Monocyte Chemotactic Proteins Mediate the Effects of Hyperglycemia in Chondrocytes: In Vitro Studies

Chemokines in Cartilage Regeneration and Degradation: New Insights

Cartilage plays a crucial role in the human body by forming long bones during development and growth to bear loads on joints and intervertebral discs. However, the increasing prevalence of cartilage degenerative disorders is a growing public health concern, especially due to the poor innate regenerative capacity of cartilage. Chondrocytes are a source of several inflammatory mediators that play vital roles in the pathogenesis of cartilage disorders. Among these mediators, chemokines have been explored as potential contributors to cartilage degeneration and regeneration. Our review focuses on the progress made during the last ten years in identifying the regulators and roles of chemokines and their receptors in different mechanisms related to chondrocytes and cartilage. Recent findings have demonstrated that chemokines influence cartilage both positively and negatively. Their induction and involvement in either process depends on the local molecular environment and is both site- and time-dependent. One of the challenges in defining the role of chemokines in cartilage pathology or regeneration is the apparent redundancy in the interaction of chemokines with their receptors. Hence, it is crucial to determine, for each situation, whether targeting specific chemokines or their receptors will help in developing effective therapeutic strategies for cartilage repair.

Ascorbic Acid vs Calcitriol in Influencing Monocyte Chemoattractant Protein-1, Nitric Oxide, Superoxide Dismutase, as Markers of Endothelial Dysfunction: In Vivo Study in Atherosclerosis Rat Model

Introduction

Ascorbic acid and calcitriol were frequently utilized in conjunction as therapy during the COVID-19 pandemic, and individuals with minor symptoms had notable improvements. There have been a few studies, often with conflicting findings, that examine the use of them for endothelium restoration and numerous clinical trial studies that failed to establish the efficacy. The aim of this study was to find the efficacy of ascorbic acid compared to calcitriol on the inflammatory markers monocyte chemoattractant protein-1 (MCP-1), nitric oxide (NO), and superoxide dismutase (SOD), as protective agents which play an important role in the early stages of atherosclerosis formation. This study was an experimental in vivo study.

Methods

The total of 24 male Rattus norvegicus strain Wistar rats were divided into 4 groups, namely: control/normal group (N), atherosclerosis group (DL) given atherogenic diet, atherosclerosis group given atherogenic diet and ascorbic acid (DLC), and atherosclerosis group given atherogenic diet and calcitriol (DLD) treatment for 30 days.

Results

Ascorbic acid and calcitriol treatment was significantly effective (P<0.05) in lowering expression of MCP-1 and increasing NO and SOD level. Calcitriol was superior to ascorbic acid in increasing SOD (P<0.05). There was no significant difference between ascorbic acid and calcitriol in decreasing MCP-1 and increasing NO (P>0.05).

Discussion

Both treatments could reduce MCP-1, and increase NO and SOD by increasing antioxidants. In this study calcitriol was superior to ascorbic acid in increasing SOD, but not NO and decreasing MCP-1. According to the theory, it was found that calcitriol through nuclear factor erythroid 2-related factor 2 (Nrf2) causes a direct increase in the amount of SOD. Nrf2 is an emerging regulator of cellular resistance to oxidants.

Conclusion

Ascorbic acid and calcitriol treatment was able to reduce MCP-1 and increase NO and SOD in atherosclerosis rat. Calcitriol was significantly superior in increasing SOD levels compared to ascorbic acid.