Bone homeostasis seems to be controlled by delicate and subtle “cross talk” between the nervous system and “osteo-neuromediators” that control bone remodeling. The purpose of this study was to evaluate the effect of interactions between neuropeptides and human bone morphogenetic protein 2 (hBMP2) on human osteoblasts. We also investigated the effects of neuropeptides and hBMP2 on gap junction intercellular communication (GJIC). Osteoblasts were treated with neuropeptide Y (NPY), substance P (SP), or hBMP2 at three concentrations. At various intervals after treatment, cell viability was measured by the MTT assay. In addition, cellular alkaline phosphatase (ALP) activity and osteocalcin were determined by colorimetric assay and radioimmunoassay, respectively. The effects of NPY, SP and hBMP on GJIC were determined by laser scanning confocal microscopy. The viability of cells treated with neuropeptides and hBMP2 increased significantly in a time-dependent manner, but was inversely associated with the concentration of the treatments. ALP activity and osteocalcin were both reduced in osteoblasts exposed to the combination of neuropeptides and hBMP2. The GJIC of osteoblasts was significantly increased by the neuropeptides and hBMP2. These results suggest that osteoblast activity is increased by neuropeptides and hBMP2 through increased GJIC. Identification of the GJIC-mediated signal transduction capable of modulating the cellular activities of bone cells represents a novel approach to studying the biology of skeletal innervation.

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Purpose: Osteoarthritis (OA) is the most prevalent musculoskeletal disorder worldwide. It is a persistent debilitating disease of weightbearing synovial joints, knee being the most affected joint. Degradation of articular cartilage is the structural trademark of the disease. There is growing concern regarding the impact of knee OA on the quality of life (QoL) of individuals. The RAND 36 item Short Form Health Survey (SF-36) questionnaire is a generic measure to quantify the health related quality of life (QoL) under eight physical and emotional domains. This study was conducted to explore/ assess the status of QoL in knee OA subjects and correlation of each domain with age, gender, radiological Kellgren & Lawrence (KL) grade, WOMAC score, VAS score and MRI based articular cartilage volume. Methods: In this cross-sectional study, a total of sixty subjects with KOA were recruited using American College of Rheumatology criteria from the outpatient clinic of Orthopaedic Department of King George's Medical University (KGMU). The study was approved by Institutional Ethics Committee of KGMU. Informed consent was obtained from all the participants. The exclusion criteria for KOA subjects were evidence of secondary OA such as gout, infection, trauma, congenital & developmental disorders affecting knee joint and contraindication to MRI (metal implant, claustrophobia, pregnancy). In subjects with bilateral KOA, left knee was chosen for analysis. Radiological imaging (weight bearing antero-posterior view) of the selected knee was performed. In unilateral KOA, the knee with clinical symptoms was similarly imaged. Radiographs were evaluated for severity by KL grading system. Each subject had MRI of the same knee for which X-ray was performed. Knees were imaged on 1.5 Tesla whole body magnetic resonance unit (GE Signa Excite) using a commercial transmit-receive extremity coil. ACV was measured by means of image processing on an independent work station using software programme AW Volume Share 4.The selfreported pain, stiffness and physical function were assessed using subscales of the Western Ontario and McMaster Universities (WOMAC) index along with total WOMAC scores in subjects with KOA. Visual Analogue Scale (VAS) score was also used for pain assessment. SF-36 item health related survey RAND-36 sub-scales were used to assess quality of life of the subjects. All the variables were compared with domains of SF-36 questionnaire. Results: The mean percentage in QoL domains were 32.22 (general health), 46.38 (pain), 46.66 (physical function), 55.55 (role limitation (RL) due to physical health), 66.65 (RL due to emotional problems), 48.33 (energy/ fatigue), 62.22 (emotional well being), 75 (social functioning). Mean age of the subjects was 50.38þ12.08 years and it was significantly correlated with physical function domain of QoL. A statistically significant difference in QoL between both the genders was observed in physical function (p¼0.04), RL due to physical health (< 0.001), energy/ fatigue (p¼0.013), emotional well being (p¼0...