Sudden death and aborted sudden death have been observed in patients with biallelic variants in TECRL. However, phenotypes have only begun to be described and no data are available on medical therapy after long-term follow-up. An international, multi-centre retrospective review was conducted. We report new cases associated with TECRL variants and long-term follow-up from previously published cases. We present 10 cases and 37 asymptomatic heterozygous carriers. Median age at onset of cardiac symptoms was 8 years (range 1–22 years) and cases were followed for an average of 10.3 years (standard deviation 8.3), right censored by death in three cases. All patients on metoprolol, bisoprolol, or atenolol were transitioned to nadolol or propranolol due to failure of therapy. Phenotypes typical of both long QT syndrome and catecholaminergic polymorphic ventricular tachycardia (CPVT) were observed. We also observed divergent phenotypes in some cases despite identical homozygous variants. None of 37 heterozygous family members had a cardiac phenotype. Patients with biallelic pathogenic TECRL variants present with variable cardiac arrhythmia phenotypes, including those typical of long QT syndrome and CPVT. Nadolol and propranolol may be superior beta-blockers in this setting. No cardiac disease or sudden death was present in patients with a heterozygous genotype.

Infections with Vibrio vulnificus are commonly fatal, and the speed and accuracy of diagnosis and treatment is directly linked to mortality. The main aims of this study were to investigate the clinical characteristics of six patients with V. vulnificus infections retrospectively and to determine the effect of treatment with tigecycline (TGC) alone compared with doxycycline plus ceftazidime (DOX/CAZ). The medical records of patients were reviewed. The species-specific and pathogenic gene markers were detected by PCR, and multilocus sequence typing (MLST) was performed. Furthermore, the effects of TGC and of DOX/CAZ were determined using time-kill assays. MLST revealed six different sequence types and five of them were novel. The complete clinical pattern (vcg type C, CPS operon allele 1, 16S-rRNA type B) was found in one strain and the others had a mixed pattern. The lesion was mainly located at the distal end of the extremities and the most common clinical symptoms were fever, pain, erythema, and local swelling. The in vitro time-kill assay indicated that TGC monotherapy at a concentration of 0.1mg/l had a rapid bactericidal effect against the six tested V. vulnificus strains at 24h. TGC alone might be a better potential therapeutic option than the traditional combination of DOX/CAZ against V. vulnificus.

Sudden cardiac death (SCD) caused by ventricular arrhythmias is the leading cause of mortality of cardiovascular disease. Mutation in TECRL, an endoplasmic reticulum protein, was first reported in catecholaminergic polymorphic ventricular tachycardia during which a patient succumbed to SCD. Using loss- and gain-of-function approaches, we investigated the role of TECRL in murine and human cardiomyocytes. Tecrl (knockout, KO) mouse shows significantly aggravated cardiac dysfunction, evidenced by the decrease of ejection fraction and fractional shortening. Mechanistically, TECRL deficiency impairs mitochondrial respiration, which is characterized by reduced adenosine triphosphate production, increased fatty acid synthase (FAS) and reactive oxygen species production, along with decreased MFN2, p-AKT (Ser473), and NRF2 expressions. Overexpression of TECRL induces mitochondrial respiration, in PI3K/AKT dependent manner. TECRL regulates mitochondrial function mainly through PI3K/AKT signaling and the mitochondrial fusion protein MFN2. Apoptosis inducing factor (AIF) and cytochrome C (Cyc) is released from the mitochondria into the cytoplasm after siTECRL infection, as demonstrated by immunofluorescent staining and western blotting. Herein, we propose a previously unrecognized TECRL mechanism in regulating CPVT and may provide possible support for therapeutic target in CPVT.

Background: Kawasaki disease (KD) is an acute systemic vasculitis that can lead to acquired heart disease in children mostly from in developed countries. The previous research showed that B cells in KD patients underwent a profound change in both the cell numbers and types after intravenous immunoglobulin (IVIG) therapy.Methods: We performed the single-cell RNA-sequencing for the peripheral blood mononuclear cells (PBMCs) from three febrile patients and three KD patients to investigate the possible mechanism underlying B cell developmental dysfunction in KD. The pseudo-time analysis was employed to study the developmental trajectories of the PBMCs in febrile control and KD patients.Results: Overall single-cell expression profiles show that the biological processes of immunity, B cell activation pathway and their related biological entities are repressed in KD patients before IVIG treatment compared to febrile patient and KD patients after IVIG treatment. The differentially expressed gene analyses further demonstrate that B cell signaling pathway is downregulated in B cells and plasma blast cells of KD patients before treatment while cell cycle genes and MYC gene are upregulated in dendritic cells (DCs) and hematopoietic stem and progenitor cells (HSPCs) of KD patients before treatment. The biological process of immune response is upregulated in the HSPCs of KD patients before treatment in our dataset while the biological process of inflammatory response is upregulated in the HSPCs of KD patients before treatment in GSE168732 dataset. Single-cell trajectory analyses demonstrate that KD patients before treatment have a shortened developmental path in which B cells and T cells are failed to differentiate into separate lineages. HSPD1 and HSPE1 genes show an elevated expression level in the early cell development stage of KD patients before treatment accompanied with the repression of MYC, SPI1, MT2A and UBE2C genes. Our analyses of all B cells from KD patients before treatment show most of B cells are arrested in a transitional state with an ill developmental path compared with febrile patients and KD patients after treatment.Conclusion: Our results indicate that the immune premature HSPCs accompanied with the abnormal expression dynamics of cell cycle and SPI1 genes are the mechanism underlying B cell developmental dysfunction in KD patients.

Aims. This study is aimed at examining whether fatty acid synthase (FAS) can regulate mitochondrial function in hypoxia‐induced pulmonary arterial hypertension (PAH) and its related mechanism. Results. The expression of FAS significantly increased in the lung tissue of mice with hypoxia‐induced PAH, and its pharmacological inhibition by C75 ameliorated right ventricle cardiac function as revealed by echocardiographic analysis. Based on transmission electron microscopy and Seahorse assays, the mitochondrial function of mice with hypoxia was abnormal but was partially reversed after C75 injection. In vitro studies also showed an increase in the expression of FAS in hypoxia‐induced human pulmonary artery smooth muscle cells (HPASMCs), which could be attenuated by FAS shRNA as well as C75 treatment. Meanwhile, C75 treatment reversed hypoxia‐induced oxidative stress and activated PI3K/AKT signaling. shRNA‐mediated inhibition of FAS reduced its expression and oxidative stress levels and improved mitochondrial respiratory capacity and ATP levels of hypoxia‐induced HPASMCs. Conclusions. Inhibition of FAS plays a crucial role in shielding mice from hypoxia‐induced PAH, which was partially achieved through the activation of PI3K/AKT signaling, indicating that the inhibition of FAS may provide a potential future direction for reversing PAH in humans.