Ginkgolide B effectively mitigates neuropathic pain by suppressing the activation of the NLRP3 inflammasome through the induction of mitophagy in rats.

Neuropathic pain is a pathological state induced by the aberrant generation of pain signals within the nervous system. Ginkgolide B(GB), an active component found of Ginkgo. biloba leaves, has neuroprotective properties. This study aimed to explore the effects of GB on neuropathic pain and its underlying mechanisms. In the in vivo study, we adopted the rat chronic constriction injury model, and the results showed that GB(4 mg/kg) treatment effectively reduced pain sensation in rats and decreased the expressions of Iba-1 (a microglia marker), NLRP3 inflammasome, and inflammatory factors, such as interleukin (IL)-1ß, in the spinal cord 7 days post-surgery. In the in vitro study, we induced microglial inflammation using lipopolysaccharide (500 ng/mL) / adenosine triphosphate (5 mM) and treated it with GB (10, 20, and 40 µM). GB upregulated the expression of mitophagy proteins, such as PINK1, Parkin, LC3 II/I, Tom20, and Beclin1, and decreased the cellular production of reactive oxygen species. Moreover, it lowered the expression of inflammation-related proteins, such as Caspase-1, IL-1ß, and NLRP3 in microglia. However, this effect was reversed by Parkin shRNA/siRNA or the autophagy inhibitor 3-methyladenine (5 mM). These findings reveal that GB alleviates neuropathic pain by mitigating neuroinflammation through the activation of PINK1-Parkin-mediated mitophagy.

Fibroblast Growth Factor 9 Inhibited Apoptosis in Random Flap via the ERK1/2-Nrf2 Pathway to Improve Tissue Survival.

BACKGROUND: The application of random pattern skin flaps is limited in plastic surgery reconstruction due to necrosis. Fibroblast growth factor 9 (FGF9) was reported to exert a protective effect against myocardial damage and cerebral ischemia injury, but the impact of FGF9 in random flap survival is still unclear. In this study, we used a mouse model of random flaps to verify that FGF9 can directly increase flap survival area and blood flow intensity by promoting angiogenesis. MATERIALS AND METHODS: In total, 84 male C57BL/6 mice weighing between 22 and 25 g were randomly divided into three groups (n = 28 each group). After skin flap operation, one group served as a control, a treatment group received FGF9, and a treatment group received FGF9+U0126. All flap samples were incised on postoperative day 7. RESULTS: Our results showed that flap survival was significantly increased in the FGF9 group compared with that in the control group. This protective function was restrained by U0126. The results of histopathology, laser Doppler, and fluorescent staining all showed significant increases in capillary count, collagen deposition, and angiogenesis. FGF9 also significantly increased the expression of antioxidant stress proteins SOD1, eNOS, HO-1, vascular marker proteins CD31, VE cadherin, and pericyte marker protein PDGFRß. Western blot showed that the phosphorylation degree of ERK1/2 increased after FGF9 treatment, and the expression of Nrf2, a downstream factor, was u-regulated. Western blot and immunofluorescence results of apoptosis-related proteins cleaved caspase-3, BAX, and Bcl2 showed that FGF9 inhibited apoptosis. ERK inhibitor U01926 reduced the beneficial effects of FGF9 on skin flap survival, including promoting angiogenesis, and showing antiapoptosis and antioxidative stress activities. CONCLUSIONS: Exogenous FGF9 stimulates angiogenesis of random flap and survival of tissue. the impact of FGF9 is closely linked to the prevention of oxidative stress mediated by ERK1/2-Nrf2. In the function of FGF9 in promoting effective angiogenesis, there may be a close interaction in the FGF9-FGFR-PDGFR-ERK-VE cadherin pathway. In particular, PDGFR and VE cadherin may interact.

Differences between novel hybrid mode flaps and traditional perforator flaps at the level of metabolites using LC-MS.

The multi-territory perforator flaps are widely used in plastic surgery. However, partial necrosis flap in the potential territory remains a challenge to plastic surgeons. We raised a novel "hybrid nourished mode" (HNM) flap based on the multi-territory deep inferior epigastric perforator (DIEP) flap to improve flap survival. Thirty-two rabbits were randomly divided into DIEP and HNM groups. Untargeted metabolic mechanisms between the DIEP and HNM groups were performed using LC-MS under the filter criteria of fold change >20.0 times or <0.05, and variable importance in projection (VIP) value was set at ≥1, P < 0.05. Between the two groups, flap survival, perfusion, microvasculature, histopathology, and immunohistochemistry of CD31 were assessed on post-operative day 7. We screened 16 different metabolites that mainly participated in biosynthesis of secondary metabolites, aminoacyl transfer RNA biosynthesis, phenylalanine metabolism, arginine and proline metabolism, among others. The results of the HNM flaps were higher than those of the DIEP flaps (P < 0.05) in the aspects of flap survival, flap perfusion, and microvasculature. Compared with the DIEP flaps, HNM has a stronger advantage in tissue metabolism. This study provided us with a better understanding and strong evidence in terms of metabolites on how HNM achieves the survival of large multi-territory perforator flaps.

A new insight on peripheral nerve repair: the technique of internal nerve splinting.

OBJECTIVE: Neuropathic pain produced by symptomatic neuromas is an important problem after peripheral nerve injury (PNI). End-to-end anastomosis of the nerve stump for PNI is well established but cannot efficiently prevent neuroma-in-continuity formation. METHODS: Sciatic nerve injury was used in the experimental model. Seventy-two rats were randomly divided into four groups: rats with nerve anastomosis sites supported with silicone tubes represented the internal nerve splinting (INS) group (n = 18); rats with end-to-end nerve anastomosis represented control group 1 (CON1) (n = 18); rats with INS and the nerve anastomosis site represented control group 2 (CON2) (n = 18); and rats that underwent the same surgical procedures for skin and muscle operations but without sciatic nerve injury represented the normal group (n = 18). RESULTS: Gross evaluations of the nerve anastomosis sites, gastrocnemius muscle atrophy, axonal regeneration and remyelination, neuropathic pain, and scar hyperplasia of the neuromas were performed, as well as motor function evaluations. Axonal regeneration, remyelination, and gastrocnemius muscle atrophy were similar between the INS group and CON1 (p > 0.05). However, neuropathic pain and scar hyperplasia-as evaluated according to the expression of anti-sigma-1 receptor antibody and anti-α-smooth muscle actin, respectively-and the weight ratios of the neuromas were reduced in the INS group compared with those of CON1 and CON2 (p < 0.05). CONCLUSIONS: Application of INS in nerve repair effectively prevented traumatic neuroma-in-continuity formation and inhibited neuropathic pain without influencing nerve regeneration in rats.