Browsing by Author "Lichtman, Aron H."
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Item Diacylglycerol lipase beta inhibition reverses nociceptive behaviour in mouse models of inflammatory and neuropathic pain(Wiley, 2016-02-16) Wilkerson, Jenny L.; Ghosh, Sudeshna; Mason, Brittany L.; Crowe, Molly S.; Hsu, Kulung; Wise, Laura E.; Kinsey, Steven G.; Damaj, Mohamad Imad; Cravatt, Benjamin F.; Lichtman, Aron H.; Baǧdaş, Deniz; Uludağ Üniversitesi/Tıp Fakültesi/Deney Hayvanları Yetiştirme ve Araştırma Merkezi.; 15062425700Background and PurposeInhibition of diacylglycerol lipase (DGL) prevents LPS-induced pro-inflammatory responses in mouse peritoneal macrophages. Thus, the present study tested whether DGL inhibition reverses allodynic responses of mice in the LPS model of inflammatory pain, as well as in neuropathic pain models. Experimental ApproachInitial experiments examined the cellular expression of DGL and inflammatory mediators within the LPS-injected paw pad. DAGL- (-/-) mice or wild-type mice treated with the DGL inhibitor KT109 were assessed in the LPS model of inflammatory pain. Additional studies examined the locus of action for KT109-induced antinociception, its efficacy in chronic constrictive injury (CCI) of sciatic nerve and chemotherapy-induced neuropathic pain (CINP) models. Key ResultsIntraplantar LPS evoked mechanical allodynia that was associated with increased expression of DGL, which was co-localized with increased TNF- and prostaglandins in paws. DAGL- (-/-) mice or KT109-treated wild-type mice displayed reductions in LPS-induced allodynia. Repeated KT109 administration prevented the expression of LPS-induced allodynia, without evidence of tolerance. Intraplantar injection of KT109 into the LPS-treated paw, but not the contralateral paw, reversed the allodynic responses. However, i.c.v. or i.t. administration of KT109 did not alter LPS-induced allodynia. Finally, KT109 also reversed allodynia in the CCI and CINP models and lacked discernible side effects (e.g. gross motor deficits, anxiogenic behaviour or gastric ulcers). Conclusions and ImplicationsThese findings suggest that local inhibition of DGL at the site of inflammation represents a novel avenue to treat pathological pain, with no apparent untoward side effects.Item Effects of paclitaxel on the development of neuropathy and affective behaviors in the mouse(Elsevier, 2017-05-01) Toma, Wisam; Kyte, S. Lauren; Alkhlaif, Yasmin; Alsharari, Shakir D.; Lichtman, Aron H.; Chen, Zhi-Jian; Del fabbro, Egidio; Bigbee, John W.; Gewirtz, David A.; Damaj, M. Imad; Bağdas, Deniz; Uludağ Üniversitesi/Veteriner Fakültesi/Deney Hayvanları Yetiştirme ve Araştırma Merkezi.; 15062425700Paclitaxel, one of the most commonly used cancer chemotherapeutic drugs, effectively extends the progression-free survival of breast, lung, and ovarian cancer patients. However, paclitaxel and other chemotherapy drugs elicit peripheral nerve fiber dysfunction or degeneration that leads to peripheral neuropathy in a large proportion of cancer patients. Patients receiving chemotherapy also often experience changes in mood, including anxiety and depression. These somatic and affective disorders represent major dose-limiting side effects of chemotherapy. Consequently, the present study was designed to develop a preclinical model of paclitaxel-induced negative affective symptoms in order to identify treatment strategies and their underlying mechanisms of action. Intraperitoneal injections of paclitaxel (8 mg/kg) resulted in the development and maintenance of mechanical and cold allodynia. Carboplatin, another cancer chemotherapeutic drug that is often used in combination with paclitaxel, sensitized mice to the nociceptive effects of paclitaxel. Paclitaxel also induced anxiety-like behavior, as assessed in the novelty suppressed feeding and light/dark box tests. In addition, paclitaxel-treated mice displayed depression-like behavior during the forced swim test and an anhedonia-like state in the sucrose preference test. In summary, paclitaxel produced altered behaviors in assays modeling affective states in C57BL/6J male mice, while increases in nociceptive responses were longer in duration. The characterization of this preclinical model of chemotherapy-induced allodynia and affective symptoms, possibly related to neuropathic pain, provides the basis for determining the mechanism(s) underlying severe side effects elicited by paclitaxel, as well as for predicting the efficacy of potential therapeutic interventions.Item In vivo interactions between alpha 7 nicotinic acetylcholine receptor and nuclear peroxisome proliferator-activated receptor-alpha: Implication for nicotine dependence(Elsevier, 2017-03-04) Jackson, Asti; Muldoon, Pretal P.; Lichtman, Aron H.; Carroll, F. Ivy; Greenwald, Mark; Miles, Michael F.; Damaj, M. Imad; Bağdaş, Deniz; Uludağ Üniversitesi/Tıp Fakültesi/Deney Hayvanları Yetiştirme ve Araştırma Merkezi.; 15062425700Chronic tobacco use dramatically increases health burdens and financial costs. Limitations of current smoking cessation therapies indicate the need for improved molecular targets. The main addictive component of tobacco, nicotine, exerts its dependency effects via nicotinic acetylcholine receptors (nAChRs). Activation of the homomeric alpha 7 nAChR reduces nicotine's rewarding properties in conditioned place preference (CPP) test and i.v. self-administration models, but the mechanism underlying these effects is unknown. Recently, the nuclear receptor peroxisome proliferator-activated receptor type-alpha (PPAR alpha) has been implicated as a downstream signaling target of the alpha 7 nAChR in ventral tegmental area dopamine cells. The present study investigated PPAR alpha as a possible mediator of the effect of alpha 7 nAChR activation in nicotine dependence. Our results demonstrate the PPAR alpha antagonist GW6471 blocks actions of the alpha 7 nAChR agonist PNU282987 on nicotine reward in an unbiased CPP test in male ICR adult mice. These findings suggests that alpha 7 nAChR activation attenuates nicotine CPP in a PPAR alpha-dependent manner. To evaluate PPAR alpha activation in nicotine dependence we used the selective and potent PPAR alpha agonist, WY-14643 and the clinically used PPAR alpha activator, fenofibrate, in nicotine CPP and we observed attenuation of nicotine preference, but fenofibrate was less potent. We also studied PPAR alpha in nicotine dependence by evaluating its activation in nicotine withdrawal. WY-14643 reversed nicotine withdrawal signs whereas fenofibrate had modest efficacy. This suggests that PPAR alpha plays a role in nicotine reward and withdrawal and that further studies are warranted to elucidate its function in mediating the effects of alpha 7 nAChRs in nicotine dependence.Item The interaction between alpha 7 nicotinic acetylcholine receptor and nuclear peroxisome proliferator-activated receptor-alpha represents a new antinociceptive signaling pathway in mice(Elsevier, 2017-06-08) Donvito, Giulia; Toma, Wisam; Rahimpour, Elnaz; Jackson, Asti; Meade, Julie A.; Alsharari, Shakir; Kulkarni, Abhijit R.; Carroll, F. Ivy; Lichtman, Aron H.; Papke, Roger L; Thakur, Ganesh A.; Damaj, M. Imad; Bağdaş, Deniz; Uludağ Üniversitesi/Tıp Fakültesi/Deney Hayvanları Yetiştirme ve Araştırma Merkezi.; 15062425700Recently, alpha 7 nicotinic acetylcholine receptors (nAChRs), primarily activated by binding of orthosteric agonists, represent a target for anti-inflammatory and analgesic drug development. These receptors may also be modulated by positive allosteric modulators (PAMs), ago-allosteric ligands (ago-PAMs), and alpha 7-silent agonists. Activation of 00 nAChRs has been reported to increase the brain levels of endogenous ligands for nuclear peroxisome proliferator-activated receptors type-alpha (PPAR-alpha), palmitoylethanolamide (PEA) and oleoylethanolamide (OEA), in a Ca2+-dependent manner. Here, we investigated potential crosstalk between alpha 7 nAChR and PPAR-alpha, using the formalin test, a mouse model of tonic pain. Using pharmacological and genetic approaches, we found that PNU282987, a full alpha 7 agonist, attenuated formalin-induced nociceptive behavior in alpha 7 -dependent manner. Interestingly, the selective PPAR-alpha antagonist GW6471 blocked the antinociceptive effects of PNU282987, but did not alter the antinociceptive responses evoked by the alpha 7 nAChR PAM PNU120596, ago-PAM GAT107, and silent agonist NS6740. Moreover, GW6471 administered systemically or spinally, but not via the intraplantar surface of the formalin-injected paw blocked PNU282987-induced antinociception. Conversely, exogenous administration of the naturally occurring PPAR-alpha agonist PEA potentiated the antinociceptive effects of PNU282987. In contrast, the cannabinoid 031 antagonist rimonabant and the CB2 antagonist SR144528 failed to reverse the antinociceptive effects of PNU282987. These findings suggest that PPAR-alpha plays a key role in a putative antinociceptive alpha 7 nicotinic signaling pathway.Item Nicotine prevents and reverses paclitaxel-induced mechanical allodynia in a mouse model of CIPN(American Society for Pharmacology and Experimental Therapy, 2018-01-01) Kyte, S. Lauren; Toma, Wisam; Meade, Julie A.; Schurman, Lesley D.; Lichtman, Aron H.; Chen, Zhi-Jian; Del Fabbro, Egidio; Fang, Xianjun; Bigbee, John W.; Damaj, M. Imad; Gewirtz, David A.; Bağdaş, Deniz; Uludağ Üniversitesi/Tıp Fakültesi/Farmakoloji Anabilim Dalı.; EOB-5882-2022; 15062425700Chemotherapy-induced peripheral neuropathy (CIPN), a consequence of peripheral nerve fiber dysfunction or degeneration, continues to be a dose-limiting and debilitating side effect during and/or after cancer chemotherapy. Paclitaxel, a taxane commonly used to treat breast, lung, and ovarian cancers, causes CIPN in 59-78% of cancer patients. Novel interventions are needed due to the current lack of effective CIPN treatments. Our studies were designed to investigate whether nicotine can prevent and/or reverse paclitaxel-induced peripheral neuropathy in a mouse model of CIPN, while ensuring that nicotine will not stimulate lung tumor cell proliferation or interfere with the antitumor properties of paclitaxel. Male C57BL/6J mice received paclitaxel every other day for a total of four injections (8 mg/kg, i.p.). Acute (0.3-0.9 mg/kg, i.p.) and chronic (24 mg/kg per day, s.c.) administration of nicotine respectively reversed and prevented paclitaxel-induced mechanical allodynia. Blockade of the antinociceptive effect of nicotine with mecamylamine and methyllycaconitine suggests that the reversal of paclitaxel-induced mechanical allodynia is primarily mediated by the alpha 7 nicotinic acetylcholine receptor subtype. Chronic nicotine treatment also prevented paclitaxel-induced intraepidermal nerve fiber loss. Notably, nicotine neither promoted proliferation of A549 and H460 non-small cell lung cancer cells nor interfered with paclitaxel-induced antitumor effects, including apoptosis. Most importantly, chronic nicotine administration did not enhance Lewis lung carcinoma tumor growth in C57BL/6J mice. These data suggest that the nicotinic acetylcholine receptor-mediated pathways may be promising drug targets for the prevention and treatment of CIPN.Item The α7 nicotinic receptor dual allosteric agonist and positive allosteric modulator GAT107 reverses nociception in mouse models of inflammatory and neuropathic pain(Wiley, 2016-05-17) Wilkerson, Jenny L.; Kulkarni, Abhijit; Toma, Wisam; AlSharari, Shakir; Lichtman, Aron H.; Papke, Roger L.; Thakur, Ganesh A.; Damaj, M. Imad; Bağdaş, Deniz; Gül, Zülfiye; Uludağ Üniversitesi/Tıp Fakültesi/Deney Hayvanları Yetiştirme ve Araştırma Merkezi.; Uludağ Üniversitesi/Tıp Fakültesi/Farmakoloji Anabilim Dalı.; 0000-0002-8872-0074; AAF-9939-2020; 15062425700; 56086542900Background and PurposeOrthosteric agonists and positive allosteric modulators (PAMs) of the 7 nicotinic ACh receptor (nAChR) represent novel therapeutic approaches for pain modulation. Moreover, compounds with dual function as allosteric agonists and PAMs, known as ago-PAMs, add further regulation of receptor function. Experimental ApproachInitial studies examined the 7 ago-PAM, GAT107, in the formalin, complete Freund's adjuvant (CFA), LPS inflammatory pain models, the chronic constriction injury neuropathic pain model and the tail flick and hot plate acute thermal nociceptive assays. Additional studies examined the locus of action of GAT107 and immunohistochemical markers in the dorsal horn of the spinal cord in the CFA model. Key ResultsComplementary pharmacological and genetic approaches confirmed that the dose-dependent antinociceptive effects of GAT107 were mediated through 7 nAChR. However, GAT107 was inactive in the tail flick and hot plate assays. In addition, GAT107 blocked conditioned place aversion elicited by acetic acid injection. Furthermore, intrathecal, but not intraplantar, injections of GAT107 reversed nociception in the CFA model, suggesting a spinal component of action. Immunohistochemical evaluation revealed an increase in the expression of astrocyte-specific glial fibrillary acidic protein and phosphorylated p38MAPK within the spinal cords of mice treated with CFA, which was attenuated by intrathecal GAT107 treatment. Importantly, GAT107 did not elicit motor impairment and continued to produce antinociceptive effects after subchronic administration in both phases of the formalin test. Conclusions and ImplicationsCollectively, these results provide the first proof of principle that 7 ago-PAMs represent an effective pharmacological strategy for treating inflammatory and neuropathic pain.