastric gavaged or not with PA (80, 40 and 20 mg/kg) for 8 weeks. Body weight, blood pressure (BP), renal weight, renal function and renal morphology were measured. Further, western blotting and immunohistochemical analysis were used to study the underlying mechanism.

KEY FINDINGS

Compared with the WKY group, plasmatic levels of renin, angiotensin II (Ang-II), transforming growth factor beta 1(TGF-β1), plasminogen activator inhibitor-1(PAI-1), creatinine (Cr), blood urea nitrogen (BUN), renal index, mRNA levels of ERK1/2 and α-SMA were significantly increased in SHR. Histology results showed that renal tubular injury and tubulointerstitial fibrosis occurred in SHR. After administration, SBP of captopril group decreased at each week after administration, especially at 3, 5, 6 7 and 8 weeks (P < 0.05 or P < 0.01). There is no significant effect was assessed in the olive oil group. Decreased plasma Cr, Renin, Ang-II, TGF-β1, PAI-1, SCFAs and Renin, TGF-β1, PAI-1 in renal tissues were observed significantly in captopril (P <0.05 or P < 0.01). Plasma BUN, Ang-II, TGF-β1 and PAI-1 in renal tissues decreased in the olive oil group significantly (P <0.05 or P < 0.01). PA (80, 40 and 20 mg/kg) lowered BP and plasmatic levels of Renin, Ang-II, TGF-β1 and PAI-1. Treatment with PA (40, 20 mg/kg) decreased levels of Cr, BUN and suppressed of activation of pro-fibrosis cytokines including TGF-β1 in kidney. There is no ameliorative change in the olive oil group and the captopril group (P > 0.05) while PA treatment alleviated renal tubular injury and produced dramatic collagen fibre area reductions in mesangial membrane, basement membrane, and renal interstitium obviously (P < 0.05 or P < 0.01). Treatment of SHR with PA-inhibited MFB activation and downregulated mRNA of α-SMA. Treatment with PA suppressed excessive production of the extracellular matrix (ECM) via decreasing Col I, III and FN, downregulating mRNA of tissue inhibitor of TIMP-1 along with upregulating mRNA of MMP-9. The expression of Col III and MMP-9 mRNA-reduced in the captopril group (P < 0.05). In addition, the expression of ERK1/2 and pERK1/2 also reduced in the captopril group significantly (P < 0.05 or P < 0.01). Treatment with PA (20 mg/kg) downregulated proteins expression of Raf-1, ERK1/2 and pERK1/2 and mRNA expression of Ras, Raf-1 and ERK1/2.

CONCLUSIONS

Overall, PA restored normal BP, alleviated renal dysfunction and renal fibrosis, possibly by suppressing Ang II and TGF-β1-mediated Ras/Raf-1/ERK1/2 signalling pathway.

The Angiogenesis Inhibitor Isthmin-1 (ISM1) Is Overexpressed in Experimental Models of Glomerulopathy and Impairs the Viability of Podocytes

Focal segmental glomerulosclerosis (FSGS) is a major cause of end-stage renal disease and remains without specific treatment. To identify new events during FSGS progression, we used an experimental model of FSGS associated with nephroangiosclerosis in rats injected with L-NAME (N_ω-nitro-L-arginine methyl ester). After transcriptomic analysis we focused our study on the role of Isthmin-1 (ISM1, an anti-angiogenic protein involved in endothelial cell apoptosis. We studied the renal expression of ISM1 in L-NAME rats and other models of proteinuria, particularly at the glomerular level. In the L-NAME model, withdrawal of the stimulus partially restored basal ISM1 levels, along with an improvement in renal function. In other four animal models of proteinuria, ISM1 was overexpressed and localized in podocytes while the renal function was degraded. Together these facts suggest that the glomerular expression of ISM1 correlates directly with the progression-recovery of the disease. Further in vitro experiments demonstrated that ISM1 co-localized with its receptors GRP78 and integrin αvβ5 on podocytes. Treatment of human podocytes with low doses of recombinant ISM1 decreased cell viability and induced caspase activation. Stronger ISM1 stimuli in podocytes dropped mitochondrial membrane potential and induced nuclear translocation of apoptosis-inducing factor (AIF). Our results suggest that ISM1 participates in the progression of glomerular diseases and promotes podocyte apoptosis in two different complementary ways: one caspase-dependent and one caspase-independent associated with mitochondrial destabilization.

Salvianolate injection for hypertensive nephropathy patients who were using valsartan: A systematic review and meta-analysis

Background: The treatment of hypertensive nephropathy has remained unchanged for many years. Salvianolate is the main active component extracted from Salvia Miltiorrhiza. The current studies seem to suggest that salvianolate has a certain therapeutic effect on hypertensive nephropathy. Objective: The purpose of this meta-analysis is to evaluate the effect and safety of salvianolate on hypertensive nephropathy under the condition of standardized use of valsartan. Methods: We conducted a systematic search (unlimited initial date to 22 October 2022) in PubMed, Web of Science, the Cochrane Library, Embase, China National Knowledge Infrastructure, Wanfang Data knowledge service platform, China Science and Technology Journal Database, China Biomedical Literature Service System. Searching for the study of salvianolate on hypertensive nephropathy. Two reviewers independently included the study that met the inclusion criteria, and extracted data, evaluated the quality of the study. We use RevMan5.4 and stata15 software for this meta-analysis. We use GRADEprofiler 3.2.2 software for evidence quality assessment. Results: This meta-analysis included seven studies (525 patients). Compared with the use of valsartan combined with conventional treatment, salvianolate combined with valsartan and conventional treatment can further improve the efficacy (RR = 1.28, 95%CI:1.17 to 1.39), reduce blood pressure [systolic blood pressure (MD = 8.98, 95%CI:-12.38 to -5.59); diastolic blood pressure (MD = 5.74, 95%CI:-7.20 to -4.29)], serum creatinine (MD = -17.32, 95%CI:-20.55 to -14.10), blood urea nitrogen (MD = -1.89, 95%CI:-3.76 to -0.01), urine microalbumin (MD = -23.90, 95%CI:-26.54 to -21.26), and urinary protein to creatinine ratio (MD = -1.92, 95%CI:-2.15 to -1.69), cystatin C (MD = -1.04, 95%CI: -1.63 to -0.45) and increase calcitonin gene-related peptide (MD = 18.68, 95%CI:12.89 to 24.46) without increasing adverse reactions (RR = 2.20, 95%CI:0.52 to 9.40). But it has no additional effect on endothelin-1 and malondialdehyde. The quality of evidence ranged from moderate to very low. Conclusion: This meta-analysis shows that the salvianolate can further improve renal function of hypertensive nephropathy patients based on valsartan was used. Therefore, salvianolate can be used as a clinical supplement for hypertensive nephropathy. However, the quality of the evidence is not high due to the uneven quality of the included studies and the insufficient sample size, we still need a lot of large sample size studies with more perfect design to confirm these results. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022373256, identifier CRD42022373256.

Review on Molecular Mechanism of Hypertensive Nephropathy

Hypertension, a prevalent chronic ailment, has the potential to impair kidney function, and thereby resulting in hypertensive nephropathy. The escalating incidence of hypertensive nephropathy attributed to the aging population in urban areas, has emerged as a prominent cause of end-stage renal disease. Nevertheless, the intricate pathogenesis of hypertensive nephropathy poses considerable obstacles in terms of precise clinical diagnosis and treatment. This paper aims to consolidate the research findings on the pathogenesis of hypertensive nephropathy by focusing on the perspective of molecular biology.

Hypertensive Nephropathy: Unveiling the Possible Involvement of Hemichannels and Pannexons

Hypertension is one of the most common risk factors for developing chronic cardiovascular diseases, including hypertensive nephropathy. Within the glomerulus, hypertension causes damage and activation of mesangial cells (MCs), eliciting the production of large amounts of vasoactive and proinflammatory agents. Accordingly, the activation of AT1 receptors by the vasoactive molecule angiotensin II (AngII) contributes to the pathogenesis of renal damage, which is mediated mostly by the dysfunction of intracellular Ca²⁺ ([Ca²⁺]_i) signaling. Similarly, inflammation entails complex processes, where [Ca²⁺]_i also play crucial roles. Deregulation of this second messenger increases cell damage and promotes fibrosis, reduces renal blood flow, and impairs the glomerular filtration barrier. In vertebrates, [Ca²⁺]_i signaling depends, in part, on the activity of two families of large-pore channels: hemichannels and pannexons. Interestingly, the opening of these channels depends on [Ca²⁺]_i signaling. In this review, we propose that the opening of channels formed by connexins and/or pannexins mediated by AngII induces the ATP release to the extracellular media, with the subsequent activation of purinergic receptors. This process could elicit Ca²⁺ overload and constitute a feed-forward mechanism, leading to kidney damage.

Development of an In-House EphA2 ELISA for Human Serum and Measurement of Circulating Levels of EphA2 in Hypertensive Patients with Renal Dysfunction

Identifying novel biomarkers of kidney function in patients with chronic kidney disease (CKD) has strong clinical value as current measures have limitations. This study aims to develop and validate a sensitive and specific ephrin type-A receptor 2 (EphA2) enzyme-linked immunosorbent assay (ELISA) for human serum, and determine whether its results correlate with traditional renal measures in patients with hypertension. The novel ELISA of the current study was validated and used to measure circulating EphA2 levels in 80 hypertensive patients with and without kidney function decline (eGFR less than 60 mL/min/1.73 m2). Validation of the EphA2 ELISA showed good recovery (87%) and linearity (103%) and no cross-reactivity with other Eph receptors. Patients with kidney function decline had lower diastolic blood pressure, and higher UPCR and EphA2 than those without kidney function decline. The association of age and eGFR with EphA2 was maintained in the stepwise multiple regression analysis. In a multivariate logistic model, EphA2 was associated with a lower eGFR (<60 mL/min/1.73 m2) after adjustment for age, sex, and UPCR. High circulating EphA2 levels have potential application as a clinical biomarker for the presence of CKD in patients with hypertension.

Superoxide dismutase as a protective factor for microalbuminuria in hypertensive patients

Oxidative stress had been linked to hypertensive renal impairment in previous investigations. Superoxide dismutase (SOD) was a clinically available oxidative stress biomarker. The association between SOD and the microalbuminuria in hypertensive patients has not been established. From January 2017 to December 2018, data on 690 patients with essential hypertension were collected retrospectively at Shandong Provincial Qianfoshan Hospital. Patients were divided into hypertension with microalbuminuria group (HM) and hypertension without microalbuminuria group (NHM). Clinical data from patients were collected and compared between the two groups. Spearman correlation analysis was used to analyze the correlation between UACR and SOD. Univariate and multivariate logistic regression analyses were used to screen for the risk factors for HM. Our research included 556 patients in the NHM group and 134 patients in the HM group. Spearman correlation analysis showed a negative correlation between SOD and UACR (P < 0.001). Multivariate logistic regression analysis showed SOD was an independent protective factor in hypertensive patients with HM. In hypertensive patients, a substantial, negative correlation between SOD and early renal damage was found, suggesting that SOD may protect renal function.

Nefroangioesclerosis: actualización

Nephroangiosclerosis or kidney disease that accompanies chronic essential arterial hypertension has been known for more than a hundred years. The definitive diagnosis is established by renal biopsy, which is reserved for doubtful cases or atypical presentation, being in most cases a presumptive clinical diagnosis. The objective of this review is to analyse the main controversies that currently exist related to nephroangiosclerosis: inaccuracy in epidemiological aspects (prevalence and incidence unknown), diagnostic difficulties and lack of correlation studies between clinical data and histopathology, progression factors in Caucasians. Currently, with advances in genetic studies in hypertension, not using or redefining the term hypertensive kidney disease for another condition such as nephropathy related to the present genetic alteration is being considered.

Angiotensin-(1-9) in hypertension

Angiotensin-(1-9) [Ang-(1-9)] is a peptide of the non-canonical renin-angiotensin system (RAS) synthesized from angiotensin I by the monopeptidase angiotensin-converting enzyme type 2 (ACE2). Using osmotic minipumps, infusion of Ang-(1-9) consistently reduces blood pressure in several rat hypertension models. In these animals, hypertension-induced end-organ damage is also decreased. Several pieces of evidence suggest that Ang-(1-9) is the endogenous ligand that binds and activates the type-2 angiotensin II receptor (AT2R). Activation of AT2R triggers different tissue-specific signaling pathways. This phenomenon could be explained by the ability of AT2R to form different heterodimers with other G protein-coupled receptors. Because of the antihypertensive and protective effects of AT2R activation by Ang-(1-9), associated with a short half-life of RAS peptides, several synthetic AT2R agonists have been synthesized and assayed. Some of them, particularly CGP42112, C21 and novokinin, have demonstrated antihypertensive properties. Only two synthetic AT2R agonists, C21 and LP2-3, have been tested in clinical trials, but none of them like an antihypertensive. Therefore, Ang-(1-9) is a promising antihypertensive drug that reduces hypertension-induced end-organ damage. However, further research is required to translate this finding successfully to the clinic.

Prediction model of renal function recovery for primary membranous nephropathy with acute kidney injury

Background and objectives

The clinical and pathological impact factors for renal function recovery in acute kidney injury (AKI) on the progression of renal function in primary membranous nephropathy (PMN) with AKI patients have not yet been reported, we sought to investigate the factors that may influence renal function recovery and develop a nomogram model for predicting renal function recovery in PMN with AKI patients.

Methods

Two PMN with AKI cohorts from the Nephrology Department, the First Affiliated Hospital of Wenzhou Medical University during 2012–2018 and 2019–2020 were included, i.e., a derivation cohort during 2012–2018 and a validation cohort during 2019–2020. Clinical characteristics and renal pathological features were obtained. The outcome measurement was the recovery of renal function within 12 months. Lasso regression was used for clinical and pathological features selection. Prediction model was built and nomogram was plotted. Model evaluations including calibration curves were performed.

Result

Renal function recovery was found in 72 of 124 (58.1%) patients and 41 of 72 (56.9%) patients in the derivation and validation cohorts, respectively. The prognostic nomogram model included determinants of sex, age, the comorbidity of hypertensive nephropathy, the stage of glomerular basement membrane and diuretic treatment with a reasonable concordance index of 0.773 (95%CI,0.716–0.830) in the derivation cohort and 0.773 (95%CI, 0.693–0.853) in the validation cohort. Diuretic use was a significant impact factor with decrease of renal function recovery in PMN with AKI patients.

Conclusion

The predictive nomogram model provides useful prognostic tool for renal function recovery in PMN patients with AKI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02882-9.