Anti-biofilm potential of human senescence marker protein 30 against Mycobacterium smegmatis

Human senescence marker protein 30 (huSMP30) has been characterized as a multifaceted protein consisting of various enzymatic and cellular functions. It catalyzes the interconversion of L-gulonate and L-gulono-γ-lactone in the ascorbate biosynthesis pathway. Therefore, we hypothesized that it could be a potential anti-biofilm agent against pathogenic bacteria due to its lactonase activity. In order to corroborate this, the huSMP30 was recombinantly expressed, purified, and analyzed for its ability to inhibit Mycobacterium smegmatis biofilm formation, which showed a concentration-dependent inhibition as compared to the untreated control group. Further, in silico analysis was performed to redesign the huSMP30 with enhanced lactonase activity. Molecular docking analysis of the huSMP30 and lactone substrates facilitated the selection of three single amino acid substitutions (E18H, N154Q, and D204V), which were created using a PCR-based site-directed mutagenesis reaction. These mutant proteins and the wild-type huSMP30 were purified, and the effects on the enzymatic activity and biofilm formation were studied. The mutants E18H and D204V showed non-significant effects on specific lactonase activity, catalytic efficiency, and anti-biofilm property; however, the mutant N154Q showed significant improvement in the specific lactonase activity, catalytic efficiency, and inhibition in the biofilm formation. The protein stability analysis revealed that the wild-type huSMP30 and its designed mutants were stable at 37 °C for up to 4 days. In conclusion, the anti-biofilm property of the huSMP30 has been established, and an engineered version, N154Q, inhibits biofilm formation with greater efficiency. Human SMP30 is a versatile protein with multiple cellular and enzymatic functions, however, its anti-biofilm potential has not been explored. Our work presents the method to produce soluble and active huSMP30 in the E. coli expression system and establishes its role as an anti-biofilm agent against Mycobacterium smegmatis owing to its lactonase activity. Our results provide support for the future advancement of huSMP30 as a potential anti-biofilm agent targeting pathogenic Mycobacterium species.

Characterization of a novel recombinant calcium-binding protein from Arca subcrenata and its anti-hepatoma activities in vitro and in vivo

Previous studies demonstrated that ASP-3 was a novel calcium-binding protein from Arca subcrenata that effectively inhibited the proliferation of HepG2 cells. To further study the antitumor activity and mechanism of ASP-3, the cytotoxic effects of recombinant ASP-3 were evaluated in HepG2 cells. The results demonstrated that ASP-3 inhibited the proliferation of HepG2 cells by competitively binding to the EGF binding pocket of EGFR and inhibiting the JAK-STAT, RAS-RAF-MEK-ERK, and PI3K-Akt-mTOR signaling pathways mediated by EGFR. ASP-3 significantly inhibited tumor growth in a HepG2 cell subcutaneous xenograft nude mouse model, and its (25 mg/kg and 75 mg/kg) tumor inhibition rates were 46.92 % and 60.28 %, respectively. Furthermore, the crystal structure of ASP-3 was resolved at 1.4 Å. ASP-3 formed as a stable dimer and folded as an EF-Hand structure. ASP-3 stably bound to domain I and domain III of the EGFR extracellular region by using molecular docking and molecular dynamics simulation analysis. Compared with the endogenous ligand EGF, ASP-3 displayed a stronger interaction with EGFR. These experimental results indicated that recombinant ASP-3 possessed an effective anti-hepatoma effect. So, it might be a potential molecule for liver cancer therapy.

Potential role of PRKCSH in lung cancer: bioinformatics analysis and a case study of Nano ZnO

PRKCSH, also known as glucosidase II beta, functions as a contributor to lung tumorigenesis by regulating the cell cycle in a p53-dependent manner under severe environmental stress. However, the prognostic value and molecular mechanisms by which the level of PRKCSH is significantly increased in cancer cells are not clearly understood. Here, we first generated a biological profile of PRKCSH expression changes in cancers by analysing bioinformatic data from cancer databases. We found that higher PRKCSH expression was correlated with a poorer prognosis and greater infiltration of most immune cell types in patients with lung cancer. In particular, PRKCSH expression showed significant negative correlations with the level of STAT6 (r = -0.31, p < 0.001) in lung cancer tissues. We further found that PRKCSH deficiency promoted G2/M arrest in response to zinc oxide nanoparticle (Nano ZnO) treatment in A549 cells. With regard to the mechanism, PRKCSH deficiency may induce STAT6 translocation to the nucleus to activate p53 expression through binding to the p53 promoter region from -365 bp to +126 bp. Eventually, activated p53 contributed to Nano-ZnO-induced G2/M arrest in lung cancer cells. Taken together, our data provide new insights into immunotherapy target choices and the prognostic value of PRKCSH. Since the G2/M cell cycle checkpoint is crucial for lung cancer prognosis, targeting PRKCSH expression to suppress the activation of the STAT6/p53 pathway is a potential therapeutic strategy for managing lung cancer.

Cartilage Acidic Protein a Novel Therapeutic Factor to Improve Skin Damage Repair?

Fish skin has been gaining attention due to its efficacy as a human-wound-treatment product and to identify factors promoting its enhanced action. Skin fibroblasts have a central role in maintaining skin integrity and secrete extra cellular matrix (ECM) proteins, growth factors and cytokines to rapidly repair lesions and prevent further damage or infection. The effects on scratch repair of the ubiquitous but poorly characterized ECM protein, cartilage acidic protein 1 (CRTAC1), from piscine and human sources were compared using a zebrafish SJD.1 primary fibroblast cell line. A classic in vitro cell scratch assay, immunofluorescence, biosensor and gene expression analysis were used. Our results demonstrated that the duplicate sea bass Crtac1a and Crtac1b proteins and human CRTAC-1A all promoted SJD.1 primary fibroblast migration in a classic scratch assay and in an electric cell impedance sensing assay. The immunofluorescence analysis revealed that CRTAC1 enhanced cell migration was most likely caused by actin-driven cytoskeletal changes and the cellular transcriptional response was most affected in the early stage (6 h) of scratch repair. In summary, our results suggest that CRTAC1 may be an important factor in fish skin promoting damage repair.

S100A14 inhibits cell growth and epithelial-mesenchymal transition (EMT) in prostate cancer through FAT1-mediated Hippo signaling pathway

Prostate cancer (PCA) is an epithelial malignant tumor occurring in the prostate gland. It is the second most common male cancer in the world and one of the top five cancer deaths in men. To combat this disease, it is needed to identify important tumor suppressor genes and elucidate the molecular mechanisms. S100 calcium-binding protein A14 (S100A14), a member of the S100 family, is located on chromosome 1q21.3 and contains an EF-hand motif that binds calcium. S100A14 is involved in a variety of tumor biological processes in several types of cancers. Its expression level and related biological functions are tissue or tumor specific. However, its possible effects on prostate cancer are still unclear. Herein, we found the low expression of S100A14 in human prostate cancer tissues and cell lines. S100A14 suppressed the proliferation of prostate cancer cells and promoted cell apoptosis. Additionally, S100A14 suppressed the motility and EMT processes of prostate cancer cells. We further found S100A14 promoted the expression of FAT1 and activated the Hippo pathway, which, therefore, suppressed the prostate cancer progression. The in vivo assays confirmed that S100A14 suppressed tumor growth of prostate cancer cells through FAT1-mediated Hippo pathway in mice. In conclusion, we clarified the mechanism underlying S100A14 suppressing prostate cancer progression and, therefore, we thought S100A14 could serve as a tumor suppressor protein.

Protective effects of Nesfatin-1 peptide on cerebral ischemia reperfusion injury via inhibition of neuronal cell death and enhancement of antioxidant defenses

Nesfatin-1 is a novel peptide with anorexigenic and anti-hyperglycemic properties. According to previous studies, this multi-functional peptide protects dopaminergic cells against neurotoxicity via anti-apoptotic effects. In addition, Nesfatin-1 protects myocardial tissue after myocardial infarction via anti-inflammatory and anti-apoptotic mechanisms. In this study, we investigated the neuroprotective effects of nesfatin-1 against cerebral ischemia reperfusion injury in the CA1 area of hippocampus in rats. 56 male Wistar rats (240-270 g) were randomly selected and allocated into four groups: (1) sham, (2) nesfatin-1, (3) ischemia/reperfusion, (4) ischemia/reperfusion+nesfatin-1. Cerebral ischemia induced by the occlusion of the common carotid arteries for 20 min was followed by reperfusion. Saline as a vehicle and nesfatin-1 (20 μg/kg) were injected intraperitoneally (IP) at the start of cerebral reperfusion. Apoptotic and necrotic cell death was detected by TUNEL and Nissl staining. Malondialdehyde (MDA) and antioxidant enzymes (GSH and SOD) levels were measured by the ELISA method. The results showed that cerebral ischemia increased the apoptotic and necrotic cell death in the CA1 area of hippocampus, while, treatment with nesfatin-1significantly reduced apoptotic and necrotic cell death. Moreover, the MDA levels of the hippocampus in ischemic rats were higher, whereas in nesfatin-1-treated rats the MDA levels were decreased. Furthermore, the SOD and GSH levels in the ischemic rats were decreased, whilst in ischemic rats treated with nesfatin-1, the SOD and GSH levels were increased. This study for the first time found that nesfatin-1 treatment improves CA1 hippocampus injuries after cerebral ischemia through preventing neuronal cell death and enhancement of antioxidant defenses.

[About the prognostic role of fibulin-5 protein in the progression of pathological vascular remodeling in patients with isolated sistolic arterial hypertension.]

Today, arterial hypertension (AH) is often associated with accelerated aging. In the structure of AH in persons over 65 years of age, the most common form is isolated systolic hypertension (ISAH), the mechanisms of development of which remain unexplained. Molecular regulation of remodeling of smooth muscle cells of vessels, changes in which, along with perivascular fibrosis and endothelial dysfunction, lead to increased sensitivity to procontractile mediators and calcification, forms the basis of mechanisms of vascular aging and rigidity. Clinically, this process is manifested in ISAH in individuals of an early period of old age and senile age. The search for new diagnostic molecular markers and the development of pharmacological correction of mechanisms of vascular wall aging in ISAH is an urgent and timely task. The review presents an analysis of current data from medical literature about the participation of fibulin-5 protein in the process of elastogenesis in the vascular wall, as well as in molecular pathological pathways of inflammation and aging of the vascular wall in ISAH. The role of multifunctional signal molecule fibulin-5 in the age-related loss of elasticity of the vascular wall is shown. Presented is the perspective of creating a drug from the group of senolitics based on fibulin-5 molecule, as well as modern application possibilities for preventing aging of the vascular wall of the drug Cytoflavin (active ingredients in 1 ml of solution: succinic acid, 100 mg; nicotinamide, 10 mg; riboxin, 20 mg riboflavin mononucleotide, 2 mg).

Mesenchymal stromal cells-derived matrix Gla protein contribute to the alleviation of experimental colitis

Crohn's disease (CD) is a chronic inflammatory bowel disease that is difficult to treat. However, previous preclinical and clinical studies have shown that mesenchymal stromal cells (MSCs) are a promising therapeutic approach, whereas the exact underlying molecular mechanisms of MSCs in treating CD remain unclear. Furthermore, the heterogeneity of MSCs, as well as the in vivo microenvironments may influence the therapeutic efficacy. In our previous study, we found that a subpopulation of mouse MSCs with a high expression of matrix Gla protein (MGP), one of the members of vitamin K-dependent protein family, possessed better immunoregulatory properties. Therefore, in this study we investigate whether the abundant MSCs-derived MGP participate in the therapeutic mechanisms for MSCs treating CD. Obvious suppression of cell proliferation and cytokine production in T cells were observed in vitro through MSCs-derived MGP. Moreover, MGP alleviated the clinical and histopathological severity of colonic inflammation in mouse experimental colitis models to a remarkable degree. Our results indicate that MGP might be a novel important mediator of MSCs-mediated immunomodulation in treating CD.

Anti-inflammatory effects of nesfatin-1 on acetic acid-induced gastric ulcer in rats: involvement of cyclo-oxygenase pathway

In order to elucidate the contribution of cycloxygenase (COX) enzymes in the anti-oxidant and anti-inflammatory mechanisms of nesfatin-1, which improves the healing process of chronic gastric ulcers, either acetic acid (80%; ulcer groups; n = 40) or saline (control groups; n = 40) was applied to the serosal surface of male Sprague Dawley rats' stomachs for 1 min. Both the control and ulcer groups were treated daily with either i.p. saline or nesfatin-1 (0.3 μg/kg; for 3 days). Nesfatin-1-treatment was preceded with i.p. saline, COX-2 inhibitor NS-398 (2 mg/kg), COX-1 inhibitor ketorolac (3 mg/kg) or non-selective COX inhibitor indomethacin (5 mg/kg) for 3 days. The rats were decapitated at the end of the third day, and their trunk blood was collected for the measurements of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-10 using ELISA. The induction of ulcers resulted in increased macroscopic scores, along with elevated gastric malondialdehyde, luminol- and lucigenin-enhanced chemiluminescence levels and myeloperoxidase activity. On the other hand, nesfatin-1 treatment abolished these elevations. Depleted glutathione, superoxide dismutase and catalase activity levels in the saline-treated ulcer group were preserved in the nesfatin-1-treated ulcer group. Increased levels of serum TNF-α, IL-1β, IL-10 in the saline-treated ulcer group, as compared to control group, were significantly decreased in the nesfatin-1-treated ulcer group. The inhibition of COX-1, and/or COX-2 reversed most of the alterations induced with nesfatin-1, but COX-2-blockade was consistently more effective to abolish all nesfatin-1-induced changes. Our results suggest that nesfatin-1 ameliorates ulcer-induced inflammatory response through the modulation of oxidant-antioxidant balance. As selective pharmacological inhibition of COX-1 or COX-2 suppresses the antioxidant/anti-inflammatory effects of nesfatin-1, it appears that nesfatin-1 decreases inflammatory mediators and neutrophil migration by a COX-dependent mechanism, especially by a COX-2- dependent mechanism, during the ulcer healing stage.

[Matrix Gla protein as natural inhibitor of vascular calcification and potential treatment target]

Vascular calcification was once regarded as an advanced stage of atherosclerosis only. However, calcification is currently considered as highly regulated and potentially reversible process.Matrix Gla protein (MGP) represents natural inhibitor of vascular calcification, whereas vitamin K is key co-factor of its maturation to the active form. There is accumulating evidence that vitamin K status and corresponding MGP activity may influence cardiovascular risk. This review summarizes pathophysiological mechanism and recent evidence relative to MGP. Moreover, available data concerning vitamin K supplementation are depicted.

CCN1 induces hepatic ductular reaction through integrin αvβ₅-mediated activation of NF-κB

Liver cholestatic diseases, which stem from diverse etiologies, result in liver toxicity and fibrosis and may progress to cirrhosis and liver failure. We show that CCN1 (also known as CYR61), a matricellular protein that dampens and resolves liver fibrosis, also mediates cholangiocyte proliferation and ductular reaction, which are repair responses to cholestatic injury. In cholangiocytes, CCN1 activated NF-κB through integrin αvβ5/αvβ3, leading to Jag1 expression, JAG1/NOTCH signaling, and cholangiocyte proliferation. CCN1 also induced Jag1 expression in hepatic stellate cells, whereupon they interacted with hepatic progenitor cells to promote their differentiation into cholangiocytes. Administration of CCN1 protein or soluble JAG1 induced cholangiocyte proliferation in mice, which was blocked by inhibitors of NF-κB or NOTCH signaling. Knock-in mice expressing a CCN1 mutant that is unable to bind αvβ5/αvβ3 were impaired in ductular reaction, leading to massive hepatic necrosis and mortality after bile duct ligation (BDL), whereas treatment of these mice with soluble JAG1 rescued ductular reaction and reduced hepatic necrosis and mortality. Blockade of integrin αvβ5/αvβ3, NF-κB, or NOTCH signaling in WT mice also resulted in defective ductular reaction after BDL. These findings demonstrate that CCN1 induces cholangiocyte proliferation and ductular reaction and identify CCN1/αvβ5/NF-κB/JAG1 as a critical axis for biliary injury repair.

Bioactivity and circulation time of PEGylated NELL-1 in mice and the potential for osteoporosis therapy

Osteoporosis is a progressive bone disease due to low osteoblast activity and/or high osteoclast activity. NELL-1 is a potential therapy for osteoporosis because it specifically increases osteoblast differentiation. However, similar to other protein drugs, the bioavailability of NELL-1 may be limited by its in vivo half-life and rapid clearance from body. The purpose of the present study is to prolong NELL-1 circulation time in vivo by PEGylation with three monomeric PEG sizes (5, 20, 40 kDa). While linear PEG 5k yielded the most efficient PEGylation and the most thermally stable conjugate, linear PEG 20k resulted in the conjugate with the highest Mw and longest in vivo circulation. Compared to non-modified NELL-1, all three PEGylated conjugates showed enhanced thermal stability and each prolonged the in vivo circulation time significantly. Furthermore, PEGylated NELL-1 retained its osteoblastic activity without any appreciable cytotoxicity. These findings motivate further studies to evaluate the efficacy of PEGylated NELL-1 on the prevention and treatment of osteoporosis.

Experimental healing of preexisting gastric ulcers induced by hormones controlling food intake ghrelin, orexin-A and nesfatin-1 is impaired under diabetic conditions. A key to understanding the diabetic gastropathy?

Hormonal peptides like ghrelin, orexin A (OXA) or nesfatin-1 not only regulate appetite, which is their basic biological function, but also contribute to mechanisms responsible for maintaining integrity of the gastric mucosa. Previous studies including those from our laboratory have revealed that their gastroprotective effect results from cooperation with other factors responsible for protection of the gastric mucosa, including prostaglandin (PG) synthesis pathway, nitric oxide (NO) and the sensory afferent fibres releasing the vasoactive neurotransmitters. The aim of the present study was to determine whether ghrelin, orexin-A (OX-A) or nesfatin-1 with their protective effect on the gastric mucosa, also can modify the healing of chronic gastric ulcers. Furthermore, an attempt was made to explain participation of these peptides in healing processes of chronic gastric ulcers with comorbid conditions for the human beings resulted from diabetes mellitus. In our study, a model of gastric ulcers caused by concentrated acetic acid to induce the chronic gastric ulcers was used, while the clinical condition corresponding to diabetes was induced by single injection of streptozotocin (STZ). We found that ghrelin, OX-A and nesfatin-1 accelerate dynamics of the acetic acid ulcers healing, confirmed by a reduction in the ulcer area and this effect was accompanied by an increase in gastric blood flow at the ulcer margin. Destruction of sensory afferent fibres with capsaicin or blocking of vanilloid receptors with capsazepine resulted in a significant reduction of ghrelin, OX-A and nesfatin-1-induced acceleration of ulcer healing. Similar results were obtained when an NO-synthase blocker, L-NNA was used in a combination with these peptides. Moreover, it was found that OX-A and nesfatin-1 failed to accelerate the healing process under diabetic condition because both these hormones induced reduction in the ulcer area and the increase in blood flow in normal, non-diabetic rats were completely lost in the group of animals with diabetes. Treatment with OX-A and nesfatin-1 increased superoxide dismutase (SOD) mRNA expression even in acetic acid ulcers concurrent with diabetes. However, the treatment with OX-A and nesfatin-1 failed to alter the increase in gastric mucosal mRNA expression for ghrelin and hypoxia-inducible factor 1-alpha (HIF-1α), this latter effect that had been strongly pronounced in diabetic animals. We conclude that the hormonal peptides involved in the regulation of satiety and hunger such as ghrelin, OX-A and nesfatin-1 contribute to the process of chronic gastric ulcers healing cooperating with NO and sensory afferent nerve endings releasing vasoactive neuropeptide CGRP. Furthermore, OX-A and nesfatin-1, the two relatively unrecognized peptides, play an essential role in healing process of chronic gastric ulcers activating the gastric blood flow at ulcer margin and the mucosal regeneration and both ulcer healing and accompanying hyperemia at ulcer margin are greatly impaired during diabetes. Possibly, loss of the healing effect of these peptides during diabetes results from an interaction with radical generation processes as reflected by an increase of mRNA expression for SOD as well as the failure of their attenuating activity on proinflammatory factors such as HIF-1α.

Long-term rescue of a familial hypertrophic cardiomyopathy caused by a mutation in the thin filament protein, tropomyosin, via modulation of a calcium cycling protein

We have recently shown that a temporary increase in sarcoplasmic reticulum (SR) cycling via adenovirus-mediated overexpression of sarcoplasmic reticulum ATPase (SERCA2) transiently improves relaxation and delays hypertrophic remodeling in a familial hypertrophic cardiomyopathy (FHC) caused by a mutation in the thin filament protein, tropomyosin (i.e., α-TmE180G or Tm180). In this study, we sought to permanently alter calcium fluxes via phospholamban (PLN) gene deletion in Tm180 mice in order to sustain long-term improvements in cardiac function and adverse cardiac remodeling/hypertrophy. While similar work has been done in FHCs resulting from mutations in thick myofilament proteins, no one has studied these effects in an FHC resulting from a thin filament protein mutation. Tm180 transgenic (TG) mice were crossbred with PLN knockout (KO) mice and four groups were studied in parallel: 1) non-TG (NTG), 2) Tm180, 3) PLNKO/NTG and 4) PLNKO/Tm180. Tm180 mice exhibit increased heart weight/body weight and hypertrophic gene markers compared to NTG mice, but levels in PLNKO/Tm180 mice were similar to NTG. Tm180 mice also displayed altered function as assessed via in situ pressure-volume analysis and echocardiography at 3-6 months and one year; however, altered function in Tm180 mice was rescued back to NTG levels in PLNKO/Tm180 mice. Collagen deposition, as assessed by Picrosirius Red staining, was increased in Tm180 mice but was similar in NTG and in PLNKO/Tm180 mice. Extracellular signal-regulated kinase (ERK1/2) phosphorylation increased in Tm180 mice while levels in PLNKO/Tm180 mice were similar to NTGs. The present study shows that by modulating SR calcium cycling, we were able to rescue many of the deleterious aspects of FHC caused by a mutation in the thin filament protein, Tm.

[Study advancement of calpain and apoptosis following cerebral ischemia]

Calpains, calcium-activated cysteine proteases with a neutral pH optimum, lead to degration of cystoskeletion and structural protein, and delayed neuronal death. The activation of calpains contribute to apoptosis. Calpain inhibitors provide a novel and potential treatment for cerebral ischemia due to improvement of cerebral infarct and ischemia.

Reversal of calcium cycling defects in advanced heart failure toward molecular therapy

Heart failure is a growing major cause of human morbidity and mortality worldwide. A wave of new insights from diverse laboratories has begun to uncover new therapeutic strategies that affect the molecular pathways within cardiomyocytes that drive heart failure progression. Using an integrative approach that employs insights from genetic-based studies in mouse and humans and in vivo somatic gene transfer studies, we have uncovered a new link between stress signals mediated by mechanical stretch and defects in sarcoplasmic reticulum (SR) calcium cycling. An intrinsic mechanical stress sensing system is embedded in the Z disc of cardiomyocytes, and defects in stretch responses can lead to heart failure progression and associated increases in wall stress. Reversal of the chronic increases in wall stress by promoting SR calcium cycling can prevent and partially reverse heart failure progression in multiple genetic and acquired model systems of heart failure in both small and large animals. We propose that reversal of advanced heart failure is possible by targeting the defects in SR calcium cycling, which may be a final common pathway for the progression of many forms of heart failure.

Adenovirus-mediated calponin h1 gene therapy directed against peritoneal dissemination of ovarian cancer: bifunctional therapeutic effects on peritoneal cell layer and cancer cells

PURPOSE

Calponin h1 (CNh1), one of the family of actin-binding proteins, stabilizes the filaments of actin and modulates various cellular biological phenotypes. Recent studies revealed the close correlation between the invasive tumor spread and the reduced expression of CNh1 and alpha-smooth muscle actin in the surrounding stromal cells. The purpose of this study is to evaluate the efficacy of i.p. CNh1 gene therapy against peritoneal dissemination of ovarian cancer.

EXPERIMENTAL DESIGN

We used an adenoviral vector to induce the CNh1 gene into peritoneal cells and ovarian cancer cells as a means of enhancing or inducing the expression of alpha-smooth muscle actin as well as CNh1. The efficacy of gene transfer was examined by in vitro cell culture and in vivo animal experiments.

RESULTS

The formation of longer and thicker actin fibers was observed in each transfected cell line, and the localization of these fibers coincided with that of externally transducted CNh1. With respect to changes in cell behavior, the CNh1-transfected peritoneal cells acquired an ability to resist ovarian cancer-induced shrinkage in cell shape; thus, cancer cell invasion through the monolayer of peritoneal cells was inhibited. In addition, CNh1-transfected ovarian cancer cells showed suppressed anchorage-independent growth and invasiveness, the latter of which accompanied impaired cell motility. The concomitant CNh1 transfection into both peritoneal cells and ovarian cancer cells produced an additive inhibitory effect with respect to cancer cell invasion through the peritoneal cell monolayer. By in vivo experiments designed to treat nude mice that had been i.p. inoculated with ovarian cancer cells, we found that the i.p. injected CNh1 adenovirus successfully blocked cancer-induced morphologic changes in peritoneal cell surface and significantly prolonged the survival time of tumor-bearing mice. Moreover, CNh1 adenovirus could successfully enhance the therapeutic effect of an anticancer drug without increase in side effects.

CONCLUSIONS

Thus, CNh1 gene therapy against peritoneal dissemination of ovarian cancer is bifunctionally effective (i.e., through inhibitory effects on the infected peritoneal cell layers that suppress cancer invasion and through direct antitumor effects against invasion and growth properties of cancer cells).

Calpain inhibition: a therapeutic strategy targeting multiple disease states

The calpains represent a well-conserved family of calcium-dependent cysteine proteases. They consist of several ubiquitous and tissue specific isoforms and exhibit broad substrate specificity influencing many aspects of cell physiology including migration, proliferation and apoptosis. Calpain activity in vivo is tightly regulated by its natural endogenous inhibitor calpastatin. Calpastatin specifically inhibits calpain and not other cysteine proteases by interaction with several sites on the calpain molecule. Inappropriate regulation of the calpain-calpastatin proteolytic system is associated with several important human pathological disorders including muscular dystrophy, cancer, Alzheimer's disease, neurological injury, ischaemia/reperfusion injury, atherosclerosis, diabetes and cataract formation. Recent advances in elucidating the tertiary structures of calpain 2 and its regulatory domain calpain 4, together with identification of new modes of regulating calpain activity provide new opportunities for the design of novel calpain inhibitors. Several classes of inhibitors, including peptidyl epoxide, aldehyde, and ketoamide inhibitors, targeting the active site have proven effective against the calpains and are in the process of evaluation in animal models of human disease. However, a major limitation to the clinical use of such inhibitors is their lack of specificity among cysteine proteases and other proteolytic enzymes. The development of a new class of calpain inhibitors that interact with domains outside of the catalytic site of calpain may provide greater specificity and therapeutic potential.

Fibulins and cancer: friend or foe?

The fibulins are a family of secreted glycoproteins, which are characterised by repeated epidermal-growth-factor-like domains and a unique C-terminal structure. Six distinct fibulin genes, encoding at least nine protein products generated by alternative splicing, have been identified. Considerable evidence is available pointing towards a structural role for fibulins within the extracellular matrix. Fibulins have been shown to modulate cell morphology, growth, adhesion and motility. The dysregulation of certain fibulins occurs in a range of human disorders, including cancer. Indeed, both tumour suppressive and oncogenic activities have been proposed for members of the fibulin family. Herein, we discuss the possible roles of fibulins in cancer, in addition to their diagnostic and therapeutic potential.

Hevin/SC1, a matricellular glycoprotein and potential tumor-suppressor of the SPARC/BM-40/Osteonectin family

Hevin is an extracellular matrix-associated, secreted glycoprotein belonging to the secreted protein acidic and rich in cysteine (SPARC) family of matricellular proteins. It contains three conserved structural domains that are implicated in the regulation of cell adhesion, migration, and proliferation. Hevin is expressed during embryogenesis and tissue remodeling and is especially prominent in brain and vasculature. Its down-regulation in a number of cancers and the possibility of its functional compensation by SPARC has led to recent interest in hevin as a tumor suppressor and regulator of angiogenesis.

Antimicrobial psoriasin (S100A7) protects human skin from Escherichia coli infection

Human healthy skin is continuously exposed to bacteria, but is particularly resistant to the common gut bacterium Escherichia coli. We show here that keratinocytes secrete, as the main E. coli-killing compound, the S100 protein psoriasin in vitro and in vivo in a site-dependent way. In vivo treatment of human skin with antibodies to psoriasin inhibited its E. coli-killing properties. Psoriasin was induced in keratinocytes in vitro and in vivo by E. coli, indicating that its focal expression in skin may derive from local microbial induction. Zn(2+)-saturated psoriasin showed diminished antimicrobial activity, suggesting that Zn(2+) sequestration could be a possible antimicrobial mechanism. Thus, psoriasin may be key to the resistance of skin against E. coli.

[Atherosclerosis and vascular calcification in hemodialysis patients]

Cardiovascular disease is the largest cause of mortality in hemodialysis patients. Cardiovascular mortality is fivefold to twentyfold higher in hemodialysis patients than in the general population. Atherosclerosis and vascular calcification are the characteristic complications in hemodialysis patients. Hemodialysis patients have traditional risk factors such as abnormal lipid metabolism and uremia-related risk factors such as oxidative stress and hyperphosphatemia. Oxidative stress takes place by increased production of oxidants by leukocytes and antioxidant loss of vitamin C and E. Oxidatively modified LDL exist in the circulation by excess of oxidative stress in hemodialysis patients. Oxidative stress is a major contributor to accelerated development atherosclerosis. Oxidative stress and hyperphosphatemia also influence vascular calcification. The pattern of vascular calcification in hemodialysis patient is characterized by mineral deposition in the tunica media. It is reported that the obvious calcification in aorta and artery of the MGP knockout mouse is recognized. It is indicated that MGP has the inhibitory effect of the calcification of vessel wall. Vitamin E protects atherosclerosis and vascular calcification in hemodialysis patients. It is also important to control hyperphosphatemia for vascular calcification.

Suppression of peritoneal dissemination through protecting mesothelial cells from retraction by cancer cells

In a previous study, we demonstrated that calponin h1 suppressed tumor growth of transformed cells and that the peritonitis carcinomatosa induced by mouse B16-F10 melanoma (F10) cells was more extensive in calponin h1-deficient (CN(-/-)) mice with fragility of mesothelial (MS) cells than in their calponin h1-wild (CN(+/+)) counterparts. In our study, we assessed the therapeutic effect of calponin h1 on peritoneal dissemination. F10 cells were overlaid on the cultured CN(+/+) or CN(-/-) MS cells and the effect of calponin h1 on retraction of MS cells was evaluated. Then, an adenoviral vector with the calponin h1 gene (AdGFP-CN) inserted was constructed and was applied to CN(-/-) MS cells or CN(-/-) mouse peritoneum to investigate its suppressive effect on the peritoneal dissemination caused by F10 cells. Greater retraction and invasion of F10 cells were observed in CN(-/-) MS than in CN(+/+) cells in vitro, while down-regulation of calponin h1 was observed in CN(+/+) MS cells prior to the invasion of F10 cells. Infecting CN(-/-) MS cells with AdGFP-CN prevented their retraction and the invasion of F10 cells. Peritoneal dissemination was prominently suppressed in AdGFP-CN-infected CN(-/-) mice, and the survival of those mice was significantly prolonged. Thus, calponin h1 functioned to protect host MS cells from the invasion of F10 cells.

Inhibition of calpains prevents neuronal and behavioral deficits in an MPTP mouse model of Parkinson's disease

The molecular mechanisms mediating degeneration of midbrain dopamine neurons in Parkinson's disease (PD) are poorly understood. Here, we provide evidence to support a role for the involvement of the calcium-dependent proteases, calpains, in the loss of dopamine neurons in a mouse model of PD. We show that administration of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) evokes an increase in calpain-mediated proteolysis in nigral dopamine neurons in vivo. Inhibition of calpain proteolysis using either a calpain inhibitor (MDL-28170) or adenovirus-mediated overexpression of the endogenous calpain inhibitor protein, calpastatin, significantly attenuated MPTP-induced loss of nigral dopamine neurons. Commensurate with this neuroprotection, MPTP-induced locomotor deficits were abolished, and markers of striatal postsynaptic activity were normalized in calpain inhibitor-treated mice. However, behavioral improvements in MPTP-treated, calpain inhibited mice did not correlate with restored levels of striatal dopamine. These results suggest that protection against nigral neuron degeneration in PD may be sufficient to facilitate normalized locomotor activity without necessitating striatal reinnervation. Immunohistochemical analyses of postmortem midbrain tissues from human PD cases also displayed evidence of increased calpain-related proteolytic activity that was not evident in age-matched control subjects. Taken together, our findings provide a potentially novel correlation between calpain proteolytic activity in an MPTP model of PD and the etiology of neuronal loss in PD in humans.

Calpain in the pathophysiology of spinal cord injury: neuroprotection with calpain inhibitors

Spinal cord injury (SCI) evokes an increase in intracellular free Ca(2+) level resulting in activation of calpain, a Ca(2+)-dependent cysteine protease, which cleaves many cytoskeletal and myelin proteins. Calpain is widely expressed in the central nervous system (CNS) and regulated by calpastatin, an endogenous calpain-specific inhibitor. Calpastatin degraded by overactivation of calpain after SCI may lose its regulatory efficiency. Evidence accumulated over the years indicates that uncontrolled calpain activity mediates the degradation of many cytoskeletal and membrane proteins in the course of neuronal death and contributes to the pathophysiology of SCI. Cleavage of the key cytoskeletal and membrane proteins by calpain is an irreversible process that perturbs the integrity and stability of CNS cells leading to cell death. Calpain in conjunction with caspases, most notably caspase-3, can cause apoptosis of the CNS cells following trauma. Aberrant Ca(2+) homeostasis following SCI inevitably activates calpain, which has been shown to play a crucial role in the pathophysiology of SCI. Therefore, calpain appears to be a potential therapeutic target in SCI. Substantial research effort has been focused upon the development of highly specific inhibitors of calpain and caspase-3 for therapeutic applications. Administration of cell permeable and specific inhibitors of calpain and caspase-3 in experimental animal models of SCI has provided significant neuroprotection, raising the hope that humans suffering from SCI may be treated with these inhibitors in the near future.

Anti-tumor activities of the angiogenesis inhibitors interferon-inducible protein-10 and the calreticulin fragment vasostatin

Tumor growth depends upon an adequate supply of oxygen and nutrients achieved through angiogenesis and maintenance of an intact tumor vasculature. Therapy with individual agents that target new vessel formation or existing vessels has suppressed experimental tumor growth, but rarely resulted in the eradication of tumors. We therefore tested the combined anti-tumor activity of vasostatin and interferon-inducible protein-10 (IP-10), agents that differently target the tumor vasculature. Vasostatin, a selective and direct inhibitor of endothelial cell proliferation, significantly reduced Burkitt tumor growth and tumor vessel density. IP-10, an "angiotoxic" chemokine, caused vascular damage and focal necrosis in Burkitt tumors. When combined, vasostatin plus IP-10 reduced tumor growth more effectively than each agent alone, but complete tumor regression was not observed. Microscopically, these tumors displayed focal necrosis and reduction in vessel density. Combination therapy with the inhibitors of angiogenesis vasostatin and IP-10 is effective in reducing the rate of tumor growth but fails to induce tumor regression, suggesting that curative treatment may require supplemental drugs targeting directly the tumor cells.

Calponin h1 induced a flattened morphology and suppressed the growth of human fibrosarcoma HT1080 cells

Calponin h1 (CNh1) is an actin-binding protein that is expressed mainly in smooth muscle cells and is known to regulate smooth muscle contraction. Recently, re-expression of CNh1 in leiomyosarcoma cell lines is reported to suppress cell proliferation and tumorigenicity. However, little is known about the associated cellular structural and functional changes. Since CNh1 is also detected in normal fibroblasts, we hypothesised that CNh1 would also inhibit cell proliferation of the fibrosarcoma cells, HT1080, in which CNh1 is suppressed. An expression vector of human CNh1 complementary DNA was transfected into human HT1080 cells by a calcium-phosphate precipitation method. CNh1-transfected cells exhibited a flattened morphology with organised actin filaments, a significant decrease in cell motility and enhancement in adhesion to fibronectin in association with an increase in integrin alpha5beta1 expression. Anchorage-independent growth and tumorigenicity in nude mice were suppressed in the CNh1-transfected cells. Our results suggest that CNh1 may have a role as a tumour suppressor in human fibrosarcoma by influencing cytoskeletal activities.

Laminin binding to the calreticulin fragment vasostatin regulates endothelial cell function

Vasostatin, the 1-180 amino acids NH(2) domain of calreticulin, inhibits endothelial cell proliferation, angiogenesis, and tumor growth, but the mechanisms underlying these effects are unclear. We show that endothelial cells express the extracellular matrix protein laminin, including chains alpha 5 and gamma 1 and that vasostatin specifically binds to laminin. When added to endothelial cell cultures, vasostatin specifically inhibits endothelial cell attachment to laminin and by this mechanism, can reduce subsequent endothelial cell growth induced by basic fibroblast growth factor. As an angiogenesis inhibitor that specifically disrupts endothelial cell attachment to components of the extracellular matrix, vasostatin has a unique potential as a cancer therapeutic.

Current limitations in treatment of heart failure: new avenues and treatment options

Chronic heart failure is one of the main causes of death in western countries. Despite state-of-the-art treatment including angiotensin-converting enzyme inhibitors, beta-blockers, and spironolactone, survival and relief from symptoms still are unacceptably poor in patients with chronic heart failure. The present article gives an overview of current limitations in the treatment of heart failure and points out possible treatment options in the future. It seems possible to reduce or at least delay progression of heart failure by adding drugs that interfere with novel pathophysiologic aspects in heart failure activation of the neuroendocrine system, including catecholamines, angiotensin II, cytokines, and endothelins, as well as alteration of calcium homeostasis and energy depletion.

[Calcium-binding protein S100A2 in the retardation of growth and proliferation of hepatocellular carcinoma cells]

OBJECTIVE

To study the retardation effect of calcium-binding protein S100A2 on the growth and proliferation of hepatocellular carcinoma QGY7701 cells.

METHODS

After the plasmid of EGFP-S100A2 had been regrouped and introduced into the hepatocellular carcinoma QGY7701 cells with lipofectin, the expression and location of the products were observed by fluorescent microscopy. The cell growth and proliferation were monitored through cell colony formation in vitro and xenografting subcutaneously in the nude mice in vivo. The effect of S100A2 on the QGY7701 cell cycle was examined with flow cytometry.

RESULTS

The chimera protein of S100A2 and green fluorescent protein were detected and appeared to be localized in the cytoplasm and nucleus, while the green fluorescent protein was found to be localized only in the cytoplasm. The cell colony formation of QGY7701/A2 was significantly reduced as compared with the controls. The xenografted tumor of QGY7701/A2 in the nude mice showed a growth at a considerably slower rate than that of QGY7701/pc and QGY7701 groups. The cell cycle review showed retardation of QGY7701/A2 cells in the G1 phase and the DNA content was obviously reduced as compared with the controls.

CONCLUSION

The exogenous S100A2 is able to check the QGY7701 cell cycle, stop the cell growth and proliferation either in vitro or in vivo in the QGY7701 cells.

Immunoprotective activities of multiple chaperone proteins isolated from murine B-cell leukemia/lymphoma

Although the use of tumor-derived heat shock/chaperone proteins (HSPs) as anticancer vaccines is gaining wider study and acceptance, there have thus far been no reports concerning chaperone antitumor activities against disseminated hematological malignancies. We have devised an efficient and effective method for purification of the chaperone proteins grp94/gp96, HSP90, HSP70, and calreticulin from harvested A20 murine leukemia/lymphoma tumor material. We have demonstrated that these purified proteins, when used as vaccines, can induce potent and specific immunity against a lethal tumor challenge. Individual chaperone proteins were differentially effective in their abilities to provide immune protection. The increase in survival generated by the most effective chaperone vaccine, HSP70, resulted from at least a 2-log reduction in tumor burden. Syngeneic granulocyte macrophage colony-stimulating factor producing fibroblasts were injected at the site of vaccination in an attempt to augment the immune response. Surprisingly, localized granulocyte macrophage colony-stimulating factor production inhibited the protective effects of chaperone vaccination. These studies provide evidence that chaperone proteins can be isolated from B-cell tumors and used effectively to immunize against disseminated lymphoid malignancies.

Calreticulin and calreticulin fragments are endothelial cell inhibitors that suppress tumor growth

Several angiogenesis inhibitors are fragments of larger proteins that are themselves not active as angiogenesis inhibitors. Vasostatin, the N-terminal domain of calreticulin inclusive of amino acids 1-180, is an angiogenesis inhibitor that exerts antitumor effects in vivo. In the present study, we examined whether the full-length calreticulin molecule shares the antiangiogenic and antitumor activities of vasostatin. Similar to vasostatin, calreticulin selectively inhibited endothelial cell proliferation in vitro, but not cells of other lineages, and suppressed angiogenesis in vivo. When inoculated into athymic mice, calreticulin inhibited Burkitt tumor growth comparably with vasostatin. Calreticulin lacking the N-terminal 1-120 amino acids inhibited endothelial cell proliferation in vitro and Burkitt tumor growth in vivo comparably with vasostatin. An internal calreticulin fragment encompassing amino acids 120-180 also inhibited endothelial cell proliferation in vitro and angiogenesis in vivo comparably with calreticulin and vasostatin. These results suggest that the antiangiogenic activities of vasostatin reside in a domain that is accessible from the full-length calreticulin molecule and localize to calreticulin N-terminal amino acids 120-180. Thus, calreticulin and calreticulin fragments are inhibitors of angiogenesis that directly target endothelial cells, inhibit angiogenesis, and suppress tumor growth. This information may be critical in designing targeted inhibitors of pathological angiogenesis that underlies cancer and other diseases.

Amelioration of diabetes in nonobese diabetic mice with advanced disease by linomide-induced immunoregulation combined with Reg protein treatment

Oral linomide, (quinoline-3-carboxamide), has been shown to prevent autoimmune insulitis, islet destruction, and diabetes in NOD mice treated at an early stage of the disease, but confers only partial protection in animals with advanced disease. Reg protein, the gene product of a complementary DNA isolated from a regenerating rat islet library, has been previously shown to induce expansion of beta-cell mass in pancreatectomized rats. To determine the effect of treatment combining immunomodulation and Reg protein on advanced autoimmune diabetes, we treated female NOD mice with oral linomide and i.p. Reg protein injections. In 14-week-old animals with less severe disease (glucose tolerant), treatment with each agent alone resulted in amelioration of diabetes, as did treatment with Reg alone in 5-week-old prediabetic mice. In 14-week-old animals with more severe disease (glucose intolerant), only treatment with the combination of both agents, but not that with each separately, resulted in amelioration of diabetes. Our study suggests that treatment aimed at abrogation of autoimmunity combined with expansion of beta-cell mass constitutes a potential therapeutic approach for treatment of insulin-dependent diabetes mellitus.