Neutral aminopeptidase and dipeptidyl peptidase IV in the development of collagen II-induced arthritis.

This study evaluated the hypothesis that neutral (APN) and dipeptidyl-IV (DPPIV) aminopeptidase activity levels would be critical for the susceptibility to arthritis in collagen-induced model (CIA). The macroscopic signs of arthritis in CIA rats were checked and peripheral blood, synovial fluid and synovial tissue from knee joint were withdrawn. Soluble (SF) and solubilized membrane-bound (MF) fractions from the synovial tissue and peripheral blood mononuclear cells (PBMCs) were obtained. APN and DPPIV activities were fluorometrically quantified. Severe swelling in both the entire hind paws was the minimum criterion to select CIA rats with arthritis. These arthritic rats had high APN in plasma, synovial fluid and SF of the synovial tissue, together with low APN and DPPIV in MF of PBMCs and hallmark histological changes in tibio-tarsal joint. CIA rats with no macroscopic signs of arthritis were diagnosed as resistant and they had low APN in MF of the synovial tissue, low DPPIV in SF of PBMCs and high DPPIV in plasma together with histological aspects of tibio-tarsal joint similar to healthy control rats. Data suggested that APN and DPPIV activity levels are related to the development of arthritis, being protective or inducer of the susceptibility. Understanding what is controlling the compartment-specific changes of these peptidases and looking at ways in which to manipulate their activities may lead to a better knowledge of the arthritic processes and novel treatments.

Neutral aminopeptidase and dipeptidyl peptidase IV in the development of collagen II-induced arthritis

This study evaluated the hypothesis that neutral (APN) and dipeptidyl-IV (DPPIV) aminopeptidase activity levels would be critical for the susceptibility to arthritis in collagen-induced model (CIA). The macroscopic signs of arthritis in CIA rats were checked and peripheral blood, synovial fluid and synovial tissue from knee joint were withdrawn. Soluble (SF) and solubilized membrane-bound (MF) fractions from the synovial tissue and peripheral blood mononuclear cells (PBMCs) were obtained. APN and DPPIV activities were fluorometrically quantified. Severe swelling in both the entire hind paws was the minimum criterion to select CIA rats with arthritis. These arthritic rats had high APN in plasma, synovial fluid and SF of the synovial tissue, together with low APN and DPPIV in MF of PBMCs and hallmark histological changes in tibio-tarsal joint. CIA rats with no macroscopic signs of arthritis were diagnosed as resistant and they had low APN in MF of the synovial tissue, low DPPIV in SF of PBMCs and high DPPIV in plasma together with histological aspects of tibio-tarsal joint similar to healthy control rats. Data suggested that APN and DPPIV activity levels are related to the development of arthritis, being protective or inducer of the susceptibility. Understanding what is controlling the compartment-specific changes of these peptidases and looking at ways in which to manipulate their activities may lead to a better knowledge of the arthritic processes and novel treatments.

Basic aminopeptidase activity is an emerging biomarker in collagen-induced rheumatoid arthritis.

The objective of this study was to investigate the catalytic activity of basic aminopeptidase (APB) and its association with periarticular edema and circulating tumor necrosis factor (TNF)-alpha and type II collagen (CII) antibodies (AACII) in a rat model of rheumatoid arthritis (RA) induced by CII (CIA). Edema does not occur in part of CII-treated, even when AACII is higher than in control. TNF-alpha is detectable only in edematous CII-treated. APB in synovial membrane is predominantly a membrane-bound activity also present in soluble form and with higher activity in edematous than in non-edematous CII-treated or control. Synovial fluid and blood plasma have lower APB in non-edematous than in edematous CII-treated or control. In peripheral blood mononuclear cells (PBMCs) the highest levels of APB are found in soluble form in control and in membrane-bound form in non-edematous CII-treated. CII treatment distinguishes two categories of rats: one with arthritic edema, high AACII, detectable TNF-alpha, high soluble and membrane-bound APB in synovial membrane and low APB in the soluble fraction of PBMCs, and another without edema and with high AACII, undetectable TNF-alpha, low APB in the synovial fluid and blood plasma and high APB in the membrane-bound fraction of PBMCs. Data suggest that APB and CIA are strongly related.

Basic aminopeptidase activity is an emerging biomarker in collagen-inducedrheumatoid arthritis

The objective of this study was to investigate the catalytic activity of basic aminopeptidase (APB) and itsassociation with periarticular edema and circulating tumor necrosis factor (TNF)-alpha and type II collagen(CII) antibodies (AACII) in a rat model of rheumatoid arthritis (RA) induced by CII (CIA). Edema does not occurin part of CII-treated, even when AACII is higher than in control. TNF-alpha is detectable only in edematousCII-treated. APB in synovial membrane is predominantly a membrane-bound activity also present in solubleform and with higher activity in edematous than in non-edematous CII-treated or control. Synovial fluid andblood plasma have lower APB in non-edematous than in edematous CII-treated or control. In peripheral bloodmononuclear cells (PBMCs) the highest levels of APB are found in soluble form in control and in membraneboundform in non-edematous CII-treated. CII treatment distinguishes two categories of rats: one with arthritic edema, high AACII, detectable TNF-alpha, high soluble and membrane-bound APB in synovial membrane and low APB in the soluble fraction of PBMCs, and another without edema and with high AACII,undetectable TNF-alpha, low APB in the synovial fluid and blood plasma and high APB in the membranebound fraction of PBMCs. Data suggest that APB and CIA are strongly related.

Lipoic acid effects on renal function, aminopeptidase activities and oxidative stress in Crotalus durissus terrificus envenomation in mice.

Crotalus durissus terrificus envenomation has been associated with direct nephrotoxicity, rhabdomyolysis, hyperuricemia, urinary hypoosmolality, alterations in aminopeptidase activities (AP) and oxidative stress. This study evaluated the effects of lipoic acid (LA) on renal function, lethality, AP and GSSG/GSH in mice injected with C. d. terrificus venom (vCdt). The doses and routes of administration of LA and vCdt promoted no systemic myotoxicity. LA did not alter significantly the lethality of vCdt. In nonenvenomed, LA induced hypercreatinemia, urinary hyperosmolality, decrease of urinary urea and creatinine, increase of protein in plasma and in soluble fraction (SF) and decrease in membrane-bound fraction (MF) of cortex and medulla. Decreased levels of all AP (except neutral-AP in MF-medulla) were also induced by LA in nonenvenomed. LA associated with vCdt decreased plasma osmolality, hematocrit, urinary uric acid, but increased urinary and SF-medullar protein. LA mitigated the increase of protein in SF-cortex and corrected hyperuricemia, GSSG/GSH and protein in MF-cortex and MF-medulla, as well as decreased plasma neutral AP and acid AP in MF-medulla of envenomed mice. Data suggest that LA contributes to the solubilization/remotion of proteins in MF with impairment of most AP, but it could be beneficial for the treatment of the direct nephrotoxicity of vCdt.

Lipoic acid effects on renal function, aminopeptidase activities andoxidative stress in Crotalus durissus terrificus envenomation in mice

Crotalus durissus terrificus envenomation has been associated with direct nephrotoxicity, rhabdomyolysis, hyperuricemia, urinary hypoosmolality, alterations in aminopeptidaseactivities (AP) and oxidative stress. This study evaluated the effects of lipoic acid (LA) on renal function, lethality, AP and GSSG/GSH in mice injected with C. d. terrificus venom (vCdt). The doses and routes of administration of LA and vCdt promoted no systemic myotoxicity. LA did not alter significantly the lethality of vCdt. In nonenvenomed, LA induced hypercreatinemia, urinary hyperosmolality, decrease of urinary urea and creatinine, increase of protein in plasma and in soluble fraction (SF) and decrease in membraneboundfraction (MF) of cortex and medulla. Decreased levels of all AP (except neutral-AP in MF-medulla) were also induced by LA in nonenvenomed. LA associated with vCdt decreased plasma osmolality, hematocrit, urinary uric acid, but increased urinary and SF-medullar protein. LA mitigated the increase of protein in SF-cortex and corrected hyperuricemia, GSSG/GSH and protein in MF-cortex and MF-medulla, as well as decreased plasma neutral AP and acid AP in MF-medulla of envenomed mice. Data suggest that LA contributes to the solubilization/remotion of proteins in MF with impairment of most AP,but it could be beneficial for the treatment of the direct nephrotoxicity of vCdt.

Peptidase activities in the semen from the ductus deferens and uterus of the neotropical rattlesnake Crotalus durissus terrificus.

To understand the role of peptidases in seminal physiology of Crotalus durissus terrificus, intra- and inter-seasonal activity levels of acid (APA), basic (APB), puromycin-sensitive (APN-PS) and puromycin-insensitive neutral (APN-PI), cystyl (CAP), dipeptidyl-IV (DPPIV), type-1 pyroglutamyl (PAP-I) and prolyl-imino (PIP) aminopeptidases as well as prolyl endopeptidase (POP) were evaluated in soluble (SF) and/or membrane-bound (MF) fractions of semen collected from the ductus deferens of the male reproductive tract and from the posterior portion of the uterus. Seminal APB, PIP and POP were detected in SF, while other peptidases were detected in SF and MF. Only the convoluted posterior uterus in winter and autumn had semen. Relative to other examined peptidases, in general, APN-PI, APN-PS and APB activities were predominant in the semen from the uterus and throughout the year in the semen from the ductus deferens, suggesting their great relevance in the seminal physiology of C. d. terrificus. The levels of peptidase activities in the ductus deferens semen varied seasonally and were different from those of semen in the uterus, suggesting that their modulatory actions on susceptible peptides are integrated to the male reproductive cycle events and spermatozoa viability of this snake.

Seasonal variation of peptidase activities in the reproductive tract of Crotalus durissus terrificus.

Seasonal quantitative patterns of acid (APA), basic (APB), puromycin-sensitive (APN-PS) and puromycin-insensitive neutral (APN-PI), cystyl (CAP), dipeptidyl IV (DPPIV), type-1 pyroglutamyl (PAP-I) and prolyl-imino (PIP) aminopeptidases and prolyl oligopeptidase (POP) activities in soluble (SF) and solubilized membrane-bound (MF) fractions from ductus deferens, vagina and uterus were studied to evaluate their relationships with the reproductive cycle and the extensive long-term spermatozoa storage (LTSS) of the Neotropical rattlesnake Crotalus durissus terrificus. APB, PIP and POP were detected only in SF, while other peptidases were detected in SF and MF. APB, APN-PI and APN-PS were predominant in most tissues in all seasons. Peptidase activities had a common pattern of increment during the dry season (winter/autumn), which coincides with the mating period (autumn) and LTSS in the female (winter), as well as the reduction of spermatozoa motility and maintenance of fertilization capacity of spermatozoa. The high CAP activity in the soluble fraction of the vagina during winter, compared to summer (time of parturition) and spring, coincides with the relaxation of this tissue. In the soluble fraction, the low PAP-I activity of the ductus deferens coincided with its high activity in the vagina during the winter; and the inverse occurred in summer, which is consistent with the physiological process of preserving spermatozoon viability. In conclusion, the studied peptidase activities had seasonal and tissue-specific characteristics, which suggest a relevant role in the reproductive physiology of C. d. terrificus.

Aminopeptidase activities, oxidative stress and renal function in Crotalus durissus terrificus envenomation in mice.

Acute renal failure is a serious condition of Crotalus bites, which could be treated with statins. The effects of Crotalus durissus terrificus venom (vCdt) and simvastatin on renal function, oxidative stress and representative plasma, urinary and renal aminopeptidase (AP) activities were evaluated in mice. Eighty percent LD50 of vCdt caused hyperuricemia and urinary hypoosmolality (100%) and hypercreatinemia (60%). Plasma neutral, pyroglutamyl and dipeptidyl IV and renal soluble and membrane-bound APs were susceptible to vCdt. Cortical and medullar oxidative stress (GSSG/GSH ratio) was increased by vCdt. Simvastatin (3mg/kg body wt.) altered urinary creatinine and urea, membranal protein in cortex and medulla, plasma neutral and dipeptidyl IV APs and most of renal APs in nonenvenomed, and exacerbated hypercreatinemia, but mitigated uricosuria, renal oxidative stress and protein increase in envenomed. Hyperuricemia and urinary hypoosmolality are early signs of indirect myotoxicity of vCdt with diagnostic significance. In kidney, oxidative stress and alteration of protein content and AP activities suggest membrane destruction, enzyme release and protein loss, which may be due to direct tissue damage. Plasma AP activities might be nephrotoxicity markers of C. d. terrificus envenomation. The deleterious effects of simvastatin on creatinemia and APs constitute important restrictions to its use within the antivenom therapy.

Peptidase activities in Crotalus durissus terrificus semen

To understand the role of peptidases in seminal physiology of Crotalus durissus terrificus, activity levels of representative enzymes in semen and their sensitivities to inhibitors, cofactors, and peptide hormones were evaluated. The existence of seminal fractions and the association of peptidases with these fractions were also characterized for the first time in snakes. The prominent inhibitors of aminopeptidases (APs) were amastatin for acid, basic, and neutral; bestatin for basic; and diprotin A for dipeptidyl-IV. Cystyl and prolyl-imino APs were similarly susceptible to the majority of these inhibitors. The basic and neutral were characterized as metallo-peptidases, acid AP was activated by MnCl2, and cystyl, prolyl-imino, and type I pyroglutamyl were characterized as sulphydryl-dependent APs. Angiotensin II, vasotocin, bradykinin, fertilization-promoting peptide, and TRH altered the majority of these peptidase activities; these peptides are possible substrates and/or modulators of these peptidases. Peptidase activities were found in all seminal fractions: seminal plasma (SP), prostasome-like (PR) structures, and soluble (S-) and membrane-bound fractions (MFs) of spermatozoa. The levels of activity of each peptidase varied among different seminal fractions. in SP, the higher activities were puromycin-insensitive neutral and basic APs. in PR, the higher activity was puromycin-insensitive neutral AP. In spermatozoa, the higher activity in subcellular SF was puromycin-sensitive neutral, while in MF both puromycin-sensitive and -insensitive neutral APs were equally higher than the other examined peptidases. Data suggested that these peptidases, mainly basic and neutral, have a high relevance in regulating seminal functions of C. d. terrificus.