- Dihydromyricetin Inhibits Inflammation of Fibroblast-like Synoviocytes through Regulation of NF-κB Signaling in Collagen-Induced Arthritis Rats. [Journal Article]
- JPJ Pharmacol Exp Ther 2018 Dec 10
- Dihydromyricetin (DMY), the main flavonoid of Ampelopsis grossedentata, has a potent anti-inflammation activity. However, the effect of DMY on the chronic autoimmune arthritis remains undefined. In t...
Dihydromyricetin (DMY), the main flavonoid of Ampelopsis grossedentata, has a potent anti-inflammation activity. However, the effect of DMY on the chronic autoimmune arthritis remains undefined. In this study we investigated the therapeutic effects of DMY on collagen-induced arthritis (CIA). Wistar rats were immunized with bovine type II collagen to establish CIA and then administered intraperitoneally (i.p.) with DMY (5, 25 and 50 mg/kg) every other day for five weeks. Paw swelling, clinical scoring and histologic analysis were performed to determine the therapeutic effects of DMY on arthritis development in CIA rats. The results showed that treatment with DMY significantly reduced the erythema and swelling in the paws of CIA rats. The pathological analysis of the knee joints and the peripheral blood cytokine assay confirmed the anti-arthritic effects of DMY on synovitis and inflammation. Fibroblast-like synoviocytes (FLSs) were isolated from the synovium of CIA rats and treated with 10 ng/ml interleukin (IL)-1β. DMY significantly inhibited the proliferation, migration and inflammation of IL-1β-induced FLSs, while it significantly increased IL-1β-induced FLSs apoptosis in a dose-dependent manner (6.25-25 μM). Moreover, DMY suppressed the phosphorylation of IκB kinase (IKK) and inhibitor of NF-κB alpha (IκBα), and subsequently reduced IL-1β-induced nucleus translocation of NF-κB in FLSs. Through molecular docking assay we demonstrated that DMY could directly bind to the Thr9 and Asp88 residues in IKKα and the Asp95, Asn142, and Gln167 residues in IKKβ. These findings demonstrated that DMY could alleviate inflammation in CIA rats and attenuate IL-1β-induced activities in FLSs through suppressing the NF-κB signaling.
- Divergent Cytotoxic and Metabolically Stimulative Functions of Sigma-2 Receptors: Structure-activity Relationships of 6-acetyl-3-(4-(4-(4-fluorophenyl)piperazin-1-yl)butyl)benzo[d]oxazol-2(3H)-one (SN79) Derivatives. [Journal Article]
- JPJ Pharmacol Exp Ther 2018 Dec 07
- Sigma-2 receptors, recently identified as TMEM97, have been implicated in cancer and neurodegenerative disease. Structurally distinct sigma-2 receptor ligands induce cell death in tumor cells, linkin...
Sigma-2 receptors, recently identified as TMEM97, have been implicated in cancer and neurodegenerative disease. Structurally distinct sigma-2 receptor ligands induce cell death in tumor cells, linking sigma-2 receptors to apoptotic pathways. Recently, we reported that sigma-2 receptors can also stimulate glycolytic hallmarks; effects consistent with a pro-survival function and upregulation in cancer cells. Both apoptotic and metabolically stimulative effects were observed with compounds related to the canonical sigma-2 antagonist, SN79. Here we investigate a series of 6-substituted SN79 analogs in order to assess the structural determinants governing these divergent effects. Substitutions on the benzoxazolone ring of the core SN79 structure resulted in high-affinity sigma-2 receptor ligands (Ki = 0.56-17.9 nM), with replacement of the heterocyclic oxygen by -NMe (N-methylbenzimidazolones) generally decreasing sigma-1 affinity and a sulfur substitution (benzothiazolones) imparting high affinity at both subtypes, lowering subtype selectivity. Substitution at the 6-position with -COCH3, -NO2, -NH2, or -F resulted in ligands that were not cytotoxic. Five of these ligands induced an increase in metabolic activity, as measured by increased reduction of MTT in human SK-N-SH neuroblastoma cells, further supporting a role for sigma-2 receptors in metabolism. Substitution with 6-isothiocyanate resulted in ligands that were sigma-2 selective and that irreversibly bound to the sigma-2 receptor, but not to sigma-1. These ligands induced cell death upon both acute and continuous treatment (EC50 = 7.6 - 32.8 μM), suggesting that irreversible receptor binding plays a role in cytotoxicity. These ligands will be useful for further study of these divergent roles of sigma-2 receptors.
- Diuretic, natriuretic, and vasodepressor activity of a lipid fraction enhanced in medium of cultured mouse medullary interstitial cells by a selective FAAH inhibitor. [Journal Article]
- JPJ Pharmacol Exp Ther 2018 Dec 07
- The relationship between the endocannabinoid system in the renal medulla and the long-term regulation of blood pressure is not understood. To investigate the possible role of the endocannabinoid syst...
The relationship between the endocannabinoid system in the renal medulla and the long-term regulation of blood pressure is not understood. To investigate the possible role of the endocannabinoid system in renomedullary interstitial cells, mouse medullary interstitial cells (MMICs) were obtained, cultured and characterized for their responses to treatment with a selective inhibitor of fatty acid amide hydrolase (FAAH), PF-3845. Treatment of MMICs with PF-3845 increased cytoplasmic lipid granules detected by Sudan Black B staining and multilamellar bodies identified by transmission electron microscopy. HPLC analyses of lipid extracts of MMIC culture medium revealed a 205nm-absorbing peak that showed responsiveness to PF-3845 treatment. The biologic activities of the PF-3845-induced product (PIP) isolated by HPLC were investigated in anesthetized, normotensive surgically-instrumented mice. Intramedullary and intravenous infusion of PIP at low dose rates (0.5-1 AU/10 min) stimulated diuresis and natriuresis, whereas at higher doses, these parameters returned toward baseline but mean arterial pressure (MAP) was lowered. Whereas intravenous bolus doses of PIP stimulated diuresis, GFR and medullary blood flow (MBF) and reduced or had no effect on MAP, an intraperitoneal bolus injection of PIP reduced MAP, increased MBF, and had no effect on urine parameters. These data support a model whereby PF-3845 treatment of MMICs results in increased secretion of a neutral lipid which acts directly to promote diuresis and natriuresis and indirectly through metabolites to produce vasodepression. Efforts to identify the structure of the PF-3845-induced lipid and its relationship to the previously proposed renomedullary antihypertensive lipids are ongoing.
- Anti-claudin antibodies as a concept for development of claudin-directed drugs. [Journal Article]
- JPJ Pharmacol Exp Ther 2018 Dec 07
- Claudin (CLDN) proteins, a tetra-transmembrane family containing over 20 members, have been identified as a key structural and functional component of intercellular seals, tight junctions (TJs). CLDN...
Claudin (CLDN) proteins, a tetra-transmembrane family containing over 20 members, have been identified as a key structural and functional component of intercellular seals, tight junctions (TJs). CLDNs are involved in the barrier and fence functions of TJs. Loosening the TJ barrier is one strategy for increasing drug absorption and delivery to the brain. Due to aberrant CLDN expression, the TJ fence function is frequently dysregulated in carcinogenesis. In addition, CLDN-1 is a co-receptor for the hepatitis C virus. Together these characteristics indicate CLDNs as promising targets for drug development, and CLDN binders are potential candidates for delivering drugs, treating cancer, and preventing viral infection. Before 2008, a receptor-binding fragment of Clostridium perfringens enterotoxin was the only CLDN binder available. Since then, several challenges regarding the generation of monoclonal antibodies against CLDNs have been surmounted, leading to breakthroughs in CLDN-targeted drug development. Here, we provide an overview of the recent progress in technology using created CLDN binders--anti-CLDN monoclonal antibodies.
- Inhibitory effects of Mas-related gene (Mrg) C receptor on chronic morphine-induced spinal glial activation. [Journal Article]
- JPJ Pharmacol Exp Ther 2018 Nov 28
- Glial activation plays a pivotal role in morphine tolerance. This study investigated effect of Mas-related gene (Mrg) C receptor on morphine-induced activation of microglia and astrocytes in the spin...
Glial activation plays a pivotal role in morphine tolerance. This study investigated effect of Mas-related gene (Mrg) C receptor on morphine-induced activation of microglia and astrocytes in the spinal cord and its underlying mechanisms. Intrathecal (i.t.) administration of morphine (20 µg, daily) for 6 days induced a great decline of morphine antinociception and increased expression of GFAP and OX-42 in the spinal dorsal horn. These changes were greatly attenuated by the intermittent co-injection of bovine adrenal medulla 8-22 (BAM8-22, 1 nmol), a specific agonist of MrgC receptor. These modulatory effects were accompanied by the reduction of P2X4 and interleukin-1β (IL-1β) expressions in the spinal dorsal horn. Chronic morphine increased the expression of fractalkine in medium- and small-sized neurons of dorsal root ganglia (DRG). The treatment of BAM8-22 inhibited these changes as well as the increase of TLR4 protein in DRG. Chronic treatment of DRG explant cultures with morphine (3.3 µM, 5 days) increased the levels of fractalkine mRNA. Application of BAM8-22 (10 nM) for 60 min completely blocked the increase of fractalkine mRNA induced by morphine. Our findings indicate that the inhibition of morphine tolerance by MrgC receptor was associated with the modulation of astrocytes and microglia in the spinal dorsal horn and fractalkine and TLR4 expressions in DRG. As MrgC receptor is exclusively located in DRG, intermittent combination of MrgC receptor agonist could be a promising adjunct for chronic use of opiates with limited side effects.
- Development of human target validation classification that predicts future clinical efficacy. [Journal Article]
- JPJ Pharmacol Exp Ther 2018 Nov 27
- Fewer new medicines have become available to patients during the last decades. Clinical efficacy failures in late phase development have been identified as a common cause of this decline. Improved wa...
Fewer new medicines have become available to patients during the last decades. Clinical efficacy failures in late phase development have been identified as a common cause of this decline. Improved ways to ensure early selection of the right drug targets when it comes to efficacy is therefore a highly desirable goal. The aim of this work was to develop a strategy to facilitate selection of novel targets already in the discovery phase which later on in clinical development would demonstrate efficacy. A cross-functional team at AstraZeneca with extensive experience of drug discovery and development participated in several workshops to identify the critical elements that contribute to building human target validation (HTV; the relevance of the target from a human perspective). The elements were consolidated into a ten-point HTV classification system that was ranked from lowest to highest in terms of perceived impact on future clinical efficacy. Using fifty years of legacy research and development (R&D) data the ability of the ten-point HTV classification to predict future clinical efficacy was evaluated. Drug targets were classified as having low, medium or high HTV at the time of candidate drug (CD) selection. Comparing this HTV classification with later clinical development efficacy data showed that HTV classification was highly predictive of future clinical efficacy success. This new strategy for HTV assessment provides a novel approach to early prediction of clinical efficacy and a better understanding of portfolio risk.
- Reversal and prevention of the respiratory-depressant effects of heroin by the novel µ opioid receptor antagonist methocinnamox in rhesus monkeys. [Journal Article]
- JPJ Pharmacol Exp Ther 2018 Nov 21
- One consequence of the ongoing opioid epidemic is a large number of overdose deaths. Naloxone reverses opioid-induced respiratory depression; however, its short duration of action limits the protecti...
One consequence of the ongoing opioid epidemic is a large number of overdose deaths. Naloxone reverses opioid-induced respiratory depression; however, its short duration of action limits the protection it can provide. Methocinnamox (MCAM) is a novel opioid receptor antagonist with a long duration of action. This study examined the ability of MCAM to prevent and reverse the respiratory-depressant effects (minute volume [VE]) of heroin in 5 monkeys. MCAM (0.32 mg/kg) was given before heroin to determine whether it prevents respiratory depression; heroin dose-effect curves were generated 1, 2, 4, and 8 days later, and these effects were compared to those of naltrexone (0.032 mg/kg). Heroin dose dependently decreased VE. MCAM and naltrexone prevented respiratory depression, shifting the heroin dose-effect curve at least 10-fold rightward. MCAM, but not naltrexone, attenuated these effects of heroin for 4 days. MCAM (0.1-0.32 mg/kg) was given 30 min after heroin to determine whether it reverses respiratory depression; heroin dose-effect curves were generated 1, 2, 4, 8, and 16 days later, and these effects were compared to those of naloxone (0.0032-0.1 mg/kg). MCAM and naloxone reversed respiratory depression within 30 min, although only MCAM antagonized heroin on subsequent days. Thus, MCAM prevents and reverses respiratory depression, the potentially lethal effect of heroin, longer than currently used opioid receptor antagonists. Because of its sustained effects, MCAM might provide more effective rescue from and protection against the fatal respiratory-depressant effects of opioids, thereby improving treatment of opioid overdose.
- Nicotine modulates growth factors and microRNA to promote inflammatory and fibrotic processes. [Journal Article]
- JPJ Pharmacol Exp Ther 2018 Nov 16
- Idiopathic pulmonary fibrosis (IPF) is a fatal disease that destroys the structure and function of the lungs. Risk factors include advanced age and genetic predisposition. However, tobacco use is the...
Idiopathic pulmonary fibrosis (IPF) is a fatal disease that destroys the structure and function of the lungs. Risk factors include advanced age and genetic predisposition. However, tobacco use is the chief modifiable risk factor. The prevalence of tobacco use in IPF reaches up to 80%. Although tobacco smoke contains over 5,000 chemicals, nicotine is a major component. Nicotine is a bioactive molecule that acts upon nicotinic acetylcholine receptors expressed on neuronal and non-neuronal cells including endothelial cells. Accordingly, it has pleiotropic effect including on cell proliferation and angiogenesis. The angiogenic effect is partly mediated by stimulation of growth factors including FGF, PDGF, and VEGF. Nintedanib, FDA-approved drug for IPF, works by inhibiting receptors for these growth factors suggesting pathobiologic role of the growth factors in IPF, and a potential mechanism by which tobacco use may exacerbate the disease process. Additionally, nicotine downregulates anti-inflammatory microRNAs (miRs) in lung cells. Here, we profiled the expression of miRs in lung tissues explanted from lung injury model and examined the effect of nicotine on one of the identified miRs (miR-24) and its downstream targets. Our data shows that miR-24 is downregulated during lung injury and is suppressed by nicotine. We also found that nicotine upregulates the expression of inflammatory cytokines targeted by miR-24. Finally, nicotine stimulated growth factors, fibroblast proliferation, collagen release and expression of myofibroblast markers. Taken together, nicotine, alone or as component of tobacco smoke, may accelerate the disease process in IPF through stimulation of growth factors and downregulation of anti-inflammatory miRs.
- Alpha-tocopherol potentiates the cervical resistance decreasing effects of COX-inhibitors in pregnant rats: the putative role of cyclooxygenase-2 inhibition. [Journal Article]
- JPJ Pharmacol Exp Ther 2018 Nov 15
- Vitamin E and their analogues as antioxidant and lipid soluble compounds can have diverse effects on the physiological processes. By binding to receptors and enzymes, they may modify the action of dr...
Vitamin E and their analogues as antioxidant and lipid soluble compounds can have diverse effects on the physiological processes. By binding to receptors and enzymes, they may modify the action of drugs. It has been proved that alpha-tocopherol succinate modifies the effects of β2 agonist terbutaline and cyclooxygenase (COX) inhibitors on rat trachea and myometrium. Our aim was to investigate how alpha-tocopherol and COX inhibitors may influence cervical resistance in rats. The cervical resistance of non-pregnant and 22-day-pregnant Sprague-Dawley rats was determined in an isolated organ bath in vitro. Alpha-tocopherol-succinate (10-7 M) was used, while the COX non-selective diclofenac (10-6 M), the COX-2 selective rofecoxib (10-6 M) and the COX-1 selective SC-560 (10-6 M) were applied as inhibitors. The COX activities of the cervices were measured by enzyme-immunoassay. The modifying effect of single doses of COX-inhibitors and tocopherol on the onset of labor was investigated in vivo. The cervical resistance of non-pregnant samples was not changed by either alpha-tocopherol or COX inhibitors. On pregnant cervices, tocopherol, diclofenac or rofecoxib pretreatment decreased cervical resistance that was further reduced by COX-inhibitors after pretreatment with tocopherol. Alpha-tocopherol elicited a significant COX-2 enzyme inhibition in pregnant cervical samples. By co-administration of tocopherol and rofecoxib, the parturition was initiated earlier than in the other groups. It is supposed that COXs play a significant role not only in cervical ripening, but also in the contraction of the cervical smooth muscle a few hours before parturition. This latter action may be developed by COX-2 liberated prostaglandins.
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- A pragmatic utility function to describe the risk-benefit composite of opioid and non-opioid analgesic medication. [Journal Article]
- JPJ Pharmacol Exp Ther 2018 Nov 15
- It is not straightforward to simultaneously evaluate benefits and harms of pain management, as different drugs may possess different analgesia and adverse effect profiles. Utility functions, derived ...
It is not straightforward to simultaneously evaluate benefits and harms of pain management, as different drugs may possess different analgesia and adverse effect profiles. Utility functions, derived from the pharmacokinetics and pharmacodynamics of individual outcome parameters, have been constructed to address this problem. Here we construct "pragmatic" utility functions based on measurements of benefit and harms, but without making assumptions about the underlying pharmacokinetics and pharmacodynamics. Using data from two previous studies, utility functions were designed by estimating the probability of occurrence of benefit and harm and combining these into one function. Study 1 was a clinical trial on the effect of oral pregabalin on pain relief in chronic pancreatitis patients, with end-points analgesia and dizziness monitored for 21 days. Study 2 was an experimental study on the effect of intravenous fentanyl on antinociception and respiratory depression in healthy volunteers. From study 1 the utility function was negative the first week of treatment, indicative of the greater probability of dizziness than analgesia, but positive thereafter. From study 2 the utility function showed a nadir 30 minutes after dosing, after which the probability function slowly increased towards zero. A pragmatic utility function based on the probability of two binary outcomes, analgesia and adverse effect, was successfully constructed using data from two previous studies. Results yielded valuable insights into the utility of treatment and may be highly educative for physicians and may be used in development of potent analgesics with serious side effects.