To define the clinical, pathological and molecular genetic characteristics of a family with mild spondyloepiphyseal dysplasia (SED) and precocious osteoarthritis.The proband was a 46-year-old man with precocious generalized OA, tall stature, mild chondrodysplasia and moderate deafness. His daughter, aged 21, showed similar clinical features. Electron microscopic (EM) analysis of collagen from an affected joint of the proband was performed. DNA was extracted from whole blood on the proband, his affected daughter, unaffected wife and second daughter, to look for a mutation in exons 31 or 11, sites where point mutations have been previously described in mild forms of SED. After finding no mutation in exon 31, exon 11 of COL2A1 was further analyzed. Exon 11 was amplified using polymerase chain reaction (PCR), and screening for the mutation was undertaken using a restriction enzyme digestion, the recognition sequence of which is altered by this point mutation. Sequence analysis was then performed.Electron microscopic (EM) analysis of cartilage from the proband showed thin appearing collagen fibrils organized into parallel lamellar structures. DNA studies revealed a single base change in one allele of exon 11 which produced an arginine to cysteine mutation at position 75 of the triple helix of type II collagen in the proband and his affected daughter.This is the 2nd example of an Arginine75-Cysteine mutation associated with SED; in our case, however, contrasting clinical features were present. Recurrent mutations at a few specific sites of COL2A1 suggest the possibility of susceptibility "hot spots" for mutational events.
Mitochondrial dysfunction, oxidative stress and chondrocyte death are important contributors to the development and pathogenesis of osteoarthritis (OA). In this study, we determined the expression and role of Parkin in the clearance of damaged/dysfunctional mitochondria, regulation of reactive oxygen species (ROS) levels and chondrocyte survival under pathological conditions.Human chondrocytes were from the unaffected area of knee OA cartilage (n = 12) and were stimulated with IL-1β to mimic pathological conditions. Mitochondrial membrane depolarization and ROS levels were determined using specific dyes and flow cytometry. Autophagy was determined by Western blotting for ATG5, Beclin1, immunofluorescence staining and confocal microscopy. Gene expression was determined by RT-qPCR. siRNA, wild-type and mutant Parkin plasmids were transfected using Amaxa system. Apoptosis was determined by PI staining of chondrocytes and TUNEL assay.IL-1β-stimulated OA chondrocytes showed high levels of ROS generation, mitochondrial membrane damage, accumulation of damaged mitochondria and higher incidence of apoptosis. IL-1β stimulation of chondrocytes with depleted Parkin expression resulted in sustained high levels of ROS, accumulation of damaged/dysfunctional mitochondria and enhanced apoptosis. Parkin translocation to depolarized/damaged mitochondria and recruitment of p62/SQSTM1 was required for the elimination of damaged/dysfunctional mitochondria in IL-1β-stimulated OA chondrocytes. Importantly we demonstrate that Parkin elimination of depolarized/damaged mitochondria required the Parkin ubiquitin ligase activity and resulted in reduced ROS levels and inhibition of apoptosis in OA chondrocytes under pathological conditions.Our data demonstrates that Parkin functions to eliminate depolarized/damaged mitochondria in chondrocytes which is necessary for mitochondrial quality control, regulation of ROS levels and chondrocyte survival under pathological conditions.
Multiple TCRBV genes have been implicated in experimental autoimmune myasthenia gravis (EAMG) pathogenesis in susceptible H-2(b) strains of mice. We studied the contribution of specific TCRBV and AV genes in EAMG pathogenesis using B10.BV8S2 transgenic mice (H-2[b]). The TCR transgenic mice predominantly have TCRBV8S2 transgene, but can use any of the endogenous AV gene repertoire. The transgenic mice were immunized with acetylcholine receptor (AChR) in CFA and evaluated for EAMG pathogenesis. Although the lymphocyte responses to AChR in B10.BV8S2 transgenic and nontransgenic TCR wild-type mice were equivalent, a marked reduction in lymphocyte response to the dominant AChR alpha chain peptide 146-162 was observed in the TCR transgenic mice. After boosting with AChR in CFA, anti-AChR Abs were detected in the serum, and 14 of 42 (33%) of the TCR transgenic mice developed clinical EAMG. Furthermore, EAMG in TCR transgenic mice was prevented by treatment with mAb to TCRBV8, which depleted BV8-expressing T cells. Cloning and sequencing of TCRAV genes from AChR-reactive T cells from B10.BV8S2 transgenic mice revealed a pattern of restricted TCRAV gene usage. The majority (60%) of the clones sequenced showed a sequence identical with that of the TCRAV1S8 gene. In the normal spleen cells of TCR transgenic mice, AV gene usage was more random. Thus, despite the presence of a complete endogenous TCRAV repertoire in B10.BV8S2 transgenic mice, T cells responding to AChR preferentially used a single endogenous TCRAV gene, thus implicating the involvement of the TCRAV1S8 gene in EAMG pathogenesis.
This article contains data related to the article "Wogonin, a plant derived small molecule exerts potent anti-inflammatory and chondroprotective effects through activation of ROS/ERK/Nrf2 signaling pathways in human Osteoarthritis chondrocytes" (Khan et al. 2017) [1]. The data are related to effects of Wogonin on the viability and IL-1β-stimulated activation of NF-κB and ERK1/2, JNK1/2 and p38 MAPKs in human OA chondrocytes. Gene expression data representing the chondrogenic phenotype and the efficiency of Nrf2 knockdown in monolayer culture of human OA chondrocytes were shown. Moreover, mass spectrometric calibration curve of Wogonin used to quantify the intracellular uptake were also presented. The data are presented in the form of figures and significance of these has been given in the research article (Khan et al. 2017) [1].
Osteoarthritis (OA) of the knee and hip is a debilitating disease affecting more women than men and the risk of developing OA increases precipitously with aging. Rheumatoid arthritis (RA), the most common form of inflammatory joint diseases, is a disease of unknown etiology and affects approximately 1% of the population worldwide, and unlike OA, generally involves many joints because of the systemic nature of the disease. Non-steroidal anti-inflammatory drugs (NSAIDs) are the first drugs of choice for the symptomatic treatment of both OA and RA. Because of the risks associated with the use of NSAIDs and other limitations, the use of alternative therapies, such as acupuncture and medicinal herbs, is on the rise and according to reports approximately 60-90% of dissatisfied arthritis patients are likely to seek the option of complementary and alternative medicine (CAM). This paper reviews the efficacy of some of the common herbs that have a history of human use and their anti-inflammatory or antiarthritic properties have been evaluated in animal models of inflammatory arthritis, in studies employing well defined and widely accepted in vitro models that use human chondrocytes/cartilage explants or in clinical trials. Available data suggests that the extracts of most of these herbs or compounds derived from them may provide a safe and effective adjunctive therapeutic approach for the treatment of OA and RA. This, in turn, argues for trials to establish efficacy and optimum dosage of these compounds for treating human inflammatory and degenerative joint diseases.