RESUMO
Human umbilical cord mesenchymal stem cells (UCMSCs) have recently been shown to hold great therapeutic potential for the treatment of spinal cord injury (SCI). However, the number of engrafted cells has been shown to decrease dramatically post-transplantation. Physioxia is known to enhance the paracrine properties and immune modulation of stem cells, a notion that has been applied in many clinical settings. We therefore hypothesized that preconditioning of UCMSCs in physioxic environment would enhance the regenerative properties of these cells in the treatment of rat SCI. UCMSCs were pretreated with either atmospheric normoxia (21% O2, N-UCMSC) or physioxia (5% O2, P-UCMSC). The MSCs were characterized using flow cytometry, immunocytochemistry, and real-time polymerase chain reaction. Furthermore, 10(5) N-UCMSC or P-UCMSC were injected into the injured spinal cord immediately after SCI, and locomotor function as well as cellular, molecular and pathological changes were compared between the groups. We found that N-UCMSC and P-UCMSC displayed similar surface protein expression. P-UCMSC grew faster, while physioxia up-regulated the expression of trophic and growth factors, including hepatocyte growth factor (HGF), brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor(VEGF), in UCMSCs. Compared to N-UCMSC, treatment with P-UCMSC was associated with marked changes in the SCI environment, with a significant increase in axonal preservation and a decrease in the number of caspase-3+ cells and ED-1+ macrophages. These changes were accompanied by improved functional recovery. Thus, the present study indicated that preculturing UCMSCs under 5% lowered oxygen physioxic conditions prior to transplantation improves their therapeutic potential for the treatment of SCI in rats.
Assuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical/métodos , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/metabolismo , Traumatismos da Medula Espinal/terapia , Animais , Apoptose , Hipóxia Celular , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Modelos Animais de Doenças , Humanos , Macrófagos/patologia , Macrófagos/fisiologia , Células-Tronco Mesenquimais/patologia , Microglia/patologia , Microglia/fisiologia , Regeneração Nervosa , Distribuição Aleatória , Ratos , Recuperação de Função Fisiológica , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/fisiopatologiaRESUMO
<p><b>OBJECTIVE</b>To analyze the risk factors of nonspecific low back pain in community populations.</p><p><b>METHODS</b>Two community populations were investigated using questionnaires in this case-control study. The questionnaire was designed to collect data including age, gender, body weight, marriage, education, income, occupation, labor intensity, smoking, alcohol drinking and social mental status. The subjects with low back pain constituted the case group and those without low back pain served as the control group, and the data was analyzed by a Logistic regression model.</p><p><b>RESULTS</b>A total of 1747 community residents participated in this survey, among whom 398 subjects had low back pain and 1126 subjects without low back pain were selected as the control group. Of all the latent risk factors of low back pain in Logistic regression model, gender was the most relevant factor (OR=3.5522) followed by education (OR=1.958), labor intensity (OR=1.956), marital status (OR=1.612), vibration source exposure (OR=1.491), BMI (OR=1.127) and age (OR=1.060).</p><p><b>CONCLUSION</b>Gender, education, labor intensity, marriage, vibration source exposure and BMI are risk factors of nonspecific low back pain in community populations, and exercises and mental status can be protective factors against low back pain.</p>
