Publications

2020
Gopi Muthusamy, Joardar, Siddhartha Narayan , Samanta, Indranil , Isore, Devi Prasad , Roy, Barun , and Maiti, Tapas Kumar . 2020. Dietary Administered Purified Β-Glucan Of Edible Mushroom (Pleurotus Florida) Provides Immunostimulation And Protection In Broiler Experimentally Challenged With Virulent Newcastle Disease Virus. The Journal Of Basic And Applied Zoology, 81, 1, Pp. 55. doi:10.1186/s41936-020-00180-0. Publisher's Version Abstract
To study the immunomodulatory and protective role of dietary administered purified β-glucan obtained from edible mushroom (Pleurotus florida) in commercial broiler chicken, experimentally challenged with virulent Newcastle disease virus (NDV) on 7th day post treatment. Mushroom glucan (MG) at 15 mg/kg feed (group A) and MG at 30 mg/kg feed (group B) was administered to broiler birds for 20 days keeping control birds (group C) with a normal diet throughout. After 7 days post treatment, three groups of birds (n = 4, in each case) were challenged with virulent NDV. The immunological parameters were assessed to observe the protective efficacy of MG.
R. Rozner, Vernikov, J. , Griess-Fishheimer, S. , Travinsky, T. , Penn, S. , Schwartz, B. , Mesilati-Stahy, R. , Argov-Argaman, N. , Shahar, R. , and Monsonego-Ornan, E. . 2020. The Role Of Omega-3 Polyunsaturated Fatty Acids From Different Sources In Bone Development. Nutrients, 12, 11. doi:10.3390/nu12113494. Publisher's Version Abstract
N-3 polyunsaturated fatty acids (PUFAs) are essential nutrients that must be obtained from the diet. We have previously showed that endogenous n-3 PUFAs contribute to skeletal development and bone quality in fat-1 mice. Unlike other mammals, these transgenic mice, carry the n-3 desaturase gene and thus can convert n-6 to n-3 PUFAs endogenously. Since this model does not mimic dietary exposure to n-3 PUFAs, diets rich in fish and flaxseed oils were used to further elucidate the role of n-3 PUFAs in bone development. Our investigation reveals that dietary n-3 PUFAs decrease fat accumulation in the liver, lower serum fat levels, and alter fatty acid (FA) content in liver and serum. Bone analyses show that n-3 PUFAs improve mechanical properties, which were measured using a three-point bending test, but exert complex effects on bone structure that vary according to its source. In a micro-CT analysis, we found that the flaxseed oil diet improves trabecular bone micro-architecture, whereas the fish oil diet promotes higher bone mineral density (BMD) with no effect on trabecular bone. The transcriptome characterization of bone by RNA-seq identified regulatory mechanisms of n-3 PUFAs via modulation of the cell cycle and peripheral circadian rhythm genes. These results extend our knowledge and provide insights into the molecular mechanisms of bone remodeling regulation induced by different sources of dietary n-3 PUFAs.
2019
T. Oren, Nimri, L. , Yehuda-Shnaidman, E. , Staikin, K. , Hadar, Y. , Friedler, A. , Amartely, H. , Slutzki, M. , Pizio, A.D. , Niv, M.Y. , Peri, I. , Graeve, L. , and Schwartz, B. . 2019. Recombinant Ostreolysin Induces Brown Fat-Like Phenotype In Hib-1B Cells. Mol Nutr Food Res, 63, 5, Pp. e1970012. doi:10.1002/mnfr.201970012. Publisher's Version
Erez Israeli, Adler Berken, Nastacia , Gover, Ofer , Waechtershaeuser, Eike , Graeve, Lutz , and Schwartz, Betty . 2019. Recombinant Ostreolysin (Roly) Inhibits The Anti-Adipogenic Hedgehog (Hh) Signaling Pathway In 3T3-L1 Cells. Journal Of Functional Foods, 59, Pp. 185-193. doi:https://doi.org/10.1016/j.jff.2019.05.028. Publisher's Version Abstract
Obesity is a nutrition-associated disorder result of an imbalance between energy intake and energy expenditure. Changing adipocytes differentiation patterns is considered as a strategy to treat obesity-related disorders. Recently, much interest is focused on the role of posttranslational modifications of tubulin on adipocyte differentiation. We recently demonstrated that a recombinant version of the fungal protein Ostreolysin (rOly) drastically affects metabolism of adipose tissue. The aim of the present study is to extend our understanding of the in vitro effects of rOly on different adipocytes. We demonstrate that rOly inhibits the anti-adipogenic Hedgehog (Hh) signaling pathway in 3T3-L1 cells. Additionally, rOly affected the gene expression levels of SQSTM1 and Collagen type 1, which are mediated by AMP-activated protein kinase (AMPK) activity in 3T3-L1 cells. We provide a potential molecular mechanistic approach describing that the effect of rOly on adipocytes is mediated by tubulin acetylation and AMPK phosphorylation.
2018
R. Shaoul, Moati, D. , Schwartz, B. , Pollak, Y. , and Sukhotnik, I. . 2018. Effect Of Pomegranate Juice On Intestinal Recovery Following Methotrexate-Induced Intestinal Damage In A Rat Model. J Am Coll Nutr, 37, 5, Pp. 406-414. doi:10.1080/07315724.2017.1413961. Publisher's Version Abstract
BACKGROUND/AIMS: Several studies have demonstrated the antimicrobial, antihelminthic, and antioxidant potential of the active ingredients of pomegranate (PMG) extracts, suggesting their preventive and curative role in several gastrointestinal disorders. In the present study, the authors evaluated the effects of oral PMG supplementation on intestinal structural changes, enterocyte proliferation, and apoptosis during methotrexate (MTX)-induced intestinal damage in a rat. METHODS: Male rats were divided into 4 experimental groups: control rats; CONTR-PMG rats were treated with oral PMG given by gavage once a day 72 hours before and 72 hours following vehicle injection; MTX rats were treated with single dose of methotrexate; and MTX-PMG rats were treated with oral PMG following injection of MTX. Intestinal mucosal damage, mucosal structural changes, enterocyte proliferation, and enterocyte apoptosis were determined 72 hours following MTX injection. Western blotting was used to determine phosphorylated extracellular signal-regulated kinase (p-ERK) and caspase 3 protein levels. RESULTS: MTX-PMG rats demonstrated greater jejunal and ileal bowel and mucosal weights, greater jejunal and ileal mucosal DNA and protein levels, greater villus height in jejunum and ileum and crypt depth in ileum, compared with MTX animals. A significant decrease in enterocyte apoptosis in ileum of MTX-PMG rats (vs MTX) was associated with a decrease in caspase 3 protein expression as well as increased cell proliferation, which was correlated with elevated p-ERK protein levels. CONCLUSIONS: Treatment with oral PMG prevents mucosal injury and improves intestinal recovery following MTX injury in the rat.
A. Bein, Eventov-Friedman, S. , Arbell, D. , and Schwartz, B. . 2018. Intestinal Tight Junctions Are Severely Altered In Nec Preterm Neonates. Pediatr Neonatol, 59, 5, Pp. 464-473. doi:10.1016/j.pedneo.2017.11.018. Publisher's Version Abstract
BACKGROUND & AIMS: Necrotizing Enterocolitis (NEC) is a severe inflammatory disorder of the intestine endangering the health and survival of preterm infants. It is well established that the gut barrier is severely damaged in NEC patients, nonetheless an in depth investigation of modifications at the transcriptional and translational levels of tight junction genes and proteins during NEC are still missing. The aim of this study was to investigate changes in the expression of tight junctions and other associated proteins during NEC and determine their correlation to the disease severity. METHODS: We examined intestinal specimens from six NEC patients and compared them with six control specimens from patients that underwent surgeries for reasons other than NEC. The expression of genes was analyzed by real time PCR and protein expression by immunohistochemistry. RESULTS: The tight junction genes ZO-1, occludin, cingulin and claudin-4 were significantly down regulated in NEC. Furthermore TLR4, BAX and SIRT1 genes were found to be significantly down regulated while HIF-1A showed a trend of up regulation in NEC patients. These changes were found to correlate with the severity of the disease. Additionally we demonstrated in an ex-vivo model that hypoxic conditions initiated a destructive process of the epithelial barrier. We also showed that the expression of the tight junction proteins ZO-1 and occludin were significantly down regulated in NEC specimens. CONCLUSIONS: The expression of tight junction proteins and their encoding genes are significantly altered in NEC. We surmise that SIRT1 and HIF-1A may play a role in controlling these effects.
L. Nimri, Staikin, K. , Peri, I. , Yehuda-Shnaidman, E. , and Schwartz, B. . 2018. Ostreolysin Induces Browning Of Adipocytes And Ameliorates Hepatic Steatosis. J Gastroenterol Hepatol, 33, 12, Pp. 1990-2000. doi:10.1111/jgh.14259. Publisher's Version Abstract
BACKGROUND AND AIM: Non-alcoholic fatty liver disease (NAFLD) is associated with all features of the metabolic syndrome. Deposition of excess triglycerides in liver cells, a hallmark of NAFLD, is associated with loss of insulin sensitivity. Ostreolysin (Oly) is a 15-kDa fungal protein known to interact with cholesterol-enriched raft-like membrane domains. We aim to test whether a recombinant version of Oly (rOly) can induce functional changes in vitro in adipocytes or in vivo in mice fed a high-fat diet (HFD). METHODS: White preadipocyte 3T3-L1 cells or mouse primary adipocytes treated with rOly. Male C57BL/6 mice were fed a control or HFD and treated with saline or with rOly (1 mg/kg BW) every other day for 4 weeks. RESULTS: White preadipocyte 3T3-L1 cells or mouse primary adipocytes treated with rOly acquire a browning phenotype through activation of 5' adenosine monophosphate-activated protein kinase and downregulation of tumor necrosis factor alpha-mediated activation of IkappaB kinase epsilon and TANK-binding kinase 1. HFD-fed mice treated with rOly showed a 10% reduction in BW and improved glucose tolerance, which paralleled improved expression of liver and adipose functionality, metabolism, and inflammation status, mimicking the in vitro findings. CONCLUSION: This study provides first evidence of rOly's prevention of HFD-induced NAFLD by stimulating liver and adipose muscle tissue functionality and oxidative potential, improving glucose tolerance, and ameliorating the metabolic profile of diet-induced obese mice.
I. Sukhotnik, Moati, D. , Shaoul, R. , Loberman, B. , Pollak, Y. , and Schwartz, B. . 2018. Quercetin Prevents Small Intestinal Damage And Enhances Intestinal Recovery During Methotrexate-Induced Intestinal Mucositis Of Rats. Food Nutr Res, 62. doi:10.29219/fnr.v62.1327. Publisher's Version Abstract
Background: Gastrointestinal mucositis occurs as a consequence of cytotoxic treatment. Quercetin (QCT) is a bioflavonoid that exerts significant antioxidant activity and anti-inflammatory as well as anti-malignancy properties. Objective: To evaluate the effects of oral QCT consumption in preventing intestinal mucosal damage and stimulating intestinal recovery following methotrexate (MTX)-induced intestinal damage in a rat model. Design: Male Sprague-Dawley rats were divided into four groups: Control Group A (CONTR) - rats were treated with 2 cc of saline given by gavage for 6 days. Group B (CONTR-QCT) - rats were treated with QCT (100 mg/kg in 2 ml saline) given by gavage 3 days before and 3 days after intraperitoneal (IP) injection of saline. Group C (MTX) - rats were injected a single dose (25 mg/kg) of MTX IP. Group D (MTX-QCT) rats were treated with QCT (similar to Group B) 3 days before and 3 days after IP MTX injection. Intestinal mucosal parameters (bowel and mucosal weight, mucosal DNA and protein content, and villus height and crypt depth), enterocytes proliferation, and enterocyte apoptosis degree were investigated at sacrifice on the 4th day after MTX or saline injection. Results: Administration of QCT to MTX-treated rats resulted in: (1) significant decrease in intestinal injury score, (2) significant increase in intestinal and mucosal weight in jejunum and ileum, (3) increase on the protein content of the ileum, (4) increase in the villus height in the ileum, (5) increase of crypt depth of jejunum and ileum, and (6) increase in cell proliferation in the jejunum and ileum compared to MTX-nontreated group. Conclusions: Administration of QCT prevents intestinal damage and improves intestinal recovery following MTX-induced intestinal damage in a rat. We surmise that the effect of QCT is based on induction of cell proliferation in the crypt rather than inhibition of apoptosis.
2017
Diana Shefer-Weinberg, Sasson, Shlomo , Schwartz, Betty , Argov-Argaman, Nurit , and Tirosh, Oren . 2017. Deleterious Effect Of N-3 Polyunsaturated Fatty Acids In Non-Alcoholic Steatohepatitis In The Fat-1 Mouse Model. Clinical Nutrition Experimental, 12, Pp. 37-49. doi:https://doi.org/10.1016/j.yclnex.2016.12.003. Publisher's Version Abstract
Summary Non-alcoholic fatty liver disease (NAFLD) represents a spectrum of pathologies, ranging from hepatocellular steatosis to non-alcoholic steatohepatitis (NASH), fibrosis and cirrhosis. It has been suggested that fish oil containing n-3 polyunsaturated fatty acids (n-3 PUFA) induce beneficial effects in NAFLD. However, n-3 PUFA are sensitive to peroxidation that generate free radicals and reactive aldehydes. We aimed at determining whether changing the tissue ratio of n-3 to n-6 PUFA may be beneficial or alternatively harmful to the etiology of NAFLD. The transgenic Fat-1 mouse model was used to determine whether n-3 PUFA positively or negatively affect the development of NAFLD. fat-1mice express the fat-1 gene of Caenorhabditis elegans, which encodes an n-3 fatty-acid desaturase that converts n-6 to n-3 fatty acids. Wild-type C57BL/6 mice served as the control group. Both groups of mice were fed methionine and choline deficient (MCD) diet, which induces NASH within 4 weeks. The study shows that NASH developed faster and was more severe in mice from the fat-1 group when compared to control C57BL/6 mice. This was due to enhanced lipid peroxidation of PUFA in the liver of the fat-1 mice as compared to the control group. Results of our mice study suggest that supplementing the diet of individuals who develop or have fatty livers with n-3 PUFA should be carefully considered and if recommended adequate antioxidants should be added to the diet in order to reduce such risk.
The gene coding the transcription factor HNF-4α is located on chromosome 20q and is expressed in the liver, pancreas, kidneys, stomach and in the small and large intestine, where it controls important aspects related to morphogenesis and epithelial function. Mucin type MUC4 and MUC2, and β-catenin are representative genes controlled by HNF-4α and expressed in colonic tissue. We used in the present study immunohistochemical analyses to detect different levels of expression of the above mentioned proteins in colonic tissues of colorectal cancer and ulcerative colitis patients. We demonstrate high expression levels of HNF-4α in normal colon tissue, however, in adenoma, HNF-4α levels of expression decreased and in carcinoma of the large intestine; the levels were very low or invisible. Similarly, in ulcerative colitis patients the expression HNF-4α levels of the protein were significantly lower than the control group. Expression levels of MUC2 and MUC4 levels were significantly lower in the adenocarcinoma and ulcerative colitis groups than in the control group. In contrast, the expression level of β-catenin increased and changed from a membrane to a nuclear localization in the adenocarcinoma group only. We surmise that HNF-4α plays an important role in prevention of ulcerative colitis and colorectal cancer in humans. As a result, altered expression of the proteins MUC2 and MUC4 controlled by HNF-4α indicate that the defensive role attributed to them is not properly performed. In contrast, the Wnt / β-catenin pathway controlled by HNF-4α becomes active in samples from the stage of the adenoma and reached its peak in the carcinoma samples.
A. Bein, Zilbershtein, A. , Golosovsky, M. , Davidov, D. , and Schwartz, B. . 2017. Lps Induces Hyper-Permeability Of Intestinal Epithelial Cells. J Cell Physiol, 232, 2, Pp. 381-390. doi:10.1002/jcp.25435. Publisher's Version Abstract
Necrotizing Enterocolitis (NEC) is a severe inflammatory disorder leading to high morbidity and mortality rates. A growing body of evidence demonstrate the key role of the Toll like receptor 4 (TLR4) in NEC. This membranal receptor recognizes lipopolysaccharides (LPS) from the bacterial wall and triggers an inflammatory response. The aim of the present study was to elucidate the effect of LPS on paracellular permeability known to be severely affected in NEC. IEC-18 cells were treated with LPS and the effects on morphology, paracellular permeability and their associated gene and protein expressions were measured. Our results show that LPS down regulated the expression of occludin and ZO-1 mRNAs while up regulating Cdkn1a. In addition LPS caused a significant increase in paracellular permeability and epithelial barrier damage. Finally ZO-1 protein was found to be spatially disarrayed in the intercellular junctions in response to LPS. We conclude that LPS adversely affected the functionality of the intestinal epithelial barrier suggesting a new mechanism by which bacterial infection may contribute to the development of NEC. J. Cell. Physiol. 232: 381-390, 2017. (c) 2016 Wiley Periodicals, Inc.
S. Avni, Ezove, N. , Hanani, H. , Yadid, I. , Karpovsky, M. , Hayby, H. , Gover, O. , Hadar, Y. , Schwartz, B. , and Danay, O. . 2017. Olive Mill Waste Enhances Alpha-Glucan Content In The Edible Mushroom Pleurotus Eryngii. Int J Mol Sci, 18, 7. doi:10.3390/ijms18071564. Publisher's Version Abstract
Mushroom polysaccharides are edible polymers that have numerous reported biological functions; the most common effects are attributed to beta-glucans. In recent years, it became apparent that the less abundant alpha-glucans also possess potent effects in various health conditions. Here we explore several Pleurotus species for their total, beta and alpha-glucan content. Pleurotus eryngii was found to have the highest total glucan concentrations and the highest alpha-glucans proportion. We also found that the stalks (stipe) of the fruit body contained higher glucan content then the caps (pileus). Since mushrooms respond markedly to changes in environmental and growth conditions, we developed cultivation methods aiming to increase the levels of alpha and beta-glucans. Using olive mill solid waste (OMSW) from three-phase olive mills in the cultivation substrate. We were able to enrich the levels mainly of alpha-glucans. Maximal total glucan concentrations were enhanced up to twice when the growth substrate contained 80% of OMSW compared to no OMSW. Taking together this study demonstrate that Pleurotus eryngii can serve as a potential rich source of glucans for nutritional and medicinal applications and that glucan content in mushroom fruiting bodies can be further enriched by applying OMSW into the cultivation substrate.
L. Nimri, Spivak, O. , Tal, D. , Schalling, D. , Peri, I. , Graeve, L. , Salame, T.M. , Yarden, O. , Hadar, Y. , and Schwartz, B. . 2017. A Recombinant Fungal Compound Induces Anti-Proliferative And Pro-Apoptotic Effects On Colon Cancer Cells. Oncotarget, 8, 17, Pp. 28854-28864. doi:10.18632/oncotarget.15859. Publisher's Version Abstract
Finding intracellular pathways and molecules that can prevent the proliferation of colon cancer cells can provide significant bases for developing treatments for this disease. Ostreolysin (Oly) is a protein found in the mushroom Pleurotus ostreatus, and we have produced a recombinant version of this protein (rOly).We measured the viability of several colon cancer cells treated with rOly. Xenografts and syngeneic colon cancer cells were injected into in vivo mouse models, which were then treated with this recombinant protein.rOly treatment induced a significant reduction in viability of human and mouse colon cancer cells. In contrast, there was no reduction in the viability of normal epithelial cells from the small intestine. In the search for cellular targets of rOly, we showed that it enhances the anti-proliferative activity of drugs targeting cellular tubulin. This was accompanied by a reduction in the weight and volume of tumours in mice injected with rOly as compared to their respective control mice in two in vivo models.Our results advance the functional understanding of rOly as a potential anti-cancer treatment associated with pro-apoptotic activities preferentially targeting colon cancer cells.
T. Oren, Nimri, L. , Yehuda-Shnaidman, E. , Staikin, K. , Hadar, Y. , Friedler, A. , Amartely, H. , Slutzki, M. , Pizio, A.D. , Niv, M.Y. , Peri, I. , Graeve, L. , and Schwartz, B. . 2017. Recombinant Ostreolysin Induces Brown Fat-Like Phenotype In Hib-1B Cells. Mol Nutr Food Res, 61, 9. doi:10.1002/mnfr.201700057. Publisher's Version Abstract
SCOPE: Brown adipose tissue (BAT) is the main regulator of thermogenesis by increasing energy expenditure through the uncoupling of oxidative metabolism from ATP synthesis. There is a growing body of evidence for BAT being the key responsible organ in combating obesity and its related disorders. Herein we propose the fungal protein ostreolysin (Oly), which has been previously shown to bind to cholesterol-enriched raft-like membrane domains (lipid rafts) of mammalian cells, as a suitable candidate for interaction with brown preadipocytes. The aim of the present study was therefore to characterize the mechanism by which a recombinant version of ostreolysin (rOly) induces brown adipocyte differentiation. METHODS AND RESULTS: Primary isolated brown preadipocytes or HIB-1B brown preadipocyte cells were treated with rOly and the effects on morphology, lipid accumulation, respiration rate, and associated gene and protein expression were measured. rOly upregulated mRNA and protein levels of factors related to brown adipocyte differentiation, induced lipid droplet formation, and increased cellular respiration rate due to expression of uncoupling protein 1. rOly also upregulated beta-tubulin expression, and therefore microtubules might be involved in its mechanism of action. CONCLUSION: rOly promotes brown adipocyte differentiation, suggesting a new mechanism for rOly's contribution to the battle against obesity.
2015
L. Nesiel-Nuttman, Doron, S. , Schwartz, B. , and Shoseyov, O. . 2015. Human Rnaset2 Derivatives As Potential Anti-Angiogenic Agents: Actin Binding Sequence Identification And Characterization. Oncoscience, 2, 1, Pp. 31-43. doi:10.18632/oncoscience.100. Publisher's Version Abstract
Human RNASET2 (hRNASET2) has been demonstrated to exert antiangiogenic and antitumorigenic effects independent of its ribonuclease capacity. We suggested that RNASET2 exerts its antiangiogenic and antitumorigenic activities via binding to actin and consequently inhibits cell motility. We focused herein on the identification of the actin binding site of hRNASET2 using defined sequences encountered within the whole hRNASET2 protein. For that purpose we designed 29 different hRNASET2-derived peptides. The 29 peptides were examined for their ability to bind immobilized actin. Two selected peptides-A103-Q159 consisting of 57 amino acids and peptide K108-K133 consisting of 26 amino acids were demonstrated to have the highest actin binding ability and concomitantly the most potent anti-angiogenic activity. Further analyses on the putative mechanisms associated with angiogenesis inhibition exerted by peptide K108-K133 involved its location during treatment within the HUVE cells. Peptide K108-K133 readily penetrates the cell membrane within 10 min of incubation. In addition, supplementation with angiogenin delays the entrance of peptide K108-K133 to the cell suggesting competition on the same cell internalization route. The peptide was demonstrated to co-localize with angiogenin, suggesting that both molecules bind analogous cellular epitopes, similar to our previously reported data for ACTIBIND and trT2-50.
L. Nimri, Saadi, J. , Peri, I. , Yehuda-Shnaidman, E. , and Schwartz, B. . 2015. Mechanisms Linking Obesity To Altered Metabolism In Mice Colon Carcinogenesis. Oncotarget, 6, 35, Pp. 38195-209. doi:10.18632/oncotarget.5561. Publisher's Version Abstract
There are an increasing number of reports on obesity being a key risk factor for the development of colon cancer. Our goal in this study was to explore the metabolic networks and molecular signaling pathways linking obesity, adipose tissue and colon cancer. Using in-vivo experiments, we found that mice fed a high-fat diet (HFD) and injected with MC38 colon cancer cells develop significantly larger tumors than their counterparts fed a control diet. In ex-vivo experiments, MC38 and CT26 colon cancer cells exposed to conditioned media (CM) from the adipose tissue of HFD-fed mice demonstrated significantly lower oxygen consumption rate as well as lower maximal oxygen consumption rate after carbonyl cyanide-4-trifluoromethoxy-phenylhydrazone treatment. In addition, in-vitro assays showed downregulated expression of mitochondrial genes in colon cancer cells exposed to CM prepared from the visceral fat of HFD-fed mice or to leptin. Interestingly, leptin levels detected in the media of adipose tissue explants co-cultured with MC38 cancer cells were higher than in adipose tissue explants cultures, indicating cross talk between the adipose tissue and the cancer cells. Salient findings of the present study demonstrate that this crosstalk is mediated at least partially by the JNK/STAT3-signaling pathway.
A. Bein, Lubetzky, R. , Mandel, D. , and Schwartz, B. . 2015. Timp-1 Inhibition Of Occludin Degradation In Caco-2 Intestinal Cells: A Potential Protective Role In Necrotizing Enterocolitis. Pediatr Res, 77, 5, Pp. 649-55. doi:10.1038/pr.2015.26. Publisher's Version Abstract
BACKGROUND: Necrotizing enterocolitis (NEC), a common intestinal disease affecting premature infants, is a major cause of morbidity and mortality. Previous reports indicate an upregulation of intestinal matrix metalloproteinases (MMPs) activity that may play key roles on the higher permeability of the intestinal barrier, typical to NEC. Recently, TIMP-1, a natural inhibitor of MMP's, was found to be over expressed in preterm human breast milk (HBM). Previous studies have shown that infants fed with HBM have a significant reduction in the incidence of NEC. The aim of the present study was to investigate the possible role that TIMP-1 may play on the maintenance of tight junctions and therefore the gut barrier integrity. METHODS: Timp-1-treated Caco-2 intestinal cells were tested for MMP-2 enzymatic activity and cell junction integrity. RESULTS: TIMP-1 inhibited MMP-2 activity, which induced a significant increase in the expression of occludin but not of claudin-4. TIMP-1 did not affect apoptosis. CONCLUSION: One of the putative mechanisms associated with HBM protection against NEC is mediated by TIMP-1, which downregulates MMP-2 activity, inhibits the degradation of occluding, and preserves tight junctions and gut barrier integrity.
2014
N. Koren, Simsa-Maziel, S. , Shahar, R. , Schwartz, B. , and Monsonego-Ornan, E. . 2014. Exposure To Omega-3 Fatty Acids At Early Age Accelerate Bone Growth And Improve Bone Quality. J Nutr Biochem, 25, 6, Pp. 623-33. doi:10.1016/j.jnutbio.2014.01.012. Publisher's Version Abstract
Omega-3 fatty acids (FAs) are essential nutritional components that must be obtained from foods. Increasing evidence validate that omega-3 FAs are beneficial for bone health, and several mechanisms have been suggested to mediate their effects on bone, including alterations in calcium absorption and urinary calcium loss, prostaglandin synthesis, lipid oxidation, osteoblast formation and inhibition of osteoclastogenesis. However, to date, there is scant information regarding the effect of omega-3 FAs on the developing skeleton during the rapid growth phase. In this study we aim to evaluate the effect of exposure to high levels of omega-3 FAs on bone development and quality during prenatal and early postnatal period. For this purpose, we used the fat-1 transgenic mice that have the ability to convert omega-6 to omega-3 fatty acids and the ATDC5 chondrogenic cell line as models. We show that exposure to high concentrations of omega-3 FAs at a young age accelerates bone growth through alterations of the growth plate, associated with increased chondrocyte proliferation and differentiation. We further propose that those effects are mediated by the receptors G-protein coupled receptor 120 (GPR120) and hepatic nuclear factor 4alpha, which are expressed by chondrocytes in culture. Additionally, using a combined study on the structural and mechanical bone parameters, we show that high omega-3 levels contribute to superior trabecular and cortical structure, as well as to stiffer bones and improved bone quality. Most interestingly, the fat-1 model allowed us to demonstrate the role of maternal high omega-3 concentration on bone growth during the gestation and postnatal period.
L. Nesiel-Nuttman, Schwartz, B. , and Shoseyov, O. . 2014. Human Recombinant Truncated Rnaset2, Devoid Of Rnase Activity; A Potential Cancer Therapeutic Agent. Oncotarget, 5, 22, Pp. 11464-78. doi:10.18632/oncotarget.2562. Publisher's Version Abstract
Human RNASET2 has been implicated in antitumorigenic and antiangiogenic activities, independent of its ribonuclease capacities. We constructed a truncated version of human RNASET2, starting at E50 (trT2-50) and devoid of ribonuclease activity. trT2-50 maintained its ability to bind actin and to inhibit angiogenesis and tumorigenesis. trT2-50 binds to cell surface actin and formed a complex with actin in vitro. The antiangiogenic effect of this protein was demonstrated in human umbilical vein endothelial cells (HUVECs) by its ability to arrest tube formation on Matrigel, induced by angiogenic factors. Immunofluorescence staining of HUVECs showed nuclear and cytosolic RNASET2 protein that was no longer detectable inside the cell following trT2-50 treatment. This effect was associated with disruption of the intracellular actin network. trT2-50 co-localized with angiogenin, suggesting that both molecules bind (or compete) for similar cellular epitopes. Moreover, trT2-50 led to a significant inhibition of tumor development. Histological analysis demonstrated abundant necrotic tissue and a substantial loss of endothelial structure in trT2-50-treated tumors. Collectively, the present results indicate that trT2-50, a molecule engineered to be deficient of its catalytic activity, still maintained its actin binding and anticancer-related biological activities. We therefore suggest that trT2-50 may serve as a potential cancer therapeutic agent.