OBJECTIVE: To explore the clinical and genetic characteristics of a Chinese pedigree affected with Hypertrophic cardiomyopathy (HCM) due to a truncating variant of ALPK3 gene. METHODS: A 44-year-old male admitted to Taizhou Hospital of Zhejiang Province on December 29, 2018 was selected as the study subject. Whole-exome sequencing (WES) was carried out, and candidate variant was interpreted by following the guidelines from the American College of Medical Genetics and Genomics (ACMG). For ALPK3 was considered an autosomal recessive gene, the WES results was considered insufficient to explain his phenotype. In April 2023, the proband's WES data were re-analyzed using updated annotation pipelines, and peripheral blood samples were collected from his first-degree relatives (mother and brother) for Sanger sequencing validation. Conservation analysis and protein structural modeling were performed to assess the impact of the variant. Clinical evaluation and genetic counseling were provided to the proband's family members. Relevant literature on ALPK3tv-induced HCM patients were searched in Wanfang Data Knowledge Service Platform, CNKI, and PubMed database using "ALPK3" and "hypertrophic cardiomyopathy" as keywords. Clinical characteristics of HCM patients with heterozygous ALPK3tv variants were summarized and compared with the clinical characteristics of HCM patients with positive sarcomere-associated gene variants (SARC+). This study was approved by the Medical Ethics Committee of Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University (Ethics No.: K20230314). RESULTS: The proband was a 44-year-old male who was transferred to our institution on December 29, 2018 due to "chest tightness and pain for 6 months, exacerbated for 2 days". Emergency coronary angiography was performed, which led to a preliminary diagnosis of "acute coronary syndrome", and the patient was admitted to the Cardiology Department for treatment. Based on electrocardiogram and echocardiogram findings, the diagnosis was revised as HCM. The patient's condition has stabilized post-coronary angiography, and he was discharged with improved condition. On January 2019, WES was conducted to determine the etiology of the proband's HCM. WES results identified a novel heterozygous c.2156dupC (p.Pro720ThrfsTer53) truncating variant in the ALPK3 gene. At that time, the inheritance pattern could not explain the phenotype. In 2022, a literature indicated that heterozygous ALPK3tv could lead to autosomal dominant HCM. Consequently, in April 2023, the proband's whole-exome data were re-annotated, revealing changes in the transcript and protein versions, with the updated site annotated as ALPK3 (NM_020778.5): c.1550dupC (p.Pro518ThrfsTer53). Sanger sequencing confirmed that the proband's mother and brother also carried this variant. The mother exhibited obstructive HCM, while the brother showed no related phenotype. Bioinformatics analysis demonstrated conservation of this site across multiple species, and the variant has resulted in the loss of a protein domain. Based on ACMG guidelines, the variant was classified as likely pathogenic. Literature review and Bayesian calculation further elevated the pathogenicity rating, indicating that this variant was the cause of HCM in the patient. Literature study revealed distinctions between HCM caused by this variant type and SARC+ HCM. The age of onset among heterozygous ALPK3tv patients was delayed by approximately 10 years compared to SARC+ patients. Both forms of HCM exhibited a male predominance, which was particularly marked in individuals with ALPK3tv. Electrocardiographic left ventricular hypertrophy was more prevalent in heterozygous ALPK3tv patients than in SARC+ patients. The incidence of apical or concentric hypertrophy patterns was higher in heterozygous ALPK3tv patients compared to asymmetric septal hypertrophy, which predominated in SARC+ patients. ALPK3tv patients exhibited lower penetrance and later onset compared to SARC+ patients. A positive correlation between left ventricular wall thickness and age was noted in female patients only. CONCLUSION In this pedigree, the proband has presented with HCM, characterized by echocardiographic evidence of apical left ventricular hypertrophy without significant outflow tract obstruction or extracardiac phenotypes. Although his mother and brother had carried the same heterozygous ALPK3 (NM_020778.5) c.1550dupC (p.Pro518ThrfsTer53), the mother exhibited severe obstructive HCM, while the brother was asymptomatic, suggesting incomplete or age-dependent penetrance within the family. This study has enriched the evidence for the pathogenicity of ALPK3tv among Chinese HCM pedigrees and underscored the importance of periodic literature reviews and genetic re-analysis for unresolved genetic testing results.
Humans ; Male ; Pedigree ; Adult ; Cardiomyopathy, Hypertrophic/genetics* ; Heterozygote ; Asian People/genetics* ; Exome Sequencing ; Mutation ; China ; Female ; East Asian People

Objective:To effectively express the receptor binding domain (RBD) of SARS-CoV-2 spike protein in Pichia pastoris and to evaluate its immunogenicity. Methods:The gene encoding the RBD protein was synthesized and cloned into the pPICZαA plasmid. After linearization, the plasmid was transferred and integrated into the genome of Pichia pastoris. The expressed RBD protein in culture supernatant was analyzed by Western blot and Biolayer interferometry. After screening, a single clone expressing the RBD protein was selected. The high-level expression of RBD protein was achieved by optimizing the fermentation process, including the salt concentration adjusting of the medium and induction condition optimization (pH, temperature and duration). The immunogenicity of the expressed RBD protein was evaluated in a mouse model. Results:A single clone with a high expression level of RBD protein was obtained and named RBD-X33. The expression level of RBD protein in the fermentation supernatant reached up to 240 mg/L after optimization of the induction condition (HBSM medium, pH=6.5±0.3, 22℃ and 120 h). In the mouse experiment, the recombinant RBD protein was formulated with Alum+ CpG dual adjuvant and injected into mice. The binding IgG antibody levels were up to 2.7×10 6 tested by ELISA and the neutralizing antibody levels were up to 726.8 tested by live virus neutralizing antibody assay (prototype). Conclusions:The RBD protein could be efficiently expressed in Pichia pastoris and induce stronger immune response in animals. This study suggested that the recombinant SARS-CoV-2 RBD protein expressed in Pichia pastoris could serve as a candidate antigen in the development of SARS-CoV-2 vaccine.

OBJECTIVE： To prepare Baicalin-loaded Polyethylene glycol-derivatized phosphatidylethanolamine （BAI@PEG-PE） nanomicelles， and to characterize it and study its cytotoxicity. METHODS： BAI@PEG-PE nanomicelles were prepared by film hydration method and their appearance characteristics were observed. The particle size， polydispersity index， Zeta potential， drug-loading amount and encapsulation efficiency of the nanomicelles were detected. Drug release of BAI raw material and BAI@PEG-PE nanomicelles in pH 7.4 phosphate buffer were compared within 1-84 h. Using coumarin 6 as fluorescent probe， the distribution of PEG-PE nanomicelles in H9c2 cardiomyocytes were observed. H9c2 cardiomyocytes were divided into model group， BAI raw material group and BAI@PEG-PE nanomicelles group. After treated with serum-free DMEM medium containing no or corresponding drugs for 0.5 h， isoproterenol was used to induce cardiomyocyte apoptosis. Nuclear morphology， cell apoptosis rate and protein expression of Bcl-2 and Bax were compared with among 3 groups. RESULTS： Prepared BAI@PEG-PE nanomicelles were uniform globular shape. The particle size was （16.7±0.8） nm， PDI was 0.11±0.01 and Zeta-potential was （－18.4±0.6） mV； drug-loading amount was （7.84±0.65）％， encapsulation efficiency was （85.7±4.9）％ （n＝3）. Accumulative release rate was 76.5％ within 84 h. BAI raw material was released completely within 24 h. PEG-PE nanomicelles could strengthen the intake of coumarin 6 in H9c2 cardiomyocytes， mainly gathering around mitochondria. Compared with model group， the apoptosis morphology of cardiomyocytes were improved significantly in BAI raw material group and BAI@PEG-PE nanomicelles group； apoptosis rate was decreased significantly； protein expression of Bcl-2 was increased significantly； protein expression of Bax was decreased significantly with statistical significance （P＜0.05 or P＜0.01）. Above effects of BAI@PEG-PE nanomicelles group were more significant （P＜0.05 or P＜0.01）. CONCLUSIONS： BAI@PEG-PE nanomicelles are prepared successfully， and show significant sustained-release effect and myocardial targeting， and can prevent cardiomyocyte apoptosis.