IntroductionNeuropathic pain is a debilitating condition. The importance of neuroimmune interactions in neuropathic pain has been evidenced by the involvement of different immune cells in peripheral and central sensitization of pathological pain. Macrophages and microglia are the most abundant immune cells activated in injured nerves and spinal cord, respectively. Several lines of evidence showed that macrophage/microglia survival, activation, proliferation, and differentiation require the involvement of macrophage-colony stimulating factor. In this study, we investigated whether blocking macrophage-colony stimulating factor/colony stimulating factor 1 receptor signaling can be effective in relieving neuropathic pain.Materials and methodsPartial sciatic nerve ligation was performed in mice to induce neuropathic pain behavior. Mice were orally treated with a selective colony stimulating factor 1 receptor inhibitor, PLX5622, daily in both preventive (two days prior to surgery until D14 post-partial sciatic nerve ligation) and reversal paradigms (D28–D33 post-partial sciatic nerve ligation). Animal neuropathic pain behavior was monitored using von Frey hairs and acetone application. Phenotype of macrophages in injured nerves was analyzed at D3 and D33 post-injury using flow cytometry analysis. The effect of PLX5622 on microglia activation in lumbar spinal cord was further examined by immunohistochemistry using Iba-1 antibody.ResultsSignificant alleviation of both mechanical and cold allodynia was observed in PLX5622-treated animals, both in preventive and reversal paradigms. PLX5622 treatment reduced the total number of macrophages in injured nerves, it appears colony stimulating factor 1 receptor inhibition affected more specifically CD86+ (M1 like) macrophages. Consequently, the expression of various pro-inflammatory cytokines (TNF-α, IL-1β) was reduced. Microglia activation in dorsal horn of lumbar spinal cord following partial sciatic nerve ligation was significantly inhibited with PLX5622 treatment in both preventive and reversal paradigms.ConclusionMacrophages in peripheral nerve and microglia in the spinal cord are required in the generation and maintenance of injury-associated neuropathic pain. Blocking macrophage-colony stimulating factor/colony stimulating factor 1 receptor signaling on these myeloid cells along the pain transmission pathway is an effective strategy to alleviate neuropathic pain.

Funding information Daewoong Pharmaceutical CompanyAims: DWP16001 is a novel sodium-glucose cotransporter-2 inhibitor under development for the treatment of type 2 diabetes mellitus. This study was conducted to evaluate the pharmacokinetics, pharmacodynamics and safety of DWP16001 after single and multiple doses in healthy subjects.Methods: A randomized, double-blind, placebo-and active-controlled, single-and multiple-dose study was conducted. Twelve subjects in each dose group received a single dose (0.2, 0.5, 1.0, 2.0 or 5.0 mg) or multiple doses (0.1, 0.3, 0.5, 1.0 or 2.0 mg once daily for 15 consecutive days) of DWP16001, dapagliflozin 10 mg or placebo at a ratio of 8:2:2. Serial blood and interval urine samples were collected for the pharmacokinetic and pharmacodynamic analyses. The safety and tolerability of DWP16001 were also assessed.Results: A dose-dependent increase in the urinary glucose excretion was observed after a single dose, and the steady state urinary glucose excretion was 50-60 g/d after multiple doses in the dose range of 0.3-2.0 mg. DWP16001 was rapidly absorbed with the time to peak plasma concentration of 1.0-3.0 hours, and it exhibited a mean elimination half-life of 13-29 hours. The systemic exposure to DWP16001 increased proportionally with multiple dose administrations in the range of 0.1-2.0 mg. DWP16001 was well tolerated in all dose groups. Conclusion: DWP16001 induced glucosuria in a dose-dependent manner, and systemic exposure was observed after multiple doses. DWP16001 was well tolerated in single oral doses of up to 5.0 mg and in multiple oral doses of up to 2.0 mg.

Background. The innovative pure laparoscopic living donor right hepatectomy (LLDRH) procedure for liver transplantation has never been fully compared to open living donor right hepatectomy (OLDRH). We aimed to compare the donor safety and graft results of pure LLDRH to those of OLDRH. Methods. From May 2013 to July 2017, 288 consecutive donors underwent either OLDRH (n = 197) or pure LLDRH (n = 91). After propensity score matching, 72 donors were included in each group. The primary outcome was postoperative complications during a 90-day follow-up period. Comprehensive complication index, duration of hospital stay, need for additional pain control, readmission, and donor outcomes were also compared. Results. The incidence of major complication during the 90-day follow-up was higher in the LLDRH group than the OLDRH group (6.6% vs 15.4%, P = 0.017) but was not statistically significant in propensity-matched analysis (11.1% vs 13.9%, odds ratio [OR], 1.29; 95% confidence interval [CI], 0.47-3.51; P = 0.62). A right hepatic duct <1 cm was independently associated with complication in the pure LLDRH group (odds ratio, 4.01; 95% confidence interval, 1.08-14.99; P = 0.04). Conclusions. In the initial 91 pure LLDRH cases, incidence of major complication was higher than in the OLDRH group, but the difference was not significant in propensity-matched analysis. A right hepatic duct verified as <1 cm may be related to increased frequency of complications in pure LLDRH donors. Further analysis is needed.

Oro-facial pain following injury and infection is frequently observed in dental clinics. While neuropathic pain evoked by injury associated with nerve lesion has an involvement of glia/immune cells, inflammatory hyperalgesia has an exaggerated sensitization mediated by local and circulating immune mediators. To better understand the contribution of central nervous system (CNS) glial cells in these different pathological conditions, in this study we sought to characterize functional phenotypes of glial cells in response to trigeminal nerve injury (loose ligation of the mental branch), infection (subcutaneous injection of lipopolysaccharide-LPS) and to sterile inflammation (subcutaneous injection of complete Freund's adjuvant-CFA) on the lower lip. Each of the three insults triggered a specific pattern of mechanical allodynia. In parallel with changes in sensory response, CNS glial cells reacted distinctively to the challenges. Following ligation of the mental nerve, both microglia and astrocytes in the trigeminal nuclear complex were highly activated, more prominent in the principal sensory nucleus (Pr5) and subnucleus caudalis (Sp5C) area. Microglial response was initiated early (days 3-14), followed by delayed astrocytes activation (days 7-28). Although the temporal profile of microglial and astrocyte reaction corresponded respectively to the initiation and chronic stage of neuropathic pain, these activated glial cells exhibited a low profile of cytokine expression. Local injection of LPS in the lower lip skin also triggered a microglial reaction in the brain, which started in the circumventricular organs (CVOs) at 5 hours post-injection and diffused progressively into the brain parenchyma at 48 hours. This LPS-induced microglial reaction was accompanied by a robust induction of IκB-α mRNA and pro-inflammatory cytokines within the CVOs. However, LPS induced microglial activation did not specifically occur along the pain signaling pathway. In contrast, CFA injection led to minor microglial morphological changes and an induction of IκB-α mRNA in the CVO regions; a significant increase in IL-1β and IL-6 mRNA started only at 48 hours post-injection, when the induced pain-related behavior started to resolve. Our detailed analysis of CNS glial response clearly revealed that both nerve injury and oro-facial infection/inflammation induced CNS glial activation, but in a completely different pattern, which suggests a remarkable plasticity of glial cells in response to dynamic changes in their microenvironment and different potential involvement of this non-neuronal cell population in pathological pain development.