Dynamic regulation of human endogenous retroviruses mediates factor-induced reprogramming and differentiation potential.

Pluripotency can be induced in somatic cells by overexpressing transcription factors, including POU class 5 homeobox 1 (OCT3/4), sex determining region Y-box 2 (SOX2), Kruppel-like factor 4 (KLF4), and myelocytomatosis oncogene (c-MYC). However, some induced pluripotent stem cells (iPSCs) exhibit defective differentiation and inappropriate maintenance of pluripotency features. Here we show that dynamic regulation of human endogenous retroviruses (HERVs) is important in the reprogramming process toward iPSCs, and in re-establishment of differentiation potential. During reprogramming, OCT3/4, SOX2, and KLF4 transiently hyperactivated LTR7s--the long-terminal repeats of HERV type-H (HERV-H)--to levels much higher than in embryonic stem cells by direct occupation of LTR7 sites genome-wide. Knocking down LTR7s or long intergenic non-protein coding RNA, regulator of reprogramming (lincRNA-RoR), a HERV-H-driven long noncoding RNA, early in reprogramming markedly reduced the efficiency of iPSC generation. KLF4 and LTR7 expression decreased to levels comparable with embryonic stem cells once reprogramming was complete, but failure to resuppress KLF4 and LTR7s resulted in defective differentiation. We also observed defective differentiation and LTR7 activation when iPSCs had forced expression of KLF4. However, when aberrantly expressed KLF4 or LTR7s were suppressed in defective iPSCs, normal differentiation was restored. Thus, a major mechanism by which OCT3/4, SOX2, and KLF4 promote human iPSC generation and reestablish potential for differentiation is by dynamically regulating HERV-H LTR7s

Clinical Features of Idiopathic Interstitial Pneumonia with Systemic Sclerosis-Related Autoantibody in Comparison with Interstitial Pneumonia with Systemic Sclerosis.

Patients with idiopathic interstitial pneumonias sometimes have a few features of connective tissue disease (CTD) and yet do not fulfil the diagnostic criteria for any specific CTD.This study was conducted to elucidate the characteristics, prognosis, and disease behavior in patients with interstitial lung disease (ILD) associated with systemic sclerosis (SSc)-related autoantibodies.We retrospectively analyzed medical records of 72 ILD patients: 40 patients with SSc (SSc-ILD) and 32 patients with SSc-related autoantibody-positive ILD but not with CTD (ScAb-ILD), indicating lung-dominant CTD with SSc-related autoantibody.Patients with SSc-ILD were predominantly females and non-smokers, and most had nonspecific interstitial pneumonia confirmed by high-resolution computed tomography (HRCT) and pathological analysis. However, about half of the patients with ScAb-ILD were male and current or ex-smokers. On HRCT analysis, honeycombing was more predominant in patients with ScAb-ILD than with SSc-ILD. Pathological analysis showed the severity of vascular intimal or medial thickening in the SSc-ILD patients to be significantly higher than that in the ScAb-ILD patients. Survival curves showed that the patients with ScAb-ILD had a significantly poorer outcome than those with SSc-ILD.Data from this study suggest that lung-dominant CTD with SSc-related autoantibody is a different disease entity from SSc-ILD

Association between serum ferritin level and decreased diffusion capacity 3 months after the onset of COVID-19 pneumonia.

BackgroundCoronavirus disease 2019 (COVID-19) pneumonia can have prolonged sequelae and lead to respiratory dysfunction, mainly because of impaired diffusion capacity for carbon monoxide (DLCO). The clinical factors associated with DLCO impairment, including blood biochemistry test parameters, remain unclear.MethodsPatients with COVID-19 pneumonia who underwent inpatient treatment between April 2020 and August 2021 were included in this study. A pulmonary function test was performed 3 months after onset, and the sequelae symptoms were investigated. Clinical factors, including blood test parameters and abnormal chest shadows on computed tomography, of COVID-19 pneumonia associated with DLCO impairment were investigated.ResultsIn total, 54 recovered patients participated in this study. Twenty-six patients (48%) and 12 patients (22%) had sequelae symptoms 2 and 3 months after, respectively. The main sequelae symptoms at 3 months were dyspnea and general malaise. Pulmonary function tests showed that 13 patients (24%) had both DLCO 686.5 ng/mL (odds ratio: 11.08, 95% confidence interval [CI]: 1.84-66.59; p = 0.009) was most strongly associated with DLCO impairment.ConclusionsDecreased DLCO was the most common respiratory function impairment, and ferritin level was a significantly associated clinical factor. Serum ferritin level could be used as a predictor of DLCO impairment in cases of COVID-19 pneumonia

Kaplan-Meier survival curves of all-cause mortality.

<p>Overall cumulative 5-year mortality was 24.4%. (A) Patients with ScAb-ILD (dotted line) had worse survival than those with SSc-ILD (dashed line) (p = 0.011). (B) In patients with ScAb-ILD, those with extensive disease (dashed line) had worse survival than those with limited disease (solid line) (p = 0.015). (C) In patients with SSc-ILD, those with KL-6 ≥ 1000 U/mL (dashed line) had worse survival than those with KL-6 < 1000 U/mL (solid line) (p = 0.049). (D) The survival curves for patients with each type of autoantibody were not significantly different (p = 0.905 for comparison between anti-scleroderma-70 and anti-U1 RNP antibody, p = 0.089 for comparison between anti-scleroderma-70 and anti-centromere antibody, and p = 0.137 for comparison between anti-U1 RNP and anti-centromere antibody).</p