Publications

A. Drori, A. Permyakova, R. Hadar, S. Udi, A. Nemirovski, and J. Tam. 2019. “Cannabinoid-1 receptor regulates mitochondrial dynamics and function in renal proximal tubular cells.” Diabetes, Obesity and Metabolism, 21, 1, Pp. 146-159. Publisher's Version Abstract
Aims: To evaluate the specific role of the endocannabinoid/cannabinoid type-1 (CB1R) system in modulating mitochondrial dynamics in the metabolically active renal proximal tubular cells (RPTCs). Materials and methods: We utilized mitochondrially-targeted GFP in live cells (wild-type and null for the CB1R) and electron microscopy in kidney sections of RPTC-CB1R-/- mice and their littermate controls. In both in vitro and in vivo conditions, we assessed the ability of CB1R agonism or fatty acid flux to modulate mitochondrial architecture and function. Results: Direct stimulation of CB1R resulted in mitochondrial fragmentation in RPTCs. This process was mediated, at least in part, by modulating the phosphorylation levels of the canonical fission protein dynamin-related protein 1 on both S637 and S616 residues. CB1R-induced mitochondrial fission was associated with mitochondrial dysfunction, as documented by reduced oxygen consumption and ATP production, increased reactive oxygen species and cellular lactate levels, as well as a decline in mitochondrial biogenesis. Likewise, we documented that exposure of RPTCs to a fatty acid flux induced CB1R-dependent mitochondrial fission, lipotoxicity and cellular dysfunction. Conclusions: CB1R plays a key role in inducing mitochondrial fragmentation in RPTCs, leading to a decline in the organelle's function and contributing to the renal tubular injury associated with lipotoxicity and other metabolic diseases. © 2018 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.
S. Baraghithy, R. Smoum, A. Drori, R. Hadar, A. Gammal, S. Hirsch, M. Attar-Namdar, A. Nemirovski, Y. Gabet, Y. Langer, Y. Pollak, C.P. Schaaf, M.E. Rech, V. Gross-Tsur, I. Bab, R. Mechoulam, and J. Tam. 2019. “Magel2 Modulates Bone Remodeling and Mass in Prader-Willi Syndrome by Affecting Oleoyl Serine Levels and Activity.” Journal of Bone and Mineral Research, 34, 1, Pp. 93-105. Publisher's Version Abstract
Among a multitude of hormonal and metabolic complications, individuals with Prader-Willi syndrome (PWS) exhibit significant bone abnormalities, including decreased BMD, osteoporosis, and subsequent increased fracture risk. Here we show in mice that loss of Magel2, a maternally imprinted gene in the PWS critical region, results in reduced bone mass, density, and strength, corresponding to that observed in humans with PWS, as well as in individuals suffering from Schaaf-Yang syndrome (SYS), a genetic disorder caused by a disruption of the MAGEL2 gene. The low bone mass phenotype in Magel2 -/- mice was attributed to reduced bone formation rate, increased osteoclastogenesis and osteoclast activity, and enhanced trans-differentiation of osteoblasts to adipocytes. The absence of Magel2 in humans and mice resulted in reduction in the fatty acid amide bone homeostasis regulator, N-oleoyl serine (OS), whose levels were positively linked with BMD in humans and mice as well as osteoblast activity. Attenuating the skeletal abnormalities in Magel2 -/- mice was achieved with chronic administration of a novel synthetic derivative of OS. Taken together, Magel2 plays a key role in modulating bone remodeling and mass in PWS by affecting OS levels and activity. The use of potent synthetic analogs of OS should be further tested clinically as bone therapeutics for treating bone loss. © 2018 American Society for Bone and Mineral Research. © 2018 American Society for Bone and Mineral Research
M. Eger, M. Bader, D. Bree, R. Hadar, A. Nemerovski, J. Tam, D. Levy, C.G. Pick, and Y. Gabet. 2019. “Bone Anabolic Response in the Calvaria Following Mild Traumatic Brain Injury is Mediated by the Cannabinoid-1 Receptor.” Scientific Reports, 9, 1. Publisher's Version Abstract
Brain trauma was clinically associated with increased osteogenesis in the appendicular skeleton. We showed previously in C57BL/6J mice that mild traumatic brain injury (mTBI) transiently induced bone formation in the femur via the cannabinoid-1 (CB1) receptor. Here, we subjected ICR mice to mTBI and examined the bone response in the skull using microCT. We also measured mast cell degranulation (MCD)72 h post-injury. Finally, we measured brain and calvarial endocannabinoids levels post-mTBI. mTBI led to decreased bone porosity on the contralateral (untouched) side. This effect was apparent both in young and mature mice. Administration of rimonabant (CB1 inverse agonist) completely abrogated the effect of mTBI on calvarial porosity and significantly reduced MCD, compared with vehicle-treated controls. We also found that mTBI resulted in elevated levels of anandamide, but not 2-arachidonoylglycerol, in the contralateral calvarial bone, whereas brain levels remained unchanged. In C57BL/6J CB1 knockout mice, mTBI did not reduce porosity but in general the porosity was significantly lower than in WT controls. Our findings suggest that mTBI induces a strain-specific CB1-dependent bone anabolic response in the skull, probably mediated by anandamide, but seemingly unrelated to inflammation. The endocannabinoid system is therefore a plausible target in management of bone response following head trauma. © 2019, The Author(s).
M. Ben-David-Naim, A. Dagan, E. Grad, G. Aizik, M.M. Nordling-David, A.M. Clyne, Z. Granot, and G. Golomb. 2019. “Targeted siRNA nanoparticles for mammary carcinoma therapy.” Cancers, 11, 4. Publisher's Version Abstract
Non-viral, polymeric-based, siRNA nanoparticles (NPs) have been proposed as promising gene delivery systems. Encapsulating siRNA in targeted NPs could confer improved biological stability, extended half-life, enhanced permeability, effective tumor accumulation, and therapy. In this work, a peptide derived from apolipoprotein B100 (ApoB-P), the protein moiety of low-density lipoprotein, was used to target siRNA-loaded PEGylated NPs to the extracellular matrix/proteoglycans (ECM/PGs) of a mammary carcinoma tumor. siRNA against osteopontin (siOPN), a protein involved in breast cancer development and progression, was encapsulated into PEGylated poly(d,l-lactic-co-glycolic acid) (PLGA) NPs using the double emulsion solvent diffusion technique. The NPs obtained possessed desired physicochemical properties including  200 nm size, a neutral surface charge, and high siOPN loading of  5 µg/mg. ApoB-P-targeted NPs exhibited both enhanced binding to isolated ECM and internalization by MDA-MB-231 human mammary carcinoma cells, in comparison to non-targeted NPs. Increased accumulation of the targeted NPs was achieved in the primary mammary tumor of mice xenografted with MDA-MB-231 mammary carcinoma cells as well as in the lungs, one of the main sites affected by metastases. siOPN NPs treatment resulted in significant inhibition of tumor growth (similar bioactivity of both formulations), accompanied with significant reduction of OPN mRNA levels ( 40% knockdown of mRNA levels). We demonstrated that targeted NPs possessed enhanced tumor accumulation with increased therapeutic potential in mice models of mammary carcinoma © 2019 by the authors. Licensee MDPI, Basel, Switzerland.
H. Pahima, P.G. Puzzovio, and F. Levi-Schaffer. 2019. “2B4 and CD48: A powerful couple of the immune system.” Clinical Immunology, 204, Pp. 64-68. Publisher's Version Abstract
The signaling lymphocytic activation molecule (SLAM) family of receptors (SLAMF) is a group of receptors belonging to the CD2 family. It is composed of several members expressed on many hematopoietic cells. Most of the receptors interact in a homophilic fashion with neighboring cells. Their distribution and binding properties, together with their ability to function as both activating and inhibitory receptors, put them as key players in the immune system regulation. Several SLAM family receptors have been extensively investigated. This review mainly focuses on CD244 (2B4 or SLAMF4,) and CD48, particularly as expressed by the key cells of allergy, mast cells and eosinophils. © 2018 Elsevier Inc.
L. Magid, S. Heymann, M. Elgali, L. Avram, Y. Cohen, S. Liraz-Zaltsman, R. Mechoulam, and E. Shohami. 2019. “Role of CB2 Receptor in the Recovery of Mice after Traumatic Brain Injury.” Journal of Neurotrauma, 36, 11, Pp. 1836-1846. Publisher's Version Abstract
Cannabis is one of the most widely used plant drugs in the world today. In spite of the large number of scientific reports on medical marijuana, there still exists much controversy surrounding its use and the potential for abuse due to the undesirable psychotropic effects. However, recent developments in medicinal chemistry of novel non-psychoactive synthetic cannabinoids have indicated that it is possible to separate some of the therapeutic effects from the psychoactivity. We have previously shown that treatment with the endocannabinoid 2-AG, which binds to both CB1 and CB2 receptors 1 h after traumatic brain injury in mice, attenuates neurological deficits, edema formation, infarct volume, blood-brain barrier permeability, neuronal cell loss at the CA3 hippocampal region, and neuroinflammation. Recently, we synthesized a set of camphor-resorcinol derivatives, which represent a novel series of CB2 receptor selective ligands. Most of the novel compounds exhibited potent binding and agonistic properties at the CB2 receptors with very low affinity for the CB1 receptor, and some were highly anti-inflammatory. This selective binding correlated with their intrinsic activities. HU-910 and HU-914 were selected in the present study to evaluate their potential effect in the pathophysiology of traumatic brain injury (TBI). In mice and rats subjected to closed-head injury and treated with these novel compounds, we showed enhanced neurobehavioral recovery, inhibition of tumor necrosis factor α production, increased synaptogenesis, and partial recovery of the cortical spinal tract. We propose these CB2 agonists as potential drugs for development of novel therapeutic modality to TBI. Copyright © 2019, Mary Ann Liebert, Inc.
M.T. Joy, E. Ben Assayag, D. Shabashov-Stone, S. Liraz-Zaltsman, J. Mazzitelli, M. Arenas, N. Abduljawad, E. Kliper, A.D. Korczyn, N.S. Thareja, E.L. Kesner, M. Zhou, S. Huang, T.K. Silva, N. Katz, N.M. Bornstein, A.J. Silva, E. Shohami, and S.T. Carmichael. 2019. “CCR5 Is a Therapeutic Target for Recovery after Stroke and Traumatic Brain Injury.” Cell, 176, 5, Pp. 1143-1157.e13. Publisher's Version Abstract
We tested a newly described molecular memory system, CCR5 signaling, for its role in recovery after stroke and traumatic brain injury (TBI). CCR5 is uniquely expressed in cortical neurons after stroke. Post-stroke neuronal knockdown of CCR5 in pre-motor cortex leads to early recovery of motor control. Recovery is associated with preservation of dendritic spines, new patterns of cortical projections to contralateral pre-motor cortex, and upregulation of CREB and DLK signaling. Administration of a clinically utilized FDA-approved CCR5 antagonist, devised for HIV treatment, produces similar effects on motor recovery post stroke and cognitive decline post TBI. Finally, in a large clinical cohort of stroke patients, carriers for a naturally occurring loss-of-function mutation in CCR5 (CCR5-Δ32) exhibited greater recovery of neurological impairments and cognitive function. In summary, CCR5 is a translational target for neural repair in stroke and TBI and the first reported gene associated with enhanced recovery in human stroke. © 2019 Elsevier Inc. Genetic and small molecule-based perturbation of CCR5 promotes functional recovery from stroke and traumatic brain injury. © 2019 Elsevier Inc.
L. Friedman, R. Smoum, M. Feldman, R. Mechoulam, and D. Steinberg. 2019. “Does the Endocannabinoid Anandamide Affect Bacterial Quorum Sensing, Vitality, and Motility?” Cannabis and Cannabinoid Research, 4, 2, Pp. 102-109. Publisher's Version Abstract
Introduction: The endocannabinoid anandamide (AEA) is a neurotransmitter produced and released "on demand." Numerous studies have been conducted on AEA and on the endocannabinoid system (ECS), but none of them have investigated their effect on prokaryotes. Quorum sensing (QS) is a process of bacteria-bacteria communication. In this cross-Talk, the bacteria secrete and recognize signal molecules termed autoinducers (AIs). It has been shown that the QS system regulates expression of many physiological and virulence factors of bacteria. Materials and Methods: QS was measured using the bioluminescence property of the bacterium Vibrio harveyi. The effect of AEA on QS-related gene expression was measured using real-Time polymerase chain reaction. 0.18% agar plates were used for surface movement assay. Results: No dose response of AEA could be determined up to 100 μg/mL on bacterial growth either wild-Type (WT) V. harveyi or mutant strains. However on addition of AEA, QS was reduced significantly for WT and other V. harveyi strains mutated at different locations of the QS cascade (BB152; HAI-1 synthase mutant, BB886; Sensor-2-, BB170; Sensor-1-, MM30; AI-2). Genes related to the QS pathway, such as luxS, showed significant reduction in expression in the presence of AEA. Motility tests showed that continuous exposure to AEA reduced V. harveyi ability to spread on a soft agar surface, but pre-exposure to AEA did not have any effect on its motility. Conclusions: This study presents the first evidence that the endocannabinoid AEA affects specific functions of a prokaryotic organism (e.g., QS and motility). Our results present novel, not yet been observed biological functions of the ECS, namely as a possible line of defense against bacteria. © Copyright 2019, Mary Ann Liebert, Inc., publishers 2019.
Y. Mostinski, D. Lankri, Y. Konovalov, R. Nataf, and D. Tsvelikhovsky. 2019. “Proline-promoted dehydroxylation of α-ketols.” Chemical Science, 10, 40, Pp. 9345-9350. Publisher's Version Abstract
A new single-step proline-potassium acetate promoted reductive dehydroxylation of α-ketols is reported. We introduce the unexplored reactivity of proline and, for the first time, reveal its ability to function as a reducing agent. The developed metal-free and open-flask operation generally results in good yields. Our protocol allows the challenging selective dehydroxylation of hydroxyketones without affecting other functional groups. This journal is © The Royal Society of Chemistry.
PURPOSE: Mechanisms related the crosstalk between adipocytes and colon cancer cells are still not clear. We hypothesize that molecules and adipocytokines generated from the adipose tissue of obese individuals accentuate the effect on the metabolic reprogramming in colon cancer cells, i.e. induce disarray in energy metabolism networks of the targeted affected colonic epithelial cells, prompting their malignant phenotype. METHODS: To explore the mechanistic behind this crosstalk we conducted a co-culture model system using human colon cancer cells having different malignant abilities and adipocytes from different depots and subjects. RESULTS: The results demonstrate that co-culturing aggressive colon cancer cells such as HM-7 cells, with Visceral or Subcutaneous adipocytes (VA or SA respectively) from lean/obese subjects significantly up-regulate the secretion of the adipokines IL-8, MCP1, and IL-6 from the adipocytes. Surprisingly, the response of co-culturing HM-7 cells with obese SA was substantially more significant. In addition, these effects were significantly more pronounced when using HM-7 cells as compared to the less malignant HCT116 colon cancer cells. Moreover, the results showed that HM-7 cells, co-cultured with VA or SA from obese subjects, expressed higher levels of fatty acid binding protein 4; thus, the conditioned media obtained from the wells contained HM-7 cells and adipocytes from obese subjects was significantly more efficient in promoting invasion of HM-7 cells. CONCLUSIONS: We conclude that interaction between adipocytes and colon cancer cells, especially the highly malignant cells, results in metabolic alterations in colon cancer cells and in highly hypertrophy phenotype which characterized by increasing adipokines secretion from the adipocytes. © 2019 The Authors
V. Vetvicka, G. Gover, H. Hayby, O. Danay, N. Ezov, Y. Hadar, and B. Schwartz. 2019. “Immunomodulating effects exerted by glucans extracted from the king oyster culinary-medicinal mushroom pleurotus eryngii (agaricomycetes) grown in substrates containing various concentrations of olive mill waste.” International Journal of Medicinal Mushrooms, 21, 8, Pp. 765-781. Publisher's Version Abstract
We have recently demonstrated that we could enhance glucan content in Pleurotus eryngii following cultivation of the mushrooms on a substrate containing different concentrations of olive mill solid waste (OMSW). These changes are directly related to the content of OMSW in the growing substrate. Using dextran sulfate sodium (DSS)-inflammatory bowel disease (IBD) mice model, we measured the colonic inflammatory response to the different glucan preparations. We found that the histology damaging score (HDS) resulting from DSS treatment reach a value of 11.8 ± 2.3 were efficiently downregulated by treatment with the fungal extracted glucans. Glucans extracted from stalks cultivated at 20% OMSW downregulated to a HDS value of 6.4 ± 0.5 whereas those cultivated at 80% OMSW showed the strongest effects (5.5 ± 0.6). Similar downregulatory effects were obtained for expression of various intestinal cytokines. All tested glucans were equally effective in regulating the number of CD14/CD16 monocytes from 18.2 ± 2.7% for DSS to 6.4 ± 2.0 for DSS + glucans extracted from stalks cultivated at 50% OMSW. We tested the effect of glucans on lipopolysaccharide- induced production of TNF-α, which demonstrated that stalk-derived glucans were more effective than caps-derived glucans. Isolated glucans competed with anti-Dectin-1 and anti-CR3 antibodies, indicating that they contain β-glucans recognized by these receptors. In conclusion, the most effective glucans in ameliorating IBD-associated symptoms induced by DSS treatment in mice were glucan extracts prepared from the stalk of P. eryngii grown at higher concentrations of OMSW. We conclude that these stress-induced growing conditions may be helpful in selecting more effective glucans derived from edible mushrooms. © 2019 by Begell House, Inc.
A. Amrani, Y.O. Rosenberg, A. Meshoulam, W. Said-Ahmad, C. Turich, N. Luu, T. Jacksier, A. Stankiewicz, S. Feinstein, and A. Shurki. 2019. “Sulfur isotopic composition of gas-phase organic sulfur compounds provides insights into the thermal maturation of organic-rich rocks.” Geochimica et Cosmochimica Acta, 259, Pp. 91-108. Publisher's Version Abstract
Volatile and gas phase organic sulfur compounds (VOSCs) are important components in subsurface reservoir fluids and despite their relatively low concentrations, can provide important information about organic matter origin, diagenetic transformation, thermal maturation, and oil and gas generation, expulsion, and migration. We present an approach for the utilization of VOSC concentration and compound specific S isotopes ratio (δ34S) data as a new geochemical tool to study natural gas origin and formation. We studied the formation pathways of VOSCs, their δ34S values, and interaction with an organic-rich sedimentary rock (or ‘source rock’) from the Ghareb Formation (Type II-S kerogen) deposited in an upwelling marine environment. The immature source rock was subjected to laboratory controlled thermal maturation. We used a semi-open, non-isothermal pyrolysis system heated between 200 and 440 °C, and analyzed the molecular composition and compound specific δ34S values of the evolved gases at various thermal maturity stages. Formation of VOSCs commenced at 206 °C, a temperature generally associated with less thermally mature systems, and typically before the onset of oil generation for similar organic-rich source rocks, allowing study of low thermal maturity conditions (∼0.3 %Roeq). Overall, the VOSCs obtained had δ34S values similar to the bulk kerogen values (mostly within 4‰). However, thiol (or mercaptan) δ34S values closely followed those of H2S (Δ34Sthiols-H2S = −1 ± 1‰) throughout the experiment. Ab-initio calculations for the S isotopic exchange between H2S and thiols were close to the experimental observations. This suggests that thiols rapidly attained equilibrium with H2S despite their very short residence time in the system (minutes to hours). Furthermore, throughout the experiment, the concentrations of the six different thiols were found to be proportional to the coexisting, concentration ratio of [H2]/[H2S]. The proportionality factors of the 6 different thiols strongly correlate with reported heats of formation (ΔHf°), further supporting the notion that the generation of thiols in the system rapidly reached equilibrium. At pyrolysis temperatures up to 350 °C, δ34S and concentration values of other VOSCs produced in the gas phase, including sulfides and thiophenes, probably represent generation from S-containing moieties in kerogen and bitumen with limited interaction with co-existing H2S. The reaction of hydrocarbons and H2S to produce VOSCs is inversely correlated with thermal stability, i.e. thiols > sulfides > thiophenes. Therefore, the δ34S values, concentrations and distributions of VOSCs can be utilized as a proxy for reaction extent and formation mechanism of petroleum and H2S, including primary generation by thermal maturation, or potentially other processes such as migration and thermochemical sulfate reduction. This work demonstrates a novel and useful geochemical tool to study the source and fate of natural gas in the subsurface. © 2019 Elsevier Ltd
U. Bulbake, A. Singh, A.J. Domb, and W. Khan. 2019. “Therapeutic macromolecular iron chelators.” Current Medicinal Chemistry, 26, 2, Pp. 323-334. Publisher's Version Abstract
Iron is a key element for every single living process. On a fundamental level, targeting iron is a valuable approach for the treatment of disorders caused by iron overload. Utilizing iron chelators as therapeutic agents has received expanding consideration in chelation therapy. Approved low molecular weight (MW) iron chelators to treat iron overload may experience short half-lives and toxicities prompting moderately high adverse effects. In recent years, polymeric/macromolecular iron chelators have received attention as therapeutic agents. Polymeric iron chelators show unique pharmaceutical properties that are different to their conventional small molecule counterparts. These polymeric iron chelators possess longer plasma half-lives and reduced toxicities, thus exhibiting a significant supplement to currently using low MW iron chelator therapy. In this review, we have briefly discussed polymeric iron chelators and factors to be considered when designing clinically valuable iron chelators. We have also discussed applications of polymeric iron chelators in the diseases caused by iron overload associated with transfusional hemosiderosis, neurodegenerative disorders, malaria and cancer. With this, research findings for new polymeric iron chelators are also covered. © 2019 Bentham Science Publishers.
N.Y. Steinman and A.J. Domb. 2019. “Injectable pasty biodegradable polyesters derived from castor oil and hydroxyl-acid lactones.” Journal of Pharmacology and Experimental Therapeutics, 370, 3, Pp. 736-741. Publisher's Version Abstract
Pasty polymers offer a platform for injectable implants for drug delivery. A library of biodegradable pasty polymers was synthesized by bulk ring-opening polymerization of lactide, glycolide, trimethylene carbonate, or caprolactone using castor oil or 12-hydroxy stearic acid as hydroxyl initiators and stannous octoate as the catalyst. Some of the polymers behaved as Newtonian liquids. Pasty polymers of poly(caprolactone) and poly(trimethylene carbonate) were stable under physiologic conditions for over 1 month in vitro, whereas polymers of poly(lactic-co-glycolic acid) degraded within 10 days. These pasty polymers offer a platform for pasty injectable biodegradable carriers for drugs and fillers. Copyright © 2019 by The American Society for Pharmacology and Experimental Therapeutics.

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