Objective: To investigate the effects of chemokine like factor 1 (CKLF1) on proliferation and metabolism of chondrocytes. Methods: Cell culture, 3H TdR and 3H Proline incorporation methods were used. Chondrocytes were harvested from rabbit articular cartilage. First passage cells were seeded on 96 well plates. After synchronization,the medium was replaced by DMEM containing 5% FCS with various concentration of CKLF1 conditioned medium. The synthesis of mucopolysaccharide was detected by Saffraan O staining. The transcription of inducible nitricoxide synthase (iNOS) was detected by semi quantitative RT-PCR. Results: CKLF1 inhibited the DNA, collagen and mucopolysaccharide synthesis significantly, meanwhile, stimulated the transcription of iNOS. Conclusion: CKLF1 inhibits the proliferation and matrix synthesis of chondrocytes, which might be an important factor resulting in cartilage destructive lesions. CKLF1 may exert its effects on chondrocytes through iNOS pathway.

Objective: To characterize the expression of programmed cell death 5 (PDCD5) in normal and osteoarthritic human cartilage. Methods: Articular cartilage specimens were obtained from 20 patients with osteoarthritis and 10 with femoral neck (normal cartilage) at the time of arthroplasty. Expression of PDCD5 was detected by flow cytometry, immunofluorescence, RT-PCR and immunohistochemical analysis. Results: PDCD5 expression in osteoarthritis cartilage was significantly higher than in normal cartilage especially in the nucleus. PDCD5 positive chondrocytes were mainly observed in the superficial and deep zone of osteoarthritis tissue sections,and in contrast, in the superficial and middle regions of normal controls. Conclusion: Since apoptotic chondrocyte death occurs more frequently in osteoarthritis compared to normal cartilage and PDCD5 is an apoptosis related protein, the different expression patterns of PDCD5 in osteoarthritis and normal cartilage suggest that it might be involved in the pathogenesis of osteoarthritis.

OBJECTIVE: To explore the genetic basis for a child featuring complex cortical dysplasia and other brain malformations (CDCBM3). METHODS: Genomic DNA was extracted from peripheral blood samples from the patient and his parents. Whole exome sequencing (WES) was carried out for the family trio. Suspected variant was verified by Sanger sequencing. RESULTS: The proband, a 1-year-and-2-month old Chinese boy, had presented with motor developmental delay, lissencephaly, severe cognitive impairments, absent speech and congenital laryngomalacia. WES revealed that he has harbored a heterozygous missense variant of the KIF2A gene, namely NM_001098511.2: c.952G>A, p.Gly318Arg (GRCh37/hg19). The highly conserved residue is located around the ATP nucleotide-binding pocket in the kinesin motor domain (PM1). The variant was not found in the Genome Aggregation Database and the 1000 Genomes Project (PM2), and was predicted to be deleterious on the gene product by multiple in silico prediction tools (PP3). This variant was unreported previously and was de novo in origin (PS2). Based on the ACMG guidelines, it was categorized as likely pathogenic (PS2+PM1+PM2+PP3). Furthermore, the congenital laryngomalacia found in our patient was absent in previously reported CDCBM3 cases. CONCLUSION The novel variant of the KIF2A gene probably underlay the disorders in the proband. Above finding has expanded the phenotypic and mutational spectrum of CDCBM3.
Asians/genetics* ; Brain ; China ; Humans ; Infant ; Kinesins/genetics* ; Male ; Malformations of Cortical Development/genetics* ; Whole Exome Sequencing

OBJECTIVE: To explore the genotype-phenotype correlation of a case with GM1-gangliosidosis caused by compound heterogenic variants in GLB1. METHODS: Genomic DNA was extracted from peripheral blood samples from the patient and her parents. Trio-based whole-exome sequencing (WES) was performed for the family and suspected mutation was verified by Sanger sequencing. RESULTS: The proband, a 2-year-3-month old Chinese girl, presented with psychomotor deterioration, absent speech, intellectual disabilities and behavior problem. Trio-based WES has identified compound heterozygosity for 2 variants in the GLB1 gene: NM_000404.2:c.1343A>T, p.Asp448Val and c.1064A>C, p.Gln355Pro (GRCh37/hg19),which was inherited from the mother and father, respectively. Homozygous or compound heterozygous pathogenic variants in GLB1, encoding β-galactosidase, are responsible for GM1-gangliosidosis,an autosomal recessive lysosomal storage disorder characterized by variable degrees of neurodegeneration and skeletal abnormalities. The p.Asp448Val variant has been classified as pathogenic for GM1 gangliosidosis in medical literatures for the reason that functional studies demonstrated that expression of the p.Asp448Val variant in COS-1 cells resulted in no detectable β-galactosidase activity compared to wild type GLB1. The p.Gln355Pro variant has not been reported in literatures or database. The variant is highly conserved residue (PM1), and was not found in either the Genome Aggregation Database or the 1000 Genomes Project (PM2) and was predicted to have a deleterious effect on the gene product by multiple in silico prediction tools (PP3). Next, the β-galactosidase activity of the patient's peripheral blood leukocytes was determined by fluorescent method. The result was 0.0 nmol/mg. It showed that the p.Gln355Pro variant also resulted in loss of β-galactosidase activity, thus the variant was classified into clinical pathogenic variant. CONCLUSION Our study expands the mutational spectrum of the GLB1 gene and provides genetic counseling for the family.
Asians/genetics* ; China ; Female ; G(M1) Ganglioside ; Gangliosidosis, GM1/genetics* ; Humans ; Mutation ; beta-Galactosidase/genetics*

OBJECTIVE: To explore the genotype-phenotype correlation in a child with Kabuki syndrome type 1 (KS1) caused by a mosaic frameshift variant of KMT2D gene. METHODS: Trio-based whole exome sequencing (WES) was carried for the patient and her parents. Candidate variant was verified by Sanger sequencing. RESULTS: The proband, a 3-year-and-2-month-old Chinese girl, presented with distinctive facial features, cognitive impairment, mild developmental delay, dermatoglyphic abnormalities, minor skeletal anomalies, ventricular septal defect, and autistic behavior. Trio-based WES revealed that the proband has carried a de novo mosaic frameshit variant of the KMT2D gene, namely NM_003482.3:c.13058delG (p.Pro4353Argfs*31) (GRCh37/hg19), for which the mosaicism rate was close to 21%. The variant was unreported previously and was confirmed by Sanger sequencing. Chromosomal microarray analysis (CMA) has revealed no pathogenic or likely pathogenic copy number variations. Compared with previously reported cases, our patient has presented obvious behavior anomalies including autism, anxiety and sleep problems, which were rarely reported. CONCLUSION This study has expanded the spectrum of KMT2D gene variants, enriched the clinical phenotypes of KS1, and facilitated genetic counseling for the family.
Abnormalities, Multiple ; China ; DNA Copy Number Variations ; DNA-Binding Proteins/genetics* ; Face/abnormalities* ; Female ; Hematologic Diseases ; Humans ; Infant ; Neoplasm Proteins/genetics* ; Phenotype ; Vestibular Diseases