Pathophysiological role of Na-Cl cotransporter in kidneys, blood pressure, and metabolism.

The Na-Cl cotransporter (NCC) is a well-recognized regulator of ion transportation in the kidneys that facilitates Na+ reabsorption in the distal convoluted tubule. It is also the pharmacologic inhibitory target of thiazide diuretics, a class of front-line antihypertensive agents that have been widely used for decades. NCC is a potent regulator of Na+ reabsorption and homeostasis. Hence, its overactivation and suppression lead to hypertension and hypotension, respectively. Genetic mutations that affect NCC function contribute to several diseases such as Gordon and Gitelman syndromes. We summarized the role of NCC in various physiologic processes and pathological conditions, such as maintaining ion and water homeostasis, controlling blood pressure, and influencing renal physiology and injury. In addition, we discussed the recent advancements in understanding cryo-EM structure of NCC, the regulatory mechanisms and binding mode of thiazides with NCC, and novel physiologic implications of NCC in regulating the cross-talk between the immune system and adipose tissue or the kidneys. This review contributes to a comprehensive understanding of the pivotal role of NCC in maintaining ion homeostasis, regulating blood pressure, and facilitating kidney function and NCC's novel role in immune and metabolic regulation.

DY131 activates ERRγ/TFAM axis to protect against metabolic disorders and acute kidney injury.

Renal tubular injury is considered as the main pathological feature of acute kidney injury (AKI), and mitochondrial dysfunction in renal tubular cells is implicated in the pathogenesis of AKI. The estrogen-related receptor γ (ERRγ) is a member of orphan nuclear receptors which plays a regulatory role in mitochondrial biosynthesis, energy metabolism and many metabolic pathways. Online datasets showed a dominant expression of ERRγ in renal tubules, but the role of ERRγ in AKI is still unknown. In the present study, we investigated the role of ERRγ in the pathogenesis of AKI and the therapeutic efficacy of ERRγ agonist DY131 in several murine models of AKI. ERRγ expression was reduced in kidneys of AKI patients and AKI murine models along with a negative correlation to the severity of AKI. Consistently, silencing ERRγ in vitro enhanced cisplatin-induced tubular cells apoptosis, while ERRγ overexpression in vivo utilizing hydrodynamic-based tail vein plasmid delivery approach alleviated cisplatin-induced AKI. ERRγ agonist DY131 could enhance the transcriptional activity of ERRγ and ameliorate AKI in various murine models. Moreover, DY131 attenuated the mitochondrial dysfunction of renal tubular cells and metabolic disorders of kidneys in AKI, and promoted the expression of the mitochondrial transcriptional factor A (TFAM). Further investigation showed that TFAM could be a target gene of ERRγ and DY131 might ameliorate AKI by enhancing ERRγ-mediated TFAM expression protecting mitochondria. These findings highlighted the protective effect of DY131 on AKI, thus providing a promising therapeutic strategy for AKI.

WWP2 deletion aggravates acute kidney injury by targeting CDC20/autophagy axis.

INTRODUCTION: Acute kidney injury (AKI) is associated with high morbidity and mortality rates. The molecular mechanisms underlying AKI are currently being extensively investigated. WWP2 is an E3 ligase that regulates cell proliferation and differentiation. Whether WWP2 plays a regulatory role in AKI remains to be elucidated. OBJECTIVES: We aimed to investigate the implication of WWP2 in AKI and its underlying mechanism in the present study. METHODS: We utilized renal tissues from patients with AKI and established AKI models in global or tubule-specific knockout (cKO) mice strains to study WWP2's implication in AKI. We also systemically analyzed ubiquitylation omics and proteomics to decipher the underlying mechanism. RESULTS: In the present study, we found that WWP2 expression significantly increased in the tubules of kidneys with AKI. Global or tubule-specific knockout of WWP2 significantly aggravated renal dysfunction and tubular injury in AKI kidneys, whereas WWP2 overexpression significantly protected tubular epithelial cells against cisplatin. WWP2 deficiency profoundly affected autophagy in AKI kidneys. Further analysis with ubiquitylation omics, quantitative proteomics and experimental validation suggested that WWP2 mediated poly-ubiquitylation of CDC20, a negative regulator of autophagy. CDC20 was significantly decreased in AKI kidneys, and selective inhibiting CDC20 with apcin profoundly alleviated renal dysfunction and tubular injury in the cisplatin model with or without WWP2 cKO, indicating that CDC20 may serve as a downstream target of WWP2 in AKI. Inhibiting autophagy with 3-methyladenine blocked apcin's protection against cisplatin-induced renal tubular cell injury. Activating autophagy by rapamycin significantly protected against cisplatin-induced AKI in WWP2 cKO mice, whereas inhibiting autophagy by 3-methyladenine further aggravated apoptosis in cisplatin-exposed WWP2 KO cells. CONCLUSION: Taken together, our data indicated that the WWP2/CDC20/autophagy may be an essential intrinsic protective mechanism against AKI. Further activating WWP2 or inhibiting CDC20 may be novel therapeutic strategies for AKI.

Copy number variants at 4q31.3 affecting the regulatory region of FBXW7 associated with neurodevelopmental delay.

Emerging research has demonstrated that genomic alterations disrupting topologically associated domains (TADs) and chromatin interactions underlie the pathogenic mechanisms of specific copy number variants (CNVs) in neurodevelopmental disorders. We report two patients with a de novo deletion and a duplication in chromosome 4q31, potentially causing FBX-related neurodevelopmental syndrome by affecting the regulatory region of FBXW7. High-throughput chromosome conformation capture (Hi-C) analysis using available capture data in neural progenitor cells revealed the rewiring of the TAD boundary close to FBXW7. Both patients exhibited facial dysmorphisms, cardiac and limb abnormalities, and neurodevelopmental delays, showing significant clinical overlap with previously reported FBXW7-related features. We also included an additional 10 patients with CNVs in the 4q31 region from the literature and the DECIPHER database for Hi-C analysis, which confirmed that disruption of the regulatory region of FBXW7 likely contributes to the developmental defects observed in these patients.

Genetic or pharmacologic blockade of mPGES-2 attenuates renal lipotoxicity and diabetic kidney disease by targeting Rev-Erbα/FABP5 signaling.

Diabetic kidney disease (DKD) is one of the most common complications of diabetes, and no specific drugs are clinically available. We have previously demonstrated that inhibiting microsomal prostaglandin E synthase-2 (mPGES-2) alleviated type 2 diabetes by enhancing ß cell function and promoting insulin production. However, the involvement of mPGES-2 in DKD remains unclear. Here, we aimed to analyze the association of enhanced mPGES-2 expression with impaired metabolic homeostasis of renal lipids and subsequent renal damage. Notably, global knockout or pharmacological blockage of mPGES-2 attenuated diabetic podocyte injury and tubulointerstitial fibrosis, thereby ameliorating lipid accumulation and lipotoxicity. These findings were further confirmed in podocyte- or tubule-specific mPGES-2-deficient mice. Mechanistically, mPGES-2 and Rev-Erbα competed for heme binding to regulate fatty acid binding protein 5 expression and lipid metabolism in the diabetic kidney. Our findings suggest a potential strategy for treating DKD via mPGES-2 inhibition.

Inhibition of RAC attenuates Adriamycin-induced podocyte injury.

Minimal Change Disease (MCD), which is associated with podocyte injury, is the leading cause of nephrotic syndrome in children. A considerable number of patients experience relapses and require prolonged use of prednisone and immunosuppressants. Multi-drug resistance and frequent relapses can lead to disease progression to focal and segmental glomerulosclerosis (FSGS). To identify potential targets for therapy of podocyte injury, we examined microarray data of mRNAs in glomerular samples from both MCD patients and healthy donors, obtained from the GEO database. Differentially expressed genes (DEGs) were used to construct the protein-protein interactions (PPI) network through the application of the search tool for the retrieval of interacting genes (STRING) tool. The most connected genes in the network were ranked using cytoHubba. 16 hub genes were selected and validated by qRT-PCR. RAC2 was identified as a potential therapeutic target for further investigation. By downregulating RAC2, Adriamycin (ADR)-induced human podocytes (HPCs) injury was attenuated. EHT-1864, a small molecule inhibitor that targets the RAC (RAC1, RAC2, RAC3) family, proved to be more effective than RAC2 silencing in reducing HPCs injury. In conclusion, our research suggests that EHT-1864 may be a promising new molecular drug candidate for patients with MCD and FSGS.

A novel gain-of-function STAT3 variant in infantile-onset diabetes associated with multiorgan autoimmunity.

BACKGROUND: Germline gain-of-function (GOF) variants in the signal transducer and activator of transcription 3 (STAT3) gene lead to a rare inherited disorder characterized by early-onset multiorgan autoimmunity. METHODS: We described a Chinese patient with infantile-onset diabetes and multiorgan autoimmunity. The patient presented with early-onset type 1 diabetes and autoimmune hypothyroidism at 7 months. During the 7.5-year follow-up, she developed pseudo-celiac enteropathy at 1 year of age and showed severe growth retardation. Whole-exome sequencing was performed and the novel variant was further assessed by in vitro functional assays. RESULTS: Whole-exome sequencing revealed a novel variant (c.1069G>A, p.Glu357Lys) in the DNA-binding domain of STAT3. In vitro functional studies revealed that p.Glu357Lys was a GOF variant by increasing STAT3 transcriptional activity and phosphorylation. In addition, the STAT3 Glu357Lys variant caused dysregulation of insulin gene expression by enhancing transcriptional inhibition of the insulin gene enhancer binding protein factor 1 (ISL1). CONCLUSION: In the current study, we describe clinical manifestations and identify a novel STAT3 GOF variant (c.1069G>A) in a Chinese patient. This activating variant impairs insulin expression by increasing transcriptional inhibition of its downstream transcription factor ISL1, which could be involved in the pathogenesis of early-onset diabetes.

Diagnostic yield and novel candidate genes by next generation sequencing in 166 children with intrahepatic cholestasis.

BACKGROUND AND AIMS: Cholestatic liver disease is a leading referral to pediatric liver transplant centers. Inherited disorders are the second most frequent cause of cholestasis in the first month of life. METHODS: We retrospectively characterized the genotype and phenotype of 166 participants with intrahepatic cholestasis, and re-analyzed phenotype and whole-exome sequencing (WES) data from patients with previously undetermined genetic etiology for newly published genes and novel candidates. Functional validations of selected variants were conducted in cultured cells. RESULTS: Overall, we identified disease-causing variants in 31% (52/166) of our study participants. Of the 52 individuals, 18 (35%) had metabolic liver diseases, 9 (17%) had syndromic cholestasis, 9 (17%) had progressive familial intrahepatic cholestasis, 3 (6%) had bile acid synthesis defects, 3(6%) had infantile liver failure and 10 (19%) had a phenocopy of intrahepatic cholestasis. By reverse phenotyping, we identified a de novo variant c.1883G > A in FAM111B of a case with high glutamyl transpeptidase (GGT) cholestasis. By re-analyzing WES data, two patients were newly solved, who had compound heterozygous variants in recently published genes KIF12 and USP53, respectively. Our additional search for novel candidates in unsolved WES families revealed four potential novel candidate genes (NCOA6, CCDC88B, USP24 and ATP11C), among which the patients with variants in NCOA6 and ATP11C recapitulate the cholestasis phenotype in mice models. CONCLUSIONS: In a single-center pediatric cohort, we identified monogenic variants in 22 known human intrahepatic cholestasis or phenocopy genes, explaining up to 31% of the intrahepatic cholestasis patients. Our findings suggest that re-evaluating existing WES data from well-phenotyped patients on a regular basis can increase the diagnostic yield for cholestatic liver disease in children.

Roxadustat ameliorates experimental colitis in mice by regulating macrophage polarization through increasing HIF level.

BACKGROUND: Gastro-intestinal (GI) tract inflammation is as a result of inflammatory hypoxia which is also induced by long-standing group of disorders like inflammatory-bowel disease (IBD). Regulation of GI immune homeostasis by macrophage involves hypoxia-inducible factor (HIF). As inhibitor of HIF prolyl hydroxylase, roxadustat (ROX) increases the levels of HIF. METHODS: We induced experimental colitis (EC) model in mice via dextran-sulfate sodium (DSS) to evaluate ROX role in above-mentioned disease. RESULTS: ROX ameliorated EC in mice by blocking colonic length shorten and loss of body weight, thereby reducing scores of disease-activity index (DAI) and histopathology. ROX significantly reduced inflammatory cytokines levels, suppressed M1 and increased M2 macrophage polarization in colonic tissues. Besides, ROX blocked declining hematocrit (HCT) level in blood and increased HIF-1-α and HIF-2-α level in colonic tissues. The inhibitor of HIF-1- α, KC7F2 decreased body weight and colonic length in ROX-treated DSS mice. Meanwhile, DAI scores and histopathology in KC7F2 treated DSS mice were markedly higher than that of treatment with ROX alone. KC7F2 treatments also significantly increased inflammatory cytokines levels, respectively promoted and reduced polarization of M1 and M2 macrophages in colonic tissue from ROX treated mice. Further, KC7F2 treatments inhibited ROX induced HCT level increasing in blood and decreased HIF-1-α and HIF-2-α level in colonic tissue. CONCLUSION: Collectively, we discovered that ROX ameliorated EC in mice by regulating macrophage polarization through promotion of HIF expression. GENERAL SIGNIFICANCE: Taken together, we developed a new application of ROX, which provides new ideas and a scientific basis for IBD treatment.

Targeting mPGES-2 to protect against acute kidney injury via inhibition of ferroptosis dependent on p53.

Acute kidney injury (AKI) is a clinical syndrome with high morbidity and mortality but no specific therapy. Microsomal prostaglandin E synthase-2 (mPGES-2) is a PGE2 synthase but can metabolize PGH2 to malondialdehyde by forming a complex with heme. However, the role and mechanism of action of mPGES-2 in AKI remain unclear. To examine the role of mPGES-2, both global and tubule-specific mPGES-2-deficient mice were treated with cisplatin to induce AKI. mPGES-2 knockdown or overexpressing HK-2 cells were exposed to cisplatin to cause acute renal tubular cell injury. The mPGES-2 inhibitor SZ0232 was used to test the translational potential of targeting mPGES-2 in treating AKI. Additionally, mice were subjected to unilateral renal ischemia/reperfusion to further validate the effect of mPGES-2 on AKI. Interestingly, both genetic and pharmacological blockage of mPGES-2 led to decreased renal dysfunction and morphological damage induced by cisplatin and unilateral renal ischemia/reperfusion. Mechanistic exploration indicated that mPGES-2 deficiency inhibited ferroptosis via the heme-dependent regulation of the p53/SLC7A11/GPX4 axis. The present study indicates that mPGES-2 blockage may be a promising therapeutic strategy for AKI.

Mitochondrial antiviral signaling protein: a potential therapeutic target in renal disease.

Mitochondrial antiviral signaling protein (MAVS) is a key innate immune adaptor on the outer mitochondrial membrane that acts as a switch in the immune signal transduction response to viral infections. Some studies have reported that MAVS mediates NF-κB and type I interferon signaling during viral infection and is also required for optimal NLRP3 inflammasome activity. Recent studies have reported that MAVS is involved in various cancers, systemic lupus erythematosus, kidney diseases, and cardiovascular diseases. Herein, we summarize the structure, activation, pathophysiological roles, and MAVS-based therapies for renal diseases. This review provides novel insights into MAVS's role and therapeutic potential in the pathogenesis of renal diseases.

Plk1 promotes renal tubulointerstitial fibrosis by targeting autophagy/lysosome axis.

The prevalence of chronic kidney disease (CKD) has been increasing over the past decades. However, no effective therapies are available for delaying or curing CKD. Progressive fibrosis is the major pathological feature of CKD, which leads to end-stage renal disease (ESRD). The present study showed that Polo-like kinase 1 (Plk1) was upregulated in the kidneys of CKD patients and mice subjected to unilateral ureteral obstruction (UUO) with location in proximal tubules and tubulointerstitial fibroblasts. Pharmacological inhibition, genetic silencing or knockout of Plk1 attenuated obstructive nephropathy due to suppressed fibroblast activation mediated by reduced autophagic flux. We found Plk1 plays a critical role in maintaining intralysosomal pH by regulating ATP6V1A phosphorylation, and inhibition of Plk1 impaired lysosomal function leading to blockade of autophagic flux. In addition, Plk1 also prevented partial epithelial-mesenchymal transition (pEMT) of tubular epithelial cells via autophagy pathway. In conclusion, this study demonstrated that Plk1 plays a pathogenic role in renal tubulointerstitial fibrosis by regulating autophagy/lysosome axis. Thus, targeting Plk1 could be a promising strategy for CKD treatment.

Diagnostic yield and novel candidate genes for neurodevelopmental disorders by exome sequencing in an unselected cohort with microcephaly.

OBJECTIVES: Microcephaly is caused by reduced brain volume and most usually associated with a variety of neurodevelopmental disorders (NDDs). To provide an overview of the diagnostic yield of whole exome sequencing (WES) and promote novel candidates in genetically unsolved families, we studied the clinical and genetic landscape of an unselected Chinese cohort of patients with microcephaly. METHODS: We performed WES in an unselected cohort of 103 NDDs patients with microcephaly as one of the features. Full evaluation of potential novel candidate genes was applied in genetically undiagnosed families. Functional validations of selected variants were conducted in cultured cells. To augment the discovery of novel candidates, we queried our genomic sequencing data repository for additional likely disease-causing variants in the identified candidate genes. RESULTS: In 65 families (63.1%), causative sequence variants (SVs) and clinically relevant copy number variants (CNVs) with a pathogenic or likely pathogenic (P/LP) level were identified. By incorporating coverage analysis to WES, a pathogenic or likely pathogenic CNV was detected in 15 families (16/103, 15.5%). In another eight families (8/103, 7.8%), we identified variants in newly reported gene (CCND2) and potential novel neurodevelopmental disorders /microcephaly candidate genes, which involved in cell cycle and division (PWP2, CCND2), CDC42/RAC signaling related actin cytoskeletal organization (DOCK9, RHOF), neurogenesis (ELAVL3, PPP1R9B, KCNH3) and transcription regulation (IRF2BP1). By looking into our data repository of 5066 families with NDDs, we identified additional two cases with variants in DOCK9 and PPP1R9B, respectively. CONCLUSION: Our results expand the morbid genome of monogenic neurodevelopmental disorders and support the adoption of WES as a first-tier test for individuals with microcephaly.

TRAF1 improves cisplatin-induced acute kidney injury via inhibition of inflammation and metabolic disorders.

BACKGROUND: Cisplatin-induced acute kidney injury (AKI) is a severe clinical complication with no satisfactory therapies in the clinic. Tumor necrosis factor receptor (TNFR)-associated factor 1 (TRAF1) plays a vital role in both inflammation and metabolism. However, the TRAF1 effect in cisplatin induced AKI needs to be evaluated. METHODS: We observed the role of TRAF1 in eight-week-old male mice and mouse proximal tubular cells both treated with cisplatin by examining the indicators associated with kidney injury, apoptosis, inflammation, and metabolism. RESULTS: TRAF1 expression was decreased in cisplatin-treated mice and mouse proximal tubular cells (mPTCs), suggesting a potential role of TRAF1 in cisplatin-associated kidney injury. TRAF1 overexpression significantly alleviated cisplatin-triggered AKI and renal tubular injury, as demonstrated by reduced serum creatinine (Scr) and urea nitrogen (BUN) levels, as well as the ameliorated histological damage and inhibited upregulation of NGAL and KIM-1. Moreover, the NF-κB activation and inflammatory cytokine production enhanced by cisplatin were significantly blunted by TRAF1. Meanwhile, the increased number of apoptotic cells and enhanced expression of BAX and cleaved Caspase-3 were markedly decreased by TRAF1 overexpression both in vivo and vitro. Additionally, a significant correction of the metabolic disturbance, including perturbations in energy generation and lipid and amino acid metabolism, was observed in the cisplatin-treated mice kidneys. CONCLUSION: TRAF1 overexpression obviously attenuated cisplatin-induced nephrotoxicity, possibly by correcting the impaired metabolism, inhibiting inflammation, and blocking apoptosis in renal tubular cells. GENERAL SIGNIFICANCE: These observations emphasize the novel mechanisms associated to metabolism and inflammation of TRAF1 in cisplatin-induced kidney injury.

TP53RK Drives the Progression of Chronic Kidney Disease by Phosphorylating Birc5.

Renal fibrosis is a common characteristic of various chronic kidney diseases (CKDs) driving the loss of renal function. During this pathological process, persistent injury to renal tubular epithelial cells and activation of fibroblasts chiefly determine the extent of renal fibrosis. In this study, the role of tumor protein 53 regulating kinase (TP53RK) in the pathogenesis of renal fibrosis and its underlying mechanisms is investigated. TP53RK is upregulated in fibrotic human and animal kidneys with a positive correlation to kidney dysfunction and fibrotic markers. Interestingly, specific deletion of TP53RK either in renal tubule or in fibroblasts in mice can mitigate renal fibrosis in CKD models. Mechanistic investigations reveal that TP53RK phosphorylates baculoviral IAP repeat containing 5 (Birc5) and facilitates its nuclear translocation; enhanced Birc5 displays a profibrotic effect possibly via activating PI3K/Akt and MAPK pathways. Moreover, pharmacologically inhibiting TP53RK and Birc5 using fusidic acid (an FDA-approved antibiotic) and YM-155(currently in clinical phase 2 trials) respectively both ameliorate kidney fibrosis. These findings demonstrate that activated TP53RK/Birc5 signaling in renal tubular cells and fibroblasts alters cellular phenotypes and drives CKD progression. A genetic or pharmacological blockade of this axis serves as a potential strategy for treating CKDs.

Metabolic reprogramming of renal epithelial cells contributes to lithium-induced nephrogenic diabetes insipidus.

Lithium, mainstay treatment for bipolar disorder, frequently causes nephrogenic diabetes insipidus (NDI) and renal injury. However, the detailed mechanism remains unclear. Here we used the analysis of metabolomics and transcriptomics and metabolic intervention in a lithium-induced NDI model. Mice were treated with lithium chloride (40 mmol/kg chow) and rotenone (ROT, 100 ppm) in diet for 28 days. Transmission electron microscopy showed extensive mitochondrial structural abnormalities in whole nephron. ROT treatment markedly ameliorated lithium-induced NDI and mitochondrial structural abnormalities. Moreover, ROT attenuated the decrease of mitochondrial membrane potential in line with the upregulation of mitochondrial genes in kidney. Metabolomics and transcriptomics data demonstrated that lithium activated galactose metabolism, glycolysis, and amino sugar and nucleotide sugar metabolism. All these events were indicative of metabolic reprogramming in kidney cells. Importantly, ROT ameliorated metabolic reprogramming in NDI model. Based on transcriptomics analysis, we also found the activation of MAPK, mTOR and PI3K-Akt signaling pathways and impaired focal adhesion, ECM-receptor interaction and actin cytoskeleton in Li-NDI model were inhibited or attenuated by ROT treatment. Meanwhile, ROT administration inhibited the increase of Reactive Oxygen Species (ROS) in NDI kidneys along with enhanced SOD2 expression. Finally, we observed that ROT partially restored the reduced AQP2 and enhanced urinary sodium excretion along with the blockade of increased PGE2 output. Taken together, the current study demonstrates that mitochondrial abnormalities and metabolic reprogramming play a key role in lithium-induced NDI, as well as the dysregulated signaling pathways, thereby serving as a novel therapeutic target.

Role of cuproptosis in understanding diseases.

Cell death is involved in a wide range of physiological and pathological processes. Recently, the term "cuproptosis" was coined to describe a novel type of cell death. This type of cell death, characterized by copper accumulation and proteotoxic stress, is a copper-dependent manner of death. Despite the progress achieved toward a better understanding of cuproptosis, mechanisms and related signaling pathways in physiology and pathology across various diseases remain to be proved. This mini review summarizes current research on cuproptosis and diseases, providing insights into prospective clinical therapies via targeting cuproptosis.

Roles of DNA damage in renal tubular epithelial cells injury.

The prevalence of renal diseases including acute kidney injury (AKI) and chronic kidney disease (CKD) is increasing worldwide. However, the pathogenesis of most renal diseases is still unclear and effective treatments are still lacking. DNA damage and the related DNA damage response (DDR) have been confirmed as common pathogenesis of acute kidney injury and chronic kidney disease. Reactive oxygen species (ROS) induced DNA damage is one of the most common types of DNA damage involved in the pathogenesis of acute kidney injury and chronic kidney disease. In recent years, several developments have been made in the field of DNA damage. Herein, we review the roles and developments of DNA damage and DNA damage response in renal tubular epithelial cell injury in acute kidney injury and chronic kidney disease. In this review, we conclude that focusing on DNA damage and DNA damage response may provide valuable diagnostic biomarkers and treatment strategies for renal diseases including acute kidney injury and chronic kidney disease.

Compound heterozygous variants in WLS gene causes Zaki syndrome.

Biallelic Wnt ligand secretion mediator (WLS gene) variants are associated with Zaki syndrome (OMIM: #619648). Here, we report the first case with Zaki syndrome in the Chinese population. Whole-exome gene sequencing (WES) identified compound heterozygous variants in the WLS gene (c.1427A > G; p.Tyr476Cys and c.415C > T, p.Arg139Cys; NM_001002292) in a 16-year-old boy presenting with facial dysmorphism, astigmatism, renal agenesis, and cryptorchidism. In vitro functional characterization showed that the two variants led to decreased WLS production and secretion of WNT3A, eventually affecting the WNT signal. We also found that the decreased mutant WLS expression can be rescued by 4-Phenylbutyric acid (4-PBA).

Reduction of NADPH oxidase 4 in adipocytes contributes to the anti-obesity effect of dihydroartemisinin.

Artemisinin derivatives have been found to have anti-obesity effects recently, but the mechanism is still controversial. Herein, long-term DHA treatment in obese mice significantly reduced the body weight and improved glucose metabolism. However, short-term DHA treatment did not affect glucose metabolism in obese mice, suggesting that the improved glucose metabolism in mice with DHA treatment could be secondary to body weight reduction. Consistent with previous reports, we observed that DHA inhibited the differentiation of adipocytes. Mechanistically, DHA significantly reduced the expression of NADPH oxidase 4 (NOX4) in white adipose tissue (WAT) of mice and differentiated adipocytes, and using NOX4 siRNA or the NOX4 inhibitor GKT137831 significantly attenuated adipocyte differentiation. Over-expression of NOX4 partially reversed the inhibition effect of DHA on adipogenic differentiation of preadipocytes. In addition, targeted proteomics analysis showed that DHA improved the abnormality of metabolic pathways. In conclusion, DHA significantly reduced fat mass and improved glucose metabolism in obese mice, possibly by inhibiting NOX4 expression to suppress adipocyte differentiation and lipid accumulation in adipocytes.