Intermedin (IMD) is a novel member of the calcitonin/calcitonin gene-related peptide family. Endoplasmic reticulum stress (ERS) has been implicated in the pathology of renal ischemia/reperfusion (IRI). In the present study, we investigated whether IMD could reduce ERS damage after renal ischemia. The kidneys of SD rats were subjected to 45 min of warm ischemia followed by 24 h of reperfusion. The hypoxia/reoxygenation(H/R) model in NRK-52E cells consisted of hypoxia for 1 h and reoxygenation for 2 h. IMD was over-expressed in vivo and in vitro using the vector pcDNA3.1-IMD. The serum creatinine concentration and lactate dehydrogenase (LDH) activity in the plasma were determined. Histologic examinations of renal tissues were performed with PAS staining. Real-time PCR and Western blotting were used to determine the mRNA and protein levels, respectively. Additionally, ER staining was used to detect the ERS response. In the rat renal IRI model, we found that IMD gene transfer markedly improved renal function and pathology and decreased LDH activity and cell apoptosis compared with the kidneys that were transfected with the control plasmid. IMD significantly attenuated the ERS stress parameters compared with IRI group. Indeed, IMD down-regulated glucose-regulated protein 78 (GRP78), C/EBP homologous protein(CHOP), and caspase 12 protein and mRNA levels. Moreover, in the NRK-52E cell H/R model, IMD overexpression prevented the apoptosis induced by H/R. Furthermore, IMD ameliorated the ER structural changes and concomitantly decreased the levels of GRP78, CHOP and caspase-12. This study revealed that IMD protects against renal IRI by suppressing ERS and ERS-related apoptosis.

Metabolic syndrome (MetS) includes obesity, diabetes, dyslipidemia and hypertension. Its incidence is rapidly increasing worldwide, particularly in postmenopausal women. Estrogens regulate glucose homeostasis and lipid metabolism via estrogen receptors 1 (ESR1) and 2 (ESR2). The current study aimed to elucidate associations of MetS with ESR1 and ESR2 gene polymorphisms in postmenopausal Chinese women. This case-control study included 304 postmenopausal women (154 and 150 control and MetS patients, respectively). Clinical indicators related to MetS were assessed. Two ESR1 (PvuII and XbaI) and two ESR2 (RsaI and AluI) polymorphisms were evaluated by polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis. ESR1 polymorphisms were significantly different between MetS patients and healthy controls. G allele frequency for the XbaI polymorphism was significantly higher in patients than in control patients (p = 0.004, OR = 1.610, 95%CI 1.169–2.18). The haplotypes A–T (p = 0.015) and G–C (p = 0.024) showed significant differences. The minor alleles of the XbaI and PvuII gene polymorphisms in both homozygous and heterozygous forms showed associations with elevated waist circumference, fasting serum insulin and HOMA-IR. The minor G allele in homozygous and heterozygous forms of the RsaI and AluI gene polymorphisms showed associations with elevated total cholesterol and LDL-C. In postmenopausal Chinese women, ESR1 polymorphism and the haplotypes A–T and G–C of XbaI–PvuII are associated with MetS, unlike ESR2 polymorphisms. Patients harboring the G allele of XbaI have elevated BMI, waist circumference, systolic and diastolic BP, FBG, HOMA-IR, total cholesterol, TG, LDL-C and NAFLD (%), and reduced HDL-C.

Intermedin [IMD, adrenomedullin-2 (ADM-2)] attenuates renal fibrosis by inhibition of oxidative stress. However, the precise mechanisms remain unknown. Heme oxygenase-1 (HO-1), an antioxidant agent, is associated with antifibrogenic effects. ADM is known to induce HO-1. Whether IMD has any effect on HO-1 is unclear. Herein, we determined whether the antifibrotic properties of IMD are mediated by induction of HO-1. Renal fibrosis was induced by unilateral ureteral obstruction (UUO) performed on male Wistar rats. Rat proximal tubular epithelial cell line (NRK-52E) was exposed to rhTGF-β1 (10 ng/ml) to establish an in vitro model of epithelial-mesenchymal transition (EMT). IMD was over-expressed in vivo and in vitro using the vector pcDNA3.1-IMD. Zinc protoporphyrin (ZnPP) was used to block HO-1 enzymatic activity. IMD effects on HO-1 expression in the obstructed kidney of UUO rat and in TGF-β1-stimulated NRK-52E were analyzed by real-time RT-PCR, Western blotting or immunohistochemistry. HO activity in the obstructed kidney, contralateral kidney of UUO rat and NRK-52E was examined by measuring bilirubin production. Renal fibrosis was determined by Masson trichrome staining and collagen I expression. Macrophage infiltration and IL-6 expression were evaluated using immunohistochemical analysis. In vivo and in vitro EMT was assessed by measuring α-smooth muscle actin (α-SMA) and E-cadherin expression using Western blotting or immunofluorescence, respectively. HO-1 expression and HO activity were increased in IMD-treated UUO kidneys or NRK-52E. The obstructed kidneys of UUO rats demonstrated significant interstitial fibrosis on day 7 after operation. In contrast, kidneys that were treated with IMD gene transfer exhibited minimal interstitial fibrosis. The obstructed kidneys of UUO rats also had greater macrophage infiltration and IL-6 expression. IMD restrained infiltration of macrophages and expression of IL-6 in UUO kidneys. The degree of EMT was extensive in obstructed kidneys of UUO rats as indicated by decreased expression of E-cadherin and increased expression of α-SMA. In vitro studies using NRK-52E confirmed these observations. EMT was suppressed by IMD gene delivery. However, all of the above beneficial effects of IMD were eliminated by ZnPP, an inhibitor of HO enzyme activity. This study demonstrates that IMD attenuates renal fibrosis by induction of HO-1.

Awareness of the spectrum of clinical manifestations of systemic lupus erythematosus (SLE), especially uncommon changes, is essential for diagnosis and effective management of patients. A 26-year-old Chinese man with SLE initially manifested cutaneous papulonodular mucinosis and developed acute Guillain-Barré syndrome and class V lupus nephritis 2 years later. His cutaneous nodules had not been idententified for 2 years and were resected by surgical procedures twice until SLE was diagnosed. The kidney biopsy revealed class V lupus nephritis. The patient responded well to a short course of intravenous immunoglobulins and his muscle strength almost completely recovered. So far, he has undergone five cycles of cyclophosphamide combined with hydroxychloroquine and tapering prednisone, resulting in partial remission of lupus nephritis and disappearance of hypocomplementemia. We reported a rare case of male patient with SLE with manifestation of class V lupus nephritis, Guillain-Barré syndrome and papulonodular mucinosis.

The Wnt/β-catenin pathway represents a promising therapeutic target for mitigating kidney fibrosis. Corin possesses the homologous ligand binding site (Frizzled-cysteine rich domain, Fz-CRD) similar to Frizzled proteins, which act as receptors for Wnt. The Fz-CRD has been found in eight different proteins, all of which, except for corin, are known to bind Wnt and regulate its signal transmission. It is hypothesized that corin may inhibit the Wnt/β-catenin signaling pathway and thereby reduce fibrogenesis. Reduced expression of corin along with the increased activity of Wnt/β-catenin signaling was found in unilateral ureteral obstruction (UUO) and ischemia/reperfusion injury (UIRI) models. In vitro, corin can bind to the Wnt1 through its Fz-CRDs and inhibit the Wnt1 function responsible for activating β-catenin. TGF-β1 inhibited corin expression, accompanied by activation of β-catenin; conversely, overexpression of corin attenuated the fibrotic effects of TGF-β1. In vivo, adenovirus-mediated overexpression of corin attenuated the progression of fibrosis, which was potentially associated with the inhibition of Wnt/β-catenin signaling and the downregulation of its target genes after UUO and UIRI. These results suggest that corin acts as an antagonist that protects the kidney from pathogenic Wnt/β-catenin signaling and from fibrosis following UUO and UIRI.

Introduction The management of immunoglobulin A (IgA) nephropathy remains a topic of debate. Hydroxychloroquine and mycophenolate mofetil (MMF) are two immunosuppressive agents that have recently garnered increased attention among patients with IgA nephropathy in China. Several studies have shown the comparable efficacy between MMF and enteric-coated mycophenolate sodium (EC-MPS), with lower adverse event rates for EC-MPS. The present study aims to evaluate the efficacy and safety of EC-MPS combined with hydroxychloroquine as an immunosuppressive regimen for patients with high-risk progressive IgA nephropathy, despite receiving routine supportive treatment. Methods and analysis This study is a multicentre, prospective, randomised controlled, open-label, blinded endpoint trial. 96 patients diagnosed with IgA nephropathy and persistent proteinuria from 12 general hospitals in Shanxi Province of China will be recruited and randomly assigned to receive either EC-MPS plus hydroxychloroquine or hydroxychloroquine alone in a 1:1 ratio. We will compare the efficacy and safety of hydroxychloroquine combined with or without oral EC-MPS (720–1080 mg/day for 6 months, and tapered to 360–540 mg/day for another 6 months) on a background of supportive care. All enrolled patients will receive standard basic treatment to achieve optimum blood pressure and the maximum tolerated dose of ACE inhibitors or angiotensin receptor blockers. The primary outcome is the change in 24-hour urine protein at 6 months relative to baseline. Participants will be subject to regular follow-up for a duration of 12 months. Ethics and dissemination This study has received ethical approval from the Ethics Committee of Shanxi Medical University Second Hospital (No. 2024YX-481). A duly signed and dated informed consent form must be obtained from each participant or his/her legal guardian prior to any operational procedures related to the trial. The result of this study will be presented and published at international conferences and in scientific journals. Trial registration number ChiCTR2400093530.