Waranee Pradit

Effects of corticosteroids and their combinations with hyaluronanon on the biochemical properties of porcine cartilage explants

BackgroundIntra-articular injection of corticosteroids is used to treat the inflammatory pain of arthritis and osteoarthritis (OA), but our previous study found a deleterious effect of these steroids on chondrocyte cells. Hyaluronic acid (HA) injection has been suggested as a means to counteract negative side effects through replenishment of synovial fluid that can decrease pain in affected joints. To better understand the effects of corticosteroids on these processes, dexamethasone (Dex) and prednisolone (Pred) were administered to porcine cartilage explants at several concentrations with and without HA. We examined corticoid effects by determining sulfate-glycosaminoglycan (s-GAG) and uronic acid (UA) content of the explant media, and safranin-O staining of the cells. Analysis of lactate dehydrogenase (LDH) activity was conducted to assess cell cytotoxicity.ResultsDex treatment significantly reduced cellular cytotoxicity compared to the other treatment groups, especially with regards to the release of s-GAG, and protects against superficial proteoglycan damage. However, there was no difference between Pred and Dex, with and without HA, in the UA content remaining in porcine cartilage explants.ConclusionsThe data suggest that combinations of Dex and Pred with HA did not have a significant effect on protection or enhancement of the articular cartilage matrix under the current conditions.

Differences in osteon structure histomorphometry between puppyhood and adult stages in the Golden Retriever

Osteon structure has been widely studied in mammals, but osteon structure in dogs has received relatively little attention, especially in terms of whether aging has any effect on osteon structure. The aim of this study was to compare the osteon structure of both flat (scapula and os coxae) and long bones (humerus, radius, ulna, metacarpus, femur and tibia) of male puppy and adult Golden Retrievers. We examined five parameters: Haversian canal diameter, Haversian canal area, osteon diameter, osteon area, and number of lacunae per osteon. Our results show that the values for Haversian canal diameter were significantly higher in the os coxae and tibia, but significantly lower in the femur of adult dogs as compared to those of puppies. The Haversian canal diameter of the other bones investigated did not show any significant differences between puppies and adult dogs. The Haversian canal area was significantly greater in the os coxae, radius and femur of adult dogs than in those of puppies. The osteon diameter and area of every bone examined were significantly smaller in puppies than in adult dogs. Lastly, the number of lacunae per osteon showed the same trend as osteon diameter and area. Plexiform bone could be found in three bones in puppies, i.e. the femur, humerus and tibia. Overall, the results of this study should provide basic knowledge on the microanatomy of cortical bone in dogs and on the possible influence age.

Articular Cartilage Gene Expression after Coxofemoral Joint Luxation in the Dog

This study examined the relationship between days of hip luxation and the expression of various mRNA. Twenty-six articular cartilages were used in the experiment: 3 samples were from normal dogs and 23 samples were collected from the femoral heads of hips that had been luxated for different lengths of time. Ten mRNA, including nonapoptotic genes (AGG, COL2A1, MMP-3, HAS-1, HAS-2, and TIMP-1) and apoptotic genes (BAX, BCL-2, CAS-3, and CAS-9), were studied for their expression using real-time PCR. We found very high correlation between expression level and luxation days (r 2 > 0.9) in COL2A1, MMP-3, HAS-1, HAS-2, TIMP-1, BAX, and CAS-9, while the others (AGG, BCL-2, and CAS-3) also showed high correlation (r 2 = 7–9). And we found a significant difference (P < 0.05) in the expression of transcripts depending on the number of luxation days. In conclusion, a delay in joint reduction may increase the chances of development of osteoarthritis.

In vitro Effects of Polysaccharide Gel Extracted from Durian Rinds (Durio zibethinus L.) on the Enzymatic Activities of MMP-2, MMP-3 and MMP-9 in Canine Chondrocyte Culture

Osteoarthritis (OA) is a major joint disease found in animals, especially dogs, with 20% rate of incidence. The alternative therapy using medicinal plants has been of interest for a long time. Polysaccharide gel (PG) extracted from durian rinds (Durio zibethinus L.) was first isolated in 1998 for use in pharmaceuticals with its efficiency in open wound healing and antimicrobial activity. In this study, different concentrations of PG (1-100 g/ml) were used to evaluate the effect on canine chondrocytes through enzymatic activities of matrix metalloproteinase 2 (MMP-2), MMP-3 and MMP-9 concerning OA. The results showed that both proteolytic activities of MMP-2 and MMP-9 were inhibited significantly using the extract starting at a concentration of 50 g/ml. For MMP-3, enzymatic activity could not be inhibited by the PG extract in canine chondrocytes at any concentration level (1-100 g/ml). This could suggest that PG extract has a strong potential to inhibit MMP-2 and MMP-9 activities.

Dystroglycan 1: A new candidate gene for patellar luxation in Chihuahua dogs

Aim: The objective of this study was to uncover new candidate genes related to patellar luxation (PL) in dogs to select for those with low susceptibility for breeding purposes. Materials and Methods: The inter simple sequence repeat (ISSR) technique was performed to construct DNA fingerprints of 61 Chihuahua dogs with PL and 30 healthy Chihuahua dogs. DNA polymorphisms were detected by comparing the sequences between the affected and unaffected dogs, using the pairwise alignments in MultAlin. Genotyping was performed using allele-specific polymerase chain reaction (AS-PCR). The association analysis of ISSR DNA fingerprints and genotypes or phenotypes was performed using the Chi-square (χ2) model and generalized linear model (GLM), respectively. Results: Two single nucleotide polymorphisms (SNPs), namely SNP1UBC811 (g.91175C>G) and SNP2UBC811 (g.92259T>C), were found in the intron of the Dystroglycan 1 (DAG1) gene, which was obtained using the PL-related marker UBC811 primer (p=0.02), and genotyped by AS-PCR. When investigated using the GLM, g.91175C>G had a significant association with PL (p=0.0424), whereas g.92259T>C did not have such an association (p=0.0959). Conclusion: DAG1 might be one of the genes related to PL in Chihuahuas and could aid the process of marker-assisted selection in genetic breeding for Chihuahua dogs without PL.

Comparison of the effects of cefazolin and ceftriaxone on canine chondrocyte culture

Cephalosporins (CEFs) are antibiotics frequently used to treat bone infections and septic arthritis. The effects of CEFs on chondrocytes have not been studied until now. Cefazolin (cef1) and ceftriaxone (cef3), first-and third-generation CEFs, were selected to investigate their direct effects on normal and osteoarthritic (OA) primary canine chondrocytes, which were either nonstimulated or stimulated with the pro-inflammatory cytokine IL-1β. In our results, treatment with CEFs increased the negative effects on both conditioned normal and OA chondrocytes, especially when applied to IL-1β-stimulated cells (inflammatory stimulus). CEFs significantly decreased cell viability and induced apoptotic cell death in both normal and OA chondrocytes; moreover, treatment with cef1 caused necrotic cell death in OA chondrocytes. Cef3 treatment could increase s-GAG synthesis in normal cells preincubated with IL-1β, while cef1 had no significant effect. The expression of TNF was clearly downregulated after cef3 treatments, whereas it was upregulated after cef1 treatments. However, cef3 induced stronger downregulation of TIMP1 and the extracellular matrix component genes COL2A1 and ACAN. In conclusion, these results suggest both the cytotoxic effects of CEFs and their adverse effects on chondrogenic marker genes at the transcriptional level, which provide additional insight into the clinical application of cef1 and cef3.