Alomone Labs Ltd.

West Jerusalem, Israel

Alomone Labs Ltd.

West Jerusalem, Israel
SEARCH FILTERS
Time filter
Source Type

Cherki R.S.,Alomone Labs Ltd | Cherki R.S.,Atrial Fibrillation Research Laboratory | Kolb E.,Alomone Labs Ltd | Langut Y.,Alomone Labs Ltd | And 4 more authors.
Toxicon | Year: 2014

Voltage dependent sodium (NaV) channels are large membrane spanning proteins which lie in the basis of action potential generation and propagation in excitable cells and hence are essential mediators of neuronal signaling. Inhibition of NaV channel activity is one of the core mechanisms to treat conditions related to neuronal hyperexcitability, such as epilepsy in the clinic. NaV channel blockers are also extensively used to locally inhibit action potential generation and related pain perceptions in the form of local anesthetics. Here we describe the isolation, biochemical characterization, synthesis and in vitro characterization of two potent Na V channel blockers from the venom of the Paraphysa scrofa (Phrixotrichus auratus) tarantula spider. Both Voltage sensor toxin 3 (VSTx-3, κ-theraphotoxin-Gr4a) and GTx1-15 (Toxin Gtx1-15), were originally isolated from the venom of the related tarantula Grammostola rosea and described as KV and CaV channel blockers, respectively. In our hands, GTx1-15 was shown to be a potent inhibitor of tetrodotoxin (TTX)-sensitive channels (IC50 0.007 μM for hNaV1.7 and 0.12 μM for hNaV1.3 channels), with very little effect on TTX-resistant (NaV1.5 and NaV1.8) channels. VSTx-3 was demonstrated to be a potent, TTX-sensitive sodium channel blocker and especially, potent blocker of NaV1.8 channels (IC50 0.19 μM for hNaV1.3, 0.43 μM for hNaV1.7 and 0.77 μM for hNaV1.8 channels). Such potent inhibitors with differential selectivity among NaV channel isoforms may be used as tools to study the roles of the different channels in processes related to hyperexcitability and as lead compounds to treat pathological pain conditions. © 2013 The Authors. Published by Elsevier Ltd. All rights reserved.


Bloch M.B.D.,Hebrew University of Jerusalem | Yavin E.,Hebrew University of Jerusalem | Nissan A.,The Surgical Center | Ariel I.,Hebrew University of Jerusalem | And 4 more authors.
Journal of Controlled Release | Year: 2017

To increase colonoscopy competence in ambiguous situations (e.g. the existence of flat polyps), an explicit in situ (at real time) diagnosis at the molecular level is required. We have previously shown that the affinity of fluorescent cationic polyacrylamide (Flu-CPAA) to malignant regions in the colon mucosa can be improved by conjugating the recognition peptide EPPT1 to the polymer backbone (to form Flu-CPAA-Pep). Using another recognition peptide, namely VRPMPLQ, we elucidated in the present study the effect of linker type and conjugating methods on Flu-CPAA-VRPMPLQ cytotoxicity and on its affinity to cell lines as well as human colorectal cancer (CRC) biopsies. In order to derive the relationship between the response variable and the experimental factors in a minimal set of experiments, a computerized statistical design of experiment (DoE) strategy was implemented. Data were collected in a six-factor factorial design to study the effect of experimental factors (independent variables) on the ability of the Flu-CPAA polymers to bind specifically to the colon cancer cell lines or the human biopsies (the response). It was found that the presence of VRPMPLQ on the Flu-CPAA improved the polymer's affinity to the human CRC biopsies and to the colon cancer cell lines representing stage B in the Duke severity staging system. The cytotoxicity of Flu-CPAA with high charge density was reduced after conjugated with VRPMPLQ. The replacement of Ahx linker by PEG linker of similar length did not affect the affinity to the human biopsies, nor did it affect cytotoxicity. However, elongating the PEG linker reduced the in vitro affinity to the colon cancer cell lines and to human CRC biopsies. Changing the conjugation method from condensation (amide bond formation) to the click conjugation method did not affect the affinity properties of the polymers. It did reduce, however, the polymer cytotoxicity. We suggest that Flu-CPAA-Pep, with the VRPMPLQ peptide as a recognition moiety, could serve for early diagnosis and screening of CRC patients during endoscopic procedures. © 2017 Elsevier B.V.


Kc R.,Rush University Medical Center | Li X.,Rush University Medical Center | Kroin J.S.,Rush University Medical Center | Liu Z.,Rush University Medical Center | And 11 more authors.
Annals of the Rheumatic Diseases | Year: 2016

Objectives A key clinical paradox in osteoarthritis (OA), a prevalent age-related joint disorder characterised by cartilage degeneration and debilitating pain, is that the severity of joint pain does not strictly correlate with radiographic and histological defects in joint tissues. Here, we determined whether protein kinase Cδ (PKCδ), a key mediator of cartilage degeneration, is critical to the mechanism by which OA develops from an asymptomatic joint-degenerative condition to a painful disease. Methods OA was induced in 10-week-old PKCδ null (PKCδ-/-) and wild-type mice by destabilisation of the medial meniscus (DMM) followed by comprehensive examination of the histology, molecular pathways and knee-pain-related-behaviours in mice, and comparisons with human biopsies. Results In the DMM model, the loss of PKCδ expression prevented cartilage degeneration but exacerbated OA-associated hyperalgesia. Cartilage preservation corresponded with reduced levels of inflammatory cytokines and of cartilage-degrading enzymes in the joints of PKCδ-deficient DMM mice. Hyperalgesia was associated with stimulation of nerve growth factor (NGF) by fibroblast-like synovial cells and with increased synovial angiogenesis. Results from tissue specimens of patients with symptomatic OA strikingly resembled our findings from the OA animal model. In PKCd null mice, increases in sensory neuron distribution in knee OA synovium and activation of the NGF-tropomyosin receptor kinase (TrkA) axis in innervating dorsal root ganglia were highly correlated with knee OA hyperalgesia. Conclusions Increased distribution of synovial sensory neurons in the joints, and augmentation of NGF/TrkA signalling, causes OA hyperalgesia independently of cartilage preservation. © 2016 BMJ Publishing Group Ltd & European League Against Rheumatism.


Brass D.,Alomone Labs Ltd. | Grably M.R.,Alomone Labs Ltd. | Bronstein-Sitton N.,Alomone Labs Ltd. | Gohar O.,Alomone Labs Ltd. | Meir A.,Alomone Labs Ltd.
Purinergic Signalling | Year: 2012

The broad expression pattern of the G protein-coupled P2Y receptors has demonstrated that these receptors are fundamental determinants in many physiological responses, including neuromodulation, vasodilation, inflammation, and cell migration. P2Y receptors couple either G q or G i upon activation, thereby activating different signaling pathways. Ionotropic ATP (P2X) receptors bind extracellular nucleotides, a signal which is transduced within the P2X protein complex into a cation channel opening, which usually leads to intracellular calcium concentration elevation. As such, this family of proteins initiates or shapes several cellular processes including synaptic transmission, gene expression, proliferation, migration, and apoptosis. The ever-growing range of applications for antibodies in the last 30 years attests to their major role in medicine and biological research. Antibodies have been used as therapeutic tools in cancer and inflammatory diseases, as diagnostic reagents (flow cytometry, ELISA, and immunohistochemistry, to name a few applications), and in widespread use in biological research, including Western blot, immunoprecipitation, and ELISPOT. In this article, we will showcase several of the advances that scientists around the world have achieved using the line of antibodies developed at Alomone Labs for P2Y and P2X receptors. © 2011 The Author(s).


PubMed | Alomone Labs Ltd
Type: | Journal: Toxicon : official journal of the International Society on Toxinology | Year: 2013

Voltage dependent sodium (Na(V)) channels are large membrane spanning proteins which lie in the basis of action potential generation and propagation in excitable cells and hence are essential mediators of neuronal signaling. Inhibition of Na(V) channel activity is one of the core mechanisms to treat conditions related to neuronal hyperexcitability, such as epilepsy in the clinic. Na(V) channel blockers are also extensively used to locally inhibit action potential generation and related pain perceptions in the form of local anesthetics. Here we describe the isolation, biochemical characterization, synthesis and in vitro characterization of two potent Na(V) channel blockers from the venom of the Paraphysa scrofa (Phrixotrichus auratus) tarantula spider. Both Voltage sensor toxin 3 (VSTx-3, -theraphotoxin-Gr4a) and GTx1-15 (Toxin Gtx1-15), were originally isolated from the venom of the related tarantula Grammostola rosea and described as K(V) and Ca(V) channel blockers, respectively. In our hands, GTx1-15 was shown to be a potent inhibitor of tetrodotoxin (TTX)-sensitive channels (IC 0.007 M for hNa(V)1.7 and 0.12 M for hNa(V)1.3 channels), with very little effect on TTX-resistant (Na(V)1.5 and NaV1.8) channels. VSTx-3 was demonstrated to be a potent, TTX-sensitive sodium channel blocker and especially, potent blocker of Na(V)1.8 channels (IC 0.19 M for hNa(V)1.3, 0.43 M for hNa(V)1.7 and 0.77 M for hNa(V)1.8 channels). Such potent inhibitors with differential selectivity among Na(V) channel isoforms may be used as tools to study the roles of the different channels in processes related to hyperexcitability and as lead compounds to treat pathological pain conditions.


PubMed | Alomone Labs Ltd.
Type: Journal Article | Journal: Purinergic signalling | Year: 2012

The broad expression pattern of the G protein-coupled P2Y receptors has demonstrated that these receptors are fundamental determinants in many physiological responses, including neuromodulation, vasodilation, inflammation, and cell migration. P2Y receptors couple either G(q) or G(i) upon activation, thereby activating different signaling pathways. Ionotropic ATP (P2X) receptors bind extracellular nucleotides, a signal which is transduced within the P2X protein complex into a cation channel opening, which usually leads to intracellular calcium concentration elevation. As such, this family of proteins initiates or shapes several cellular processes including synaptic transmission, gene expression, proliferation, migration, and apoptosis. The ever-growing range of applications for antibodies in the last 30years attests to their major role in medicine and biological research. Antibodies have been used as therapeutic tools in cancer and inflammatory diseases, as diagnostic reagents (flow cytometry, ELISA, and immunohistochemistry, to name a few applications), and in widespread use in biological research, including Western blot, immunoprecipitation, and ELISPOT. In this article, we will showcase several of the advances that scientists around the world have achieved using the line of antibodies developed at Alomone Labs for P2Y and P2X receptors.

Loading Alomone Labs Ltd. collaborators
Loading Alomone Labs Ltd. collaborators