Connexin 43-modified bone marrow stromal cells reverse the imatinib resistance of K562 cells via Ca 2+ -dependent gap junction intercellular communication / 中华医学杂志(英文版)

BACKGROUND@#Imatinib mesylate (IM) resistance is an emerging problem for chronic myeloid leukemia (CML). Previous studies found that connexin 43 (Cx43) deficiency in the hematopoietic microenvironment (HM) protects minimal residual disease (MRD), but the mechanism remains unknown.@*METHODS@#Immunohistochemistry assays were employed to compare the expression of Cx43 and hypoxia-inducible factor 1α (HIF-1α) in bone marrow (BM) biopsies of CML patients and healthy donors. A coculture system of K562 cells and several Cx43-modified bone marrow stromal cells (BMSCs) was established under IM treatment. Proliferation, cell cycle, apoptosis, and other indicators of K562 cells in different groups were detected to investigate the function and possible mechanism of Cx43. We assessed the Ca 2+ -related pathway by Western blotting. Tumor-bearing models were also established to validate the causal role of Cx43 in reversing IM resistance.@*RESULTS@#Low levels of Cx43 in BMs were observed in CML patients, and Cx43 expression was negatively correlated with HIF-1α. We also observed that K562 cells cocultured with BMSCs transfected with adenovirus-short hairpin RNA of Cx43 (BMSCs-shCx43) had a lower apoptosis rate and that their cell cycle was blocked in G0/G1 phase, while the result was the opposite in the Cx43-overexpression setting. Cx43 mediates gap junction intercellular communication (GJIC) through direct contact, and Ca 2+ is the key factor mediating the downstream apoptotic pathway. In animal experiments, mice bearing K562, and BMSCs-Cx43 had the smallest tumor volume and spleen, which was consistent with the in vitro experiments.@*CONCLUSIONS@#Cx43 deficiency exists in CML patients, promoting the generation of MRD and inducing drug resistance. Enhancing Cx43 expression and GJIC function in the HM may be a novel strategy to reverse drug resistance and promote IM efficacy.

The clinical observation of serum specific biomarkers in patients with chronic graft-versus-host disease / 中华血液学杂志

Objective@#Chronic graft-versus-host disease (cGVHD) is a major long-term complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT) . It is important to study the changes of serum biomarkers expression in patients for early diagnosis and treatment.@*Methods@#The expression levels of five serum protein markers (IL-1b, IL-16, CXCL9, CCL19, CCL17) in patients with or without cGVHD after allo-HSCT were detected by liquid suspension microarray.@*Results@#Compared with the control group without cGVHD, the expression levels of CXCL9 and CCL17 in serum of patients with cGVHD were significantly increased (P<0.05) . CCL17 was correlated with the severity of cGVHD (P<0.001) . CXCL9 was significantly increased in the serum of patients with skin lesion (P<0.01) , and CCL17 was significantly expressed in cGVHD patients with liver as the target organ (P<0.01) .@*Conclusion@#The combination of CXCL9 and CCL17 can be used as serum biomarkers of cGVHD, which has certain reference value in assisting the diagnosis and evaluation of cGVHD severity.

Exploration on the cultivation of medical students' innovation ability based on the extracurricular activities of cell biology class / 中华医学教育探索杂志

The cultivation of innovation ability of medical students is requirement of the Times.Considering the shortcomings of the existing teaching methods,many specialized designs for teaching were implemented in the extracurricular activities of cell biology such as critical literature study,independent experiment and participation in the research of department project.It is proved that this teaching activity did well in expanding the contents of the formal class,training the practicing skills,inspiring independent think ing and improving the ability of research and innovation.

Calcitonin gene-related peptide inhibits the expression of Nod-like receptor protein 3 to Dromote osteoblast differentiation in mouse osteoblasts in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aims to investigate the regulatory effects of calcitonin gene-related peptide (CGRP) on Nod-like receptor protein 3 (NLRP3) and interleukin-1β (IL-1β) to promote osteoblast differentiation.</p><p><b>METHODS</b>Different concentrations of CGRP (0, 10, 30, 100 ng · mL⁻¹) were added to mouse osteoblasts in vitro. The mRNA and protein expression levels of both NLRP3 and IL-1β were examined using Real-time polymerase chain reaction and Western blot, respectively. Moreover, the concentrations of IL-1β protein and intracellular reactive oxygen species (ROS) were detected using enzyme-linked immunosorbent assay and flow cytometry, respectively. The osteogenic differentiation of mouse osteoblasts was identified through alizarin red staining.</p><p><b>RESULTS</b>The protein and mRNA expression levels of both NLRP3 and IL-1β significantly decreased (P < 0.05) with increasing CGRP concentration. Moreover, the contents of intracellular ROS gradually decreased (P<0.05). The osteogenic differentiation of the osteoblasts was more enhanced in the group treated with 100 ng · mL⁻¹ CGRP than in the empty group (0 ng · mL⁻¹ CGRP).</p><p><b>CONCLUSION</b>CGRP promotes osteoblast differentiation by inhibiting the expression of inflammatory factors.</p>

Experimental study on the effects of the nerve growth factor regulating calcitonin gene-related peptide in promoting the proliferation of MG-63 in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the nerve growth factor (NGF) regulating the expression of calcitonin gene-related peptide (CGRP) in promoting the proliferation of osteoblast-like cell (MG-63) and thus illustrate the mechanism of the NGF in wound healing.</p><p><b>METHODS</b>Different concentrations of NGF were used to stimulate MG-63. The expression of CGRP was detected by real-time quantitative polymerase chain reaction (RT-QPCR) and enzyme-linked immunosorbent assay after 1, 2, 3, and 4 days. The proliferation of MG-63 was detected by cell counting kit-8 (CCK-8). The expression of CGRP mRNA and the proliferation of MG-63 were then detected by RT-QPCR and CCK-8 after adding the NGF receptor blocker.</p><p><b>RESULTS</b>Compared with the blank control group, the expression of CGRP significantly increased by stimulating the NGF. The expression of CGRP was positively related to the concentration of NGF (P<0.05). Moreover, the expression of CGRP increased by prolonging the NGF stimulation time. The proliferation of MG-63 increased after stimulating the NGF (P<0.05). After adding the NGF receptor blocker, the expression of CGRP and the proliferation of MG-63 correspondingly decreased (P<0.05).</p><p><b>CONCLUSION</b>NGF can up-regulate the expression of CGRP and increase the proliferation of MG-63. Therefore, NGF plays a significant role in wound healing.</p>

Culture of outer root sheath cells of murine vibrissa follicles in vitro and expression of uPA/uPAR / 第三军医大学学报

Objective To establish a method for the cultivation of hain follicle outer root sheath (ORS) cells of murine vibrissa and to study their expression of uPA/uPAR. Methods The ORS cells of murine vibrissa were cultured by combination of enzyme digestion and tissue culture with the feeder layer of dermal sheath cells of the hair follicle. The cells and their uPA/uPAR expression were identified by immunocytochemistry (ICC). Results The feeder layer of DS was suitable for the culture of ORS cells. ORS cells expressed uPA/uPAR protein. Conclusion The DS of hair follicle is a better feeder layer for the growth of ORS cells. ORS cells have the ability to migrate and proliferate.

Roles of uPA and uPA-R in the course of repair after human embryo corneal alkali burn in vitro / 第三军医大学学报

Objective To explore the roles of urokinase type PA (uPA) and uPA receptor (uPA R) in the course of repair after human embryo corneal alkali burn in vitro . Methods After the alkali burn model in vitro was established successfully, some techniques such as the observation of cell culture and morphology, ICC and image analysis were used. Results No significant difference was found between the cells from corneal limbus and central cornea and almost all of them expressed AE1/AE3. The expressions of uPA and uPA R increased to the maximum at about 24 h after alkali burn. uPA expression distributed mainly in the cytoplasm but uPA R expression distributed mainly in the cell membrane. Conclusion The corneal epithelial cells of comparatively high purity can be acquired by tissue culture. There probably exists difference in development and vitality between embryo and adult cornea. There might be commonness of the roles of uPA and uPA R in epithelial tissue.

Effects of endotoxin preconditioning on NOS activity in rat brain after global brain ischemia/reperfusion / 第三军医大学学报

Objective To determine the effects and significance of endotoxin preconditioning on iNOS activity,nNOS activity in rat cerebral cortex,hippocampus and cerebella region after global brain ischemia/reperfusion.Methods Global ischemia for 20 min was made by four-vessel occlusion model(4-vo) in 60 Wistar rats,among which 30 were injected of 20 ?g/kg MPL through caudal vein 24 h before model establishment.Another 8 rats undergoing sham operation served as controls.The dynamic change of iNOS activity,nNOS activity and neuron density of the cerebral cortex,hippocampus and cerebella region were observed at 1,4,8 h after reperfusion. Results The activity of iNOS and nNOS decreased significantly after endotoxin preconditioning in the regions mentioned above,as compared with that of rats only undergoing the ischemia/reperfusion.The neuron number in rat hippocampus decreased after ischemia/reperfusion,but no significant difference was found between control and endotoxin preconditioning groups.Conclusion The activity of iNOS and nNOS changed significantly after global brain ischemia/reperfusion.That endotoxin preconditioning decreased iNOS and nNOS activities may be the protective mechanism.

Effects of endotoxin preconditioning on inflammatory response after global brain ischemia in rats / 第三军医大学学报

Objective To determine the protective effects of endotoxin preconditioning on the brain ischemic injury and explore its protective mechanism. Methods Global ischemia for 20 min by four-vessel occlusion model was used in 140 Wistar rats, in which 70 rats were pretreated with MPL at dose of 20 ?g/kg 24 h before global ischemia. Another 10 Wistar rats served as normal controls. Ischemic neurons and neuron density of the hippocampal CA1 region, MPO activity, TNF-? activity, IL-1? activity were assayed at 4, 12, 24, 48, 72, 120, 168 h after reperfusion. Results Pretreatment with endotoxin produced significant reductions in ischemic neuron number, MPO activity, TNF-? activity and IL-1? activity. Conclusion Endotoxin preconditioning protects brain from subsequent ischemic injury, in which the suppression of cellular inflammation may be the protective mechanism.