ERS Mediated by GRP-78/PERK/CHOP Signaling Is Involved in Fluoride-Induced Ameloblast Apoptosis.

Fluoride can be widely ingested from the environment, and its excessive intake could result in adverse effects. Dental fluorosis is an early sign of fluoride toxicity which can cause esthetic and functional problems. Though apoptosis in ameloblasts is one of the potential mechanisms, the specific signal cascade is in-conclusive. High-throughput sequencing and molecular biological techniques were used in this study to explore the underlying pathogenesis of dental fluorosis, for its prevention and treatment. A fluorosis cell model was established. Viability and apoptosis rate of mouse ameloblast-derived cell line (LS8 cells) was measured using cell counting kit-8 (CCK-8) assay and flow cytometry analysis. Cells were harvested with or without 2-mM sodium fluoride (NaF) stimulation for high-throughput sequencing. Based on the sequencing data, subcellular structures, endoplasmic reticulum stress (ERS), and apoptosis related biomarkers were verified using transmission electron microscopy, quantitative real-time polymerase chain reaction, and Western blotting techniques. Expression of ERS markers, apoptosis related proteins, and enamel formation enzymes were detected using Western blotting after addition of 4-phenylbutyrate (4-PBA). NaF-inhibited LS8 cells displayed time- and dose- dependent viability. Additionally, apoptosis and morphological changes were observed. RNA-sequencing data showed that protein processing in endoplasmic reticulum was obviously affected. ERS and apoptosis were induced by excessive NaF. Downregulation of kallikrein-related peptidase 4 (KLK4) was also observed. Inhibition of ERS by 4-PBA rescued the apoptotic and functional protein changes in cells. Excessive fluoride induces apoptosis by activating ERS, which is mediated by GRP-78/PERK/CHOP signaling. Key proteinase is present in maturation-stage enamel; KLK4 was also affected by fluoride, but rescued by 4-PBA. This study presents a possibility for therapeutic strategies for dental fluorosis, while further exploration is required.

Effect of sleeve gastrectomy on renal oxidative stress in type 2 diabetic rats / 国际外科学杂志

Objective@#To investigate the changes of oxidative stress in kidney of type 2 diabetic rats after sleeve gastrectomy and its effect on renal function.@*Methods@#Twenty male SD rats were fed with high-fat diet and injected with streptozotocin intraperitoneally to induce type 2 diabetes mellitus. Seventeen successful induction models were divided into sham operation group (n=7) and sleeve gastrectomy (SG) group (n=10) by random number table method, and were treated with sham operation and SG respectively. The body weight, 24-hour food intake, fasting blood glucose (FBG)and serum glucagon-like peptide-1 (GLP-1) were measured before and 1, 2, 3 and 4 weeks after operation. The activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px) and malondialdehyde in renal tissue as well as blood urea nitrogen (BUN), creatinine levels and 24-hour urinary microalbumin (UALB) were measured 4 weeks after operation. Masurement data conforming to normal distribution were expressed as Mean±SD, and t-test was used for comparison between two groups.@*Results@#At the 1st, 2nd, 3rd, 4th weeks after operation, the levels of FBG in SG group was lower than those in sham operation group [(11.13±3.27) mmol/L vs (16.74±4.10) mmol/L, (9.53±2.82) mmol/L vs (19.31±3.66) mmol/L, (6.69±2.44) mmol/L vs (20.84±2.71) mmol/L, (6.58±2.96) mmol/L vs (19.99±2.85) mmol/L, all P<0.05]. In the same period, the levels of serum GLP-1 in SG group was higher than those in sham operation group [(22.61±2.92) pg/mL vs (15.42±2.39) pg/mL, (24.72±3.02) pg/mL vs (16.20±2.26) pg/mL, (24.59±2.85) pg/mL vs (15.84±2.75) pg/mL, (26.15±3.23) pg/mL vs (15.77±2.79) pg/mL, all P<0.05]. At the 4th week after operation, BUN[(5.34±0.82) mmol/L], creatinine[(39.78±6.13)]μmol/L, UALB[(31.18±6.88) mg/24 h] and renal creatinine[(5.84±0.85) nmol/mg] in SG group were lower than those in sham operation group [BUN (9.08±1.54) mmol/L, creatinine (64.07±8.63) μmol/L, UALB (67.64±9.07) mg/24 h, creatinine (10.78±1.28) nmol/mg], and the differences were statistically significant (all P<0.05). Renal SOD[(620.05±55.98) U/mg], CAT[(24.72±2.28) U/mg] and GSH-Px[(281.53±27.99) U] in SG Group were lower than those in sham operation group [SOD(392.52±45.97) U/mg, catalase (15.62±2.46) U/mg, GSH-Px (164.71±21.83) U], and the differences were statistically significant (all P<0.05).@*Conclusion@#Sleeve gastrectomy may improve renal function through reducing oxidative stress in the kidney.

Effect of sleeve gastrectomy on renal oxidative stress in type 2 diabetic rats / 国际外科学杂志

Objective To investigate the changes of oxidative stress in kidney of type 2 diabetic rats after sleeve gastrectomy and its effect on renal function.Methods Twenty male SD rats were fed with high-fat diet and injected with streptozotocin intraperitoneally to induce type 2 diabetes mellitus.Seventeen successful induction models were divided into sham operation group (n =7) and sleeve gastrectomy (SG) group (n =10) by random number table method,and were treated with sham operation and SG respectively.The body weight,24-hour food intake,fasting blood glucose (FBG)and serum glucagon-like peptide-1 (GLP-1) were measured before and 1,2,3 and 4 weeks after operation.The activities of superoxide dismutase (SOD),catalase,glutathione peroxidase (GSH-Px) and malondialdehyde in renal tissue as well as blood urea nitrogen (BUN),creatinine levels and 24-hour urinary microalbumin (UALB) were measured 4 weeks after operation.Masurement data conforming to normal distribution were expressed as Mean ± SD,and t-test was used for comparison between two groups.Results At the 1st,2nd,3rd,4th weeks after operation,the levels of FBG in SG group was lower than those in sham operation group [(11.13 ±3.27) mmol/L vs (16.74 ±4.10) mmol/L,(9.53 ±2.82) mmol/L vs (19.31 ±3.66) mmol/ L,(6.69 ±2.44) mmol/L vs (20.84 ±2.71) mmol/L,(6.58 ±2.96) mmol/L vs (19.99 ±2.85) mmol/L,all P ＜ 0.05].In the same period,the levels of serum GLP-1 in SG group was higher than those in sham operation group [(22.61 ± 2.92) pg/mL vs (15.42 ± 2.39) pg/mL,(24.72 ± 3.02) pg/mL vs (16.20 ± 2.26) pg/mL,(24.59 ±2.85) pg/mL vs (15.84±2.75) pg/mL,(26.15 ±3.23) pg/mL vs (15.77 ±2.79) pg/mL,all P＜ 0.05].At the 4th week after operation,BUN[(5.34 ±0.82) mmol/L],creatinine[(39.78 ±6.13)] μmoL/L,UALB [(31.18 ± 6.88) mg/24 h] and renal creatinine [(5.84 ± 0.85) nmol/mg] in SG group were lower than those in sham operation group [BUN (9.08 ± 1.54) mmol/L,creatinine (64.07 ± 8.63) μmol/L,UALB (67.64 ±9.07) mg/24 h,creatinine (10.78 ± 1.28) nmol/mg],and the differences were statistically significant (all P＜0.05).Renal SOD[(620.05 ±55.98) U/mg],CAT[(24.72 ±2.28) U/mg] and GSH-Px[(281.53 ± 27.99) U] in SG Group were lower than those in sham operation group [SOD(392.52 ± 45.97) U/mg,catalase (15.62 ± 2.46) U/mg,GSH-Px (164.71 ± 21.83) U],and the differences were statistically significant (all P ＜ 0.05).Conclusion Sleeve gastrectomy may improve renal function through reducing oxidative stress in the kidney.