Protease is responsible for many physiological functions and can act as growth factor for both malignant and normal cells in the processes of the cell division and DNA biosynthesis. There was clear relation between metastatic tumors and protease. The protease inhibitors found in the natural environment or synthesized but both have not been used in the treatment of human cancer. Currently, the protease inhibitors are studying thoroughly on their mechanism, action and application in the anti-cancer.
Protease Inhibitors ; neoplasms ; therapeutics

Kunitz-type serine protease inhibitors are a class of ubiquitous protease inhibitors, which play important roles in various life activities. The structures of such inhibitors are generally stable, and are usually characterized by the presence of one or several Kunitz domains in tandem, which are able to bind to serine proteases in a manner similar to substrate binding, thereby inhibiting enzyme activity. In terms of function, Kunitz-type serine protease inhibitors are involved in processes such as blood coagulation and fibrinolysis, tumor immunity, inflammation regulation, and resistance to bacterial and fungal infections. This article summarizes the advances of Kunitz-type serine protease inhibitors and provides new ideas for the development of novel Kunitz-type serine protease inhibitors.
Protease Inhibitors ; Serine Proteases ; Serine Proteinase Inhibitors

For 16 years after the finding of HIV as an agent of AIDS in 1981, HIV therapeutic drugs of reverse transcriptase inhibitors (AZT, ddI, ddC, d4T) and protease inhibitors have been developed. Recent studies also were focused on a combination therapy by using HIV therapeutic drugs or natural compounds. Korean red ginseng (KRG) of natural compounds has been well known as a good reinforcement agent in Asia. The percentage of CD3+CD4+ T cell in nine HIV-infected patients without KRG treatment averaged 17.8% on baseline and decreased 15.8% after 6 months, whereas the percentage of the cell in fifteen HIV-infected patients with KRG treatment averaged 15.3% on baseline and increased up to 18.9% after the same period. The average percentage of CD3+CD8+ T cell of KRG-nontreated and KRG-treated HIV patients increased after 6 months 47.8% to 50.7% and 44.7% to 51.4%, respectively; and the average percentage of B and NK cell in the KRG-nontreated and KRG-treated HIV patients decreased 9.4% to 7.9% and 13.0% to 9.7%, 8.9% to 8.5% and 16.2% to 11.6%, respectively, KRG, therefore, didn't have any effects on the CD3+CD8+ T cell, B cell, and NK cell. However, it seems that KRG has a potential activity for stimulating the
Asia ; HIV ; Humans ; Killer Cells, Natural ; Lymphocyte Subsets* ; Lymphocytes* ; Panax* ; Protease Inhibitors ; Reverse Transcriptase Inhibitors

Human leukocyte elastase is an important selection target of inflammation and cancer. In this paper, a high throughput screening model was established for screening human leukocyte elastase inhibitors from thousands of strains of actinomycetes. As a result, a strain, N01WA-735 with potent suppression activity was isolated. Firstly, the strain N01WA-735 was identified as Streptomyces according to morphology and biochemical analysis. The Streptomyces N01WA-735 was processed by solvent extraction, silica column chromatography, Sephadex LH-20 column chromatography and crystallization to get a pure active compound named N01WA-735E. Its chemical structure was elucidated as the same as that of the compound named BE-52440A by physicochemical properties and spectral data of UV, MS, 1H-NMR and 13C-NMR respectively. The compound showed a strong inhibitory activity against human leukocyte elastase with IC50 of 3.02 micromol/L. The compound is reported as a human leukocyte elastase inhibitor for the first time.
Humans ; Leukocyte Elastase ; antagonists & inhibitors ; Protease Inhibitors ; isolation & purification ; metabolism ; Streptomyces ; isolation & purification ; metabolism

The efficacy and safety of a single tablet regimen (STR) of elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (E/C/F/TDF) were analyzed in Phase 3 clinical trials in antiretroviral therapy (ART)-naïve and ART-experienced Asian subjects infected with human immunodeficiency virus (HIV)-1. Studies GS-US-236-102 and GS-US-236-103 were randomized, double-blind, placebo-controlled, 144-week studies conducted in ART-naïve subjects, comparing E/C/F/TDF versus efavirenz (EFV)/F/TDF or ritonavir-boosted atazanavir (ATV+RTV) plus emtricitabine/tenofovir DF (F/TDF), respectively. Studies GS-US-236-115 and GS-US-236-121 were randomized, open-label, 96-week long conducted in ART-experienced subjects, who switched to E/C/F/TDF from ritonavir-boosted protease inhibitors (PI+RTV)+F/TDF, or non-nucleoside reverse transcriptase inhibitors (NNRTI)+F/TDF regimens. The E/C/F/TDF appeared to have sustained efficacy and safety and was well tolerated in the small number of ART-naïve and ART-experienced Asian subjects.
Asian Continental Ancestry Group* ; Atazanavir Sulfate ; HIV* ; HIV-1* ; Humans ; Humans* ; Protease Inhibitors ; Reverse Transcriptase Inhibitors

A large number of protease inhibitors have been found from leeches, which are essential in various physiological and biological processes. In the curret study, a novel elastase inhibitor was purified and characterized from the leech of Hirudinaria manillensis, which was named HMEI-A. Primary structure analysis showed that HMEI-A belonged to a new family of proteins. HMEI-A exerted inhibitory effects on elastase and showed potent abilities to inhibit elastase with an inhibition constant (K
Amino Acid Sequence ; Animals ; Leeches/chemistry* ; Pancreatic Elastase/antagonists & inhibitors* ; Protease Inhibitors/pharmacology* ; Proteins

BACKGROUND/AIMS: The protease inhibitors, nafamostat and gabexate, have been used to prevent pancreatitis related to endoscopic retrograde cholangiopancreatography (ERCP). In vitro, nafamostat inhibits the pancreatic protease activities 10-100 times more potently than gabexate. We evaluated the efficacy of nafamostat for prophylaxis against post-ERCP pancreatitis in comparison with gabexate. METHODS: Five hundred patients (208 patients in the nafamostat-treated group and 292 in the gabexate-treated group) were analyzed retrospectively after selective exclusion. The incidences of pancreatitis and hyperamylasemia after the ERCP were compared between the nafamostat and gabexate groups. RESULTS: The incidences of acute pancreatitis and hyperamylasemia were 9.1% and 40.9%, respectively, in the nafamostat-treated group, and 8.6% and 39.4% in the gabexate-treated group. The frequencies of post-ERCP pancreatitis and hyperamylasemia did not differ significantly between the two groups, Post-ERCP pancreatitis in two group did not vary according to the different ERCP procedures. The mean serum amylase level at 6 h after ERCP was significantly lower in the nafamostat-treated group than in the gabexate-treated group (p=0.020). However, the difference in serum amylase level did not persist at 18 h and 36 h post-ERCP. CONCLUSIONS: Administration of nafamostat before ERCP was not inferior to gabexate in protecting against the development of pancreatitis.
Amylases ; Cholangiopancreatography, Endoscopic Retrograde ; Gabexate ; Guanidines ; Humans ; Hyperamylasemia ; Incidence ; Pancreatitis ; Protease Inhibitors ; Retrospective Studies

The current standard of care for hepatitis C infection is peginterferon/ribavirin (PegIFN/RBV). We are entering the era where direct-acting antiviral agents (DAAs) will be added to PegIFN/RBV, leading to higher sustained response rates in genotype 1 infected individuals. Currently DAAs are directed toward specific proteins involved in hepatitis C replication with NS3/NS4A protease inhibitors furthest in development. Telaprevir and boceprevir are both NS3/NS4a inhibitors that significantly improve sustained response when added to PegIFN and RBV. The hepatitis C virus (HCV) polymerase inhibitors are another promising DAA class. These molecules are divided into nucleoside/nucleotide polymerase inhibitors and nonnucleotide/nucleoside polymerase inhibitors. Nucleoside/nucleotide polymerase inhibitors have a high barrier to resistance and appear to be effective across a broad range of genotypes. Nonnucleoside polymerase inhibitors have a lower barrier of resistance and appear to be genotype specific. Preliminary data with these compounds are also promising. A third class, NS5A inhibitors, has also shown potent HCV RNA suppression in preliminary studies as monotherapy and with PegIFN and RBV. Combinations of these agents are also entering clinical trials and indeed a preliminary report has demonstrated that the combination of an NS3/4A protease inhibitor and NS5B polymerase inhibitor can effectively suppress virus in genotype 1 individuals. Future studies will concentrate on combinations of direct-acting antiviral agents without and with PegIFN and RBV. Clinicians will need to be familiar with managing side effects as well as resistance as we enter this new era.
Antiviral Agents ; Genotype ; Hepacivirus ; Hepatitis ; Hepatitis C ; Oligopeptides ; Proline ; Protease Inhibitors ; Proteins ; RNA ; Standard of Care ; Viruses

BACKGROUND/AIMS: Gabexate, a protease inhibitor, has been known to prevent pancreatic damage following ERCP. We conducted a prospective and randomized study to assess the preventive effect of gabexate. Methods: Of the 96 patients enrolled, 46 were treated with gabexate and 50 with placebo. The groups were similar with regard to sex, age, body-mass index, and the final diagnosis of ERCP. RESULTS: 24 patients (25.0%) had elevated pancreatic-enzyme levels; the frequency was similar in the two groups (P=0.48). Mean serum amylase value at 4 hours after ERCP was similar in patients with elevated basal level (220.5+/-43.2 U/L) and those with normal basal level (170.4+/-31.2 U/L). After the procedures, serum amylase values were lower in the gabexate group (137.1+/-19.8 U/L) than in the placebo group (212.0+/-50.4 U/L). The differences were not significant in the mean levels of amylase between the groups for any of imaging of the pancreatic ducts (pancreatic-duct imaging, 201.5+/-49.4 U/L, bile-duct imaging, 153.7+/-30.0 U/L). But in the patients with pancreatic duct imaging, serum amylase values were significantly higher in the placebo group (295.0+/-97.6 U/L) than in the gabexate group (112.0+/-10.6 U/L)(p<0.05). CONCLUSIONS: Prophylactic treatment with gabexate does not reduce pancreatic damage related to ERCP, but only in the patients with pancreatic duct imaging there were the significant differences between in the gabexate group and in the placebo group.
Amylases ; Cholangiopancreatography, Endoscopic Retrograde* ; Diagnosis ; Gabexate* ; Humans ; Pancreatic Ducts ; Pancreatitis ; Prospective Studies ; Protease Inhibitors

PURPOSE: We investigated the effect of ceramide on keratocyte apoptosis and pathway of ceramide-induced keratocyte apoptosis. METHODS: Cultured Newzealand White Rabbit keratocytes were exposed to various concentrations of ceramide type II, VI and phytoceramide type II, VI. LDH level was measured for the evaluation of time and concentration related apoptosis. Keratocytes were preincubated in various concentrations of CPP32-like protease inhibitor (Z-VAD-FMK, diffuse caspase inhibitor), specific caspase-8 inhibitor (IETD-CHO) and specific caspase-9 inhibitor (Z-LEHD-FMK), then were exposed to 20 micro M of 4 types of ceramide. Cytochome C immune stainining was done after exposure of keratocyte to 4 types of ceramide. RESULTS: The lower effective dose of 4 types of ceramide was 20 micro M. Apoptosis of keratocytes was dependent on ceramide exposure time. Ceramide induced keratocyte apoptosis was inhibited by CPP32-like protease inhibitor, specific caspase-8 inhibitor and specific caspase-9 inhibitor. Apoptotic keratocytes induced by ceramide were immune-stained with cytochrome C antibody. CONCLUSIONS: Ceramide induced apoptosis in cultured corneal keratocytes. This apoptosis developed according caspase cascade, especially via mitochondria.
Apoptosis* ; Caspase 8 ; Caspase 9 ; Corneal Keratocytes ; Cytochromes c ; Mitochondria ; Protease Inhibitors