We aimed to comprehensively explore the etiology of granulomatous lobular mastitis (GLM) to optimize treatment programs. We collected 30 fresh mastitis samples for metagenomic next-generation sequencing, morphological observation, and analysis of the clinical information. 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. 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.

Granulomatous lobular mastitis (GLM) is a rare inflammatory disease of the breast that clinically mimics breast cancer. However, its etiology is not completely defined. The purpose of this study was to systematically study the bacteriology of GLM using advanced detection technology. Paraffin-embedded tissue from patients with GLM was collected. DNA was extracted from the samples and analyzed using next-generation sequencing (NGS) technology, and the data were processed using bioinformatics analyses. A total of 40 patients were recruited into the study. A bioinformatics analysis revealed that a total of 17 genera or 19 species of pathogens were present in 39 of the GLM patients (97.5%). These included bacteria, fungi, and Mycobacterium tuberculosis complex group. Bacteria were found in 39 of the patient cases, while fungi were present in five. Only one case tested positive for M. tuberculosis complex. In addition, a single genus of pathogen was found in nine patients (23.1%), whereas 30 patients (76.9%) tested positive for multiple pathogens. This study profiled the microbiota of patients with GLM using NGS technology, which provides more useful information for establishing patient treatment plans.

Background: Breast phyllodes tumours (PTs) are a unique type of fibroepithelial neoplasms with metastatic potential and recurrence tendency. However, the precise nature of heterogeneity in breast PTs remains poorly understood. This study aimed to elucidate the cell subpopulations composition and spatial structure and investigate diagnostic markers in the pathogenesis of PTs.Methods: We applied single‐cell RNA sequencing and spatial transcriptomes on tumours and adjacent normal tissues for integration analysis. Immunofluorescence experiments were conducted to verify the tissue distribution of cells. Tumour cells from patients with PTs were cultured to validate the function of genes. To validate the heterogeneity, the epithelial and stromal components of tumour tissues were separated using laser capture microdissection, and microproteomics data were obtained using data‐independent acquisition mass spectrometry. The diagnostic value of genes was assessed using immunohistochemistry staining.Results: Tumour stromal cells harboured seven subpopulations. Among them, a population of widely distributed cancer‐associated fibroblast‐like stroma cells exhibited strong communications with epithelial progenitors which underwent a mesenchymal transition. We identified two stromal subpopulations sharing epithelial progenitors and mesenchymal markers. They were inferred to further differentiate into transcriptionally active stromal subpopulations continuously expressing COL4A1/2. The binding of COL4A1/2 with ITGA1/B1 facilitated a growth pattern from the stroma towards the surrounding glands. Furthermore, we found consistent transcriptional changes between intratumoural heterogeneity and inter‐patient heterogeneity by performing microproteomics studies on 30 samples from 11 PTs. The immunohistochemical assessment of 97 independent cohorts identified that COL4A1/2 and CSRP1 could aid in accurate diagnosis and grading.Conclusions: Our study demonstrates that COL4A1/2 shapes the spatial structure of stromal cell differentiation and has important clinical implications for accurate diagnosis of breast PTs.

The kidney is a high-energy demand organ rich in mitochondria especially renal tubular cells. Emerging evidence suggests that mitochondrial dysfunction, redox imbalance and kidney injury are interconnected. Artemether has biological effects by targeting mitochondria and exhibits potential therapeutic value for kidney disease. However, the underlying molecular mechanisms have not been fully elucidated. This study was performed to determine the effects of artemether on Adriamycin-induced nephropathy and the potential mechanisms were also investigated. In vivo, an Adriamycin nephropathy mouse model was established, and mice were treated with or without artemether for 2 weeks. In vitro, NRK-52E cells were stimulated with TGF-β1 and treated with or without artemether for 24 h. Then renal damage and cell changes were evaluated. The results demonstrated that artemether reduced urinary protein excretion, recovered podocyte alterations, attenuated pathological changes and alleviated renal tubular injury. Artemether also downregulated TGF-β1 mRNA expression levels, inhibited tubular proliferation, restored tubular cell phenotypes and suppressed proliferation-related signalling pathways. In addition, artemether restored renal redox imbalance, increased mtDNA copy number and improved mitochondrial function. In summary, we provided initial evidence that artemether ameliorates kidney injury by restoring redox imbalance and improving mitochondrial function in Adriamycin nephropathy in mice. Artemether may be a promising agent for the treatment kidney disease.