Traditional Chinese medicine protects against hypertensive kidney injury in Dahl salt-sensitive rats by targeting transforming growth factor-β signaling pathway

Pharmacological inhibition of the NLRP3 inflammasome attenuates kidney apoptosis, fibrosis, and injury in Dahl salt-sensitive rats

BACKGROUND

Salt-sensitive hypertension (SSH) is the most severe form of hypertension, and the presence of NLRP3 inflammasome plays a crucial role in its pathogenesis. Although MCC950 has shown therapeutic potential for hypertension and kidney injury, its mechanism of action remains unclear.

METHODS

Dahl salt-sensitive (SS) rats and their salt-tolerant aptamer control SS-13BN (BN) rats were randomly assigned to four groups: SS rats intraperitoneally administered physiological saline (SS + vehicle) or MCC950 (SS + MCC950), and BN rats intraperitoneally administered physiological saline (BN + vehicle) or MCC950 (BN + MCC950). All rats were given 2% saline for drinking and received intraperitoneal injections of physiological saline or MCC950 (5 mg/kg) every other day. Biomarkers such as serum creatinine, urinary protein, sodium retention, NLRP3 inflammasome, inflammation, apoptosis, fibrosis, sodium channels and histopathological changes in kidney injury were evaluated in blood, urine, and kidney tissues.

RESULTS

Compared with the SS + vehicle group, the SS + MCC950 group showed significantly lower blood pressure levels. Additionally, inhibition of NLRP3 inflammasome activation was observed along with reduced inflammation, apoptosis, fibrosis, and sodium retention in the kidneys.

CONCLUSIONS

The findings suggest that pharmacological inhibition of the NLRP3 inflammasome reduces blood pressure in SS rats and alleviates related kidney injury by suppressing inflammation, apoptosis, fibrosis, and sodium retention.

Calcium Ion Attenuates Transforming Growth Factor β1-Induced Extracellular Matrix Accumulation by Inducing Smad2 Degradation through the Proteasome Pathway

Extracellular Ca2+ is the first ligand that has been confirmed to function by activating the calcium-sensing receptor (CaSR), a member of G-protein coupled receptors. CaSR controls not only calcium homeostasis, but also plays a pivotal role in many cellular processes such as cell proliferation and apoptosis; moreover, it is implicated in the development of cardiovascular diseases. TGF-β/Smads signaling pathway is a classical pathway of renal fibrosis. Here we used a culture of mesangial cells to evaluate the mechanisms of the renoprotective effects of Ca2+. We found that Ca2+ inhibits TGF-β-induced phosphorylation of Smad2 and deposition of fibronectin (FN), in turn, down-regulation of FN and phosphorylation of Smad2 was closely related to the degradation of Smad2 through the proteasomal pathway. We found that Ca2+ only downregulates the expression of Smad2 at the protein level, but has no effect on its gene expression. However, Ca2+ could downregulate TGF-β-induced expression of FN both at the protein and gene level. Hence, Smad2 acts as a transcription factor of FN, and its degradation definitely inhibits the expression of its target gene FN.

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.

Advance on Chinese Medicine for Hypertensive Renal Damage: Focus on the Complex Molecular Mechanisms

Hypertensive renal damage (HRD) is a major cause of end-stage renal disease. Among the causes of end-stage renal disease, HRD accounts for nearly 34% of the total number of cases. Antihypertensive treatment is primarily drug-based, but therapeutic efficacy is less effective and can have serious side effects. Chinese medicine (CM) has significant advantages in the treatment of HRD. CM is rich in various active ingredients and has the property of targeting multiple targets and channels. Therefore, the regulatory network of CM on disease is complex. A large number of CM have been employed to treat HRD, either as single applications or as part of compound formulations. The key possible mechanisms of CM for HRD include regulation of the renin-angiotensin-aldosterone system, antioxidation, anti-inflammation, rescue of endothelial function, regulation of vasoactive substance secretion and obesity-related factors, etc. This review summarized and discussed the recent advance in the basic research mechanisms of CM interventions for HRD and pointed out the challenges and future prospects.

Drug pair of Cornus officinalis and Radix achyranthis bidentatae improves renal injury of hypertension by regulating metabolic reprogramming mediated by eNOS

OBJECTIVE

To explore the effects and possible mechanisms of the drug pair Cornus officinalis and Radix achyranthis bidentatae (SYR-NX) on improving hypertensive kidney damage.

METHOD

SYR-NX, a formulation of Cornus officinalis and Radix Achyranthis Bidentatae with a dose ratio 1:2.5, was used in this experiment. We investigated the effects of SYR-NX on spontaneously hypertensive rats (SHR) fed with a high-salt diet and Human Kidney-2 (HK2) cells exposed to hypoxia. After 8 weeks of treatment with SYR-NX, blood pressure was tested, and β 2-Microglobulin(β2-MG), blood creatinine (S-cr), endothelial nitric oxide synthase (eNOS), nicotinamide adenine dinucleotide phosphate (NADPH), M2 pyruvate kinase (PKM2), adenosine triphosphate (ATP), pyruvate, lactate, connective tissue growth factor (CTGF) and tumor necrosis factor-α (TNF-α)were measured. HK2 cells pre-treated with SYR-NX were cultured in a three-gas hypoxic incubator chamber (5 % CO2, 1 % O2, 94 % N2) for 12 h, and then eNOS, PKM2, NADPH, ATP, pyruvate, lactate, CTGF and TNF-α were assessed.

RESULTS

SYR-NX significantly reduced SBP, DBP, β2-MG, S-cr, PKM2, pyruvate, lactate, CTGF and TNF-α, and increased eNOS, NADPH, and ATP.

CONCLUSION

SYR-NX can regulate metabolic reprogramming through eNOS and improves hypertensive kidney injury.

Nephropathy 1st inhibits renal fibrosis by activating the PPARγ signaling pathway

Renal fibrosis is a manifestation of kidney injury. Nephropathy 1st is a traditional Chinese herbal medicine that has been used as a therapy for kidney disease, but the underlying mechanisms remain elusive. The aim of this study was to investigate the role and underlying mechanisms of Nephropathy 1st on the progression of kidney disease. In the present study, unilateral ureteral obstruction was performed to establish the renal fibrosis rat model. By hematoxylin–eosin staining and immunohistochemical staining analysis, the severity of renal fibrosis was evaluated in vivo. Serum creatinine (CREA) and urea nitrogen (BUN) were measured by ELISA. The expression levels of Col-I, FN, PPARγ, and Klotho were measured by Western blot in rat NRK-49F cells and in fibrotic rats. GW9662 was used to inhibit PPARγ signaling. Metabonomic analysis showed metabolic differences among groups. Nephropathy 1st administration alleviated the progression of rat renal fibrosis and reduced serum creatinine (Scr) and BUN levels. Mechanistically, Nephropathy 1st promoted the expression of PPARγ and thus activated PPARγ signaling, thereby reducing the pro-fibrotic phenotypes of fibroblasts. The therapeutic effect of Nephropathy 1st was abrogated by the PPARγ inhibitor GW9662. Moreover, Nephropathy 1st normalized the dysregulated lipid metabolism in renal fibrosis rats. In conclusion, Nephropathy 1st alleviates renal fibrosis development in a PPARγ-dependent manner.

Protective mechanism of traditional Chinese medicine guizhi fuling pills against carbon tetrachloride-induced kidney damage is through inhibiting oxidative stress, inflammation and regulating the intestinal flora

BACKGROUND

Chemical or drug-induced kidney damage has been recognized as a critical cause of kidney failure. The oxidative stress, inflammation, and imbalance of intestinal flora caused by carbon tetrachloride (CCl₄) play a fundamental role in chronic kidney damage. Guizhi Fuling pills (GZFL) is a traditional formula consisting of five traditional Chinese medicinal herbs, which can promote blood circulation and improve kidney function. The underlying mechanisms of GZFL improving kidney damage are not fully understood yet.

AIM

The current study aimed to explore the effects of GZFL on CCl₄-induced kidney damage and intestinal microbiota in mice.

METHODS

Male ICR mice were intraperitoneally administered with 20% CCl₄ (mixed in a ratio of 1:4 in soybean oil) twice a week, for 4 weeks to induce kidney damage. Creatinine (CRE), urea nitrogen, antioxidant enzymes, and inflammatory cytokines were measured and the histology of the kidney, jejunum, and colon examination to assess kidney and intestinal damage. The expressions of nuclear factor-erythroid 2-related factor 2 (Nrf2) family members, nucleotide-binding domain and leucine-rich repeat protein 3 (NLRP3) inflammasome in kidney tissues, and the tight junction proteins in colonic tissues were detected by Western blot. The gut microbiota was analyzed through 16S rRNA gene sequencing.

RESULTS

GZFL treatment decreased the serum CRE and urea nitrogen levels. Moreover, GZFL reduced the levels of pro-inflammatory cytokines and increased antioxidant enzyme activities in kidney and colonic tissues. GZFL improved the kidney, jejunum, and colon histology. Furthermore, GZFL inhibited the expressions of NLRP3, ASC, and cleaved-Caspase-1, while Nrf2, HO-1, NQO1, GCLM, and tight junction proteins were increased. The dysbiosis of intestinal microbiota improved after GZFL treatment.

CONCLUSIONS

This study showed that GZFL could improve kidney damage, which might be mainly via the integrated regulations of the Nrf2 pathway, NLRP3 inflammasome, and composition of intestinal microbiota.

Study on the Mechanism of Bu-Shen-He-Mai Granules in Improving Renal Damage of Ageing Spontaneously Hypertensive Rats by Regulating Th17 Cell/Tregs Balance

Methods

Blood pressure and urine biochemical indices were recorded. Renal blood flow was evaluated by renal ultrasonography. Transmission electron microscopy (TEM) and HE staining were used to assess kidney and spleen morphology. Renal fibrosis was assessed using Masson staining. Serum levels of IL-6, IL-10, and IL-17A were measured using ELISAs. The density of RORγ and Foxp3 in the spleen was observed by immunofluorescence staining. The levels of Th17 cells and Tregs in blood were detected via flow cytometry. Transcriptome sequencing was performed to screen the targets of BSHM granules in hypertensive kidneys.

Results

BSHM granules decreased SBP by 21.2 mm·Hg and DBP by 8.8 mm·Hg in ageing SHRs (P < 0.05), decreased the levels of urine mALB, β2-Mg, and NAG (P < 0.01), and improved renal blood flow and arteriosclerosis. BSHM granules increased IL-10 expression (P < 0.05) while decreasing IL-6 (P < 0.01) and IL-17A (P < 0.05) levels. BSHM granules improved Foxp3 density and the number of Tregs (P < 0.01) and reduced RORγt density and the number of Th17 cells (P < 0.01). Transcriptome sequencing identified 747 differentially expressed (DE) mRNAs in kidneys after BSHM treatment. GO analysis suggested that BSHM granules act through immunoregulation.

Conclusions

BSHM granules attenuated hypertensive renal damage in ageing SHRs, by significantly increasing Tregs and decreasing Th17 cells.

TGF-β/Smad Signaling Pathway in Tubulointerstitial Fibrosis

Chronic kidney disease (CKD) was a major public health problem worldwide. Renal fibrosis, especially tubulointerstitial fibrosis, is final manifestation of CKD. Many studies have demonstrated that TGF-β/Smad signaling pathway plays a crucial role in renal fibrosis. Therefore, targeted inhibition of TGF-β/Smad signaling pathway can be used as a potential therapeutic measure for tubulointerstitial fibrosis. At present, a variety of targeting TGF-β1 and its downstream Smad proteins have attracted attention. Natural products used as potential therapeutic strategies for tubulointerstitial fibrosis have the characteristics of acting on multiple targets by multiple components and few side effects. With the continuous research and technique development, more and more molecular mechanisms of natural products have been revealed, and there are many natural products that inhibited tubulointerstitial fibrosis via TGF-β/Smad signaling pathway. This review summarized the role of TGF-β/Smad signaling pathway in tubulointerstitial fibrosis and natural products against tubulointerstitial fibrosis by targeting TGF-β/Smad signaling pathway. Additionally, many challenges and opportunities are presented for inhibiting renal fibrosis in the future.

Effects of Bushen-Jiangya granules on blood pressure and pharmacogenomic evaluation in low-to-medium-risk hypertensive patients: study protocol for a randomized double-blind controlled trial

INTRODUCTION

Hypertension is one of the most important risk factors for cardiovascular disease, and its control rates remain low worldwide. The most effective strategy is that patients with hypertension should be diagnosed and treated early. Preliminary studies showed that the Bushen Jiangya granule (BSJY) could suppress ventricular hypertrophy and inflammatory responses, lower blood pressure, and protect the target organs of hypertension. We designed a randomized, double-blind, placebo-controlled trial to evaluate the efficacy of BSJY in patients with low-to-medium risk hypertension.

METHODS AND ANALYSIS

This trial is a one-center, randomized, double-blind, placebo-controlled study. A total of 260 participants will be randomized in a 1:1 ratio to an experimental group (BSJY plus amlodipine) and a control group (placebo plus amlodipine). The trial cycle will last 8 weeks. The primary outcome is the change in 24-h average systolic and diastolic blood pressure. The secondary outcomes include heart rate variability, pharmacogenomic evaluation, improvement in TCM syndrome, and serum pro-inflammatory/anti-inflammatory cytokines between the two groups. The safety of medication will also be evaluated. All the data will be recorded in electronic case report forms and analyzed by SPSS V.22.0.

ETHICS AND DISSEMINATION

This study has been approved by the Research Ethics Committee of Guang'anmen Hospital, China Academy of Chinese Medical Sciences in Beijing, China (No. 2019-186-KY-01). The participants are volunteers, understand the process of this trial, and sign an informed consent. The results of this study will be disseminated to the public through peer-reviewed journals and academic conferences.

DISCUSSION

We hypothesize that patients with low-to-medium-risk hypertension will benefit from BSJY. If successful, this study will provide evidence-based recommendations for clinicians.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiMCTR1900002876. Registered in November 2019.