circELP2 reverse-splicing biogenesis and function as a pro-fibrogenic factor by targeting mitochondrial quality control pathway.

Idiopathic pulmonary fibrosis (IPF) is considered as a chronic, fibrosing interstitial pneumonia with unknown mechanism. The present work aimed to explore the function, biogenesis and regulatory mechanism of circELP2 in pulmonary fibrosis and evaluate the value of blocking circELP2-medicated signal pathway for IPF treatment. The results showed that heterogeneous nuclear ribonucleoprotein L initiated reverse splicing of circELP2 resulting in the increase of circELP2 generation. The biogenetic circELP2 activated the abnormal proliferation and migration of fibroblast and extracellular matrix deposition to promote pulmonary fibrogenesis. Mechanistic studies demonstrated that cytoplasmic circELP2 sponged miR-630 to increase transcriptional co-activators Yes-associated protein 1 (YAP1) and transcriptional co-activator with PDZ-binding motif (TAZ). Then, YAP1/TAZ bound to the promoter regions of their target genes, such as mTOR, Raptor and mLST8, which in turn activated or inhibited the genes expression in mitochondrial quality control pathway. Finally, the overexpressed circELP2 and miR-630 mimic were packaged into adenovirus vector for spraying into the mice lung to evaluate therapeutic effect of blocking circELP2-miR-630-YAP1/TAZ-mitochondrial quality control pathway in vivo. In conclusion, blocking circELP2-medicated pathway can alleviate pulmonary fibrosis, and circELP2 may be a potential target to treat lung fibrosis.

A 37-Year-Old Man with Myofibroblast Sarcoma Combined with Pleural Maculopathy: Case Report.

Myofibroblastic sarcoma (MS) is a malignant tumor of soft tissue or bone that can occur in children or adults, with a high rate of recurrence and metastasis. We report a case of low-grade malignant MS of the left shoulder, diagnosed based on pathological examination and immunohistochemical staining. However, the patient had unexplained pleural maculopathy. The patient passed away 6 months after the diagnosis of myofibroblast sarcoma due to multiple metastases throughout the sarcoma. Combined with the patient's history, ancillary findings, and after MDT discussion, the patient was ultimately considered to have a high probability of myofibroblast sarcoma combined with pleural maculopathy. In conclusion, when a patient is diagnosed with myofibroblast sarcoma in combination with pleural macula, in the absence of other causative factors, a deep tissue biopsy of the pleura should be actively performed to confirm the diagnosis.

Malignant pleural mesothelioma with constrictive pericarditis as the first manifestation: A case report.

Pleural mesothelioma (PM) with pericardial involvement is extremely rare. We now report a rare case of malignant PM with constrictive pericarditis as the first presentation. A 59-year-old male diagnosed with constrictive pericarditis underwent pericardiectomy and pericardial pathology revealed mesothelial hyperplasia. Eight months after surgery, the patient was admitted to the hospital with chest tightness and wheezing for 5 days. Computed tomography scan of the chest showed a left lung expansion insufficiency, limited bilateral pleural thickening, pericardial thickening with a small amount of pericardial effusion, and multiple enlarged lymph nodes in the mediastinum, bilateral supraclavicular fossa, bilateral cervical roots, and right axilla. The pleural malignancy should be possibly considered. Pathology after pleural puncture showed malignant PM. Pathology after left supraclavicular lymph node puncture biopsy showed metastatic malignant mesothelioma. The diagnosis of this patient was clear. Although malignant PM rarely involves the pericardial constriction, we cannot ignore the fact that malignant PM involves the pericardium. The patient has been diagnosed with constrictive pericarditis, accompanied by pleural thickening and pleural effusion. Without other pathogenic factors, pleural biopsy should be aggressively performed in patients with constrictive pericarditis to determine the cause.