DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Chinese herbal medicine Qing-Dai-induced pulmonary arterial hypertension in a patient with ulcerative colitis : A case report and experimental investigation

A recent case report described a case of pulmonary arterial hypertension (PAH) associated with use of the Chinese herbal medicine Qing-Dai; however, the clinical course and possible mechanisms have not been characterized. We present the case of a man with ulcerative colitis who was diagnosed with idiopathic PAH. After initiating oral beraprost therapy, the patient showed significant hemodynamic improvements and an unusual course of clinical recovery. In 2016, the Japanese Ministry of Health, Labour, and Welfare issued a warning regarding the possible side effects of Qing-Dai. We learned that our patient had been taking self-purchased Qing-Dai for 2 years. Therefore, we performed an experimental study and determined that Qing-Dai may cause PAH through a mechanism involving nitric oxide synthase inhibition and pulmonary artery endothelial dysfunction

Performance of computed tomography-derived pulmonary vasculature metrics in the diagnosis and haemodynamic assessment of pulmonary arterial hypertension

Background: Few studies have addressed the value of combining computed tomography-derived pulmonary vasculature metrics for the diagnosis and haemodynamic evaluation of pulmonary arterial hypertension (PAH). Materials and methods: We measured three computed tomography parameters for the pulmonary artery, peripheral vessels, and pulmonary veins: the ratio of the diameter of the pulmonary artery to the aorta (PA/Ao), the cross-sectional area of small pulmonary vessels <5 mm2 as a percentage of total lung area (%CSA<5), and the diameter of the right inferior pulmonary vein (PVD). The measured quantities were compared between patients with PAH (n = 45) and control subjects (n = 56), and their diagnostic performance and associations with PAH-related clinical indices, including right heart catheterization measurements, were examined. Results: PA/Ao and %CSA<5 were significantly higher in patients with PAH than in controls. Receiver-operating characteristic curve analysis for ability to diagnose PAH showed a high area under the curve (AUC) for PA/Ao (0.95) and modest AUCs for %CSA<5 (0.75) and PVD (0.56). PA/Ao correlated positively with mean pulmonary arterial pressure and PVD correlated negatively with pulmonary vascular resistance. The %CSA<5 correlated negatively with mean pulmonary arterial pressure and pulmonary vascular resistance and positively with cardiac index. Notably, the PA/Ao and PVD values divided by %CSA<5 correlated better with right heart catheterization indices than the non-divided values. Conclusion: PA/Ao, %CSA<5, and PVD are useful non-invasive pulmonary vasculature metrics, both alone and in combination, for diagnosis and haemodynamic assessment of PAH

The effects of pulmonary vasodilating agents on right ventricular parameters in severe group 3 pulmonary hypertension : a pilot study

Pulmonary arterial hypertension (PAH)-approved vasodilators improve right ventricular (RV) function in patients with PAH. However, whether PAH-approved drugs ameliorate RV morphology and function in lung disease-associated pulmonary hypertension (lung-PH) remains unclear. We aimed to prospectively evaluate the changes in RV volume and ejection fraction (RVEF) in 14 consecutive severe lung-PH patients treated with PAH-approved vasodilators. Severe lung-PH was defined as a mean pulmonary arterial pressure (MPAP) of ≥35 mmHg or an MPAP of ≥25 mmHg with a cardiac index (L/min/m2) of <2. Right heart catheterization and cardiac magnetic resonance (CMR) imaging were performed at baseline and at 3 months after starting sildenafil with or without other PAH-approved drugs. Follow-up was conducted at 3 months in 11 participants; compared with baseline values, MPAP and pulmonary vascular resistance (PVR) decreased by 18% and 37%, respectively. Baseline CMR imaging revealed an elevated RV end-diastolic volume index (RVEDVI; mL/m2) of 117.5 ± 35.9 and a below-average RVEF of 25.2% ± 7.2%; after 3 months, RVEDVI decreased by 23.7% (P = 0.0061) and RVEF increased by 32.9% (P = 0.0165). Among the 11 patients, 3 were thought to be a stable and homogenous subset in terms of background lung disease and medical management administered. These 3 patients exhibited similar ameliorations in PVR and RVEF, compared with the other 8 patients. PAH-approved drug treatment may improve RV dilatation and systolic function among patients with severe lung-PH. This study was approved by University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) on September 1, 2013 (UMIN000011541)

Various factors contribute to death in patients with different types of pulmonary hypertension : A retrospective pilot study from a single tertiary center

Background: A few studies have focused on the cause of death from different types of pulmonary hypertension (PH). This study aimed to systematically analyze the primary and secondary causes of death and compare the profiles between different PH groups. Methods: The contribution of PH to death was assessed in precapillary PH (i.e., group 1 [pulmonary arterial hypertension], group 3 [PH associated with lung disease], and group 4 [chronic thromboembolic PH]) using specific criteria; death was classified into three categories: PH death (death due to PH only), PH-related death, and PH-unrelated death. Disorders other than PH that contributed to death were analyzed, and mortality profiles were compared between groups. Results: Eighty deceased patients with PH were examined (group 1, n = 28; group 3, n = 39; and group 4, n = 13). The contribution of PH to death was significantly different between the three groups. PH death was most common in group 1 (61%), PH-related death in group 3 (56%), and PH-related death and PH-unrelated death in group 4 (38% for both). The highest contributing factor to death other than PH was respiratory failure in group 3 and malignant disease in group 4. Conclusions: Significant variations in the causes of death were observed in groups 1, 3, and 4 PH patients. In addition to PH, respiratory failure and malignant disease significantly contributed to death in group 3 and group 4 PH, respectively. Understanding the precise death cause may be important in achieving better outcomes in PH patients. (C) 2022 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved

Delayed contrast-enhanced computed tomography in patients with known or suspected cardiac sarcoidosis : A feasibility study

Objectives: To evaluate the diagnostic value of delayed contrast-enhanced computed tomography (DE-CT) for cardiac sarcoidosis (CS) in patients with or without implantable devices, including a quantitative comparison with late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Methods: Twenty-four patients (mean age, 64 ± 9 years; 17 women) with known or suspected CS underwent retrospective electrocardiogram-gated DE-CT at 80 kV with knowledge-based iterative model reconstruction. Fourteen patients without implantable devices also underwent LGE-CMR, while ten with pacemakers or implantable cardioverter-defibrillators did not. The presence of hyperenhanced myocardium was assessed visually and quantitatively using a 5-standard deviation threshold above the mean of remote myocardium. Results: Inter-observer agreement for visual detection of hyperenhanced segments on DE-CT was excellent in patients with implantable devices and in those without (κ = 0.91 and κ = 0.94, respectively). Comparisons of the percent area of hyperenhanced myocardium between DE-CT and LGE-CMR on both per-patient and per-segment analyses showed good correlations (r = 0.96 and r = 0.83, respectively; p < 0.001). The sensitivity and specificity of DE-CT for the diagnosis of CS were 94% and 33%. Conclusions: The extent of hyperenhanced lesion with DE-CT showed good agreement with LGE-CMR results. DE-CT showed high sensitivity for detecting CS and may be useful particularly in patients with contraindications to CMR

Metformin reduces circulating malondialdehyde-modified low-density lipoprotein in type 2 diabetes mellitus

Purpose: Type 2 diabetes is known to be associated with increasing cardiovascular mortality. Malondialdehyde-modified LDL (MDA-LDL) is an oxidized LDL and is increased in patients with diabetes or hypertriglyceridemia. Elevated MDA-LDL has been reported to be a risk factor of atherosclerosis or cardiovascular disease. Sitagliptin is a dipeptidyl peptidase-4 inhibitor and a new class of hypoglycemic agents. In this study, the effects of increasing the dose of metformin and add-on sitagliptin on MDA-LDL were examined in type 2 diabetes patients. Methods: Seventy patients with type 2 diabetes, inadequately controlled despite on-going treatment with metformin 500 mg/day, were enrolled in this randomized controlled trial. The patients received additional metformin (500 mg/day) or sitagliptin (50 mg/day) for 6 months, and changes in metabolic parameters including MDA-LDL were evaluated. Results: After 6 months of treatment, add-on sitagliptin (n=35) improved fasting blood glucose (FBG) and hemoglobin A1c (HbA1c) to significantly greater extent than increasing the dose of metformin (n=35). There were no differences in total cholesterol and low-density lipoprotein cholesterol levels between two groups. MDA-LDL levels (mean±S.E.) decreased significantly with increasing the dose of metformin (from 94.40±6.35 to 77.83±4.74 U/L, P 0.05). Multiple linear regression analysis identified increasing the dose of metformin treatment as the only independent factor associated with decreased MDA-LDL (β coefficient 0.367, P < 0.0119), and no significant correlation between change in MDA-LDL and fasting blood glucose or HbA1c. Conclusion: These results suggest that increasing the dose of metformin improves serum MDA-LDL levels in type 2 diabetes mellitus

Prediction of the coding sequences of unidentified human genes. VIII. 78 new cDNA clones from brain which code for large proteins in vitro

As an extension of our cDNA analysis for deducing the coding sequences of unidentified human genes, we have newly determined the sequences of 100 cDNA clones from a set of size-fractionated human brain cDNA libraries, and predicted the coding sequences of the corresponding genes, named KIAA0611 to KIAA0710. In vitro transcription-coupled translation assay was applied as the first screening to select cDNA clones which produce proteins with apparent molecular mass of 50 kDa and over. One hundred unidentified cDNA clones thus selected were then subjected to sequencing of entire inserts. The average size of the inserts and corresponding open reading frames was 4.9 kb and 2.8 kb (922 amino acid residues), respectively. Computer search of the sequences against the public databases indicated that predicted coding sequences of 87 genes were similar to those of known genes, 62 % of which (54 genes) were categorized as proteins related to cell signaling/communication, cell structure/motility and nucleic acid management. The expression profiles in 10 human tissues of all the clones characterized in this study were examined by reverse transcriptioncoupled polymerase chain reaction and the chromosomal locations of the clones were determined by using human-rodent hybrid panels. Key words: large proteins; in vitro transcription/translation; cDNA sequencing; expression profile; chromosomal location; brai