Digest Journal of Nanomaterials and Biostructures Vol. 5, No 3, July 2010, p. 857 – 862 PAPER FOR CONTROL COMPARATIVE STUDY OF CONNEXINS EXPRESSION IN DIABETIC AND NONDIABETIC WOUNDS SURABHI BAJPAI , MANISH MISHRA a , HEMANT KUMAR a , KAMLAKAR TRIPATHI a , SANTOSH KUMAR SINGH b , SARIPELLA SRIKRISHNA, HAUSHILA PRASAD PANDEY, RAKESH KUMAR SINGH * , Department of Biochemistry, Faculty of Science a Department of Medicine, Institute of Medical Sciences b Centre for Experimental Medicine and Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi – 211 005, India Wound healing is the synchronized interplay of interaction of several cellular and biochemical components. In case of diabetes this normal course of wound healing is delayed. The mechanism behind the delayed wound healing in diabetes remains unexplored. The passage of various apoptotic and inflammatory signals via gap junctions play an important role in tissue remodeling during diabetic wound healing. In this study, we compared the expression of the following connexins (Cx) namely Cx26, Cx30.3, Cx31, Cx31.1, Cx37, Cx40, Cx43 in diabetic and non-diabetic wounds. A significant increase in the levels of Cx26, Cx30.3, Cx31, Cx31.1, Cx43 with the commencement of wound repair was observed in diabetic wounds as compared to non-diabetic wounds. In contrast, Cx37 and Cx40 were not expressed in either in diabetic or non diabetic wounds. The results of this study suggest that cellular cross talking via gap junctions is as much vital during proper wound healing, and an up regulated connexin expression might leads to improper gap junctions formation attributing to the passage of various, apoptotic and inflammatory signals thereby resulting in delayed healing of chronic diabetic ulcers. (Received June 21, 2010; after revision July 26, 2010; accepted Keywords: Gap junctions, connexins, angiogenesis, diabetes, wound healing 1. Introduction According to studies carried out by World Health Organization (WHO), approximately 220 million people are suffering from diabetes worldwide, and India has the largest number of diabetic patients and the number may even go up to 69.9 million by the year 2025 [1, 2]. Chronic and persistent wounds are the common secondary complications in uncontrolled diabetes associated with significant morbidity and ailment. Diabetic foot ulcers alone are estimated to occur in 15% of total diabetic patients [3, 4]. Despite several scientific studies conducted worldwide, the etiology and underlying mechanisms of this disease have yet not been completely explored. Wound healing is the key survival process in all organisms, which involves orchestrated interplay of several cell types, proteins, proteinases, cytokines, angiogenic factors. It involves several biochemical processes of tissue repair like granular tissue formation, angiogenesis and reepithelialization [5]. All these events involve active participation of various cell types like endothelial and fibroblast cells, keratinocytes and their cross talk through gap junctions play an important role during wound healing process [6]. Connexins (Cx), the gap junction proteins, form channels between two adjacent cells and their expression is highly regulated after wound formation at the transcriptional, translational and post translational levels [7]. Till date nearly 20 connexin genes have been identified in mouse genome and 21 in the human genome [8]. Gap * Corresponding author: rakeshbhu@yahoo.com