p70 ribosomal protein S6 kinase (p70S6K), an important member of AGC family, is a kind of multifunctional Ser/Thr kinases, which plays an important role in mTOR signaling cascade. The p70 ribosomal protein S6 kinase is closely associated with diverse cellular processes such as protein synthesis, mRNA processing, glucose homeostasis, cell growth and apoptosis. Recent studies have highlighted the important role of S6K in cancer, which arose interests of scientific researchers for the design and discovery of anti-cancer agents. Herein, the mechanisms of S6K and available inhibitors are reviewed.

Aim To investigate the effect of SM-1 on seven main cytochrome P450(CYP450)in human liver microsomes.Methods Substrate or SM-1 was incubated with human liver microsomes for 30 min in vitro,and divided into control group and experimental group.The effects of SM-1 on the main phase I metabolic enzymes in human liver microsomes was detected by HPLC.Phenacetin,bupropion,paclitaxel,tolbutamide,omeprazole,dextromethorphan,testosterone were investigated as probe drugs.Results Inhibition rate of SM-1 on the classical substrate of human liver microsomal CYP was 0.05％,3.37％,0.08％,2.07％,4.20％,-0.15％and 10.84％,respectively.Conclusions SM-1 may have inhibitory effect on CYP3A4.Attention should be paid to the interaction of clinical drug induced by CYP enzyme inhibition.

Fibrosis can occur in different organs with high incidence rate and great danger. It still lacks effective drugs for prevention of fibrosis. Fluorofenidone is a newly developed drug with anti-fibrotic activity, which provides a new hope for treating the progressive fibrotic diseases. Recent studies have shown that fluorofenidone is a multifunctional small molecule with anti-inflammatory, antioxidative and anti-apoptotic eff ects. It can inhibit the activation and proliferation of myofibroblasts, promote the degradation of extracellular matrix and regulate the cellular signal transmission. Fluorofenidone can be applied to attenuate the progression of renal, hepatic and pulmonary fibrosis.
Apoptosis ; Extracellular Matrix ; Fibrosis ; Humans ; Kidney ; pathology ; Liver Cirrhosis ; Pulmonary Fibrosis ; Pyridones ; pharmacology ; Signal Transduction

Thioredoxin reductase(TrxR)is a seleniferous homodimeric flavoenzyme, which is ubiquitously expressed in all cells and plays a crucial role in the redox regulation of numerous celluar signaling pathways involved in cell survival and proliferation. TrxR maintains cellular redox equilibrium. Recent researches have illuminated that TrxR overexpressed in many tumors, is closely associated with the evolution, progression and apoptosis of tumor. TrxR contains a reactive and solvent accessible selenocysteine residue which is located on a flexible C-terminal arm of the protein. This selenocysteine is essentially involved in the catalytic cycle of TrxR and thus represents an attractive binding site for inhibitors. The TrxR inhibitors as novel target-drug in cancer therapy have been extensively studied and elucidated. This article summarized the latest progress in TrxR inhibitors according to the binding capacity of TrxR and substrate.

Protein tyrosine phosphatase 1B(PTP1B),a member of protein tyrosine phosphatases(PTPs),plays a key role in the negative regulation of insulin and leptin signalings.Recent studies showed that PTP1B had an important connection with endoplasmic reticulum(ER)stress, pancreatic beta cells proliferation and insulin secretion,and is closely related to the pathological process of type 2 diabetes mellitus(T2DM)and obesity. Therefore,PIP1B targeted inhibitors have become a research hotspot in the treatment of these metabolic disea-ses.Based on the structural features of PTP1B and its relationship with T2DM and obesity,PTP1B inhibitors were classified according to the sites of binding.Their latest research advances were reviewed in this paper,providing a reference for the development of anti-T2DM and anti-obesity drugs targeting PTP1B.

Objective To investigate the effects of fluorofenidone(AKF-PD)on diabetic kidney disease in db/db mice and its possible mechanisms.Methods(1)Fifty-six mice aged 8 weeks(half male and half female),including 42 db/db mice and 14 wild-type mice were studied.Fortytwo db/db mice randomly were divided into model group(mock-treated diabetic db/db mice),AKF-PD(250 mg· kg-1· d-1)treatment group and losartan(20 mg· kg-1· d-1)treatment group.Wild-type mice and model mice were treated with vehicle(0.5％sodium carboxymethylcellulose),while the treatment groups received either AKF-PD or losartan.After 18 weeks,the blood glucose and urinary albumin were measured,the pathological changes of kidney were observed by PAS staining.The protein expressions of type Ⅳ collagen and fibronectin(FN)in kidney tissue were detected by immunohistochemistry.(2)Mouse glomerular mesangial cells(MES-13 cells)were divided into six groups:normal glucose group(5.5 mmol/L glucose),hypertonic group(5.5 mmol/L glucose+19.5 mmol/L mannitol),high glucose group(25.0 mmol/L glucose),AKF-PD group(25.0 mmol/L glucose+400 mg/L AKF-PD)and losartan group(25.0 mmol/L glucose+2 μmol/L losartan).After 72 h treatment,the expressions of type Ⅰ collagen,type Ⅳ collagen and transforming growth factor-β1(TGF-β1)mRNA were detected by realtime PCR,and the content of TGF-β1 protein in the culture supernatant was detected by ELISA.Results(1)Compared with the wild type mice,model mice had increased weight,blood glucose and glomerulosclerosis index(all P ＜ 0.01),accompanied with heavy albuminuria,glomerular hypertrophy,mesangial area expansion and deposition of collagen type Ⅳ and FN(all P ＜ 0.01).Compared with model mice,in AKF-PD and losartan groups 24 h urinary albumin and glomerulosclerosis index decreased(all P ＜ 0.01),glomerular hypertrophy and mesangial area expansion alleviated,and the protein expressions of collagen type Ⅳ and FN were inhibited(all P ＜ 0.01).(2)Compared with the normal glucose group,the mRNA expressions of type Ⅰ collagen and type Ⅳ collagen increased in high glucose group,meanwhile the mRNA and protein expressions of TGF-β1 increased(all P ＜ 0.01).In AKF-PD and losartan groups the expressions of type Ⅰ collagen,type Ⅳ collagen and TGF-β1 were inhibited as compared with high glucose group(all P ＜ 0.05).Conclusion Fluorofenidone may play an anti-fibrotic effect in db/db mice by reducing the expression of TGF-β1 and inhibiting collagen synthesis in glomerular mesangial cells.

Objective To investigate effects of pirfenidone (PFD) on diabetic nephropathy model in db/db mice and to explore its possible mechanisms.Methods (1) Wild-type mice were as the normal control group,and db/db mice were divided into model group and PFD group,with 6 mice in each group.In the PFD group mice were administered continuously by 250 mg· kg-1· d-1 PFD for 18 weeks,and mice in the other two groups were administered by 0.5％ sodium carboxymethyl cellulose.Blood glucose and 24 h urinary albumin were measured.The pathological changes of renal tissue were evaluated by PAS staining,PASM staining,Masson staining and Sirius red staining.The expression of collagen type Ⅳ in kidney tissues was detected by immunohistochemistry.(2) Mouse mesangial cells (SV40 MES-13 cells) were cultured as research objects.They were divided into control group,hyperosmolar group,high glucose (HG) group,and 50,100,200,400,800,1600 mg/L PFD+HG group.BrdU cell proliferation test was used to evaluate cell proliferation rate.Cells were divided into control group,hyperosmolar group,HG group and PFD+HG group.The mRNA expressions of α-smooth muscle actin (α-SMA),collagen type Ⅰ,collagen type Ⅳ,transforming growth factor-β1 (TGF-β1),interleukin (IL)-1β,IL-6 and monocyte chemotactic protein-1 (MCP-1) were detected by real-time PCR.Results (1) Compared with normal control group,the model mice had higher weight,blood glucose and 24 h urinary albumin,accompanied with glomerular hypertrophy,mesangial area expansion,tubulointerstitial fibrosis and deposition of collagen type Ⅳ (all P ＜ 0.05).Compared with those in model group,in PFD group 24 h urinary albumin decreased,glomerular hypertrophy,mesangial area expansion and tubulointerstitial fibrosis alleviated,and the protein expression of collagen type Ⅳ inhibited (all P＜0.05).(2) Compared with those in HG group,MES-13 cell proliferation rates of 100,200,400,800,1600 mg/L PFD+HG groups decreased (all P ＜ 0.05),and the mRNA expressions of α-SMA,collagen type Ⅰ,collagen type Ⅳ,TGF-β1,IL-1β,IL-6 and MCP-1 reduced in 400 mg/L PFD+HG group (all P ＜ 0.05).Conclusions PFD can inhibit high glucose-induced proliferation and activation of glomerular mesangial cells,decrease the expression of TGF-β1 and proinflammatory factors,as well as reduce the synthesis of collagen,which improve renal fibrosis of db/db mice.