GSK3ß: A ray of hope for the treatment of diabetic kidney disease.

Diabetic kidney disease (DKD), a major microvascular complication of diabetes, is characterized by its complex pathogenesis, high risk of chronic renal failure, and lack of effective diagnosis and treatment methods. GSK3ß (glycogen synthase kinase 3ß), a highly conserved threonine/serine kinase, was found to activate glycogen synthase. As a key molecule of the glucose metabolism pathway, GSK3ß participates in a variety of cellular activities and plays a pivotal role in multiple diseases. However, these effects are not only mediated by affecting glucose metabolism. This review elaborates on the role of GSK3ß in DKD and its damage mechanism in different intrinsic renal cells. GSK3ß is also a biomarker indicating the progression of DKD. Finally, the protective effects of GSK3ß inhibitors on DKD are also discussed.

Impaired distal renal potassium handling in streptozotocin-induced diabetic mice.

Diabetes is closely associated with K+ disturbances during disease progression and treatment. However, it remains unclear whether K+ imbalance occurs in diabetes with normal kidney function. In this study, we examined the effects of dietary K+ intake on systemic K+ balance and renal K+ handling in streptozotocin (STZ)-induced diabetic mice. The control and STZ mice were fed low or high K+ diet for 7 days to investigate the role of dietary K+ intake in renal K+ excretion and K+ homeostasis and to explore the underlying mechanism by evaluating K+ secretion-related transport proteins in distal nephrons. K+-deficient diet caused excessive urinary K+ loss, decreased daily K+ balance, and led to severe hypokalemia in STZ mice compared with control mice. In contrast, STZ mice showed an increased daily K+ balance and elevated plasma K+ level under K+-loading conditions. Dysregulation of the NaCl cotransporter (NCC), epithelial Na+ channel (ENaC), and renal outer medullary K+ channel (ROMK) was observed in diabetic mice fed either low or high K+ diet. Moreover, amiloride treatment reduced urinary K+ excretion and corrected hypokalemia in K+-restricted STZ mice. On the other hand, inhibition of SGLT2 by dapagliflozin promoted urinary K+ excretion and normalized plasma K+ levels in K+-supplemented STZ mice, at least partly by increasing ENaC activity. We conclude that STZ mice exhibited abnormal K+ balance and impaired renal K+ handling under either low or high K+ diet, which could be primarily attributed to the dysfunction of ENaC-dependent renal K+ excretion pathway, despite the possible role of NCC.NEW & NOTEWORTHY Neither low dietary K+ intake nor high dietary K+ intake effectively modulates renal K+ excretion and K+ homeostasis in STZ mice, which is closely related to the abnormality of ENaC expression and activity. SGLT2 inhibitor increases urinary K+ excretion and reduces plasma K+ level in STZ mice under high dietary K+ intake, an effect that may be partly due to the upregulation of ENaC activity.

Population total and unbound pharmacokinetics and pharmacodynamics of ciprofol and M4 in subjects with various renal functions.

AIMS: The aim of this study was to develop a population pharmacokinetic (PK) model to simultaneously describe both total and unbound concentrations of ciprofol and its major glucuronide metabolite, M4, and to link it to the population pharmacodynamics (PD) model in subjects with various renal functions. METHODS: A total of 401 and 459 pairs of total and unbound plasma concentrations of ciprofol and M4, respectively, as well as 2190 bispectral index (BIS) data from 24 Chinese subjects with various renal functions were available. Covariates that may potentially contribute to the PK and PD variability of ciprofol were screened using a stepwise procedure. The optimal ciprofol induction dosing regimen was determined by model-based simulations. RESULTS: The PK of unbound ciprofol could best be described by a three-compartment model, while a two-compartment model could adequately describe unbound M4 PK. The concentrations of total and unbound ciprofol and M4 were linked using a linear protein binding model. The relationship between plasma concentrations of ciprofol and BIS data was best described by an inhibitory sigmoidal Emax model with a two-compartment biophase distribution compartment. Hemoglobin was the identified covariate determining the central compartment clearance of ciprofol; uric acid was a covariate affecting the central compartment clearance of M4 and protein binding rate, kB . The included covariates had no effect on the PD of ciprofol. Simulation results indicated that the label-recommended dose regimen was adequate for anaesthesia induction. CONCLUSIONS: The developed model fully characterized the population PK and PD profiles of ciprofol. No dose adjustment is required in patients with mild and moderate renal impairment.

Effect of Convalescent Plasma Therapy on Viral Shedding and Survival in Patients With Coronavirus Disease 2019.

Currently, coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been reported in almost all countries globally. No effective therapy has been documented for COVID-19, and the role of convalescent plasma therapy is unknown. In the current study, 6 patients with COVID-19 and respiratory failure received convalescent plasma a median of 21.5 days after viral shedding was first detected, all tested negative for SARS-CoV-2 RNA within 3 days after infusion, and 5 eventually died. In conclusion, convalescent plasma treatment can end SARS-CoV-2 shedding but cannot reduce the mortality rate in critically ill patients with end-stage COVID-19, and treatment should be initiated earlier.

Long noncoding RNA SMAD5-AS1 acts as a microRNA-106a-5p sponge to promote epithelial mesenchymal transition in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a malignant epithelial cancer of the head and neck with high prevalence in southern China, which is accompanied by notable invasiveness and metastasis. Long noncoding RNAs (lncRNAs) participate in the progression of various cancers including NPC. Microarray-based analysis identified highly expressed lncRNA mothers against decapentaplegic homolog 5 (SMAD5)-antisense RNA 1 (AS1) related to NPC. Interestingly, it is found that SMAD5-AS1 competitively bound to microRNA (miR)-106a-5p to regulate SMAD5. Herein, the study aimed to clarify the role of SMAD5-AS1/miR-106a-5p/SMAD5 axis in the process of epithelial mesenchymal transition (EMT) in NPC. SMAD5-AS1 was highly expressed and miR-106a-5p was poorly expressed in NPC tissues and cell lines. The NPC cells were treated with a series of small interfering RNAs, mimics, or inhibitors to explore the effects of SMAD5-AS1, SMAD5, and miR-106a-5p on EMT, cell proliferation, migration, and invasion in NPC. Of note, SMAD5-AS1 silencing or miR-106a-5p overexpression reduced expression of N-cadherin, matrix metallopeptidase 9, Snail, and Vimentin while elevating E-cadherin expression, thus inhibiting EMT, cell proliferation, migration, and invasion in NPC by down-regulation of SMAD5. Moreover, SMAD5 silencing could reduce the ability of EMT induced by SMAD5-AS1 up-regulation. SMAD5-AS1 silencing or miR-106a-5p elevation inhibited tumorigenesis in nude mice. Taken together, SMAD5-AS1 silencing suppressed EMT, cell proliferation, migration, and invasion in NPC by elevating miR-106a-5p to down-regulate SMAD5, which provided a novel therapeutic target for NPC treatment.-Zheng, Y.-J., Zhao, J.-Y., Liang, T.-S., Wang, P., Wang, J., Yang, D.-K., Liu, Z.-S. Long noncoding RNA SMAD5-AS1 acts as a microRNA-106a-5p sponge to promote epithelial mesenchymal transition in nasopharyngeal carcinoma.

Prevalence and risk factors of chronic kidney disease and diabetic kidney disease in a central Chinese urban population: a cross-sectional survey.

BACKGROUND: This study was conducted to evaluate and update the current prevalence of and risk factors for chronic kidney disease (CKD) and diabetic kidney disease (DKD) in a central Chinese urban population. METHODS: From December 2017 to June 2018, a total of 5231 subjects were randomly enrolled from 3 communities in 3 districts of Zhengzhou. CKD was defined as estimated glomerular filtration rate (eGFR) < 60 mL/min.1.73m2 or urinary albumin to creatinine ratio ≥ 30 mg/g (albuminuria). Diabetic subjects with systolic blood pressure > 140 mmHg, albuminuria or an eGFR less than 60 mL/min/1.73 m2 were classified as having DKD. Participants completed a questionnaire assessing lifestyle and relevant medical history, and blood and urine specimens were taken. Serum creatinine, uric acid, total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein and urinary albumin were assessed. The age- and sex-adjusted prevalences of CKD and DKD were calculated, and risk factors associated with the presence of reduced eGFR, albuminuria, DKD, severity of albuminuria and progression of reduced renal function were analyzed by binary and ordinal logistic regression. RESULTS: The overall adjusted prevalence of CKD was 16.8% (15.8-17.8%) and that of DKD was 3.5% (3.0-4.0%). Decreased renal function was detected in 132 participants (2.9, 95% confidence interval [CI]: 2.5-3.2%), whereas albuminuria was found in 858 participants (14.9, 95% CI: 13.9-15.9%). In all participants with diabetes, the prevalence of reduced eGFR was 6.3% (95% CI = 3.9-8.6%) and that of albuminuria was 45.3% (95% CI = 40.4-50.1%). The overall prevalence of CKD in participants with diabetes was 48.0% (95% CI = 43.1-52.9%). The results of the binary and ordinal logistic regression indicated that the factors independently associated with a higher risk of reduced eGFR and albuminuria were older age, sex, smoking, alcohol consumption, overweight, obesity, diabetes, hypertension, dyslipidemia and hyperuricemia. CONCLUSIONS: Our study shows the current prevalence of CKD and DKD in residents of Central China. The high prevalence suggests an urgent need to implement interventions to relieve the high burden of CKD and DKD in China.

Mycophenolate Mofetil Combined With Prednisone Versus Full-Dose Prednisone in IgA Nephropathy With Active Proliferative Lesions: A Randomized Controlled Trial.

BACKGROUND: Observational studies suggest that patients with immunoglobulin A nephropathy (IgAN) with active proliferative lesions show a good response to immunosuppressive treatment. STUDY DESIGN: Multicenter, prospective, randomized, controlled trial. SETTING & PARTICIPANTS: 176 patients with IgAN with active proliferative lesions (cellular and fibrocellular crescents, endocapillary hypercellularity, or necrosis), proteinuria with protein excretion ≥ 1.0g/24h, and estimated glomerular filtration rate > 30mL/min/1.73m2. INTERVENTION: Mycophenolate mofetil (MMF) group: MMF, 1.5g/d, for 6 months and prednisone, 0.4 to 0.6mg/kg/d, for 2 months and then tapered by 20% per month for the next 4 months; prednisone group: prednisone, 0.8 to 1.0mg/kg/d, for 2 months and then tapered by 20% per month for the next 4 months. All patients were followed up for another 6 months. OUTCOMES: The primary end point was complete remission rate at 6 and 12 months. RESULTS: At baseline, median estimated glomerular filtration rates were 90.2 and 94.3mL/min/1.73m2 and mean proteinuria was protein excretion of 2.37 and 2.47g/24h in the MMF and prednisone groups, respectively. At 6 months, complete remission rates were 37% (32 of 86 patients) and 38% (33 of 88 patients); the between-group difference was not statistically significant (P=0.9). At 12 months, complete remission rates were 48% (35 of 73 patients) and 53% (38 of 72 patients) in the MMF and prednisone groups, respectively; the between-group difference was not statistically significant (P=0.6). Incidences of Cushing syndrome and newly diagnosed diabetes mellitus were lower in the MMF group than in the prednisone group. LIMITATIONS: Not all participants were treated with renin-angiotensin system blockers, relatively short follow-up. CONCLUSIONS: MMF plus prednisone versus full-dose prednisone did not differ in reducing proteinuria, but patients treated with the former had fewer adverse events in patients with IgAN with active proliferative lesions.

Roles of miR-497 and its potential signaling pathway in diseases and with vascular endothelial growth factor.

MicroRNA (miRNA) is a class of small endogenous non-coding RNAs that are ∼ 22 nucleotides in length and can have structural, enzymatic and post-transcriptional regulators of gene expression targeting mRNA for translational repression and/or degradation. miR-497 is high on the list of noncoding, small, regulatory RNAs that plays important roles in the pathogenesis of some diseases and takes part in some signaling pathways in some diseases, but many questions await answers. Vascular endothelial growth factor (VEGF) is a notable chemokine that plays critical roles in angiogenesis and vasculogenesis. There might be an association between miRNA-497 and VEGF. This review was performed to sum up the roles of miR-497 and its potential signaling pathway in diseases and with VEGF.

Risk factors of nocturia (two or more voids per night) in Chinese people older than 40 years.

AIMS: To explore the risk factors of nocturia in Chinese inhabitants aged ≥40 years. METHODS: A randomized, community-based, cross-sectional study was performed on 10,160 inhabitants ≥40 years old in mainland China, via a stratified sampling approach. A questionnaire, including socio-demographics, lifestyle factors and medical history, was completed. Nocturia was defined as a threshold of two or more voids per night. Differences in prevalence between age and gender groups were ascertained by the chi-squared test. Gender-related factors were evaluated by multivariate logistic regression analysis. P < 0.05 was considered to be statistically significant. RESULTS: Data on 9,637 (94.9%) people aged 59.6 ± 9.7 years qualified for final statistical analysis. The overall prevalence of nocturia was 31.7% (3,053/9,637), and this increased with age (P < 0.001). Nocturia was significantly associated with cardiovascular disease and overactive bladder symptom score (OABSS) (P < 0.05), while sporting activities were protective (P < 0.001). Diabetes mellitus (DM) was significantly correlated with nocturia in men (P < 0.05), whereas hypertension was correlated with nocturia in women (P < 0.05). No correlation was found between nocturia and education level, occupation, civil status, tea consumption, body mass index (BMI), female birth history, and International Prostate Symptom Score. CONCLUSIONS: In Chinese people aged ≥40 years, nocturia is associated with aging, OABSS, cardiovascular disease, hypertension, and DM. Sporting activities are negatively associated with nocturia.

Efficacy and safety of Abelmoschus manihot for primary glomerular disease: a prospective, multicenter randomized controlled clinical trial.

BACKGROUND: Abelmoschus manihot, a single medicament of traditional Chinese medicine, has been widely used to treat kidney disease. This is the first randomized controlled clinical trial to assess its efficacy and safety in patients with primary glomerular disease. STUDY DESIGN: Prospective, open-label, multicenter, randomized, controlled, clinical trial. SETTING & PARTICIPANTS: From May 2010 to October 2011, a total of 417 patients with biopsy-proven primary glomerular disease from 26 hospitals participated in the study. INTERVENTIONS: A manihot in the form of a huangkui capsule, 2.5 g, 3 times per day; losartan potassium, 50mg/d; or combined treatment, a huangkui capsule at 2.5 g 3 times per day, was combined with losartan potassium, 50mg/d. The duration of intervention was 24 weeks. OUTCOMES & MEASUREMENTS: The primary outcome was change in 24-hour proteinuria from baseline after treatment. Change in estimated glomerular filtration rate (eGFR) from baseline after treatment was a secondary outcome. The 24-hour proteinuria was measured every 4 weeks and eGFR was measured at 0, 4, 12, and 24 weeks. RESULTS: Mean baseline urine protein excretion was 1,045, 1,084, and 1,073 mg/d in the A manihot, losartan, and combined groups, respectively, and mean eGFR was 108, 106, and 106 mL/min/1.73 m2, respectively. After 24 weeks of treatment, mean changes in proteinuria were protein excretion of -508, -376, and -545 mg/d, respectively (P=0.003 for A manihot vs losartan and P<0.001 for the combined treatment vs losartan). Mean eGFR did not change significantly. The incidence of adverse reactions was not different among the 3 groups (P>0.05), and there were no severe adverse events in any group. LIMITATIONS: Results cannot be generalized to those with nephrotic syndrome or reduced eGFR. CONCLUSIONS: A manihot is a promising therapy for patients with primary kidney disease (chronic kidney disease stages 1-2) with moderate proteinuria.

Ferroptosis: a potential bridge linking gut microbiota and chronic kidney disease.

Ferroptosis is a novel form of lipid peroxidation-driven, iron-dependent programmed cell death. Various metabolic pathways, including those involved in lipid and iron metabolism, contribute to ferroptosis regulation. The gut microbiota not only supplies nutrients and energy to the host, but also plays a crucial role in immune modulation and metabolic balance. In this review, we explore the metabolic pathways associated with ferroptosis and the impact of the gut microbiota on host metabolism. We subsequently summarize recent studies on the influence and regulation of ferroptosis by the gut microbiota and discuss potential mechanisms through which the gut microbiota affects ferroptosis. Additionally, we conduct a bibliometric analysis of the relationship between the gut microbiota and ferroptosis in the context of chronic kidney disease. This analysis can provide new insights into the current research status and future of ferroptosis and the gut microbiota.

Perspectives on the involvement of the gut microbiota in salt-sensitive hypertension.

Salt-sensitivity hypertension (SSH) is an independent predictor of cardiovascular event-related death. Despite the extensiveness of research on hypertension, which covers areas such as the sympathetic nervous system, the renin-angiotensin system, the vascular system, and the immune system, its pathogenesis remains elusive, with sub-optimal blood pressure control in patients. The gut microbiota is an important component of nutritional support and constitutes a barrier in the host. Long-term high salt intake can lead to gut microbiota dysbiosis and cause significant changes in the expression of gut microbiota-related metabolites. Of these metabolites, short chain fatty acids (SCFAs), trimethylamine oxide, amino acids, bile acids, and lipopolysaccharide are essential mediators of microbe-host crosstalk. These metabolites may contribute to the incidence and development of SSH via inflammatory, immune, vascular, and nervous pathways, among others. In addition, recent studies, including those on the histone deacetylase inhibitory mechanism of SCFAs and the blood pressure-decreasing effects of H2S via vascular activation, suggest that several proteins and factors in the classical pathway elicit their effects through multiple non-classical pathways. This review summarizes changes in the gut microbiota and its related metabolites in high-salt environments, as well as corresponding treatment methods for SSH, such as diet management, probiotic and prebiotic use, antibiotic use, and fecal transplantation, to provide new insights and perspectives for understanding SSH pathogenesis and the development of strategies for its treatment.

Emerging role of antidiabetic drugs in cardiorenal protection.

The global prevalence of diabetes mellitus (DM) has led to widespread multi-system damage, especially in cardiovascular and renal functions, heightening morbidity and mortality. Emerging antidiabetic drugs sodium-glucose cotransporter 2 inhibitors (SGLT2i), glucagon-like peptide-1 receptor agonists (GLP-1RAs), and dipeptidyl peptidase-4 inhibitors (DPP-4i) have demonstrated efficacy in preserving cardiac and renal function, both in type 2 diabetic and non-diabetic individuals. To understand the exact impact of these drugs on cardiorenal protection and underlying mechanisms, we conducted a comprehensive review of recent large-scale clinical trials and basic research focusing on SGLT2i, GLP-1RAs, and DPP-4i. Accumulating evidence highlights the diverse mechanisms including glucose-dependent and independent pathways, and revealing their potential cardiorenal protection in diabetic and non-diabetic cardiorenal disease. This review provides critical insights into the cardiorenal protective effects of SGLT2i, GLP-1RAs, and DPP-4i and underscores the importance of these medications in mitigating the progression of cardiovascular and renal complications, and their broader clinical implications beyond glycemic management.

Defective natriuresis contributes to hyperkalemia in db/db mice during potassium supplementation.

OBJECTIVES: Potassium supplementation reduces blood pressure and the occurrence of cardiovascular diseases, with K+-induced natriuresis playing a potential key role in this process. However, whether these beneficial effects occur in diabetes remains unknown. METHODS: In this study, we examined the impact of high-K+ intake on renal Na+/K+ transport by determining the expression of major apical Na+ transporters, diuretics responses (as a proxy for specific Na+ transporter function), urinary Na+/K+ excretion, and plasma Na+/K+ concentrations in db/db mice, a model of type 2 diabetes mellitus. RESULTS: Although db/m mice exhibited increased fractional excretion of sodium (FENa) and fractional excretion of potassium (FEK) under high-K+ intake, these responses were largely blunted in db/db mice, suggesting impaired K+-induced natriuresis and kaliuresis in diabetes. Consequently, high-K+ intake increased plasma K+ levels in db/db mice, which could be attributed to the abnormal activity of sodium-hydrogen exchanger 3 (NHE3), sodium-chloride cotransporter (NCC), and epithelial Na+ channel (ENaC), as high-K+ intake could not effectively decrease NHE3 and NCC and increase ENaC expression and activity in the diabetic group. Inhibition of NCC by hydrochlorothiazide could correct the hyperkalemia in db/db mice fed a high-K+ diet, indicating a key role for NCC in K+-loaded diabetic mice. Treatment with metformin enhanced urinary Na+/K+ excretion and normalized plasma K+ levels in db/db mice with a high-K+ diet, at least partially, by suppressing NCC activity. CONCLUSION: Collectively, the impaired K+-induced natriuresis in diabetic mice under high-K+ intake may be primarily attributed to impaired NCC-mediated renal K+ excretion, despite the role of NHE3.

Clinical and prognostic implications of serum uric acid levels on IgA nephropathy: a cohort study of 348 cases with a mean 5-year follow-up.

AIM: To assess the prognostic implications of serum uric acid levels on patients with IgA nephropathy in a longitudinal 8-year follow-up study and to identify an association between serum uric acid levels and the clinical and pathological phenotypes of IgA nephropathy. SUBJECTS AND METHODS: We reviewed the files of all consecutive patients with IgA nephropathy treated at our hospital between 2001 and 2009. Analyses were performed to investigate the association between the level of serum uric acid and both clinical and pathological phenotypes of IgA nephropathy. Prognosis was assessed based on follow-up data. RESULTS: At the same glomerular filtration rate (GFR), there was no significant difference in the levels of 24 hours proteinuria, blood urea nitrogen (BUN), and serum creatinine between the two groups with different levels of serum uric acid (p > 0.05). The prevalence of glomerular sclerosis as well as the scores of tubulointerstitial and vascular injury was greater in patients with high serum uric acid levels compared to patients with normal levels of serum uric acid (p < 0.05). At the end of the follow-up period, patients with high serum uric acid levels had a higher prevalence of reduced GFR and end stage renal disease (ESRD) than those with normal serum uric acid levels (40.82 vs. 15.70% and 64.71 vs. 35.00%, respectively; p < 0.05). CONCLUSIONS: The serum uric acid level in patients with IgA nephropathy affects the pathophysiology and prognosis of the disease. We also identified a correlation between hyperuricemia and a higher risk of renal end points.

[Epidemiology of rheumatoid arthritis in middle-aged and elderly population in Luohe City, Henan Province].

OBJECTIVE: To explore the local prevalence of rheumatoid arthritis (RA) among the middle-aged and elderly population. METHODS: A total of 8610 residents were recruited for a two-stage cluster sampling survey through a questionnaire of RA according to 2010 ACR/EULAR classification criteria. Physical examinations and blood tests were performed. RESULTS: The responding rate was 96.10%. Joint score 0, 1, 2, 3, 5 was detected in 13.62%, 7.57%, 2.79%, 1.87% and 0.23% of subjects. The prevalence of joint score 0, 1, 2, 3, 5 was 13.62%, 7.57%, 2.79%, 1.87% and 0.23%. The rate was 17.48% and 14.27% for elevated levels of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), 6.62%, 1.96% and 5.48%, 1.55% for low titer and high titer rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) positive antibody. And 63 RA cases were confirmed. The crude prevalence was 0.76% and 0.71% for standardized prevalence. Compared to males, females had a higher prevalence of RA (1.02% vs 0.39%, P < 0.01). In the population, the awareness rate was 74.60%, cure rate 71.43% and control rate 18.57% respectively. CONCLUSION: The local prevalence of RA in elderly females is higher than that in males. And the treatment and awareness rates are also low.

Gut microbiota and its metabolites - molecular mechanisms and management strategies in diabetic kidney disease.

Diabetic kidney disease (DKD) is one of the major microvascular complications of diabetes mellitus and is also one of the serious risk factors in cardiovascular events, end-stage renal disease, and mortality. DKD is associated with the diversified, compositional, and functional alterations of gut microbiota. The interaction between gut microbiota and host is mainly achieved through metabolites, which are small molecules produced by microbial metabolism from exogenous dietary substrates and endogenous host compounds. The gut microbiota plays a critical role in the pathogenesis of DKD by producing multitudinous metabolites. Nevertheless, detailed mechanisms of gut microbiota and its metabolites involved in the occurrence and development of DKD have not been completely elucidated. This review summarizes the specific classes of gut microbiota-derived metabolites, aims to explore the molecular mechanisms of gut microbiota in DKD pathophysiology and progression, recognizes biomarkers for the screening, diagnosis, and prognosis of DKD, as well as provides novel therapeutic strategies for DKD.

Activation of Kir4.1/Kir5.1 contributes to the cyclosporin A-induced stimulation of the renal NaCl cotransporter and hyperkalemic hypertension.

AIM: Cyclosporin A (CsA) is a widely used immunosuppressive drug that causes hypertension and hyperkalemia. Moreover, CsA-induced stimulation of the thiazide-sensitive NaCl cotransporter (NCC) in the kidney has been shown to be responsible for the development of hyperkalemic hypertension. In this study, we tested whether CsA induces the activation of NCC by stimulating the basolateral Kir4.1/Kir5.1 channel in the distal convoluted tubule (DCT). METHODS: Electrophysiology, immunoblotting, metabolic cages, and radio-telemetry methods were used to examine the effects of CsA on Kir4.1/Kir5.1 activity in the DCT, NCC function, and blood pressure in wild-type (WT) and kidney-specific Kir4.1 knockout (KS-Kir4.1 KO) mice. RESULTS: The single-channel patch clamp experiment demonstrated that CsA stimulated the basolateral 40 pS K+ channel in the DCT. Whole-cell recording showed that short-term CsA administration (2 h) not only increased DCT K+ currents but also shifted the K+ current (IK ) reversal potential to the negative range (hyperpolarization). Furthermore, CsA administration increased phosphorylated NCC (pNCC) levels and inhibited renal Na+ and K+ excretions in WT mice but not in KS-Kir4.1 KO mice, suggesting that Kir4.1 is required to mediate CsA effects on NCC function. Finally, long-term CsA infusion (14 days) increased blood pressure, plasma K+ concentration, and total NCC or pNCC abundance in WT mice, but these effects were blunted in KS-Kir4.1 KO mice. CONCLUSION: We conclude that CsA stimulates basolateral K+ channel activity in the DCT and that Kir4.1 is essential for CsA-induced NCC activation and hyperkalemic hypertension.

Kir4.1 deletion prevents salt-sensitive hypertension in early streptozotocin-induced diabetic mice via Na + -Cl - cotransporter in the distal convoluted tubule.

OBJECTIVES: Functional impairment of renal sodium handling and blood pressure (BP) homeostasis is an early characteristic manifestation of type 1 diabetes. However, the underlying mechanisms remain unclear. METHODS: Metabolic cages, radio-telemetry, immunoblotting, and electrophysiology were utilized to examine effects of high salt (8% NaCl, HS) intake on Na + /K + balance, BP, Na + -Cl - cotransporter (NCC) function, and basolateral K + channel activity in the distal convoluted tubule (DCT) under diabetic conditions. RESULTS: Improper Na + balance, hypernatremia, and a mild but significant increase in BP were found in streptozotocin (STZ)-induced diabetic mice in response to HS intake for 7 days. Compared to the vehicle, STZ mice showed increased Kir4.1 expression and activity in the DCT, a more negative membrane potential, higher NCC abundance, and enhanced hydrochlorothiazide-induced natriuretic effect. However, HS had no significant effect on basolateral Kir4.1 expression/activity and DCT membrane potential, or NCC activity under diabetic conditions, despite a downregulation in phosphorylated NCC abundance. In contrast, HS significantly downregulated the expression of Na + -H + exchanger 3 (NHE3) and cleaved epithelial sodium channel-γ in STZ mice, despite an increase in NHE3 abundance after STZ treatment. Kir4.1 deletion largely abolished STZ-induced upregulation of NCC expression and prevented BP elevation during HS intake. Interestingly, HS causes severe hypokalemia in STZ-treated kidney-specific Kir4.1 knockout (Ks-Kir4.1 KO) mice and lead to death within a few days, which could be attributed to a higher circulating aldosterone level. CONCLUSIONS: We concluded that Kir4.1 is required for upregulating NCC activity and may be essential for developing salt-sensitive hypertension in early STZ-induced diabetes.

[Incidence of metabolic syndrome in systemic lupus erythematosus and its influence by glucocorticoids].

OBJECTIVE: To investigate the incidence and correlative factors of metabolic syndrome (MS) in patients with systemic lupus erythematosus (SLE). METHODS: A total of 116 SLE patients and 115 controls were enrolled into the study. The incidence of MS, SLE disease activity index (SLEDAI) of patients with SLE combined with MS (MS-SLE) and patients without MS (n-MS-SLE), lupus characteristics, cumulative glucocorticoids, administration dose of glucocorticoids and hydroxychloroquine were compared between SLE group and the control group. RESULTS: The incidence of MS of SLE group was obviously higher than that of the control (34.48% vs 14.78%, P < 0.05). The ratios of patients with lower HDL-C, higher TG and higher blood pressure in SLE group (50.86%, 56.03%, 46.55%) were higher than those in the controls (34.78%, 16.52%, 20.00%, all P < 0.05). MS-SLE group had significantly higher mean waist circumference, BMI, systolic blood pressure and diastolic blood pressure and lower HDL-C than n-MS-SLE group (all P < 0.05). No significant difference was found regarding duration of disease, renal involvement, ESR, C-reactive protein,high-sensitivity C-reactive protein, SLEDAI, cumulative and current glucocorticoids use in MS-SLE group and n-MS-SLE group. The ratio of patients taking hydroxychloroquine in n-MS-SLE group was higher than that of MS-SLE group (46.05% vs 15.00%, P < 0.05). CONCLUSIONS: Patients with SLE has a higher incidence rate of MS. Hydroxychloroquine may reduce their MS incidence.