Neonatal D-bifunctional protein deficiency: a report of two cases and literature review / 中华围产医学杂志

Objective:To summarize the clinical characteristics and genetic etiology of infants with D-bifunctional protein deficiency (DBPD).Methods:This study involved two DBPD newborns who were hospitalized in the Second Affiliated Hospital of Wenzhou Medical University in August 2020 and November 2020. Clinical data including manifestations, radiographic findings and genetic testing results were retrospectively analyzed. Relevant articles up to November 2022 were retrieved from various databases including CNKI, Wanfang, CQVIP, Online Mendelian Inheritance in Man and PubMed using the terms of "D-bifunctional protein deficiency" and " HSD17B4" in both Chinese and English. Clinical data of the cases diagnosed with DBPD by genetic testing within two years of age were collected. Clinical features and genetic etiology of the children with DBPD were summarized by descriptive statistical analysis. Results:Both neonates in this report presented with dyspnea, hypotonia, intractable epilepsy, poor response, absence of primitive reflexes, and craniofacial malformation. Whole-exome sequencing revealed that patient 1 carried heterozygous variations of c.972+1G>T and c.727T>A (p.W243R) in the HSD17B4 gene, which were inherited from his father and mother, respectively. A homozygous variation of c.1333+4A>G in the HSD17B4 gene was identified in patient 2. All these mutations were pathogenic. Thirteen papers (12 in English and one in Chinese) involving 19 patients from 16 pedigrees were retrieved. Altogether 21 patients (eight males and 13 females) were included, and among them, four from two pedigrees were born to consanguineous parents. There were 21 patients with hypotonia, 20 with epileptic seizures (17 presenting with epileptic seizures within 5 d after birth) and 12 with craniofacial deformities including high forehead, long philtrum and high palatine arches. Genetic tests showed that 13 patients carried compound heterozygous variations in the HSD17B4 gene and eight patients had homozygous variations. Twenty-six variations in the HSD17B4 gene were detected, including 16 missense mutations, seven splicing mutations, two nonsense mutations and one frameshift mutation. Conclusion:DBPD should be considered and genetic tests should be given when newborns have dystonia and intractable epilepsy complicated by appearance deformity.

Molecular characterization and functional analysis of scavenger receptor class B from black tiger shrimp (Penaeus monodon)

BACKGROUND: Scavenger receptor class B (SRB) is a multifunctional protein in animals that participates in physiological processes, including recognition of a wide range of ligands. Astaxanthin is a major carotenoid found in shrimp. However, the molecular mechanism of astaxanthin and SRB protein binding has not been reported. RESULTS: In the present study, a member of the SRB subfamily, named PmSRB, was identified from the transcriptome of black tiger shrimp (Penaeus monodon). The open reading frame of PmSRB was 1557 bp in length and encoded 518 amino acids. The structure of PmSRB included a putative transmembrane structure at the N-terminal region and a CD36 domain. Multiple sequence alignment indicated that the CD36 domain were conserved. Phylogenetic analysis showed four separate branches (SRA, SRB, SRC, and croquemort) in the phylogenetic tree and that PmSRB was clustered with SRB of Eriocheir sinensis. Quantitative real-time polymerase chain reaction showed that the PmSRB gene was widely expressed in all tissues tested, with the highest expression level observed in the lymphoid organ and brain. Subcellular localization analysis revealed that PmSRB-GFP (green fluorescent protein) fusion proteins were predominantly localized in the cell membrane. The recombinant proteins of PmSRB showed binding activities against astaxanthin in vitro. CONCLUSIONS: PmSRB was identified and characterized in this study. It is firstly reported that PmSRB may take as an important mediator of astaxanthin uptake in shrimp.

Protective Effect and Mechanism of Human Lipoxin A4 on N2a Cell Injury Induced by β-Amyloid Protein 25-35 / 中国药师

Objective: To investigate the protective effect of human lipoxin A4 (LXA4) on N2a cell damage induced by β-amyloid protein 25-35 (Aβ25-35) and the underlying mechanism. Methods: Aβ25-35 was used to treat N2a cells to establish Alzheimer's disease (AD) cell injury model. Meanwhile, LXA4 was added to the experimental group at different concentrations (50, 100 and 200 nmol·L-1 ). MTT assay was used to detect the activity of N2a cells. The apoptosis was detected by Hoechst 33258-PI staining, the expression of P62 and TRAF6 mRNA was detected by RT-PCR, and the expression of P62 and TRAF6 protein was detected by Western blot. Results: Compared with that of the model group, the cell survival rate of LXA4 protective group (50,100 and 200 nmol·L-1 ) increased (P <0. 01) and the apoptosis of N2a cells induced by Aβ25-35 was reduced by LXA4 (100 and 200 nmol·L-1 ) . Compared with that of the model group, the expression of P62-mRNA and protein-P62 of N2a cells treated with Aβ25-35 increased (P <0. 05 or P <0. 01) and the expression of TRAF6-mRNA and protein-TRAF6 of N2a cells treated with Aβ25-35 were reduced (P <0. 05 or P <0. 01). Conclusion: LXA4 has protective effect on N2a cell damage induced by Aβ25-35 , and its mechanism may be related to the up-regulation of P62 gene and down-regulation of TRAF6 gene.

NS3 protease from flavivirus as a target for designing antiviral inhibitors against dengue virus

The development of novel therapeutic agents is essential for combating the increasing number of cases of dengue fever in endemic countries and among a large number of travelers from non-endemic countries. The dengue virus has three structural proteins and seven non-structural (NS) proteins. NS3 is a multifunctional protein with an N-terminal protease domain (NS3pro) that is responsible for proteolytic processing of the viral polyprotein, and a C-terminal region that contains an RNA triphosphatase, RNA helicase and RNA-stimulated NTPase domain that are essential for RNA replication. The serine protease domain of NS3 plays a central role in the replicative cycle of dengue virus. This review discusses the recent structural and biological studies on the NS2B-NS3 protease-helicase and considers the prospects for the development of small molecules as antiviral drugs to target this fascinating, multifunctional protein.