The mechanism of podocyte apoptosis is not fully understood. In addition, the role of the inositol 1,4,5-triphosphate receptor (IP3R)/glucose-regulated protein 75 (Grp75)/voltage-dependent anion channel 1 (VDAC1)/mitochondrial calcium uniporter (MCU) calcium regulation axis, which is located at sites of endoplasmic reticulum (ER) mitochondria coupling, in the mechanism of podocyte apoptosis is unclear. This study aimed to understand the roles of this axis in podocyte apoptosis and explore potential targets for podocyte protection. The expression of IP3R, Grp75, VDAC1, and MCU and mitochondrial Ca2+ were analyzed during Adriamycin- or angiotensin II-induced apoptosis in cultured mouse podocytes. The interaction between IP3R, Grp75, and VDAC1 was investigated using co-immunoprecipitation experiments. The effects of IP3R, Grp75, and MCU agonists and antagonists on mitochondrial Ca2+ and apoptosis were investigated in cultured podocytes. The podocyte-protective effects of an MCU inhibitor were further investigated in rats with Adriamycin-induced nephropathy. Increased expression of IP3R, Grp75, VDAC1 and MCU, enhanced interaction among the IP3R-Grp75-VDAC1 complex, mitochondrial Ca2+ overload, and increased active caspase-3 levels were confirmed during Adriamycin- or angiotensin II-induced mouse podocyte apoptosis. Agonists of this axis facilitated mitochondrial Ca2+ overload and podocyte apoptosis, whereas specific antagonists against IP3R, Grp75, or MCU prevented mitochondrial Ca2+ overload and podocyte apoptosis. A specific MCU inhibitor prevented Adriamycin-induced proteinuria and podocyte foot process effacement in rats. This study identified a novel pathway in which the IP3R-Grp75-VDAC1-MCU calcium regulation axis mediated podocyte apoptosis by facilitating mitochondrial Ca2+ overload. Antagonists that inhibit Ca2+ transfer from ER to mitochondria protected mouse podocytes from apoptosis. An MCU inhibitor protected podocytes and decreased proteinuria in rats with Adriamycin-induced nephropathy. Therefore, antagonists to this pathway have promise as novel podocyte-protective drugs.

Objective: Monogenic autoinflammatory diseases (AIDs) are inborn disorders caused by innate immunity dysregulation and characterized by robust autoinflammation. We aimed to present the phenotypes and genotypes of Chinese pediatric monogenic AID patients. Methods: A total of 288 pediatric patients clinically suspected to have monogenic AIDs at the Department of Pediatrics of Peking Union Medical College Hospital between November 2008 and May 2019 were genotyped by Sanger sequencing, and/or gene panel sequencing and/or whole exome sequencing. Final definite diagnoses were made when the phenotypes and genotypes were mutually verified. Results: Of the 288 patients, 79 (27.4%) were diagnosed with 18 kinds of monogenic AIDs, including 33 patients with inflammasomopathies, 38 patients with non-inflammasome related conditions, and eight patients with type 1 interferonopathies. Main clinical features were skin disorders (76%), musculoskeletal problems (66%), fever (62%), growth retardation (33%), gastrointestinal tract abnormalities (25%), central nervous system abnormalities (15%), eye disorders (16%), ear problems (9%), and cardiopulmonary disorders (8%). The causative genes were ACP5, ADA2, ADAR1, IFIH1, LPIN2, MEFV, MVK, NLRC4, NLRP3, NLRP12, NOD2, PLCG2, PSMB8, PSTPIP1, TMEM173, TNFAIP3, TNFRSF1A, and TREX1. Conclusions: The present study summarized both clinical and genetic characteristics of 18 kinds of monogenic AIDs found in the largest pediatric AID center over the past decade, with fever, skin problems, and musculoskeletal system disorders being the most prevalent clinical features. Many of the mutations were newly discovered. This is by far the first and largest monogenic AID report in Chinese pediatric population and also a catalog of the phenotypic and genotypic features among these patients.

Objective: To explore the efficacy of initial treatment of newly diagnosed childhood-onset lupus nephritis (cLN) with combination of belimumab and either cyclophosphamide, mycophenolate mofetil, tacrolimus or multitargeted therapy. Methods: A historical control study was conducted on children aged 5–17 years with newly diagnosed cLN. All patients recruited met the 2012 Systemic Lupus International Collaborating Clinics and/or 2019 European League Against Rheumatism/American College of Rheumatology classification criteria for SLE, and the 2003 International Society of Nephrology/Renal Pathology Society histopathological criteria for LN. The primary endpoint was primary efficacy renal response (PERR) at 12 months, and secondary endpoints included complete renal response (CRR), lupus low disease activity state (LLDAS) and remission (Definitions of Remission in Systemic Lupus Erythematosus (DORIS)) at 12 months, changes of SLE Disease Activity Index (SLEDAI) and dose of glucocorticoid (GC). Results: A total of 101 patients were included with 38 patients in the belimumab group and 63 patients in the standard immunotherapy group. There were no statistically significant differences between the two groups at baseline. At 12 months, compared with the standard immunotherapy group, more patients in the belimumab group had a higher PERR (97.1% vs 80.0%, χ²=3.965, p=0.046), CRR (94.1% vs 76.6%, χ²=4.679, p=0.031), LLDAS (75.0% vs 18.6%, χ²=27.84, p<0.001) and DORIS (34.4% vs 11.9%, χ²=6.626, p=0.01). The belimumab group had faster and greater reductions in SLEDAI and dose of GC (p<0.05), with a significantly higher proportion of patients with dose of GC ≤7.5 mg/day (82.9% vs 30.4%, χ²=19.737, p<0.001). In the standard immunotherapy group, 4 patients (6.3%) experienced a decline in estimated glomerular filtration rate of 30% or more at 12 months, while no patients in the belimumab group experienced worsening of renal function. There were no serious adverse events reported in two groups, and there was no significant difference in the occurrence of infection between the two groups. Conclusion: This study reported for the first time the effectiveness of combined belimumab therapy in a Chinese cohort of patients with cLN. The strategy of initial combination with belimumab helps achieve treatment targets earlier and faster GC tapering. And initial combination therapy in children with cLN with high disease activity may yield more significant benefits.

Introduction Osteonecrosis (ON) is characterised by the destruction of the normal blood supply to the bone tissue. ON is the main cause of disability in patients with systemic lupus erythematosus (SLE). Studies have reported the existence of many risk factors for SLE complicated by ON, including the use of high-dose glucocorticoids and high disease activity. The correlation between antiphospholipid antibodies (aPLs) and ON in SLE has been controversial. We aim to conduct a systematic review of the literature related to SLE, aseptic ON and aPLs, to provide a reference for the clinical screening of high-risk patients and for early prevention. Methods and analysis The following six databases will be searched: MEDLINE/PubMed, Embase, Web of Science, Chinese Biomedical Literature Database, Wan-Fang Database and China National Knowledge Infrastructure. The database searches will not be restricted by date. Case–control studies, cohort studies or observational studies that compare aPLs between SLE patients with and without ON will be considered eligible. Articles published in English and Chinese will be included. Two researchers will independently perform the processes of study selection, data extraction and study quality assessment. The Newcastle–Ottawa Quality Assessment Scale will be used to assess the quality of the retrieved studies. A meta-analysis will be performed after screening the studies. Data will be analysed using ORs for dichotomous data. Ethics and dissemination Ethical approval is not required because this systematic review will use published data. The systematic review will be electronically disseminated through a peer-reviewed publication or conference presentations. PROSPERO registration number CRD42020209637.

Objective: We conducted a retrospective case–control study to investigate the risk factors for osteonecrosis of the femoral head (ONFH) in rheumatoid arthritis (RA) patients.Methods: The clinical data of patients diagnosed with RA at Fujian Provincial Hospital from January 2013 to December 2020 were retrospectively collected and evaluated. Twenty‐two patients with ONFH were identified. Eighty‐eight age‐, sex‐, and disease duration‐matched RA patients without symptomatic ONFH were randomly selected as controls in a ratio of 1:4. Logistic regression analysis was used to analyze the risk factors.Results: The anticardiolipin (ACL)‐immunoglobulin G (IgG) concentration, clinical disease activity index, simplified disease activity index, incidence of hyperlipidemia in the case group were higher than those in the control group. Multivariate logistic regression analysis did not find the independent risk factor in ONFH patients with RA.Conclusion: The pathogenesis of ONFH in RA is related to many factors such as ACL IgG, disease activity index, and hyperlipidemia. While, we went to great lengths to explore the relationship between antiphospholipid antibodies and ONFH, but it plays a very small role.

Morphological changes of podocyte mitochondria are observed in patients with mitochondrial cytopathy and nephrotic syndrome. However, whether mitochondrial dynamics involved in podocyte in lupus nephritis (LN) is still not clear. This study aims to investigate the associations between mitochondrial morphology and podocyte lesions and laboratory and pathological features in LN. The foot process width (FPW) and mitochondrial morphology were observed through electron microscope. Then the associations between mitochondrial morphology and podocyte lesions and laboratory features were explored in various International Society of Nephrology/Renal Pathology Society class LN patients. Foot process effacement and excessive mitochondria fission in podocyte were observed and proteinuria was positively correlated with FPW. Mitochondria area, circumference, and aspect ratio were negatively correlated with BUN, and 24h-UTP positively correlated with Alb. At the same time, Alb was negatively correlated with form factor. FPW, form factor, surface density, and numerical density on area were positively correlated with 24h-UTP. Excessive mitochondrial fission is associated with podocyte damage and proteinuria, whereas the mechanism still needs to be explored.