Palmitate induces reactive oxygen species production and β-cell dysfunction by activating nicotinamide adenine dinucleotide phosphate oxidase through Src signaling.

[Aims/Introduction]Chronic hyperlipidemia impairs pancreatic β-cell function, referred to as lipotoxicity. We have reported an important role of endogenous reactive oxygen species (ROS) overproduction by activation of Src, a non-receptor tyrosine kinase, in impaired glucose-induced insulin secretion (GIIS) from diabetic rat islets. In the present study, we investigated the role of ROS production by Src signaling in palmitate-induced dysfunction of β-cells. [Materials and Methods]After rat insulinoma INS-1D cells were exposed to 0.6 mmol/L palmitate for 24 h (palmitate exposure); GIIS, ROS production and nicotinamide adenine dinucleotide phosphate oxidase (NOX) activity were examined with or without exposure to10 μmol/L 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2), a Src inhibitior, for 30 or 60 min. [Results]Exposure to PP2 recovered impaired GIIS and decreased ROS overproduction as a result of palmitate exposure. Palmitate exposure increased activity of NOX and protein levels of NOX2, a pathological ROS source in β-cells. Palmitate exposure increased the protein level of p47phox, a regulatory protein of NOX2, in membrane fraction compared with control, which was reduced by PP2. Transfection of small interfering ribonucleic acid of p47phox suppressed the augmented p47phox protein level in membrane fraction, decreased augmented ROS production and increased impaired GΙIS by palmitate exposure. In addition, exposure to PP2 ameliorated impaired GIIS and decreased ROS production in isolated islets of KK-Ay mice, an obese diabetic model with hyperlipidemia. [Conclusions]Activation of NOX through Src signaling plays an important role in ROS overproduction and impaired GΙIS caused by chronic exposure to palmitate, suggesting a lipotoxic mechanism of β-cell dysfunction of obese mice

Normal development of the middle ear in the mouse: a light microscopic study of serial sections.

Development of the ear, especially the middle ear, was studied histologically in ddN and CF mice. Primordia of the 3 ossicles and the otic capsule appeared on day 12 of pregnancy. The stapedial primordium was observed as a mass of mesenchymal cells lateral to the primordium of the otic capsule, attaching to the medial part of the facial nerve. On day 13, the stapedial primordium continued to develop with the Reichert's cartilage. On day 14, the malleus and incus were differentiated. On day 15, the 3 ossicles were mostly completed in shape, and the stapedial footplate had a bilaminar structure at this stage. This structure appeared to correspond to the lamina stapedialis in the developing human stapes.</p

Fission yeast Srr1 and Skb1 promote isochromosome formation at the centromere

Rad51 maintains genome integrity, whereas Rad52 causes non-canonical homologous recombination leading to gross chromosomal rearrangements (GCRs). Here we find that fission yeast Srr1/Ber1 and Skb1/PRMT5 promote GCRs at centromeres. Genetic and physical analyses show that srr1 and skb1 mutations reduce isochromosome formation mediated by centromere inverted repeats. srr1 increases DNA damage sensitivity in rad51 cells but does not abolish checkpoint response, suggesting that Srr1 promotes Rad51-independent DNA repair. srr1 and rad52 additively, while skb1 and rad52 epistatically reduce GCRs. Unlike srr1 or rad52, skb1 does not increase damage sensitivity. Skb1 regulates cell morphology and cell cycle with Slf1 and Pom1, respectively, but neither Slf1 nor Pom1 causes GCRs. Mutating conserved residues in the arginine methyltransferase domain of Skb1 greatly reduces GCRs. These results suggest that, through arginine methylation, Skb1 forms aberrant DNA structures leading to Rad52-dependent GCRs. This study has uncovered roles for Srr1 and Skb1 in GCRs at centromeres.Mongia P., Toyofuku N., Pan Z., et al. Fission yeast Srr1 and Skb1 promote isochromosome formation at the centromere. Communications Biology 6, 551 (2023); https://doi.org/10.1038/s42003-023-04925-9

The clinical significance of 5% change in vital capacity in patients with idiopathic pulmonary fibrosis: extended analysis of the pirfenidone trial

<p>Abstract</p> <p>Background</p> <p>Our phase III clinical trial of pirfenidone for patients with idiopathic pulmonary fibrosis (IPF) revealed the efficacy in reducing the decline of vital capacity (VC) and increasing the progression-free survival (PFS) time by pirfenidone. Recently, marginal decline in forced VC (FVC) has been reported to be associated with poor outcome in IPF. We sought to evaluate the efficacy of pirfenidone from the aspects of 5% change in VC.</p> <p>Methods</p> <p>Improvement ratings based on 5% change in absolute VC, i.e., "improved (VC ≥ 5% increase)", "stable (VC < 5% change)", and "worsened (VC ≥ 5% decrease)" at month 3, 6, 9 and 12 were compared between high-dose pirfenidone (1800 mg/day; n = 108) and placebo (n = 104) groups, and (high-dose and low-dose (1200 mg/day; n = 55)) pirfenidone (n = 163) and placebo groups. PFS times with defining the disease progression as death or a ≥ 5% decline in VC were also compared between high-dose pirfenidone and placebo groups, and low-dose pirfenidone and placebo groups. Furthermore, considering "worsened" and "non-worsened (improved and stable)" of the ratings at months 3 and 12 as "positive" and "negative", respectively, and the positive and negative predictive values of the ratings were calculated in each group.</p> <p>Results</p> <p>In the comparison of the improvement ratings, the statistically significant differences were clearly revealed at months 3, 6, 9, and 12 between pirfenidone and placebo groups. Risk reductions by pirfenidone to placebo were approximately 35% over the study period. In the comparison of the PFS times, statistically significant difference was also observed between pirfenidone and placebo groups. The positive/negative predictive values in placebo and pirfenidone groups were 86.1%/50.8% and 87.1%/71.7%, respectively. Further, the baseline characteristics of patients worsened at month 3 had generally severe impairment, and their clinical outcomes including mortality were also significantly worsened after 1 year.</p> <p>Conclusions</p> <p>The efficacy of pirfenidone in Japanese phase III trial was supported by the rating of 5% decline in VC, and the VC changes at month 3 may be used as a prognostic factor of IPF.</p> <p>Trial Registration</p> <p>This clinical trial was registered with the Japan Pharmaceutical Information Center (JAPIC) on September 13^th, 2005 (Registration Number: JAPICCTI-050121).</p

Novel functional anti-HER3 monoclonal antibodies with potent anti-cancer effects on various human epithelial cancers

Resistance of progressive cancers against chemotherapy is a serious clinical problem. In this context, human epidermal growth factor receptor 3 (HER3) can play important roles in drug resistance to HER1- and HER2- targeted therapies. Since clinical testing of anti-HER3 monoclonal antibodies (mAbs) such as patritumab could not show remarkable effect compared with existing drugs, we generated novel mAbs against anti-HER3. Novel rat mAbs reacted with HEK293 cells expressing HER3, but not with cells expressing HER1, HER2 or HER4. Specificity of mAbs was substantiated by the loss of mAb binding with knockdown by siRNA and knockout of CRISPR/Cas9-based genome-editing. Analyses of CDR sequence and germline segment have revealed that seven mAbs are classified to four groups, and the binding of patritumab was inhibited by one of seven mAbs. Seven mAbs have shown reactivity with various human epithelial cancer cells, strong internalization activity of cell-surface HER3, and inhibition of NRG1 binding, NRG1-dependent HER3 phosphorylation and cell growth. Anti-HER3 mAbs were also reactive with in vivo tumor tissues and cancer tissue-originated spheroid. Ab4 inhibited in vivo tumor growth of human colon cancer cells in nude mice. Present mAbs may be superior to existing anti-HER3 mAbs and support existing anti-cancer therapeutic mAbs

Impact of Native Coronary Artery Calcification on Lesion Outcome Following Drug-Coated Balloon Angioplasty for Treatment of In-Stent Restenosis

This study aimed to clarify whether native coronary artery（CA） calcification before index percutaneous coronary intervention（PCI） has an impact on the effectiveness of drug-coated balloon（DCB） angioplasty for the treatment of in-stent restenosis（ISR）. 100consecutive patients with 166ISR lesions underwent quantitative coronary angiography（QCA） before and after index PCI and before and after DCB angioplasty for ISR. CA calcification before index PCI was assessed by angiography and results were analyzed to reveal the predictive values for target lesion revascularization（TLR） and major adverse cardiac events（MACE）. During 1.03±1.03years of follow-up, TLR occurred in 44lesions（26.5%） and MACE in 33 patients（33%）. On multivariate analysis, CA calcification before index PCI（p=0.016）, and % diameter of stenosis（%DS）≥73%（p=0.023） and minimal lumen diameter（MLD）<0.65mm（p=0.001） before DCB angioplasty were independent predictors for TLR after DCB angioplasty. MACE was also associated with CA calcification before index PCI（p=0.01）, and %DS≥73%（p=0.001） and MLD<0.65mm（p=0.01） before DCB angioplasty, but only %DS≥73% before DCB angioplasty was an independent predictor for MACE after DCB angioplasty（p=0.039）. The combination of CA calcification before index PCI and these QCA factors before DCB angioplasty was an independent and more powerful predictor for MACE than the QCA factors alone（p<0.001）. Thereafter, the combination of CA calcification and %DS≥73% before DCB angioplasty stratified the risk of MACE after DCB angioplasty（p<0.05）. CA calcification before index PCI, as well as anatomical information at ISR, have an impact on outcome after DCB angioplasty for ISR

Case-based similar image retrieval for weakly annotated large histopathological images of malignant lymphoma using deep metric learning

In the present study, we propose a novel case-based similar image retrieval (SIR) method for hematoxylin and eosin (H&E)-stained histopathological images of malignant lymphoma. When a whole slide image (WSI) is used as an input query, it is desirable to be able to retrieve similar cases by focusing on image patches in pathologically important regions such as tumor cells. To address this problem, we employ attention-based multiple instance learning, which enables us to focus on tumor-specific regions when the similarity between cases is computed. Moreover, we employ contrastive distance metric learning to incorporate immunohistochemical (IHC) staining patterns as useful supervised information for defining appropriate similarity between heterogeneous malignant lymphoma cases. In the experiment with 249 malignant lymphoma patients, we confirmed that the proposed method exhibited higher evaluation measures than the baseline case-based SIR methods. Furthermore, the subjective evaluation by pathologists revealed that our similarity measure using IHC staining patterns is appropriate for representing the similarity of H&E-stained tissue images for malignant lymphoma