OBJECTIVE: To analyze the clinical and genetic characteristics of five Chinese pedigrees affected with short stature. METHODS: A retrospective analysis was carried out for the clinical data and results of genetic testing for the probands. A literature search was also conducted. RESULTS: The five probands have all featured short stature with a family history. Genetic testing has revealed that they have harbored variants of the ACAN gene, including p.Val2042Argfs*6, p.Val1597del, c.630-1G>A, c.23delT and c.2026+1G>A(previously reported). CONCLUSION Except for short stature, children harboring heterozygous variants of the ACAN gene may have no involvement of other systems. Some of these children may response to short-term growth hormone treatment.
Aggrecans/genetics* ; Body Height/genetics* ; Child ; China ; Genetic Testing ; Humans ; Pedigree ; Retrospective Studies

OBJECTIVE: To analyze the genetic etiology of a Chinese pedigree affected with short stature. METHODS: A child with familial short stature (FSS) who had presented at the Ningbo Women and Children's Hospital in July 2020 and his parents and paternal and maternal grandparents were selected as the study subject. Clinical data of the pedigree was collected, and the proband was subjected to routine growth and development assessment. Peripheral blood samples were collected. The proband was subjected to whole exome sequencing (WES), and the proband, his parents and grandparents were subjected to chromosomal microarray analysis (CMA). RESULTS: The height of the proband and his father was 87.7cm (-3 s) and 152 cm (-3.39 s) respectively. Both of them were found to harbor a 15q25.3-q26.1 microdeletion, which has encompassed the whole of the ACAN gene which is closely associated with short stature. The CMA results of his mother and grandparents were all negative, and above deletion has not been included in population database and related literature, and was rated as pathogenic based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). After 14 months of rhGH treatment, the height of the proband has increased to 98.5 cm (-2.07 s). CONCLUSION The 15q25.3-q26.1 microdeletion probably underlay the FSS, in this pedigree. Short-term rhGH treatment can effectively improve the height of the affected individuals.
Child ; Female ; Humans ; Male ; Aggrecans/genetics* ; Dwarfism/genetics* ; East Asian People ; Mutation ; Pedigree

OBJECTIVETo study the expression of Aggrecan and the relationship between the variable number of tandem repeats (VNTR) of Aggrecan and lumbar disc herniation (LDH).

METHODSThe disease group comprised of 74 patients already diagnosed with symptomatic LDH. The control group consisted of 15 patients restricted to spinal trauma and 113 healthy blood donors without symptoms of LDH who were not diagnosed with LDH. Disc tissue samples were obtained from surgical operations and blood samples were donated from all participants. The Aggrecan expression in isolated tissues was assessed by western blot using specific antibodies. The Aggrecan gene VNTR region was analyzed by PCR.

RESULTSThe Aggrecan expression positive rate of control group was statistically and significantly higher (control group:86.67%, disease group:13.51%;χ(2) = 34.83, P < 0.05) than that of the disease group. Moreover, there was a statistically significant higher frequency of Allele 25 or Allele 21 in disease group compared to controls (A25disease group = 22.97%, A25control group = 12.11%, χ(2)A25 = 8.20, PA25 = 0.004; A21disease group = 6.76%, A21control group = 0.39%, χ(2)A21 = 14.35, PA21 = 0.000). Compared to the participants with 2 Alleles>25 repeats, subjects with 1 or 2 Alleles ≤ 25 repeats statistically and significantly over represented the disease group without the expression of Aggrecan (χ(2) = 5.69, P = 0.017).

CONCLUSIONSThe findings suggest a relationship between Aggrecan and symptomatic LDH, where symptomatic LDH has a tendency of allele 21 and allele 25 repeats.In addition, an association between the distribution of Aggrecan gene VNTR polymorphism and the expression of Aggrecan is observed in symptomatic LDH.

Aggrecans ; biosynthesis ; Alleles ; Humans ; Intervertebral Disc Displacement ; genetics ; Minisatellite Repeats ; Polymerase Chain Reaction ; Polymorphism, Genetic

The ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family consists of 19 proteases. These enzymes are known to play important roles in development, angiogenesis and coagulation; dysregulation and mutation of these enzymes have been implicated in many disease processes, such as inflammation, cancer, arthritis and atherosclerosis. This review briefly summarizes the structural organization and functional roles of ADAMTSs in normal and pathological conditions, focusing on members that are known to be involved in the degradation of extracellular matrix and loss of cartilage in arthritis, including the aggrecanases (ADAMTS-4 and ADAMTS-5), ADAMTS-7 and ADAMTS-12, the latter two are associated with cartilage oligomeric matrix protein (COMP), a component of the cartilage extracellular matrix (ECM). We will discuss the expression pattern and the regulation of these metalloproteinases at multiple levels, including their interaction with substrates, induction by pro-inflammatory cytokines, protein processing, inhibition (e.g., TIMP-3, alpha-2-macroglobulin, GEP), and activation (e.g., syndecan-4, PACE-4).
ADAM Proteins ; antagonists & inhibitors ; chemistry ; genetics ; physiology ; Aggrecans ; metabolism ; Alternative Splicing ; Arthritis ; enzymology ; genetics ; Cartilage ; enzymology ; Endopeptidases ; genetics ; physiology ; Extracellular Matrix ; enzymology ; Humans ; Protein Structure, Tertiary

BACKGROUND: The mechanism by which mutant cartilage oligomeric matrix protein (COMP) induces a pseudoachondroplasia phenotype remains unknown, and the reason why a mutation of a minor protein of the growth plate cartilage causes total disruption of endochondral bone formation has not yet been determined. The current study was performed to investigate the effects of mutated COMP on the synthesis of the cartilage-specific major matrix proteins of Swarm rat chondrosarcoma chondrocytes. METHODS: The Swarm rat chondrosarcoma chondrocytes transfected with a chimeric construct, which consisted of a mutant gene of human COMP and an amino acid FLAG tag sequence, were cultured in agarose gel. Formation of extracellular proteoglycan and type-II collagen by the cells was evaluated by immunohistochemical staining and measuring the (35)S-sulfate incorporation. RESULTS: No difference was observed for the detection of type-II collagen among the cell lines expressing mutant COMP and the control cell lines. Histochemical staining of sulfated proteoglycans with safranin-O showed that lesser amounts of proteoglycans were incorporated into the extracellular matrix of the chondrocytes transfected with the mutant gene. (35)S-sulfate incorporation into the cell/matrix fractions demonstrated markedly lower radiolabel incorporation, as compared to that of the control cells. CONCLUSIONS: Mutation of COMP has an important impact on the processing of proteoglycans, rather than type-II collagen, in the three-dimensional culture of Swarm rat chondrosarcoma chondrocytes.
Aggrecans/analysis/*biosynthesis ; Animals ; Cells, Cultured ; Chondrocytes/*metabolism ; Chondrosarcoma/metabolism ; Collagen Type II/*biosynthesis ; Extracellular Matrix/*metabolism ; Extracellular Matrix Proteins/*genetics ; Glycoproteins/*genetics ; Humans ; Mutation ; Rats ; Transfection

Articular cartilage is a connective tissue consisting of a specialized extracellular matrix (ECM) that dominates the bulk of its wet and dry weight. Type II collagen and aggrecan are the main ECM proteins in cartilage. However, little attention has been paid to less abundant molecular components, especially minor collagens, including type IV, VI, IX, X, XI, XII, XIII, and XIV, etc. Although accounting for only a small fraction of the mature matrix, these minor collagens not only play essential structural roles in the mechanical properties, organization, and shape of articular cartilage, but also fulfil specific biological functions. Genetic studies of these minor collagens have revealed that they are associated with multiple connective tissue diseases, especially degenerative joint disease. The progressive destruction of cartilage involves the degradation of matrix constituents including these minor collagens. The generation and release of fragmented molecules could generate novel biochemical markers with the capacity to monitor disease progression, facilitate drug development and add to the existing toolbox for in vitro studies, preclinical research and clinical trials.
Aggrecans ; chemistry ; genetics ; metabolism ; Animals ; Biomarkers ; metabolism ; Cartilage, Articular ; chemistry ; metabolism ; pathology ; Collagen ; chemistry ; classification ; genetics ; metabolism ; Extracellular Matrix Proteins ; chemistry ; genetics ; metabolism ; Gene Expression ; Humans ; Osteoarthritis ; diagnosis ; genetics ; metabolism ; pathology ; Protein Isoforms ; chemistry ; classification ; genetics ; metabolism

OBJECTIVETo study the effect of RNA interference (RNAi)-mediated aggrecanase-1 gene silencing on extracellular matrix metabolism of cultured rat costochondral chondrocytes.

METHODSRat costochondral chondrocyte monolayers were obtained by microdissection and digestion. The growth and morphological changes of the chondrocytes were observed after RNAi of aggrecanase-1 gene. The mRNA expression of aggrecanase-1 was detected by RT-PCR method, and aggrecan content was determined by Western blotting.

RESULTSThe specific inhibition of aggrecanase-1 by RNAi produced no adverse effect on the morphology and growth of the chondrocytes. The mRNA of aggrecanase-1 decreased and aggrecan content increased significantly after transfection of the chondrocytes.

CONCLUSIONInhibition of aggrecanase-1 decreases aggrecan degradation in cultured rat chondrocytes. RNAi technique can be a useful means for studying extracellular matrix metabolism in the cartilage.

ADAM Proteins ; genetics ; metabolism ; ADAMTS4 Protein ; Aggrecans ; metabolism ; Animals ; Cells, Cultured ; Chondrocytes ; cytology ; metabolism ; Extracellular Matrix ; metabolism ; Female ; Procollagen N-Endopeptidase ; genetics ; metabolism ; RNA Interference ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley ; Transfection

OBJECTIVETo evaluate the effect of interleukin-6 (IL-6) on the biological behaviors of the chondrocytes in the cartilage endplate of rabbits.

METHODSChondrocytes isolated from the cartilage endplate of New Zealand rabbits, verified for their biological characteristics by such means as toluidine blue staining for type II collagen, were treated with IL-6 at different concentrations. The proliferation of the chondrocytes was evaluated by MTT assay at different time points following the treatment, the cell cycle changes were determined by flow cytometry and the changes of aggrecan and type II collagen mRNAs detected by RT-PCR.

RESULTSAt the concentrations of 10, 50 and 100 ng/ml, IL-6 did not obviously affect the rate of chondrocyte proliferation. IL-6 at 50 ng/ml resulted in no obvious changes of the cell cycle of the chondrocytes, but significantly decreased the expression of collagen IIa mRNA.

CONCLUSIONIL-6 has no effect on the proliferation and cell cycle of the chondrocytes, but at higher concentrations, it inhibits matrix synthesis of the chondrocytes to promote intervertebral disc degeneration.

Aggrecans ; genetics ; Animals ; Cartilage ; cytology ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Chondrocytes ; cytology ; drug effects ; metabolism ; Collagen Type II ; genetics ; Female ; Gene Expression Regulation ; drug effects ; Interleukin-6 ; pharmacology ; Male ; RNA, Messenger ; genetics ; metabolism ; Rabbits

OBJECTIVETo explore the isolation, in vitro culture and chondrogenic differentiation of goat bone marrow mesenchymal stem cells (BMSCs).

METHODSBone marrow was harvested from a 10-month-old Chinese goat for adherent culture of the BMSCs in vitro. Flow cytometry was performed to detect the cell surface markers of the BMSCs of the fourth generation. The induction medium (containing 10% fetal bovine serum, high-glucose DMEM, 6.25 microg/ml insulin, 6.25 microg/ml transferrin, 50 microg/ml vitamin C, 100 nmol/L DXM and 10 ng/ml transforming growth factor-beta1) was then applied for chondrogenic differentiation. Cytochemical staining, RT-PCR and Western blotting were performed to detect the expressions of type II collagen and aggrecan in the cells at the time points of 0, 1, 2 and 4 weeks.

RESULTSThe goat BMSCs grow well in vitro with a high purity in the fourth generation. The expression of chondrocyte phenotypes were observed at 1, 2 and 4 weeks, which became more obvious as the culture prolonged. The mRNA and protein expression of type II collagen and aggrecan in the BMSCs increased obvious after the induction and had reached a satisfactory level by 2 weeks.

CONCLUSIONGoat BMSCs have the potential to differentiate into chondrocytes in vitro, and the results of this study provide the experimental basis for application of goat BMSCs in bone and cartilage tissue engineering in vivo.

Aggrecans ; genetics ; metabolism ; Animals ; Bone Marrow Cells ; cytology ; Cell Culture Techniques ; Cell Differentiation ; Cell Separation ; Cells, Cultured ; Chondrocytes ; cytology ; Collagen Type II ; genetics ; metabolism ; Goats ; Mesenchymal Stromal Cells ; cytology ; RNA, Messenger ; genetics ; metabolism

OBJECTIVETo study the inhibitory effect of T-2 toxin on the expression of aggrecan and collagen II in chondrocytes and the protection of selenium against this effect.

METHODSHuman chondrocytes cultured in vitro were treated with T-2 toxin at different concentrations for varied time periods (1-5 days), and the cell viability was measured by MTT assay. Aggrecan expression was detected by toluidine blue staining and collagen II expression by immunostaining using monoclonal antibody of collagen. Aggrecan and collagen II mRNA expressions were measured by semiquantitative RT-PCR.

RESULTST-2 toxin dose- and time-dependently affected chondrocyte viability within the concentration range of 0.001-2 mg/L, the prolonged treatment time further enhanced the dose dependence of the inhibitory effect. T-2 toxin lowered aggrecan and collagen II synthesis in the chondrocytes and reduced their mRNA expressions. Selenium could partly attenuate the inhibitory effects of T-2 toxin on aggrecan mRNA expression, but showed no such effect against T-2-induced collagen II expression.

CONCLUSIONT-2 toxin can obviously inhibit aggrecan and collagen II synthesis in human chondrocytes, and selenium can partly antagonize the inhibitory effects of T-2 toxin on aggrecan.

Aggrecans ; biosynthesis ; genetics ; Cells, Cultured ; Chondrocytes ; cytology ; metabolism ; Collagen Type II ; biosynthesis ; genetics ; Dose-Response Relationship, Drug ; Fetus ; Humans ; Protective Agents ; pharmacology ; RNA, Messenger ; biosynthesis ; genetics ; Selenium ; pharmacology ; T-2 Toxin ; toxicity