scholarly journals Hemolymph protease-5 links the melanization and Toll immune pathways in the tobacco hornworm,Manduca sexta

2020 ◽  
Vol 117 (38) ◽  
pp. 23581-23587 ◽  
Author(s):  
Yang Wang ◽  
Fan Yang ◽  
Xiaolong Cao ◽  
Zhen Zou ◽  
Zhiqiang Lu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Antimicrobial Peptides ◽  
Serine Protease ◽  
Manduca Sexta ◽  
Serine Proteases ◽  
Control Mechanisms ◽  
Proteolytic Activation ◽  
Cleavage Specificity ◽  
Unique Site ◽  
Immune Pathways

Proteolytic activation of phenoloxidase (PO) and the cytokine Spätzle during immune responses of insects is mediated by a network of hemolymph serine proteases (HPs) and noncatalytic serine protease homologs (SPHs) and inhibited by serpins. However, integration and conservation of the system and its control mechanisms are not fully understood. Here we present biochemical evidence that PO-catalyzed melanin formation, Spätzle-triggered Toll activation, and induced synthesis of antimicrobial peptides are stimulated via hemolymph (serine) protease 5 (HP5) inManduca sexta. Previous studies have demonstrated a protease cascade pathway in which HP14 activates proHP21; HP21 activates proPAP2 and proPAP3, which then activate proPO in the presence of a complex of SPH1 and SPH2. We found that both HP21 and PAP3 activate proHP5 by cleavage at ESDR176*IIGG. HP5 then cleaves proHP6 at a unique site of LDLH112*ILGG. HP6, an ortholog ofDrosophilaPersephone, activates both proHP8 and proPAP1. HP8 activates proSpätzle-1, whereas PAP1 cleaves and activates proPO. HP5 is inhibited byManduca sextaserpin-4, serpin-1A, and serpin-1J to regulate its activity. In summary, we have elucidated the physiological roles of HP5, a CLIPB with unique cleavage specificity (cutting after His) that coordinates immune responses in the caterpillar.

In vivo contribution of serine proteases to the proteolytic activation of γENaC in aldosterone-infused rats

2012 ◽  
Vol 303 (7) ◽  
pp. F939-F943 ◽  
Author(s):  
Kohei Uchimura ◽  
Yutaka Kakizoe ◽  
Tomoaki Onoue ◽  
Manabu Hayata ◽  
Jun Morinaga ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Serine Protease ◽  
Serine Proteases ◽  
Serine Protease Inhibitor ◽  
Proteolytic Activation ◽  
New Strategy ◽  
Salt Sensitive Hypertension ◽  
Primary Cleavage

Aldosterone plays an important role in the regulation of blood pressure by modulating the activity of the epithelial sodium channel (ENaC) that consists of α-, β-, and γ-subunits. Aldosterone induces a molecular weight shift of γENaC from 85 to 70 kDa that is necessary for the channel activation. In vitro experiments demonstrated that a dual cleavage mechanism is responsible for this shift. It has been postulated that furin executes the primary cleavage in the Golgi and that the second cleavage is provided by other serine proteases such as prostasin or plasmin at the plasma membrane. However, the in vivo contribution of serine proteases to this cleavage remains unclear. To address this issue, we administered the synthetic serine protease inhibitor camostat mesilate (CM) to aldosterone-infused rats. CM decreased the abundance of the 70-kDa form of ENaC and led to a new 75-kDa form with a concomitant increase in the urinary Na-to-K ratio. Because CM inhibits the protease activity of serine proteases such as prostasin and plasmin, but not furin, our findings strongly indicate that CM inhibited the second cleavage of γENaC and subsequently suppressed ENaC activity. The results of our current studies also suggest the possibility that the synthetic serine protease inhibitor CM might represent a new strategy for the treatment of salt-sensitive hypertension in humans.

scholarly journals Kallistatin Ameliorates Influenza Virus Pathogenesis by Inhibition of Kallikrein-Related Peptidase 1-Mediated Cleavage of Viral Hemagglutinin

2015 ◽  
Vol 59 (9) ◽  
pp. 5619-5630 ◽  
Author(s):  
Chia-Hsing Leu ◽  
Mei-Lin Yang ◽  
Nai-Hui Chung ◽  
Yen-Jang Huang ◽  
Yu-Chu Su ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Serine Protease ◽  
Serine Proteases ◽  
Inflammatory Responses ◽  
Antiviral Agents ◽  
Influenza Virus Infection ◽  
Viral Production ◽  
Proteolytic Activation ◽  
Virus Challenge

ABSTRACTProteolytic cleavage of the hemagglutinin (HA) of influenza virus by host trypsin-like proteases is required for viral infectivity. Some serine proteases are capable of cleaving influenza virus HA, whereas some serine protease inhibitors (serpins) inhibit the HA cleavage in various cell types. Kallikrein-related peptidase 1 (KLK1, also known as tissue kallikrein) is a widely distributed serine protease. Kallistatin, a serpin synthesized mainly in the liver and rapidly secreted into the circulation, forms complexes with KLK1 and inhibits its activity. Here, we investigated the roles of KLK1 and kallistatin in influenza virus infection. We show that the levels of KLK1 increased, whereas those of kallistatin decreased, in the lungs of mice during influenza virus infection. KLK1 cleaved H1, H2, and H3 HA molecules and consequently enhanced viral production. In contrast, kallistatin inhibited KLK1-mediated HA cleavage and reduced viral production. Cells transduced with the kallistatin gene secreted kallistatin extracellularly, which rendered them more resistant to influenza virus infection. Furthermore, lentivirus-mediated kallistatin gene delivery protected mice against lethal influenza virus challenge by reducing the viral load, inflammation, and injury in the lung. Taking the data together, we determined that KLK1 and kallistatin contribute to the pathogenesis of influenza virus by affecting the cleavage of the HA peptide and inflammatory responses. This study provides a proof of principle for the potential therapeutic application of kallistatin or other KLK1 inhibitors for influenza. Since proteolytic activation also enhances the infectivity of some other viruses, kallistatin and other kallikrein inhibitors may be explored as antiviral agents against these viruses.

scholarly journals Phenotypic Analysis of Mice Lacking the Tmprss2-Encoded Protease

2006 ◽  
Vol 26 (3) ◽  
pp. 965-975 ◽  
Author(s):  
Tom S. Kim ◽  
Cynthia Heinlein ◽  
Robert C. Hackman ◽  
Peter S. Nelson
Keyword(s):  
Serine Protease ◽  
Serine Proteases ◽  
Biological Activities ◽  
Type Ii ◽  
Phenotypic Analysis ◽  
Normal Prostate ◽  
Prostate Hyperplasia ◽  
Transmembrane Serine Protease

ABSTRACT Tmprss2 encodes an androgen-regulated type II transmembrane serine protease (TTSP) expressed highly in normal prostate epithelium and has been implicated in prostate carcinogenesis. Although in vitro studies suggest protease-activated receptor 2 may be a substrate for TMPRSS2, the in vivo biological activities of TMPRSS2 remain unknown. We generated Tmprss2 −/− mice by disrupting the serine protease domain through homologous recombination. Compared to wild-type littermates, Tmprss2 −/− mice developed normally, survived to adulthood with no differences in protein levels of prostatic secretions, and exhibited no discernible abnormalities in organ histology or function. Loss of TMPRSS2 serine protease activity did not influence fertility, reduce survival, result in prostate hyperplasia or carcinoma, or alter prostatic luminal epithelial cell regrowth following castration and androgen replacement. Lack of an observable phenotype in Tmprss2 −/− mice was not due to transcriptional compensation by closely related Tmprss2 homologs. We conclude that the lack of a discernible phenotype in Tmprss2 −/− mice suggests functional redundancy involving one or more of the type II transmembrane serine protease family members or other serine proteases. Alternatively, TMPRSS2 may contribute a specialized but nonvital function that is apparent only in the context of stress, disease, or other systemic perturbation.

scholarly journals Renal effects of the serine protease inhibitor aprotinin in healthy conscious mice

2021 ◽  
Author(s):  
Stefan Wörner ◽  
Bernhard N. Bohnert ◽  
Matthias Wörn ◽  
Mengyun Xiao ◽  
Andrea Janessa ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Serine Protease ◽  
Kidney Injury ◽  
Serine Protease Inhibitor ◽  
Tubular Function ◽  
Proteolytic Activation ◽  
Salt Diet ◽  
Low Salt ◽  
Proximal Tubular ◽  
Proximal Tubular Function

AbstractTreatment with aprotinin, a broad-spectrum serine protease inhibitor with a molecular weight of 6512 Da, was associated with acute kidney injury, which was one of the reasons for withdrawal from the market in 2007. Inhibition of renal serine proteases regulating the epithelial sodium channel ENaC could be a possible mechanism. Herein, we studied the effect of aprotinin in wild-type 129S1/SvImJ mice on sodium handling, tubular function, and integrity under a control and low-salt diet. Mice were studied in metabolic cages, and aprotinin was delivered by subcutaneously implanted sustained release pellets (2 mg/day over 10 days). Mean urinary aprotinin concentration ranged between 642 ± 135 (day 2) and 127 ± 16 (day 8) µg/mL . Aprotinin caused impaired sodium preservation under a low-salt diet while stimulating excessive hyperaldosteronism and unexpectedly, proteolytic activation of ENaC. Aprotinin inhibited proximal tubular function leading to glucosuria and proteinuria. Plasma urea and cystatin C concentration increased significantly under aprotinin treatment. Kidney tissues from aprotinin-treated mice showed accumulation of intracellular aprotinin and expression of the kidney injury molecule 1 (KIM-1). In electron microscopy, electron-dense deposits were observed. There was no evidence for kidney injury in mice treated with a lower aprotinin dose (0.5 mg/day). In conclusion, high doses of aprotinin exert nephrotoxic effects by accumulation in the tubular system of healthy mice, leading to inhibition of proximal tubular function and counterregulatory stimulation of ENaC-mediated sodium transport.

scholarly journals Carbohydrate-controlled serine protease inhibitor (serpin) production in Bifidobacterium longum subsp. longum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Duboux ◽  
M. Golliard ◽  
J. A. Muller ◽  
G. Bergonzelli ◽  
C. J. Bolten ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Serine Protease ◽  
Serine Proteases ◽  
Intestinal Tract ◽  
Defense Mechanism ◽  
Inflammatory Diseases ◽  
Bifidobacterium Longum ◽  
Serine Protease Inhibitor ◽  
Innate Defense

AbstractThe Serine Protease Inhibitor (serpin) protein has been suggested to play a key role in the interaction of bifidobacteria with the host. By inhibiting intestinal serine proteases, it might allow bifidobacteria to reside in specific gut niches. In inflammatory diseases where serine proteases contribute to the innate defense mechanism of the host, serpin may dampen the damaging effects of inflammation. In view of the beneficial roles of this protein, it is important to understand how its production is regulated. Here we demonstrate that Bifidobacterium longum NCC 2705 serpin production is tightly regulated by carbohydrates. Galactose and fructose increase the production of this protein while glucose prevents it, suggesting the involvement of catabolite repression. We identified that di- and oligosaccharides containing galactose (GOS) and fructose (FOS) moieties, including the human milk oligosaccharide Lacto-N-tetraose (LNT), are able to activate serpin production. Moreover, we show that the carbohydrate mediated regulation is conserved within B. longum subsp. longum strains but not in other bifidobacterial taxons harboring the serpin coding gene, highlighting that the serpin regulation circuits are not only species- but also subspecies- specific. Our work demonstrates that environmental conditions can modulate expression of an important effector molecule of B. longum, having potential important implications for probiotic manufacturing and supporting the postulated role of serpin in the ability of bifidobacteria to colonize the intestinal tract.

scholarly journals Aedes aegypti (Diptera: Culicidae) Immune Responses with Different Feeding Regimes Following Infection by the Entomopathogenic Fungus Metarhizium anisopliae

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 95 ◽  
Author(s):  
Sara Cabral ◽  
Adriano de Paula ◽  
Richard Samuels ◽  
Rodrigo da Fonseca ◽  
Simone Gomes ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Immune Responses ◽  
Antimicrobial Peptides ◽  
Fungal Infection ◽  
Fat Body ◽  
Negative Regulator ◽  
Toll Pathway ◽  
Promising Alternative ◽  
Imd Pathway ◽  
Feeding Regimes

The mosquito Aedes aegypti is the most notorious vector of illness-causing viruses. The use of entomopathogenic fungi as bioinsecticides is a promising alternative for the development of novel mosquito control strategies. We investigate whether differences in immune responses could be responsible for modifications in survival rates of insects following different feeding regimes. Sucrose and blood-fed adult A. aegypti females were sprayed with M. anisopliae 1 × 106 conidia mL−1, and after 48 h, the midgut and fat body were dissected. We used RT-qPCR to monitor the expression of Cactus and REL1 (Toll pathway), IMD, REL2, and Caspar (IMD pathway), STAT and PIAS (JAK-STAT pathway), as well as the expression of antimicrobial peptides (Defensin A, Attacin and Cecropin G). REL1 and REL2 expression in both the midgut and fat body were higher in blood-fed fungus-challenged A. aegypti than in sucrose-fed counterparts. Interestingly, infection of sucrose-fed insects induced Cactus expression in the fat body, a negative regulator of the Toll pathway. The IMD gene was upregulated in the fat body in response to fungal infection after a blood meal. Additionally, we observed the induction of antimicrobial peptides in the blood-fed fungus-challenged insects. This study suggests that blood-fed A. aegypti are less susceptible to fungal infection due to the rapid induction of Toll and IMD immune pathways.

scholarly journals Recombinant Deg/HtrA proteases from Synechocystis sp. PCC 6803 differ in substrate specificity, biochemical characteristics and mechanism

2011 ◽  
Vol 435 (3) ◽  
pp. 733-742 ◽  
Author(s):  
Pitter F. Huesgen ◽  
Helder Miranda ◽  
XuanTam Lam ◽  
Manuela Perthold ◽  
Holger Schuhmann ◽  
...  
Keyword(s):  
Serine Proteases ◽  
Protein Quality ◽  
Biochemical Characterization ◽  
Pdz Domain ◽  
Control Mechanisms ◽  
Ph Optimum ◽  
Periplasmic Proteins ◽  
Synechocystis Sp ◽  
Pcc 6803

Cyanobacteria require efficient protein-quality-control mechanisms to survive under dynamic, often stressful, environmental conditions. It was reported that three serine proteases, HtrA (high temperature requirement A), HhoA (HtrA homologue A) and HhoB (HtrA homologue B), are important for survival of Synechocystis sp. PCC 6803 under high light and temperature stresses and might have redundant physiological functions. In the present paper, we show that all three proteases can degrade unfolded model substrates, but differ with respect to cleavage sites, temperature and pH optima. For recombinant HhoA, and to a lesser extent for HtrA, we observed an interesting shift in the pH optimum from slightly acidic to alkaline in the presence of Mg2+ and Ca2+ ions. All three proteases formed different homo-oligomeric complexes with and without substrate, implying mechanistic differences in comparison with each other and with the well-studied Escherichia coli orthologues DegP (degradation of periplasmic proteins P) and DegS. Deletion of the PDZ domain decreased, but did not abolish, the proteolytic activity of all three proteases, and prevented substrate-induced formation of complexes higher than trimers by HtrA and HhoA. In summary, biochemical characterization of HtrA, HhoA and HhoB lays the foundation for a better understanding of their overlapping, but not completely redundant, stress-resistance functions in Synechocystis sp. PCC 6803.

Serine proteases and metalloproteases associated with pathogenesis but not host specificity in the Entomophthoralean fungus Zoophthora radicans

2006 ◽  
Vol 52 (6) ◽  
pp. 550-559 ◽  
Author(s):  
J Xu ◽  
D Baldwin ◽  
C Kindrachuk ◽  
D D Hegedus
Keyword(s):  
Serine Protease ◽  
Host Specificity ◽  
Serine Proteases ◽  
Pathogenic Fungus ◽  
Diamondback Moth ◽  
Expression Patterns ◽  
Serial Passage ◽  
Infection Process ◽  
Original Strain ◽  
Zoophthora Radicans

The protease activity of a Zoophthora radicans strain that was highly infective toward Pieris brassicae (cabbage butterfly) larvae was compared with that of isogenic strains that were adapted to Plutella xylostella (diamondback moth) larvae through serial passage. All strains produced three distinct serine proteases ranging in size from 25 to 37 kDa; however, the original strain from P. brassicae also produced large amounts of an approximately 46 kDa metalloprotease. Subsequently, a cDNA encoding a 43 kDa (mature enzyme) zinc-dependent metalloprotease, ZrMEP1, was isolated from the original fungal strain and most likely corresponds to the 46 kDa protease observed with in-gel assays. ZrMEP1 possessed characteristics of both the fungalysin and thermolysin metalloprotease families found in some pulmonary and dermal pathogens. This is the first report of this type of metalloprotease from an entomo pathogenic fungus. A cDNA encoding a trypsin-like serine protease, ZrSP1, was also identified and was most similar to a serine protease from the plant pathogen Verticillium dahliae. In artificial media, ZrMEP1 and ZrSP1 were found to be differentially responsive to gelatin and catabolite repression in the fungal strains adapted to P. brassicae and P. xylostella, but their expression patterns within infected larvae were the same. It appears that while these proteases likely play a role in the infection process, they may not be major host specificity determinants.Key words: Zoophthora radicans, metalloprotease, serine protease, pathogenesis, entomopathogen, host specificity.

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