Successful immunosuppressant-free treatment of a drug-induced sarcoidosis-like reaction caused by dupilumab.

We present a case of a drug-induced sarcoidosis-like reaction (DISR) in a 34-year-old female patient who had been receiving dupilumab for eosinophilic rhinosinusitis, for seven months. Computerized tomography scans revealed multiple lymphadenopathies, and biopsies performed on the lung and skin lesions showed the presence of non-caseating granulomas. The patient's serum levels of soluble interleukin-2 receptor and angiotensin-converting enzyme were elevated. There were no findings of Mycobacterium spp, or any other bacterial infections. Based on these findings, it was suspected that the sarcoidosis-like reaction observed in this patient was caused by dupilumab. Switching the patient's treatment from dupilumab to mepolizumab improved the DISR.

The termination of UHRF1-dependent PAF15 ubiquitin signaling is regulated by USP7 and ATAD5.

UHRF1-dependent ubiquitin signaling plays an integral role in the regulation of maintenance DNA methylation. UHRF1 catalyzes transient dual mono-ubiquitylation of PAF15 (PAF15Ub2), which regulates the localization and activation of DNMT1 at DNA methylation sites during DNA replication. Although the initiation of UHRF1-mediated PAF15 ubiquitin signaling has been relatively well characterized, the mechanisms underlying its termination and how they are coordinated with the completion of maintenance DNA methylation have not yet been clarified. This study shows that deubiquitylation by USP7 and unloading by ATAD5 (ELG1 in yeast) are pivotal processes for the removal of PAF15 from chromatin. On replicating chromatin, USP7 specifically interacts with PAF15Ub2 in a complex with DNMT1. USP7 depletion or inhibition of the interaction between USP7 and PAF15 results in abnormal accumulation of PAF15Ub2 on chromatin. Furthermore, we also find that the non-ubiquitylated form of PAF15 (PAF15Ub0) is removed from chromatin in an ATAD5-dependent manner. PAF15Ub2 was retained at high levels on chromatin when the catalytic activity of DNMT1 was inhibited, suggesting that the completion of maintenance DNA methylation is essential for the termination of UHRF1-mediated ubiquitin signaling. This finding provides a molecular understanding of how the maintenance DNA methylation machinery is disassembled at the end of the S phase.

Acute respiratory failure due to Aspergillus niger infection with acute fibrinous and organazing pneumonia: A case report.

A 59-year-old woman complaining of wet cough, hemoptysis, slight fever, anorexia, and malaise was admitted to hospital with suspected lobar pneumonia. She received treatment for myocardial infarction and deep venous thrombosis caused by familial protein C deficiency. Rapid deterioration due to respiratory failure occurred despite intensive care with broad-spectrum antibiotics. At a later date, sputum examination revealed the presence of Aspergillus niger. Based on clinical and autopsy findings, she was diagnosed with acute respiratory failure due to pulmonary aspergillosis with acute fibrinous and organizing pneumonia. This is the first reported case of pulmonary aspergillosis with acute fibrinous and organizing pneumonia complicated by calcium oxalate resulting from Aspergillus niger infection, leading to severe inflammation and tissue injury in the lungs.

Two cases of superior mesenteric artery syndrome during chemotherapy in patients with lung cancer.

Superior mesenteric artery (SMA) syndrome is a rare disease, characterized by the narrowing of the third portion of the duodenum between the aorta and SMA. The cause of the stenosis is a decrease in retroperitoneal fat between the aorta and SMA. In this report, we present two cases of SMA syndrome that occurred during chemotherapy for lung cancer. The first case was a 61-year-old male treated with nanoparticle albumin-bound-paclitaxel (nab-PTX) for lung adenocarcinoma. On day 23 of the first course of nab-PTX, he was admitted to our hospital due to vomiting and weight loss of 15.6 kg in 10 months. He was diagnosed with SMA syndrome through computed tomography, and drainage was performed using a nasogastric tube. Conservative treatment was successful, and the patient was able to continue therapy with nab-PTX. The second case was a 70-year-old male with epidermal growth factor receptor (EGFR) mutation-positive non-small cell lung cancer. He was admitted to our hospital due to vomiting and dizziness while receiving treatment with pembrolizumab, as well as weight loss of 14.6 kg in 6 months. He was diagnosed with SMA syndrome using computed tomography. Conservative treatment using a nasogastric tube led to improvement, and the patient was able to continue treatment with pembrolizumab after discharge. This is the first report of SMA syndrome in patients with lung cancer undergoing chemotherapy with nab-PTX or pembrolizumab. Late diagnosis and treatment render SMA syndrome a potentially fatal disease. Vomiting and weight loss during chemotherapy are known treatment-related side effects; in patients developing these adverse effects, the presence of SMA syndrome should be suspected and managed appropriately.

HPF1-dependent PARP activation promotes LIG3-XRCC1-mediated backup pathway of Okazaki fragment ligation.

DNA ligase 1 (LIG1) is known as the major DNA ligase responsible for Okazaki fragment joining. Recent studies have implicated LIG3 complexed with XRCC1 as an alternative player in Okazaki fragment joining in cases where LIG1 is not functional, although the underlying mechanisms are largely unknown. Here, using a cell-free system derived from Xenopus egg extracts, we demonstrated the essential role of PARP1-HPF1 in LIG3-dependent Okazaki fragment joining. We found that Okazaki fragments were eventually ligated even in the absence of LIG1, employing in its place LIG3-XRCC1, which was recruited onto chromatin. Concomitantly, LIG1 deficiency induces ADP-ribosylation of histone H3 in a PARP1-HPF1-dependent manner. The depletion of PARP1 or HPF1 resulted in a failure to recruit LIG3 onto chromatin and a subsequent failure in Okazaki fragment joining in LIG1-depleted extracts. Importantly, Okazaki fragments were not ligated at all when LIG1 and XRCC1 were co-depleted. Our results suggest that a unique form of ADP-ribosylation signaling promotes the recruitment of LIG3 on chromatin and its mediation of Okazaki fragment joining as a backup system for LIG1 perturbation.

Chronic high-fat feeding impairs adaptive induction of mitochondrial fatty acid combustion-associated proteins in brown adipose tissue of mice.

Since brown adipose tissue (BAT) is involved in thermogenesis using fatty acids as a fuel, BAT activation is a potential strategy for treating obesity and diabetes. However, whether BAT fatty acid combusting capacity is preserved in these conditions has remained unclear. We therefore evaluated expression levels of fatty acid oxidation-associated enzymes and uncoupling protein 1 (Ucp1) in BAT by western blot using a diet-induced obesity C57BL/6J mouse model. In C57BL/6J mice fed a high-fat diet (HFD) over 2-4 weeks, carnitine palmitoyltransferase 2 (Cpt2), acyl-CoA thioesterase (Acot) 2, Acot11 and Ucp1 levels were significantly increased compared with baseline and control low-fat diet (LFD)-fed mice. Similar results were obtained in other mouse strains, including ddY, ICR and KK-Ay, but the magnitudes of the increase in Ucp1 level were much smaller than in C57BL/6J mice, with decreased Acot11 levels after HFD-feeding. In C57BL/6J mice, increased levels of these mitochondrial proteins declined to near baseline levels after a longer-term HFD-feeding (20 weeks), concurrent with the accumulation of unilocular, large lipid droplets in brown adipocytes. Extramitochondrial Acot11 and acyl-CoA oxidase remained elevated. Treatment of mice with Wy-14,643 also increased these proteins, but was less effective than 4 week-HFD, suggesting that mechanisms other than peroxisome proliferator-activated receptor α were also involved in the upregulation. These results suggest that BAT enhances its fatty acid combusting capacity in response to fat overload, however profound obesity deprives BAT of the responsiveness to fat, possibly via mitochondrial alteration.