Ablation of myeloid discoidin domain receptor 2 exacerbates arthritis and high fat diet induced inflammation.

Chronic systemic inflammation leads to sever disorders and diseases. It is of great importance to explore novel target for effective treatment. Discoidin domain receptor 2 (Ddr2) is a member of receptor tyrosine kinase (RTK) family and is implicated in skeletal and fat hemostasis. However, the role of Ddr2 in myeloid cells remains obscure. In this study, we conditionally deleted Ddr2 in myeloid lineage cells to generate cKO mice to investigate the role of Ddr2 in myeloid lineage cells. We found that cKO mice exhibited more severe inflammation both in collagen antibody-induced arthritis (CAIA) and high-fat diet (HFD)-induced obesity, indicating the protective role of Ddr2 against inflammation. Mechanistically, Ddr2 promotes macrophage repolarization from the M1 to M2 phenotype, and protect against systemic inflammation. Our study reveals for the first time that Ddr2 modulates macrophage repolarization and plays critical roles in macrophage-mediated inflammation, providing potential target for the intervention of inflammation and related diseases.

Prolonged ST segment and T-wave alternans with torsade de pointes secondary to hypocalcemia due to hypoparathyroidism: A case report.

Hypoparathyroidism predisposes patients to hypocalcemia. Patients with hypoparathyroidism are thus at risk of electrocardiographic abnormalities, including T-wave alternans. T-wave alternans is poorly understood and lacks uniform diagnostic criteria. Its presence suggests myocardial electrical instability, and it has become an important sign for identifying patients at high risk of malignant arrhythmias and sudden cardiac death. We report a rare case of T-wave alternans with torsade de pointes due to hypocalcemia. The etiology of T-wave alternans may easily be overlooked. It should thus be thoroughly investigated to avoid misdiagnosis and poor outcomes.

Non-diabetic ketoacidosis: A case of alcoholic ketoacidosis accompanied by hyperglycemia.

Alcoholic ketoacidosis (AKA) lacks specific clinical presentation. The results of blood testing commonly show hemoconcentration, elevated ß-hydroxybutyrate levels, and acidosis in patients with AKA. Herein, we report a case of AKA accompanied by hyperglycemia and review the related literature. Case report: AKA associated with hyperglycemia is rare, and its pathogenesis is similar to that of diabetic ketoacidosis, thereby making differentiation challenging. Accordingly, AKA is easily misdiagnosed by endocrinologists. The main symptoms of a 37-year-old female included hyperglycemia, elevated ß-hydroxybutyrate levels, and metabolic acidosis. Primary clinical presentations were severe nausea and vomiting. The patient initially diagnosed with DKA were eventually confirmed as AKA, who recovered after active therapy with rehydration and correction of hyperglycemia, electrolyte imbalance, and ketosis. This study provides a reference for clinicians to reduce missed diagnosis and the misdiagnosis rates of AKA.

MicroRNAs in IgA nephropathy.

IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. It is considered that the pathogenesis of IgAN involves the 'multiple hit theory' and the immune-inflammatory mechanism; however, these theories have certain limitations. The gold standard for diagnosing IgAN is still renal biopsy. Although renal biopsy is accurate, it is traumatic and is associated with some risks and limitations, so there is a need for non-invasive diagnostic methods. According to recent studies, microRNAs (miRNAs) play important roles in the occurrence and development of IgAN; thus, they provide the possibility of the noninvasive diagnosis of IgAN and also have some value in predicting prognosis. This review summarizes the current research status of miRNAs in the occurrence, development, diagnosis, and prognosis of IgAN. We also highlight some interesting and challenging points that require further study.

Mechanistic and therapeutic links between rheumatoid arthritis and diabetes mellitus.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent synovial inflammation and irreversible cartilage and bone damage. Despite its predominant osteoarticular and periarticular manifestations, RA is also a systematic disease associated with organ-specific extra-articular manifestation. Increasing evidence indicates that RA patients are susceptible to diabetes mellitus (DM), and RA aggravates metabolic disordered in DM, indicating the close association between RA and DM. Many factors involved in RA stimulate insulin resistance and DM development. These factors include proinflammatory cytokines (such as TNF-α, IL-6, IL-1ß), RA autoantibodies (such as rheumatoid factor, cyclic citrullinated peptide antibodies), excess RA related adipokines (such as leptin, resistin, ANGPTL4), C-creative protein, and other protein (such as TXNDC5, NLRP3, RBP4). Furthermore, commonly used RA drugs, such as conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), biological disease-modifying antirheumatic drugs (bDMARDs), and glucocorticoids, provide potential benefits in improving insulin resistance and inhibiting DM development. This review discusses the mechanistic and therapeutic links between RA and DM, aiming to provide valuable information for the prevention and treatment of DM in RA patients.

Targeting adipocytic discoidin domain receptor 2 impedes fat gain while increasing bone mass.

Obesity is closely associated with low-bone-mass disorder. Discoidin domain receptor 2 (DDR2) plays essential roles in skeletal metabolism, and is probably involved in fat metabolism. To test the potential role of DDR2 in fat and fat-bone crosstalk, Ddr2 conditional knockout mice (Ddr2Adipo) were generated in which Ddr2 gene is exclusively deleted in adipocytes by Adipoq Cre. We found that Ddr2Adipo mice are protected from fat gain on high-fat diet, with significantly decreased adipocyte size. Ddr2Adipo mice exhibit significantly increased bone mass and mechanical properties, with enhanced osteoblastogenesis and osteoclastogenesis. Marrow adipocyte is diminished in the bone marrow of Ddr2Adipo mice, due to activation of lipolysis. Fatty acid in the bone marrow was reduced in Ddr2Adipo mice. RNA-Seq analysis identified adenylate cyclase 5 (Adcy5) as downstream molecule of Ddr2. Mechanically, adipocytic Ddr2 modulates Adcy5-cAMP-PKA signaling, and Ddr2 deficiency stimulates lipolysis and supplies fatty acid for oxidation in osteoblasts, leading to the enhanced osteoblast differentiation and bone mass. Treatment of Adcy5 specific inhibitor abolishes the increased bone mass gain in Ddr2Adipo mice. These observations establish, for the first time, that Ddr2 plays an essential role in the crosstalk between fat and bone. Targeting adipocytic Ddr2 may be a potential strategy for treating obesity and pathological bone loss simultaneously.

Tacrolimus treatment after short-term intravenous methylprednisolone in incipient minimal change disease for adults: A retrospective analysis.

The present study aimed to investigate the efficacy and safety of tacrolimus for treating incipient minimal change disease in adults. The clinical data of 52 adult patients with minimal change disease of nephrotic syndrome diagnosed by renal biopsy in the First affiliated hospital of Zhengzhou University between August 2013 and August 2015 were retrospectively analyzed. According to the treatment plan, the patients were divided into a tacrolimus group and a glucocorticoid group. The efficacy and safety of tacrolimus in the treatment of minimal change disease in adult patients was analyzed and compared with that of glucocorticoids. The results revealed that the baseline characteristics of the two groups were similar (P>0.05). At 24 weeks, there was a significant difference in serum albumin between the two groups (P<0.01). The serum albumin levels of tacrolimus group was higher compared with the glucocorticoid group. In addition, the complete remission rates in the tacrolimus and glucocorticoid groups were 93.75 and 77.8%, respectively (P=0.095), and the mean complete remission time was 6.33±4.21 and 5.14±2.45 weeks, respectively (P=0.175). The relapse rate was 12.5 and 22.2% in the tacrolimus and glucocorticoid groups, respectively (P=0.368). During the follow-up, in tacrolimus group, the incidence of new onset diabetes or impaired glucose tolerance, osteoporosis, infection, abnormal liver function, Cushing's syndrome, acne and gastrointestinal symptoms were significantly less than those of glucocorticoids (P<0.05). In conclusion, tacrolimus treatment after short-time intravenous methylprednisolone is an effective treatment option with fewer adverse effects in adult onset minimal change disease.

Elevated Serum Chloride Levels Contribute to a Poor Prognosis in Patients with IgA Nephropathy.

INTRODUCTION: The identification of reliable prognostic factors is a crucial requirement for patients with IgA nephropathy (IgAN). Here, we explored the relationship between serum chloride levels and prognosis in patients with IgAN. METHODS: We recruited all patients with primary IgAN, as diagnosed by renal biopsy, between 1st January 2015 and 1st April 2019. Patients were divided two groups (high chloride group and low chloride group) based on the best cut-off values from survival receiver operating characteristic (ROC) curves. The baseline clinicopathological characteristics of two groups were then compared. Cox proportional hazard models were used to determine the prognostic value of serum chloride levels in patients with IgAN. Finally, we screened reliable prognostic indicators and built a clinical prediction model and validated the performance of the model. RESULTS: Compared with patients in the high chloride group, patients in the low chloride group had significantly lower levels of 24-hour urinary total protein (24 h-UTP), serum creatinine (sCr), and higher levels of hemoglobin (Hb), albumin (all p < 0.05), and less proportion of Oxford classification grade E1 (endothelial cell proliferation) and T2 (renal tubule atrophy or renal interstitial fibrosis). Cox analysis revealed that serum chloride level ≥ 105.4 mmol/L was a significant and independent risk factor for prognosis in patients with IgAN (p < 0.05). Serum chloride, sCr, T, hypertension, and Hb were used to generate a predictive model for prognosis. Thec-indices of our predictive model were 0.80, 0.86, and 0.78, for 1, 2, and 3 years, respectively; Brier scores were 0.06, 0.09, and 0.16, respectively. CONCLUSIONS: A serum chloride level ≥ 105.4 mmol/l was identified as a significant and independent risk factor for the prognosis of patients with IgAN. A predictive prognosis model was generated using serum chloride, sCr, T, hypertension, and Hb; this model exhibited a good predictive effect.

The soluble VEGF receptor sFlt-1 contributes to endothelial dysfunction in IgA nephropathy.

Endothelial injury is a common manifestation in IgA nephropathy (IgAN). After the previous identification of the upregulated soluble fms-like tyrosine kinase-1 (sFlt-1) correlated with endothelial injury in IgAN, in the present study, we further explored the role of sFlt-1 in endothelial injury in IgAN. We enrolled 72 patients with IgAN and detected the sFlt-1 levels. The polymeric IgA1 (pIgA1) complexes were isolated from the pooled plasma samples of another 10 patients with IgAN. Apoptosis proteins were detected in cultured human umbilical vein endothelial cells (HUVECs) with the stimulation of recombinant sFlt-1 or the caspase-9 inhibitor Z-LEHD-FMK. We identified there were positive correlations between sFlt-1 and IgA-IgG complex as well as vWF levels in patients with IgAN. The sFlt-1 levels in HUVECs were significantly upregulated by pIgA1 complex derived from IgAN patients in a concentration-dependent manner. The proliferation ability of HUVECs was damaged when stimulated with sFlt-1 protein in a time- and dose- dependent manner. And the apoptosis rate was up-regulated significantly as the stimulation concentrations of sFlt-1 increased. We found sFlt-1 challenge could significantly increase the expression of vWF. In addition, sFlt-1 increased the levels of caspase-9, caspase-3, Bax and mitochondrial membrane potential; facilitated the release of cytochrome C from mitochondria to cytoplasma. In contrast, Z-LEHD-FMK attenuated high sFlt-1-induced HUVECs apoptosis. In conclusion, our study demonstrated that sFlt-1 expression was up-regulated by the challenge of pIgA1 complex derived from patients with IgAN. Furthermore, increased sFlt-1 facilitated human umbilical vein endothelial cells apoptosis via the mitochondrial-dependent pathway.