Objective To study the effect of signal-selective parathyroid hormone (PTH) analogue peptide on Wnt signal ing factors in osteoblasts isolated from neonatal mouse, and provide theoretical basis for the mechanism of PTH’s function in bone metabolism. Methods Osteoblasts were isolated from calvaria of 2-3-day-old C57BL neonatal mouse and identified by alkal ine phosphatase (ALP) staining, and Alizarin red staining. The cells at passage 1 were divided into 4 groups: control group, PTH (1-34) group, G1R19 (1-34) group, and G1R19 (1-28) group. Then the medium was changed to α-MEM supplemented with 1%FBS. After 12 hours, trifluoroacetic acid or three peptides [(10 nmol/L PTH (1-34), 10 nmol/L G1R19 (1-34), and 100 nmol/L G1R19 (1-28)] were added into the culture medium. After 4 hours, the cells were washed gently ithcold PBS 3 times before total RNA was isolated. The expressions of Wnt related genes were measured by quantitative eal-time PCR. Results Most of the cells were polygonal and triangular; the cells were positive for ALP staining with blue cytoplasm at 14 days and the Al izarin red staining showed the formation of red mineral ized nodules in the special mineral ization induction medium at 28 days. The expressions of osteocalcin mRNA and Wnt5b mRNA in PTH (1-34) group, G1R19 (1-34) group, and G1R19 (1-28) group were significantly higher than those in control group (P lt; 0.05); the expression of Wnt2 mRNA was significantly lower than that in control group (P lt; 0.05); the expression of β-catenin mRNA in PTH (1-34) group was significantly higher than that in control group (P lt; 0.05); the expression of Wnt7b mRNA in PTH (1-34) group and G1R19 (1- 34) group was higher than that in control group, and the G1R19 (1-34) group was higher than PTH (1-34) group and G1R19 (1-28) group (P lt; 0.05). Conclusion In the Wnt-related factors, PTH (1-34) and G1R19 (1-34) affect mainly canonical Wnt signal factors, but the G1R19 (1-28) chiefly acts on non-canonical Wnt signal factors.
Objective To summarize the regulations of Hedgehog signal ing pathway on the prol iferation and multidifferentiation of mesenchymal stem cells (MSCs). Methods The related l iterature in recent years concerning the regulations of Hedgehog signal ing pathway on the biological characteristics of MSCs was reviewed and analyzed. Results Hedgehog signal ing pathway promoted the prol iferation of MSCs, and played a major role in the induction of osteogenic and chondrogenic differentiations, but it inhibited the adi pocytic differentiation. Conclusion The regulations of Hedgehog signal ing pathway in MSCs multidifferentiation and prol iferation could be used as the new therapeutic targets of tissue ischemia, osteoporosis, achondroplasia, obesity, and so on.
Objective To investigate the structure characteristics， functions， and research progress of Notch signaling pathway in digestive tumors. Methods The related literatures about the molecular genetic mechanism of Notch signaling pathway were reviewed. Results The Notch signaling pathway plays an important role not only in normal cells’ growth， differentiation， proliferation， and apoptosis but also in a variety of tumors’ occurrence and development. Conclusion The reasonable regulation to Notch signaling pathway may open up new ways to the treatment of the tumor.
Objective To investigate the role of Notch signaling pathway in pancreas development and pancreatic cancer. Methods The related literatures were reviewed and analyzed. Results Notch signaling played a role early in development by maintaining pancreatic epithelial cells in a progenitor state and delaying their differentiation until timely appropriate. Notch signaling was reactivated in the initiation and progression of pancreatic cancer. Conclusion Notch signaling pathway plays an important role in the pancreas development. Sustained Notch signaling activity promotes the progression of pancreatic cancer, and may be one of major factors in the initiation of pancreatic cancer.
Objective To investigate the role of AKT/FOXOs /atrogin-1/MuRF1 signaling pathway in skeletal muscle atrophy in rats with chronic obstructive pulmonary diseases( COPD) .Methods Passive cigarette smoking was used to establish COPD model. The protein expression of atrogin-1, MuRF1, FOXO-1, phosohorylated-AKT and total AKT were measured by Western blot. The mRNA expression of atrogin-1, MuRF1 and FOXO-1 were measured by reverse transcription-polymerase chain reaction( RT-PCR) . Results Compared with the control group, the mRNA expressions of atrogin-1, MuRF1 and FOXO-1 significantly increased in extensor digitorum longus ( EDL) of the COPD group (Plt;0.05 ) . Meanwhile the protein expression of atrogin-1 and MuRF1 significantly increased in the COPD group(Plt;0.05) , while the protein expression of FOXO-1 was not significantly different between two groups(Pgt;0.05) . In addition, , the protein expression of phosohorylated-AKTand the ratio of phosohorylated-AKT to total AKT significantly increased in EDL of the COPD group(Plt;0.05) . Conclusion The mRNA and protein expression of AKT/FOXOs/ atrogin-1 /MuRF1 in skeletal muscle are significantly increased in COPD rats, suggesting that AKT/FOXOs/ atrogin-1 /MuRF1 signalling pathway plays a crucial role in skeletal muscle atrophy of COPD.
ObjectiveTo investigate the expression of Yes-associated protein (YAP) screened by bioinformatics in rats with myocardial-ischemia reperfusion injury and establish the base for further research. MethodsThe difference of gene spectrum of rats with myocardial-ischemia reperfusion injury was analyzed by bioinformatics technique. The related signaling pathways and key genes were screened by KOBAS2.0 and KEGG. Eighteen Sprague Dawley rats were randomly divided into three groups: normal group (n=6), sham operation group (n=6) and myocardial-ischemia reperfusion injury group (n=6). The expression of target gene was detected by immunochemistry, quantitive reverse transcription polymerase chain reaction and western blotting. ResultsA total of 345 differentially expressed genes were found by bioinformatics, among which 181 were up-regulated and 164 were down-regulated. The differential genes were mainly enriched in Wnt, HIPPO, MAPK, Jak-STAT and other signaling pathways. We focused on HIPPO pathway and found that the expression of YAP increased significantly in myocardial-ischemia reperfusion injury group, compared with the normal group and sham operation group (P＜0.05). ConclusionsThe expression of YAP of HIPPO signal pathway is increased in rats with myocardial-ischemia reperfusion injury.
Hematopoietic stem cells (HSCs) are tissue specific stem cells that replenish all mature blood lineages during the lifetime of an individual. Hematopoietic cell clusters in the aorta of vertebrate embryos play a pivotal role in the formation of the adult blood system. Recently, people have learned a lot about the embryonic HSCs on their development and homing. During their differentiation, HSCs are regulated by the transcription factors, such as Runx1 and Notch signaling pathway, etc. MicroRNAs also regulate the self-renewal and differentiation of hematopoietic stem/progenitor cells on the post-transcriptional levels. Since the onset of circulation, the formation of HSCs and their differentiation into blood cells, especially red blood cells, are regulated by the hemodynamic forces. It would be of great significance if we could treat hematologic diseases with induced HSCs in vitro on the basis of fully understanding of hemotopoietic stem cell development. This review is focused on the advances in the research of HSCs' development and regulation.
Hypoxic microenvironment always exists in solid tumors, and it closely relates to the development and metastasis of solid tumor. As a main transcription factor responding to hypoxic environment, hypoxia-inducible factor (HIF) can promote tumor cell proliferation, survival, angiogenesis, and epithelial-mesenchymal transition (EMT), etc. EMT is a biological process that epithelial phenotype was transformed into mesenchymal phenotype, which is mainly associated with its signaling pathways, transcription factors, inflammatory factors and miRNAs, and plays a vital role in tumor invasion and metastasis. This paper summarizes the effects of hypoxia signaling pathway, Wnt/β-catenin signaling pathway, Notch signaling pathway, NF-κB signaling pathway, Hedgehog (Hh) signaling pathway and PI3K/Akt signaling pathway on the EMT of tumor cells.
ObjectiveTo investigate the role of PI3K/AKT/mTOR signaling pathway in skeletal muscle atrophy in rats with chronic obstructive pulmonary diseases(COPD). MethodsPassive cigarette smoking was used to establish COPD model.The protein expression of PI3K, total mTOR, phosphorylated-mTOR, total GSK-3β, phosphorylated-GSK-3β, total 4E-BP1, phosphorylated-4E-BP1, total p70S6K1 and phosphorylated-p70S6K1 in extensor digitorum longus of rats were measured by Western blot. ResultsThe protein expression of PI3K was not significantly different between two groups(P > 0.05).Compared with the control group, the protein expression of total mTOR, phosphorylated-mTOR, total GSK-3β, and phosphorylated-GSK-3βincreased significantly in the COPD group(P < 0.05).The protein expression of total 4E-BP1 and total p70S6K1 were not significantly different between two groups(P > 0.05).While the protein expression of phosphorylated-4E-BP1 and phosphorylated-p70S6K1 significantly increased in the COPD group(P < 0.05). ConclusionThe protein expressions of PI3K/AKT/mTOR signaling pathway in extensor digitorum longus increased significantly in COPD rats, suggesting that the activity of PI3K/AKT/mTOR signaling pathway increased, which may be one of the compensatory mechanism of skeletal muscle atrophy in COPD.
ObjectiveTo investigate the effect of PI3K/Akt/mTOR signaling pathway on liver injury induced by severe acute pancreatitis (SAP). MethodsForty healthy adult male Sprague-Dawley (SD) rats were randomly divided into 4 groups: Sham operation group (SO group), SAP group, PI3K inhibitor LY294002 group (LY294002 group), and mTOR kinase inhibitor rapamycin group (rapamycin group). The rat model with SAP was made by injection with 5% sodium deoxycholate through retrogradely bilio pancreatic duct. Serum levels of amylase (AMY), alanine aminotransferase (ALT), and aspartate transaminase (AST) were detected through the inferior vena at 6 h after modeling. Pathologic change of the liver was observed under the light microscope. TUNEL analysis was used to detect apoptotic index (AI) of the heptocyte. Expressions of Akt, phosphated-Akt (p-Akt), mTOR, phosphated-mTOR (p-mTOR) protein were evaluated by Western blot. Results①Compared with the SO group, the serum levels of AMY, ALT, AST, and the hepatocyte AI were significantly increased among the other three groups (P < 0.05). Compared with the SAP group, the serum levels of AMY, ALT, AST, and the hepatocyte AI were significantly decreased in the LY294002 group and rapamycin group (P < 0.05).②Compared with the SO group, the damages of the liver tissues were aggravated among the other three groups. The pathologies of the liver tissues were ameliorated in the LY294002 group and rapamycin group as compared with the SAP group.③Compared with the SO group, the levels of p-Akt/Akt, p-mTOR/mTOR were significantly increased among the other three groups (P < 0.05). Compared with the SAP group, the levels of p-Akt/Akt, p-mTOR/mTOR were significantly decreased in the LY294002 group (P < 0.05), but in the rapamycin group, only the p-mTOR/mTOR level was significantly decreased (P < 0.05). ConclusionThe activation of PI3K/Akt/mTOR signaling pathway might be one of the reasons for the liver injury induced by SAP and blocking this signaling pathway might be a potential target of preventing progress of SAP and alleviating liver injury induced by SAP.