As the most common type of protein glycosylation, N-glycosylation begins with the synthesis of the dolichol-linked oligosaccharide (DLO) precursor in the endoplasmic reticulum. The mannosyltransferase Alg1 catalyzes the addition of the first mannose molecule to DLO, serving as a key enzyme in this biochemical pathway. The defect of human ALG1 gene can lead to the congenital disorders of glycosylation (CDG), i.e., ALG1-CDG. Therefore, it is of great significance to establish the expression and activity assay system of Homo sapiens Alg1 (HsAlg1) in vitro. In this study, full-length plasmid pET28a-His6-HsAlg1 and transmembrane domain-lacking plasmid pET28a-His6-HsAlg1_23-464 were constructed and expressed in Escherichia coli, and the activity of recombinant HsAlg1 and HsAlg1_23-464 was measured by liquid chromatography tandem mass spectrometry (LC-MS) with dolichyl-pyrophosphate GlcNAc2 (DPGn2) as the substrate. The results showed that HsAlg1 had transglycosylation activity, while the activity decreased after protein purification, which was partially restored upon re-addition of membrane components. However, HsAlg1_23-464 was unable to catalyze glycosylation. The results indicate that the N-terminal transmembrane domain (TMD) of HsAlg1 plays an important role in the catalytic reaction. This study lays a foundation for further expression and activity analysis of ALG1-CDG-related mutants.
Humans ; Escherichia coli/metabolism* ; Mannosyltransferases/biosynthesis* ; Glycosylation ; Recombinant Proteins/metabolism* ; Protein Domains

Objective:To carry out genetic testing and clinical phenotypic characterization on a four-generation Chinese pedigree affected with Stickler syndrome type I and explore its genotype-phenotype correlation.Methods:A child presented at the Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine in February 2023 for micrognathia, glossoptosis and cleft palate and his family members were selected as the study subjects. Clinical data were collected from the affected members, and peripheral blood samples were obtained from 17 participants (4 patients and 13 asymptomatic individuals). Whole exome sequencing (WES) was carried out. Candidate variant was verified by Sanger sequencing. Genotype-phenotype correlations were analyzed by integrating the sequencing data with evidence from existing literature. This study has bee granted by the Ethics Committee of Guangdong Provincial Hospital of Traditional Chinese Medicine and Guangzhou Women and Children′s Medical Center (Ethics No.: 2022-406B00).Results:The four-generation pedigree has comprised 19 members. In addition to the proband, 5 affected individuals had manifested high myopia, congenital cataracts, and progressive vision loss. Two deceased members reportedly exhibited similar ocular manifestations. Among the four living patients, two had developed retinal detachment, while two others presented with chronic joint pain onset between 35 ~ 40 years of age. One patient required hip replacement surgery at age 42 secondary to femoral head necrosis. The proband, the youngest affected member, exhibited characteristic phenotypes including congenital micrognathia and cleft palate, consistent with Pierre-Robin syndrome. Genetic analysis revealed a heterozygous nonsense mutation in COL2A1 (NM_001844.5: c. 2668C>T; p. Gln890Ter) segregating with the disease in all four symptomatic patients. This variant was absent in asymptomatic family members and unaffected controls. While the mutation is listed in ClinVar, no clinical case reports has associated it with this phenotypic spectrum. It was not observed in population databases (gnomAD v4.1.0, 1000 Genomes Project, or ExAC), supporting its potential pathogenicity. Conclusion:This study has diagnosed a four-generation Chinese pedigree with Stickler syndrome type I attributed to the pathogenic COL2A1 variant c. 2668C>T (p.Gln890Ter), which is a rare nonsense mutation associated with ocular predominance and variable skeletal involvement. Notably, this family exhibited marked clinical heterogeneity despite sharing the identical genotype, which highlighted challenges in phenotype-genotype correlation. The autosomal dominant transmission pattern observed in this pedigree has provided critical insights into COL2A1-related collagenopathies and underscored the necessity of ultrasonographic monitoring for ocular anomalies in prenatal diagnostics. Above findings have advanced our understanding of pleiotropic effects in type Ⅱ collagen disorders and lay the foundation for precision-based genetic counseling, enabling targeted cascade screening and implementation of tertiary prevention strategies against congenital disabilities in high-risk families.

OBJECTIVE: To carry out genetic testing and clinical phenotypic characterization on a four-generation Chinese pedigree affected with Stickler syndrome type I and explore its genotype-phenotype correlation. METHODS: A child presented at the Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine in February 2023 for micrognathia, glossoptosis and cleft palate and his family members were selected as the study subjects. Clinical data were collected from the affected members, and peripheral blood samples were obtained from 17 participants (including 4 patients and 13 asymptomatic individuals). Whole exome sequencing (WES) was carried out. Candidate variant was verified by Sanger sequencing. Genotype-phenotype correlation was analyzed by integrating the sequencing data with evidence from existing literature. This study has bee granted by the Ethics Committee of Guangdong Provincial Hospital of Traditional Chinese Medicine and Guangzhou Women and Children's Medical Center (Ethics No.: 2022-406B00). RESULTS: The four-generation pedigree has comprised 19 members. In addition to the proband, 5 affected individuals had manifested with high myopia, congenital cataracts, and progressive vision loss. Two deceased members reportedly exhibited similar ocular manifestations. Among the four living patients, two had developed retinal detachment, while two others presented with chronic joint pain onset between 35 ~ 40 years of age. One patient required hip replacement surgery at age 42 secondary to femoral head necrosis. The proband, the youngest affected member, exhibited characteristic phenotypes including congenital micrognathia and cleft palate, consistent with Pierre-Robin syndrome. Genetic analysis revealed a heterozygous nonsense mutation in COL2A1 (NM_001844.5: c.2668C>T; p.Gln890Ter) segregating with the disease in all four symptomatic patients. This variant was absent in asymptomatic family members and unaffected controls. While the mutation is listed in ClinVar, no clinical case report has associated it with this phenotypic spectrum. It was not recorded in population databases (gnomAD v4.1.0, 1000 Genomes Project, or ExAC), supporting its potential pathogenicity. CONCLUSION This study has diagnosed a four-generation Chinese pedigree with Stickler syndrome type I attributed to the pathogenic COL2A1 variant c.2668C>T (p.Gln890Ter), which is a rare nonsense mutation associated with ocular predominance and variable skeletal involvement. Notably, this family exhibited marked clinical heterogeneity despite sharing the identical genotype, which highlighted the challenges in phenotype-genotype correlation. The autosomal dominant transmission pattern observed in this pedigree has provided critical insights into COL2A1-related collagenopathies and underscored the necessity of ultrasonographic monitoring for ocular anomalies during prenatal diagnosis. Above findings have advanced our understanding of the pleiotropic effects in type Ⅱ collagen disorders and laid the foundation for precision-based genetic counseling, enabling targeted cascade screening and implementation of tertiary prevention strategies against congenital disabilities for high-risk families.
Adolescent ; Adult ; Child ; Child, Preschool ; Female ; Humans ; Male ; Middle Aged ; Arthritis/genetics* ; Collagen Type II/genetics* ; Connective Tissue Diseases/genetics* ; Exome Sequencing ; Genetic Association Studies ; Genotype ; Hearing Loss, Sensorineural/genetics* ; Mutation ; Pedigree ; Phenotype ; Retinal Detachment/genetics* ; East Asian People/genetics*

Objective:To carry out genetic testing and clinical phenotypic characterization on a four-generation Chinese pedigree affected with Stickler syndrome type I and explore its genotype-phenotype correlation.Methods:A child presented at the Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine in February 2023 for micrognathia, glossoptosis and cleft palate and his family members were selected as the study subjects. Clinical data were collected from the affected members, and peripheral blood samples were obtained from 17 participants (4 patients and 13 asymptomatic individuals). Whole exome sequencing (WES) was carried out. Candidate variant was verified by Sanger sequencing. Genotype-phenotype correlations were analyzed by integrating the sequencing data with evidence from existing literature. This study has bee granted by the Ethics Committee of Guangdong Provincial Hospital of Traditional Chinese Medicine and Guangzhou Women and Children′s Medical Center (Ethics No.: 2022-406B00).Results:The four-generation pedigree has comprised 19 members. In addition to the proband, 5 affected individuals had manifested high myopia, congenital cataracts, and progressive vision loss. Two deceased members reportedly exhibited similar ocular manifestations. Among the four living patients, two had developed retinal detachment, while two others presented with chronic joint pain onset between 35 ~ 40 years of age. One patient required hip replacement surgery at age 42 secondary to femoral head necrosis. The proband, the youngest affected member, exhibited characteristic phenotypes including congenital micrognathia and cleft palate, consistent with Pierre-Robin syndrome. Genetic analysis revealed a heterozygous nonsense mutation in COL2A1 (NM_001844.5: c. 2668C>T; p. Gln890Ter) segregating with the disease in all four symptomatic patients. This variant was absent in asymptomatic family members and unaffected controls. While the mutation is listed in ClinVar, no clinical case reports has associated it with this phenotypic spectrum. It was not observed in population databases (gnomAD v4.1.0, 1000 Genomes Project, or ExAC), supporting its potential pathogenicity. Conclusion:This study has diagnosed a four-generation Chinese pedigree with Stickler syndrome type I attributed to the pathogenic COL2A1 variant c. 2668C>T (p.Gln890Ter), which is a rare nonsense mutation associated with ocular predominance and variable skeletal involvement. Notably, this family exhibited marked clinical heterogeneity despite sharing the identical genotype, which highlighted challenges in phenotype-genotype correlation. The autosomal dominant transmission pattern observed in this pedigree has provided critical insights into COL2A1-related collagenopathies and underscored the necessity of ultrasonographic monitoring for ocular anomalies in prenatal diagnostics. Above findings have advanced our understanding of pleiotropic effects in type Ⅱ collagen disorders and lay the foundation for precision-based genetic counseling, enabling targeted cascade screening and implementation of tertiary prevention strategies against congenital disabilities in high-risk families.

Objective:To investigate genetic variation profiles of δ-globin (HBD gene) and hematological phenotypes in Guangdong population.Methods:Retrospective case analysis was performed in this study. Blood samples of 11 616 couples who participated in free thalassemia screening in Guangzhou from July 2020 to December 2022 were collected which underwent blood routine tests and hemoglobin (Hb) capillary electrophoresis. According to the results, 154 samples were enrolled in this study: (1)group of 35 cases with HbA 2 <2.0% but no HbF band; (2)group of 64 cases with HbA 2 < 2.0% and HbF band; (3)group of 25 cases with HbA 2 <2.0% and suspected HbA 2 variants; (4) group of 25 cases with HbA 2 ≥2.0% and <3.5% and HbF band, as well as abnormal blood routine report [mean corpuscular volume (MCV) <82 fl and/or mean corpuscular hemoglobin (MCH) <27 pg]; (5)group of 5 cases with HbA 2 ≥2.0% and <3.0% accompanied with β thalassemia gene carriers Sanger sequencing was used to detect single nucleotide variants of δ-globin. Results:(1) A total of 22 genetic variations were detected, including 6 de novo variations, and the top 3 genetic variations were respectively c.-127T>C (57.02%, 65/114), c.-80T>C (9.65%, 11/114), c.349C>T (7.89%, 9/114). (2) In group of patients with HbA 2 <2.0% but no HbF band, 22 cases (62.85%, 22/35) had HBD gene variation, including 7 cases with MCV and MCH lower than reference values, 4 cases with α thalassemia; 13 cases had no HBD gene variation, including 12 cases with lower MCV and MCH. Among 19 cases with abnormal blood routine test results, levels of HbA 2 in patients (7 cases) with HBD gene variation were lower compared with those without HBD gene variation (12 cases) ( P<0.01%). (3)In group of patients with HbA 2<2.0% with HbF band, 59 cases (92.18%, 59/64) had HBD gene variations whose mutations all occurred in promoter region, and the HbF were all lower than 5.0%; 5 cases with HbF >5.0% had no HBD gene variation. (4) In group of patients with HbA 2 <2.0% and suspected HbA 2 variants, the detection rate was 100% (25/25) and δ-globin variants <1.0%. (5) In group of patients with HbA 2 ≥2.0% and <3.5% and HbF band accompanied with abnormal blood routine results, no HBD gene variation was found. (6) In group of 5 patients with HbA 2 ≥2.0% and <3.0% with β thalassemia gene carriers, HBD gene variation were found in all cases, and the level of HbA 2 was (2.62±0.17)% and HbF was (3.62±2.22)%. Conclusions:There are various genotypes of HBD gene variation, among which HBD: c.-127T>C is the most common in Guangdong population in China. Mutations in the promoter region may cause decrease in HbA 2 and increase in HbF which is mostly less than 5% but exceeds 5.0% when combined with β thalassemia. Our study enriched the gene mutation profiles of HBD gene in Guangdong population.

OBJECTIVE: To investigate how the National Health Commission of China (NHCC)-recommended Chinese medicines (CMs) modulate the major maladjustments of coronavirus disease 2019 (COVID-19), particularly the clinically observed complications and comorbidities. METHODS: By focusing on the potent targets in common with the conventional medicines, we investigated the mechanisms of 11 NHCC-recommended CMs in the modulation of the major COVID-19 pathophysiology (hyperinflammations, viral replication), complications (pain, headache) and comorbidities (hypertension, obesity, diabetes). The constituent herbs of these CMs and their chemical ingredients were from the Traditional Chinese Medicine Information Database. The experimentally-determined targets and the activity values of the chemical ingredients of these CMs were from the Natural Product Activity and Species Source Database. The approved and clinical trial drugs against these targets were searched from the Therapeutic Target Database and DrugBank Database. Pathways of the targets was obtained from Kyoto Encyclopedia of Genes and Genomes and additional literature search. RESULTS: Overall, 9 CMs modulated 6 targets discovered by the COVID-19 target discovery studies, 8 and 11 CMs modulated 8 and 6 targets of the approved or clinical trial drugs for the treatment of the major COVID-19 complications and comorbidities, respectively. CONCLUSION The coordinated actions of each NHCC-recommended CM against a few targets of the major COVID-19 pathophysiology, complications and comorbidities, partly have common mechanisms with the conventional medicines.
COVID-19/physiopathology* ; Comorbidity ; Drugs, Chinese Herbal/therapeutic use* ; Humans ; Medicine ; Medicine, Chinese Traditional ; SARS-CoV-2

As a class of multifunctional biocatalysts, halohydrin dehalogenases are of great interest for the synthesis of chiral β-substituted alcohols and epoxides. There are less than 40 halohydrin dehalogenases with relatively clear catalytic functions, and most of them do not meet the requirements of scientific research and practical applications. Therefore, it is of great significance to excavate and identify more halohydrin dehalogenases. In the present study, a putative halohydrin dehalogenase (HHDH-Ra) from Rhodospirillaceae bacterium was expressed and its enzymatic properties were investigated. The HHDH-Ra gene was cloned into the expression host Escherichia coli BL21(DE3) and the target protein was shown to be soluble. Substrate specificity studies showed that HHDH-Ra possesses excellent specificity for 1,3-dichloro-2-propanol (1,3-DCP) and ethyl-4-chloro-3-hydroxybutyrate (CHBE). The optimum pH and temperature for HHDH-Ra with 1,3-DCP as the reaction substrate were 8.0 and 30 °C, respectively. HHDH-Ra was stable at pH 6.0-8.0 and maintained about 70% of its original activity after 100 h of treatment. The thermal stability results revealed that HHDH-Ra has a half-life of 60 h at 30 °C and 40 °C. When the temperature is increased to 50 °C, the enzyme still has a half-life of 20 h, which is much higher than that of the reported enzymes. To sum up, the novel halohydrin dehalogenase from Rhodospirillaceae bacterium possesses good temperature and pH stability as well as catalytic activity, and shows the potential to be used in the synthesis of chemical and pharmaceutical intermediates.
Escherichia coli/metabolism* ; Hydrolases/metabolism* ; Rhodospirillaceae ; Substrate Specificity

Objective:To observe the changes in percentages and subsets of invariant nature kiler T (iNKT) cells in adipose and related tissues at different stages of obesity, and analyze the role of iNKT cells during chronic inflammation in adipose tissues in a mouse model of obesity established with high-fat diet.Methods:Changes in mouse body weight, mental state, glucose tolerance and insulin tolerance were recorded. Hematoxylin and eosin (HE) staining was used to observe pathological changes in adipose tissues. Flow cytometry was performed to detect the percentages and subsets of iNKT cells as well as the percentages and subtypes of macrophages. The levels of cytokines in serum samples and the culture supernatants of lymphocytes in adipose tissues were detected with CBA. The expression of related proteins in adipose tissues was detected by Western blot.Results:(1) The volume of adipose cells increased significantly after four weeks of high-fat feeding, but the infiltration of inflammatory cells was not obvious. Significantly increased infiltration of inflammatory cells was observed after 12 weeks of high-fat feeding. (2) High-fat feeding could reduce the percentage of iNKT cells, increase the proportion of iNKT1 subgroup and decrease the proportion of iNKT10 subgroup in adipose tissues. The proportion of iNKT1 subgroup in thymus increased, but that of iNKT2 subgroup decreased. The percentage of macrophages and the proportion of M1 subgroup in adipose tissues increased, while the proportion of M2 subgroup decreased, which were more obvious after 12 weeks of high-fat feeding. (3) High-fat feeding resulted in decreased expression of E4BP4 and arginase-1 (Arg-1) in adipose tissues and increased expression of inducible nitric oxide synthase (iNOS). (4) High-fat feeding significantly increased the pro-inflammatory cytokines and decreased the anti-inflammatory cytokines in mouse serum and culture supernatants of lymphocytes in adipose tissues with more significant changes observed after 12 weeks of high-fat feeding.Conclusions:Increased iNKT1 and decreased iNKT10 in obese adipose tissues might be closely related to the increased M1 polarization and the imbalance of iNKT subsets might be involved in the progression of chronic inflammation in obese adipose tissues.

Objective:To investigate the mechanism of invariant natural killer T (iNKT)2 cell improving hepatic fat deposition in nonalcoholic fatty liver (NAFL).Methods:NAFL model was established by feeding C57BL/6J mice with high fat diet. The levels of serum total cholesterol, triglyceride, high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) in the peripheral blood of mice were analyzed using automatic biochemical analyzer. The pathological changes of liver were observed with HE staining. The cell frequencies of iNKT, iNKT1, and iNKT2 in liver were detected by flow cytometry. Western blotting was used to detect the expression of sterol regulatory element binding protein 1c (SREBP-1c), peroxisome proliferator activated receptor (PPAR)-α, and nuclear factor-κB (NF-κB) in liver tissues.Results:Compared with control group, the body weight of NAFL mice increased, the levels of total cholesterol, HDL-C, LDL-C, ALT, and liver fat deposition increased, the protein expression of SREBP-1c and PPAR-α in liver increased as well as the the protein phosphorylation level of NF-κB. After intraperitoneal injection of α-galactosylceramide (α-GalCer), the levels of total cholesterol, HDL-C, and LDL-C, liver fat deposition decreased, liver SREBP-1c was down-regulated, PPAR-α expression was up-regulated, and the proportion of liver iNKT2 subgroup increased in NAFL mice.Conclusion:iNKT2 cells improve NAFL liver fat deposition, which is related to the down-regulation of SREBP-1c and up-regulation of PPAR-α.

Early-onset epilepsy is a neurological abnormality in childhood, and it is especially common in the first 2 years after birth. Seizures in early life mostly result from structural or metabolic disorders in the brain, and the genetic causes of idiopathic seizures have been extensively investigated. In this study, we identified four missense mutations in the SETD1A gene (SET domain-containing 1A, histone lysine methyltransferase): three de novo mutations in three individuals and one inherited mutation in a four-generation family. Whole-exome sequencing indicated that all four of these mutations were responsible for the seizures. Mutations of SETD1A have been implicated in schizophrenia and developmental disorders, so we examined the role of the four mutations (R913C, Q269R, G1369R, and R1392H) in neural development. We found that their expression in mouse primary cortical neurons affected excitatory synapse development. Moreover, expression of the R913C mutation also affected the migration of cortical neurons in the mouse brain. We further identified two common genes (Neurl4 and Usp39) affected by mutations of SETD1A. These results suggested that the mutations of SETD1A play a fundamental role in abnormal synaptic function and the development of neurons, so they may be pathogenic factors for neurodevelopmental disorders.