Collagen IV and Podocyte-Related Gene Variants in Patients with Concurrent IgA Nephropathy and Thin Basement Membrane Nephropathy.

INTRODUCTION: IgA nephropathy is the most common primary glomerulonephritis among adults in clinic. Thin basement membrane nephropathy is often underestimated or even omitted if it coincides with IgA nephropathy. Therefore, it is necessary to study the epidemiological, clinical, and molecular characteristics of the concurrence of this entity. METHODS: Eight patients with concurrent IgA nephropathy and thin basement membrane nephropathy (IgA-T) were retrospectively analyzed based on their clinicopathological characteristics. Genetic analysis was performed using whole-exome sequencing and Sanger's sequencing. Data of the patients with IgA nephropathy and normal basement membrane (IgA-N) and variants in the local in-house database were used as controls. All candidate variants were assessed in silico. RESULTS: The clinical manifestations of patients with IgA-T were hematuria, proteinuria, and renal insufficiency. Histopathological analysis showed mild mesangial hyperplasia, focal segmental glomerulosclerosis, podocyte activation, and foot process fusion. Crescent was rarely seen. COL4A and/or podocyte cytoskeleton and mitochondria-related gene variants were detected in seven IgA-T patients. Three patients exhibited pathogenic variants of COL4A, including a new variant. All IgA-T and one IgA-N patient possessed ITGB4 and/or PLEC variants, but there was no corresponding genotype-phenotype relationship. Six patients possessed other podocyte cytoskeleton and mitochondria-related gene variants such as NPHS2, SRGAP1, MYO1E, MYO1C, WT1, and COQ9, which were first reported in patients with IgA-T and were not in controls. Altogether, there were no significant differences in the degrees of proteinuria, serum creatinine, and eGFR during the follow-up period of 5-10 years, but there was a significant difference in the degree of proteinuria between IgA-T patients with podocyte-related gene variants and IgA-N patients. In the IgA-T group, patients with podocyte-related gene variants seemed predisposed to progress than patients without those variants, with higher proteinuria and serum creatinine and reduced eGFR. CONCLUSION: Concurrent thin basement membrane nephropathy and/or heterozygous COL4A gene pathogenic variants do not necessarily predict the short-term progress of sporadic IgA nephropathy in adults. Predisposition factors for this disease progression should be considered for detecting the variants of COL4A and podocyte cytoskeleton and mitochondria-related genes simultaneously, which also manifests the complexity and heterogeneity of IgA nephropathy with concurrent thin basement membrane nephropathy.

Etiology of granulomatous lobular mastitis based on metagenomic next-generation sequencing.

OBJECTIVES: We aimed to comprehensively explore the etiology of granulomatous lobular mastitis (GLM) to optimize treatment programs. METHODS: We collected 30 fresh mastitis samples for metagenomic next-generation sequencing, morphological observation, and analysis of the clinical information. RESULTS: Of the 30 samples, 25 were GLM; pathogens were detected in 17, these were: Corynebacterium kroppenstedtii (10 of 25, 40%); C. kroppenstedtii and Pseudomonas oleovorans (3 of 25, 12%); C. kroppenstedtii and human gammaherpesvirus 4 (1 of 25, 4%); Acinetobacter baumannii and C. kroppenstedtii (1 of 25, 4%); P. oleovorans (1 of 25, 4%); and Tepidiphilus thermophilus (1 of 25, 4%). Abnormal sex hormone levels (mainly prolactin) and/or autoimmune function were found in 12 of the 25 samples. Lipophilic antibiotics (rifampicin) were found to work effectively in patients with slow-healing wounds after surgery. CONCLUSIONS: The main pathogenic factor of GLM is C. kroppenstedtii infection, but other unusual pathogens (P. oleovorans, human gammaherpesvirus 4, A. baumannii, T. thermophilus) are likely to be closely related to GLM, particularly human gammaherpesvirus 4 (Epstein-Barr virus)-associated mastitis, which may be a new entity of mastitis. Abnormal levels of sex hormones and autoimmune function are also common causes. Therefore, lipophilic antibiotics (rifampicin) and prolactin inhibitors may be an effective treatment.

A Critical E-box in Barhl1 3' Enhancer Is Essential for Auditory Hair Cell Differentiation.

Barhl1, a mouse homologous gene of Drosophila BarH class homeobox genes, is highly expressed within the inner ear and crucial for the long-term maintenance of auditory hair cells that mediate hearing and balance, yet little is known about the molecular events underlying Barhl1 regulation and function in hair cells. In this study, through data mining and in vitro report assay, we firstly identified Barhl1 as a direct target gene of Atoh1 and one E-box (E3) in Barhl1 3' enhancer is crucial for Atoh1-mediated Barhl1 activation. Then we generated a mouse embryonic stem cell (mESC) line carrying disruptions on this E3 site E-box (CAGCTG) using CRISPR/Cas9 technology and this E3 mutated mESC line is further subjected to an efficient stepwise hair cell differentiation strategy in vitro. Disruptions on this E3 site caused dramatic loss of Barhl1 expression and significantly reduced the number of induced hair cell-like cells, while no affections on the differentiation toward early primitive ectoderm-like cells and otic progenitors. Finally, through RNA-seq profiling and gene ontology (GO) enrichment analysis, we found that this E3 box was indispensable for Barhl1 expression to maintain hair cell development and normal functions. We also compared the transcriptional profiles of induced cells from CDS mutated and E3 mutated mESCs, respectively, and got very consistent results except the Barhl1 transcript itself. These observations indicated that Atoh1-mediated Barhl1 expression could have important roles during auditory hair cell development. In brief, our findings delineate the detail molecular mechanism of Barhl1 expression regulation in auditory hair cell differentiation.