Fibroblast-derived exosomal miRNA-133 promotes cardiomyocyte-like differentiation.

OBJECTIVE: To investigate the role of exosomal miRNA-133 secreted by cardiac fibroblasts (CFs) in promoting cardiomyocyte differentiation. METHODS: Neonatal rat CFs were cultured in vitro, and the cultured CFs were divided into three groups as follows: induction, miRNA-133 high expression, and miRNA-133 inhibition. miRNA-133 was transfected into CFs with lentivirus as a vector. CFs were transfected with the miRNA-133 inhibitor, and the markers of cardiomyocyte were detected through immunofluorescence staining, Western blotting, and real-time quantitative polymerase chain reaction (qRT-PCR) at 3, 8, and 14 days, respectively. The expression levels of cardiac troponin T (cTnT) and cardiac actin (α-actin) were determined, and qRT-PCR was used to detect the expression of miRNA-133 in the fibroblast exosomes. RESULTS: CFs subjected to immunofluorescence staining expressed vimentin and discoid domain receptor 2. The exosomes secreted by CFs were observed as small vesicles of 30-100 nm via transmission electron microscopy, and Western blotting was used to detect exosome-specific protein CD63 and CD9 expression. The expression levels of cTnT, α-actin, and exosomal miRNA-133 secreted into the supernatant of the miRNA-133 high-expression group increased gradually at different time points and reached the highest level at 14 days. The expression levels of cTnT, α-actin, and exosome miRNA-133 in the miRNA-133 inhibition group were the lowest. CONCLUSION: The exosomal miRNA-133, which is derived from CFs, can promote the differentiation of fibroblasts into cardiomyocyte-like cells.

A case report of polyglandular syndrome induced by programmed death-1 inhibitor and literature review / 中华内分泌代谢杂志

We reported a case of polyglandular syndrome induced by programmed death-1(PD-1) inhibitors. The patient was a 51-years-old male with non-small cell lung cancer, treated with PD-1 inhibitor nivolumab/pembrolizumab because of postoperative subcarinal lymph node metastasis indicated by PET-CT. During 14 cycles of PD-1 inhibitor treatment, the patient successively developed primary hypothyroidism, and type 1 diabetes mellitus(T1DM). More than five months after the withdrawal of pembrolizumab, the patient experienced recurrentce. Laboratory examinations showed mild hyponatremia and hypopituitarism including ACTH and growth hormone(GH)/insulin-like growth factor-1(IGF-1) insufficiency. This is the first report of a patient diagnosed as polyglandular syndrome caused by PD-1 inhibitor. In particularly, the hypothyroidism and T1DM did not improve after drug withdrawal, while hypopituitarism was further aggravated. This case reminds us that we should pay more attention to the changes of endocrine function during and after the treatment of PD-1 inhibitor, so that we can make the correct diagnosis and take proper medical measures timely, to avoide missed diagnosis, and improper treatment.