Nerve growth factor (NGF) promotes neuronal survival and differentiation and stimulates neurite outgrowth. NGF is synthesized as a precursor-proNGF in vivo. In this paper, a pET-proNGF prokaryocyte expression vector was constructed and transformed into E. coli BL21(DE3)pLysS. The proNGF was expressed in the form of non-active aggregated monomer in E. coli after induction with IPTG. SDS-PAGE revealed the proNGF expression product had a Mr.30.2 kD. Western blotting analysis showed that the protein had good antigenicity. Fusion protein was successfully purified by Ni2+-NTA affinity chromatography and cleaved by Enterokinase and 13.1 mg proNGF was obtained from 100 mL cell culture in a typical experiment. The protein was dialyzed in a redox system containing reduced and oxidized glutathione. RP-HPLC was used to analysis the result of the refolding. The refolded proNGF protein can induce neurite outgrowth of PC12 cells, which indicated that pro-form of NGF we obtained had biological activity.
Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Humans ; Nerve Growth Factor ; biosynthesis ; genetics ; Protein Precursors ; biosynthesis ; genetics ; Protein Renaturation ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; isolation & purification

Objective:To investigate the influencing factors of prolonged postoperative ileus (PPOI) in patients undergoing pancreaticoduodenectomy (PD) during hospitalization.Methods:The data of 339 patients underwent PD admitted to the Department of Hepatobiliary Surgery of the Second Hospital of Hebei Medical University from January 2018 to September 2023 were retrospectively analyzed, including 204 males and 135 females, aged (60.6±11.2) years. Among the 339 patients, 112 (33.0%) had pancreatic tumors, 94 (27.7%) had Vater ampullary tumors, 82 (24.2%) had common bile duct tumors, and 51 (15.0%) had duodenal tumors. A total of 339 patients with PPOI were included in the PPOI group ( n=43) and those without PPOI were included in the control group ( n=296). The two groups were compared in terms of age, PD operation (open or laparoscopic), gastrojejunostomy (retrocolic or antecolic gastrojejunostomy), grade B or C pancreatic fistula, hypokalemia, and postoperative use of patient-controlled intravenous analgesia (PCIA). The index comparing P<0.05 between the two groups was further included in the multivariate logistic regression analysis to analyze the influencing factors of PPOI in PD patients. Results:There were statistically significant differences in age >70 years, PD operation, gastrojejunostomy, grade B or C pancreatic fistula, hypokalemia, and postoperative use of PCIA between the two groups (all P<0.05). Multivariate logistic regression analysis showed grade B or C pancreatic fistula ( OR=3.17, 95% CI: 1.48-6.82), open surgery ( OR=2.90, 95% CI: 1.35-6.24), retrocolic gastrojejunostomy ( OR=2.47, 95% CI: 1.23-4.95), postoperative usage of PCIA ( OR=2.61, 95% CI: 1.21-5.62), age >70 years ( OR=2.47, 95% CI: 1.71-5.19) had a high risk of PPOI during postoperative hospitalization (all P<0.05). Conclusion:Postoperative grade B or C pancreatic fistula, open surgery, retrocolic gastrojejunostomy (compares with antecolic gastrojejunostomy), postoperative using PCIA, and age >70 years are independent risk factors for PPOI in patients undergoing PD during postoperative hospitalization.

Objective:To discuss the protective effect of ginsenoside Rh1(G-Rh1)on kidney injury in the diabetic mellitus(DM)mice,and to clarify its mechanism.Methods:The diabetic kidney disease(DKD)model was prepared by using the high-fat,high-sugar diet combined with intraperitoneal injection of streptozotocin(STZ).A total of 48 C57/BL6 model mice were randomly divided into model group,nuclear factor erythroid 2-related factor 2(Nrf2)inhibitor ML385 group(ML385 group)(30 mg·kg-1),G-Rh1 group(30 mg·kg-1),and G-Rh1+ML385 group(30 mg·kg-1 G-Rh1+30 mg·kg-1 ML385),and there were 12 mice in each group.Additionally,12 C57/BL6 mice were selected as control group.After treated for 8 weeks,automatic analyzer was used to detect the levels of fasting blood glucose(FBG),blood urea nitrogen(BUN),and serum creatinine(Scr)in serum of the mice in various groups,as well as 24 h urinary protein(24 h UP)levels in urine,and the kidney index was calculated;kits were used to detect the activities of superoxide dismutase(SOD)and lactate dehydrogenase(LDH),and the levels of malondialdehyde(MDA)in kidney tissue of the mice in various groups;Western blotting method was used to detect the expression levels of Nrf2 and heme oxygenase-1(HO-1)proteins in kidney tissue of the mice in various groups.Results:Compared with control group,the levels of FBG and kidney indexes in serum of the mice in model group,ML385 group,and G-Rh1+ML385 group were significantly increased(P<0.01),and the level of FBG in serum of the mice in G-Rh1 group was significantly increased(P<0.01);compared with model group,the kidney index of the mice in ML385 group was significantly increased(P<0.05),while the levels of FBG and kidney index of the mice in G-Rh1 group were significantly decreased(P<0.05 or P<0.01);compared with G-Rh1 group,the level of FBG and kidney index of the mice in G-Rh1+ML385 group were significantly increased(P<0.01).Compared with control group,the levels of BUN and Scr in serum,and 24 h UP in urine of the mice in model group,ML385 group,G-Rh1 group,and G-Rh1+ML385 group were significantly increased(P<0.01);compared with model group,the level of BUN in serum and 24 h UP in urine of the mice in ML385 group were significantly increased(P<0.05),while the levels of BUN and Scr in serum,and 24 h UP in urine of the mice in G-Rh1 group were significantly decreased(P<0.01);compared with G-Rh1 group,the levels of BUN and Scr in serum,and 24 h UP in urine of the mice in G-Rh1+ML385 group were significantly increased(P<0.01).Compared with control group,the activities of SOD in kidney tissue of the mice in model group,ML385 group,G-Rh1 group,and G-Rh1+ML385 group were significantly decreased(P<0.01),while the levels of MDA and LDH activities were significantly increased(P<0.01);compared with model group,the activity of SOD in kidney tissue of the mice in ML385 group was significantly decreased(P<0.05),and the level of MDA was significantly increased(P<0.05);the activity of SOD in kidney tissue of the mice in of G-Rh1 group was significantly increased(P<0.01),and the level of MDA and activity of LDH were significantly decreased(P<0.01);compared with G-Rh1 group,the activity of SOD in kidney tissue of the mice in G-Rh1+ML385 group was significantly decreased(P<0.01),and the level of MDA and activity of LDH were significantly increased(P<0.01).Compared with control group,the expression levels of Nrf2 and HO-1 proteins in kidney tissue of the mice in model group,ML385 group,G-Rh1 group,and G-Rh1+ML385 group were significantly decreased(P<0.05 or P<0.01);compared with model group,the expression levels of Nrf2 and HO-1 proteins in kidney tissue of the mice in ML385 group and G-Rh1+ML385 group were significantly decreased(P<0.05),while the expression levels of Nrf2 and HO-1 proteins in kidney tissue of the mice in G-Rh1 group were significantly increased(P<0.01);compared with G-Rh1 group,the expression levels of Nrf2 and HO-1 proteins in kidney tissue of the mice in G-Rh1+ML385 group were significantly decreased(P<0.01).Conclusion:Ginsenoside Rh1 reduces the oxidative stress and improves the kidney function,providing protective effects on kidney injury in the DM mice,and its mechanism may be related to the activation of the Nrf2/HO-1 signaling pathway.