Apoptotic Bodies Derived from Fibroblast-Like Cells in Subcutaneous Connective Tissue Inhibit Ferroptosis in Ischaemic Flaps via the miR-339-5p/KEAP1/Nrf2 Axis.

Preventing and treating avascular necrosis at the distal end of the flaps are critical to surgery success, but current treatments are not ideal. A recent study shows that apoptotic bodies (ABs) generated near the site of apoptosis can be taken up and promote cell proliferation. The study reveals that ABs derived from fibroblast-like cells in the subcutaneous connective tissue (FSCT cells) of skin flaps promoted ischaemic flap survival. It is also found that ABs inhibited cell death and oxidative stress and promoted M1-to-M2 polarization in macrophages. Transcriptome sequencing and protein level testing demonstrated that ABs promoted ischaemic flap survival in endothelial cells and macrophages by inhibiting ferroptosis via the KEAP1-Nrf2 axis. Furthermore, microRNA (miR) sequencing data and in vitro and in vivo experiments demonstrated that ABs inhibited KEAP1 by delivering miR-339-5p to exert therapeutic effects. In conclusion, FSCT cell-derived ABs inhibited ferroptosis, promoted the macrophage M1-to-M2 transition via the miR-339-5p/KEAP1/Nrf2 axis and promoted ischaemic flap survival. These results provide a potential therapeutic strategy to promote ischaemic flap survival by administering ABs.

Comparison of the clinical and radiographic outcomes of cortical bone trajectory and traditional trajectory pedicle screw fixation in transforaminal lumbar interbody fusion: a randomized controlled trial.

PURPOSE: To compare the clinical outcomes and radiographic outcomes of cortical bone trajectory (CBT) and traditional trajectory (TT) pedicle screw fixation in patients treated with single-level transforaminal lumbar interbody fusion (TLIF). METHODS: This trial included a total of 224 patients with lumbar spine disease who required single-level TLIF surgery. Patients were randomly assigned to the CBT and TT groups at a 1:1 ratio. Demographics and clinical and radiographic data were collected to evaluate the efficacy and safety of CBT and TT screw fixation in TLIF. RESULTS: The baseline characteristic data were similar between the CBT and TT groups. Back and leg pain for both the CBT and TT groups improved significantly from baseline to 24 months postoperatively. The CBT group experienced less pain than the TT group at one week postoperatively. The postoperative radiographic results showed that the accuracy of screw placement was significantly increased in the CBT group compared with the TT group (P < 0.05). The CBT group had a significantly lower rate of FJV than the TT group (P < 0.05). In addition, the rate of fusion and the rate of screw loosening were similar between the CBT and TT groups according to screw loosening criteria. CONCLUSION: This prospective, randomized controlled analysis suggests that clinical outcomes and radiographic characteristics, including fusion rates and caudal screw loosening rates, were comparable between CBT and TT screw fixation. Compared with the TT group, the CBT group showed advantages in the accuracy of screw placement and the FJV rate. CLINICAL TRIALS REGISTRATION: This trial has been registered at the US National Institutes of Health Clinical Trials Registry: NCT03105167.

FGF-18 Protects the Injured Spinal cord in mice by Suppressing Pyroptosis and Promoting Autophagy via the AKT-mTOR-TRPML1 axis.

Spinal cord injury (SCI) is a severe medical condition with lasting effects. The efficacy of numerous clinical treatments is hampered by the intricate pathophysiological mechanism of SCI. Fibroblast growth factor 18 (FGF-18) has been found to exert neuroprotective effects after brain ischaemia, but its effect after SCI has not been well explored. The aim of the present study was to explore the therapeutic effect of FGF-18 on SCI and the related mechanism. In the present study, a mouse model of SCI was used, and the results showed that FGF-18 may significantly affect functional recovery. The present findings demonstrated that FGF-18 directly promoted functional recovery by increasing autophagy and decreasing pyroptosis. In addition, FGF-18 increased autophagy, and the well-known autophagy inhibitor 3-methyladenine (3MA) reversed the therapeutic benefits of FGF-18 after SCI, suggesting that autophagy mediates the therapeutic effects of FGF-18 on SCI. A mechanistic study revealed that after stimulation of the protein kinase B (AKT)-transient receptor potential mucolipin 1 (TRPML1)-calcineurin signalling pathway, the FGF-18-induced increase in autophagy was mediated by the dephosphorylation and nuclear translocation of transcription factor E3 (TFE3). Together, these findings indicated that FGF-18 is a robust autophagy modulator capable of accelerating functional recovery after SCI, suggesting that it may be a promising treatment for SCI in the clinic.

A snake cathelicidin enhances transcription factor EB-mediated autophagy and alleviates ROS-induced pyroptosis after ischaemia-reperfusion injury of island skin flaps.

BACKGROUND AND PURPOSE: Ischaemia-reperfusion (I/R) injury is a major contributor to skin flap necrosis, which presents a challenge in achieving satisfactory therapeutic outcomes. Previous studies showed that cathelicidin-BF (BF-30) protects tissues from I/R injury. In this investigation, BF-30 was synthesized and its role and mechanism in promoting survival of I/R-injured skin flaps explored. EXPERIMENTAL APPROACH: Survival rate analysis and laser Doppler blood flow analysis were used to evaluate I/R-injured flap viability. Western blotting, immunofluorescence, TdT-mediated dUTP nick end labelling (TUNEL) and dihydroethidium were utilized to examine the levels of apoptosis, pyroptosis, oxidative stress, transcription factor EB (TFEB)-mediated autophagy and molecules related to the adenosine 5'-monophosphate-activated protein kinase (AMPK)-transient receptor potential mucolipin 1 (TRPML1)-calcineurin signalling pathway. KEY RESULTS: The outcomes revealed that BF-30 enhanced I/R-injured island skin flap viability. Autophagy, oxidative stress, pyroptosis and apoptosis were related to the BF-30 capability to enhance I/R-injured flap survival. Improved autophagy flux and tolerance to oxidative stress promoted the inhibition of apoptosis and pyroptosis in vascular endothelial cells. Activation of TFEB increased autophagy and inhibited endothelial cell oxidative stress in I/R-injured flaps. A reduction in TFEB level led to a loss of the protective effect of BF-30, by reducing autophagy flux and increasing the accumulation of reactive oxygen species (ROS) in endothelial cells. Additionally, BF-30 modulated TFEB activity via the AMPK-TRPML1-calcineurin signalling pathway. CONCLUSION AND IMPLICATIONS: BF-30 promotes I/R-injured skin flap survival by TFEB-mediated up-regulation of autophagy and inhibition of oxidative stress, which may have possible clinical applications.

Bexarotene improves motor function after spinal cord injury in mice.

Spinal cord injury is a challenge in orthopedics because it causes irreversible damage to the central nervous system. Therefore, early treatment to prevent lesion expansion is crucial for the management of patients with spinal cord injury. Bexarotene, a type of retinoid, exerts therapeutic effects on patients with cutaneous T-cell lymphoma and Parkinson's disease. Bexarotene has been proven to promote autophagy, but it has not been used in the treatment of spinal cord injury. To investigate the effects of bexarotene on spinal cord injury, we established a mouse model of T11-T12 spinal cord contusion and performed daily intraperitoneal injection of bexarotene for 5 consecutive days. We found that bexarotene effectively reduced the deposition of collagen and the number of pathological neurons in the injured spinal cord, increased the number of synapses of nerve cells, reduced oxidative stress, inhibited pyroptosis, promoted the recovery of motor function, and reduced death. Inhibition of autophagy with 3-methyladenine reversed the effects of bexarotene on spinal cord injury. Bexarotene enhanced the nuclear translocation of transcription factor E3, which further activated AMP-activated protein kinase-S-phase kinase-associated protein 2-coactivator-associated arginine methyltransferase 1 and AMP-activated protein kinase-mammalian target of rapamycin signaling pathways. Intravenous injection of transcription factor E3 shRNA or intraperitoneal injection of compound C, an AMP-activated protein kinase blocker, inhibited the effects of bexarotene. These findings suggest that bexarotene regulates nuclear translocation of transcription factor E3 through the AMP-activated protein kinase-S-phase kinase-associated protein 2-coactivator-associated arginine methyltransferase 1 and AMP-activated protein kinase-mammalian target of rapamycin signal pathways, promotes autophagy, decreases reactive oxygen species level, inhibits pyroptosis, and improves motor function after spinal cord injury.

Inhibition of PLA2G4E/cPLA2 promotes survival of random skin flaps by alleviating Lysosomal membrane permeabilization-Induced necroptosis.

Necrosis that appears at the ischemic distal end of random-pattern skin flaps increases the pain and economic burden of patients. Necroptosis is thought to contribute to flap necrosis. Lysosomal membrane permeabilization (LMP) plays an indispensable role in the regulation of necroptosis. Nonetheless, the mechanisms by which lysosomal membranes become leaky and the relationship between necroptosis and lysosomes are still unclear in ischemic flaps. Based on Western blotting, immunofluorescence, enzyme-linked immunosorbent assay, and liquid chromatography-mass spectrometry (LC-MS) analysis results, we found that LMP was presented in the ischemic distal portion of random-pattern skin flaps, which leads to disruption of lysosomal function and macroautophagic/autophagic flux, increased necroptosis, and aggravated necrosis of the ischemic flaps. Moreover, bioinformatics analysis of the LC-MS results enabled us to focus on the role of PLA2G4E/cPLA2 (phospholipase A2, group IVE) in LMP of the ischemic flaps. In vivo inhibition of PLA2G4E with an adeno-associated virus vector attenuated LMP and necroptosis, and promoted flap survival. In addition, microRNA-seq helped us determine that Mir504-5p was differentially expressed in ischemic flaps. A string of in vitro and in vivo tests was employed to verify the inhibitory effect of Mir504-5p on PLA2G4E, LMP and necroptosis. Finally, we concluded that the inhibition of PLA2G4E by Mir504-5p reduced LMP-induced necroptosis, thereby promoting the survival of random-pattern skin flaps.Abbreviations: AAV: adeno-associated virus; ACTA2/α;-SMA: actin alpha 2, smooth muscle, aorta; ALOX15/12/15-LOX: arachidonate 15- lipoxygenase; c-CASP8: cleaved caspase; c-CASP3: cleaved caspase 3; CTSD: cathepsin D; CTSB: cathepsin B; CTSL: cathepsin L; DMECs: primary mouse dermal microvascular endothelial cells; ELISA: enzyme-linked immunosorbent assay; F-CHP: 5-FAM-conjugated collagen hybridizing peptide; FISH: fluorescence in situ hybridization; HUVECs: human umbilical vein endothelial cells; LAMP1: lysosomal-associated membrane protein 1; LAMP2: lysosomal-associated membrane protein 2; LC-MS: liquid chromatography-mass spectrometry; LDBF: laser doppler blood flow; LMP: lysosomal membrane permeabilization; LPE: lysophosphatidylethanolamine; LPC: lysophosphatidylcholine; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MLKL: mixed lineage kinase domain-like; NDI: N-dodecylimidazole; PECAM1/CD31: platelet/endothelial cell adhesion molecule 1; PLA2G4A/cPLA2: phospholipase A2, group IVA (cytosolic, calcium-dependent); PLA2G4E/cPLA2: phospholipase A2, group IVE; qPCR: quantitative real-time polymerase chain reaction; RIPK1: receptor (TNFRSF)-interacting serine-threonine kinase 1; RIPK3: receptor-interacting serine-threonine kinase 3; RISC: RNA-induced silencing complex; ROS: reactive oxygen species; shRNA: short hairpin RNA; SQSTM1: sequestosome 1; TBHP: tert-butyl hydroperoxide; TUNEL: terminal deoxynucleotidyl transferase dUTP nick end labelling.

Trehalose Augments Neuron Survival and Improves Recovery from Spinal Cord Injury via mTOR-Independent Activation of Autophagy.

Spinal cord injury (SCI) is a major cause of irreversible nerve injury and leads to serious tissue loss and neurological dysfunction. Thorough investigation of cellular mechanisms, such as autophagy, is crucial for developing novel and effective therapeutics. We administered trehalose, an mTOR-independent autophagy agonist, in SCI rats suffering from moderate compression injury to elucidate the relationship between autophagy and SCI and evaluate trehalose's therapeutic potential. 60 rats were divided into 4 groups and were treated with either control vehicle, trehalose, chloroquine, or trehalose + chloroquine 2 weeks prior to administration of moderate spinal cord crush injury. 20 additional sham rats were treated with control vehicle. H&E staining, Nissl staining, western blot, and immunofluorescence studies were conducted to examine nerve morphology and quantify autophagy and mitochondrial-dependent apoptosis at various time points after surgery. Functional recovery was assessed over a period of 4 weeks after surgery. Trehalose promotes autophagosome recruitment via an mTOR-independent pathway, enhances autophagy flux in neurons, inhibits apoptosis via the intrinsic mitochondria-dependent pathway, reduces lesion cavity expansion, decreases neuron loss, and ultimately improves functional recovery following SCI (all p < 0.05). Furthermore, these effects were diminished upon administration of chloroquine, an autophagy flux inhibitor, indicating that trehalose's beneficial effects were due largely to activation of autophagy. This study presents new evidence that autophagy plays a critical neuroprotective and neuroregenerative role in SCI, and that mTOR-independent activation of autophagy with trehalose leads to improved outcomes. Thus, trehalose has great translational potential as a novel therapeutic agent after SCI.

Liraglutide, a TFEB-Mediated Autophagy Agonist, Promotes the Viability of Random-Pattern Skin Flaps.

Random skin flaps are commonly used in reconstruction surgery. However, distal necrosis of the skin flap remains a difficult problem in plastic surgery. Many studies have shown that activation of autophagy is an important means of maintaining cell homeostasis and can improve the survival rate of flaps. In the current study, we investigated whether liraglutide can promote the survival of random flaps by stimulating autophagy. Our results show that liraglutide can significantly improve flap viability, increase blood flow, and reduce tissue oedema. In addition, we demonstrated that liraglutide can stimulate angiogenesis and reduce pyroptosis and oxidative stress. Through immunohistochemistry analysis and Western blotting, we verified that liraglutide can enhance autophagy, while the 3-methylladenine- (3MA-) mediated inhibition of autophagy enhancement can significantly reduce the benefits of liraglutide described above. Mechanistically, we showed that the ability of liraglutide to enhance autophagy is mediated by the activation of transcription factor EB (TFEB) and its subsequent entry into the nucleus to activate autophagy genes, a phenomenon that may result from AMPK-MCOLN1-calcineurin signalling pathway activation. Taken together, our results show that liraglutide is an effective drug that can significantly improve the survival rate of random flaps by enhancing autophagy, inhibiting oxidative stress in tissues, reducing pyroptosis, and promoting angiogenesis, which may be due to the activation of TFEB via the AMPK-MCOLN1-calcineurin signalling pathway.

Exenatide improves random-pattern skin flap survival via TFE3 mediated autophagy augment.

Random-pattern skin flaps are widely applied to rebuild and restore soft-tissue damage in reconstructive surgery; however, ischemia and subsequent ischemia-reperfusion injury lead to flap necrosis and are major complications. Exenatide, a glucagon-like peptide-1 analog, exerts therapeutic benefits for diabetic wounds, cardiac injury, and nonalcoholic fatty liver disease. Furthermore, Exenatide is a known activator of autophagy, which is a complex process of subcellular degradation that may enhance the viability of random skin flaps. In this study, we explored whether exenatide can improve skin flap survival. Our results showed that exenatide augments autophagy, increases flap viability, enhances angiogenesis, reduces oxidative stress, and alleviates pyroptosis. Coadministration of exenatide with 3-methyladenine and chloroquine, potent inhibitors of autophagy, reversed the beneficial effects, suggesting that the therapeutic benefits of exenatide for skin flaps are due largely to autophagy activation. Mechanistically, we identified that exenatide enhanced activation and nuclear translocation of TFE3, which leads to autophagy activation. Furthermore, we found that exenatide activates the AMPK-SKP2-CARM1 and AMPK-mTOR signaling pathways, which likely lead to exenatide's effects on activating TFE3. Overall, our findings suggest that exenatide may be a potent therapy to prevent flap necrosis, and we also reveal novel mechanistic insight into exenatide's effect on flap survival.

Role of pyroptosis in spinal cord injury and its therapeutic implications.

BACKGROUND: Currently, spinal cord injury (SCI) is a pathological incident that triggers several neuropathological conditions, leading to the initiation of neuronal damage with several pro-inflammatory mediators' release. However, pyroptosis is recognized as a new programmed cell death mechanism regulated by the stimulation of caspase-1 and/or caspase-11/-4/-5 signaling pathways with a series of inflammatory responses. AIM: Our current review concisely summarizes the potential role of pyroptosis-regulated programmed cell death in SCI, according to several molecular and pathophysiological mechanisms. This review also highlights the targeting of pyroptosis signaling pathways and inflammasome components and its therapeutic implications for the treatment of SCI. KEY SCIENTIFIC CONCEPTS: Multiple pieces of evidence have illustrated that pyroptosis plays significant roles in cell swelling, plasma membrane lysis, chromatin fragmentation and intracellular pro-inflammatory factors including IL-18 and IL-1ß release. In addition, pyroptosis is directly mediated by the recently discovered family of pore-forming protein known as GSDMD. Current investigations have documented that pyroptosis-regulated cell death plays a critical role in the pathogenesis of multiple neurological disorders as well as SCI. Our narrative article suggests that inhibiting the pyroptosis-regulated cell death and inflammasome components could be a promising therapeutic approach for the treatment of SCI in the near future.

TFE3, a potential therapeutic target for Spinal Cord Injury via augmenting autophagy flux and alleviating ER stress.

Background and Aim: Increasing evidence suggests that spinal cord injury (SCI)-induced defects in autophagic flux may contribute to an impaired ability for neurological repair following injury. Transcription factor E3 (TFE3) plays a crucial role in oxidative metabolism, lysosomal homeostasis, and autophagy induction. Here, we investigated the role of TFE3 in modulating autophagy following SCI and explored its impact on neurological recovery. Methods: Histological analysis via HE, Nissl and Mason staining, survival rate analysis, and behavioral testing via BMS and footprint analysis were used to determine functional recovery after SCI. Quantitative real-time polymerase chain reaction, Western blotting, immunofluorescence, TUNEL staining, enzyme-linked immunosorbent assays, and immunoprecipitation were applied to examine levels of autophagy flux, ER-stress-induced apoptosis, oxidative stress, and AMPK related signaling pathways. In vitro studies using PC12 cells were performed to discern the relationship between ROS accumulation and autophagy flux blockade. Results: Our results showed that in SCI, defects in autophagy flux contributes to ER stress, leading to neuronal death. Furthermore, SCI enhances the production of reactive oxygen species (ROS) that induce lysosomal dysfunction to impair autophagy flux. We also showed that TFE3 levels are inversely correlated with ROS levels, and increased TFE3 levels can lead to improved outcomes. Finally, we showed that activation of TFE3 after SCI is partly regulated by AMPK-mTOR and AMPK-SKP2-CARM1 signaling pathways. Conclusions: TFE3 is an important regulator in ROS-mediated autophagy dysfunction following SCI, and TFE3 may serve as a promising target for developing treatments for SCI.

α-Bisabolol suppresses the inflammatory response and ECM catabolism in advanced glycation end products-treated chondrocytes and attenuates murine osteoarthritis.

As a chronic musculoskeletal degeneration disease, osteoarthritis (OA) clinically manifests as joint pain, stiffness and a limited range of movement. OA has affected the life quality of at least one-tenth of the population but lacks satisfactory treatments. α-Bisabolol (BISA) is a small oily sesquiterpene alcohol widely found in essential oils of chamomile (Matricaria recutita), salvia and wood of Candeia and has multiple biological properties, particularly an anti-inflammatory effect. The purpose of this study is to assess the anti-inflammatory and chondroprotective effect of BISA in OA progression and explore its underlying mechanism. We isolated human chondrocytes and treated them with advanced glycation end products (AGEs) to imitate OA progression in vitro. BISA pretreatment suppressed the AGE-induced inflammatory reaction and extracellular matrix (ECM) degeneration by blocking nuclear factor kappa B (NF-κB), p38 and c-Jun N-terminal kinase (JNK) signaling. Moreover, a mouse destabilization of the medial meniscus (DMM) model was established by surgery to investigate BISA protection in vivo. BISA administration attenuated DMM-induced radiological and histopathological changes relative to the DMM group and resulted in lower OARSI scores. Taken together, the results of our study indicate the potential of BISA in OA therapy.

Metformin Promotes Axon Regeneration after Spinal Cord Injury through Inhibiting Oxidative Stress and Stabilizing Microtubule.

Spinal cord injury (SCI) is a devastating disease that may lead to lifelong disability. Thus, seeking for valid drugs that are beneficial to promoting axonal regrowth and elongation after SCI has gained wide attention. Metformin, a glucose-lowering agent, has been demonstrated to play roles in various central nervous system (CNS) disorders. However, the potential protective effect of metformin on nerve regeneration after SCI is still unclear. In this study, we found that the administration of metformin improved functional recovery after SCI through reducing neuronal cell apoptosis and repairing neurites by stabilizing microtubules via PI3K/Akt signaling pathway. Inhibiting the PI3K/Akt pathway with LY294002 partly reversed the therapeutic effects of metformin on SCI in vitro and vivo. Furthermore, metformin treatment weakened the excessive activation of oxidative stress and improved the mitochondrial function by activating the nuclear factor erythroid-related factor 2 (Nrf2) transcription and binding to the antioxidant response element (ARE). Moreover, treatment with Nrf2 inhibitor ML385 partially abolished its antioxidant effect. We also found that the Nrf2 transcription was partially reduced by LY294002 in vitro. Taken together, these results revealed that the role of metformin in nerve regeneration after SCI was probably related to stabilization of microtubules and inhibition of the excessive activation of Akt-mediated Nrf2/ARE pathway-regulated oxidative stress and mitochondrial dysfunction. Overall, our present study suggests that metformin administration may provide a potential therapy for SCI.

Minimally invasive surgery for degenerative spondylolisthesis: transforaminal or oblique lumbar interbody fusion.

Aim: To compare the outcomes of minimally invasive surgery (MIS) for degenerative spondylolisthesis transforaminal lumbar interbody fusion (TLIF) and oblique lumbar interbody fusion (OLIF). Materials & methods: The clinical and surgical characteristics and outcomes of 38 patients with MIS-OLIF and 55 with MIS-TLIF were retrospectively evaluated. Results: Procedures and hospital stay were shorter and blood loss was less, with MIS-OLIF than with MIS-OLIF. The clinical and radiographic outcomes were similar. Postoperative changes in disk height and foraminal dimension were greater and patient satisfaction was better with MIS-OLIF than with MIS-TLIF. Conclusion: The clinical findings associated with the two procedures were similar; but patients preferred MIS-OLIF, which is less invasive, to MIS-TLIF. Clinical trial registration number: ChiCTR1800019443.

Betulinic Acid Enhances the Viability of Random-Pattern Skin Flaps by Activating Autophagy.

Random-pattern skin flap replantation is commonly used to repair skin defects during plastic and reconstructive surgery. However, flap necrosis due to ischemia and ischemia-reperfusion injury limits clinical applications. Betulinic acid, a plant-derived pentacyclic triterpene, may facilitate flap survival. In the present study, the effects of betulinic acid on flap survival and the underlying mechanisms were assessed. Fifty-four mice with a dorsal random flap model were randomly divided into the control, betulinic acid group, and the betulinic acid + 3-methyladenine group. These groups were treated with dimethyl sulfoxide, betulinic acid, and betulinic acid plus 3-methyladenine, respectively. Flap tissues were acquired on postoperative day 7 to assess angiogenesis, apoptosis, oxidative stress, and autophagy. Betulinic acid promoted survival of the skin flap area, reduced tissue edema, and enhanced the number of microvessels. It also enhanced angiogenesis, attenuated apoptosis, alleviated oxidative stress, and activated autophagy. However, its effects on flap viability and angiogenesis, apoptosis, and oxidative stress were reversed by the autophagy inhibitor 3-methyladenine. Our findings reveal that betulinic acid improves survival of random-pattern skin flaps by promoting angiogenesis, dampening apoptosis, and alleviating oxidative stress, which mediates activation of autophagy.

Endothelial cell pyroptosis plays an important role in Kawasaki disease via HMGB1/RAGE/cathespin B signaling pathway and NLRP3 inflammasome activation.

Kawasaki disease (KD) is the most common cause of pediatric cardiac disease in developed countries, and can lead to permanent coronary artery damage and long term sequelae such as coronary artery aneurysms. Given the prevalence and severity of KD, further research is warranted on its pathophysiology. It is known that endothelial cell damage and inflammation are two essential processes resulting in the coronary endothelial dysfunction in KD. However, detailed mechanisms are largely unknown. In this study, we investigated the role of pyroptosis in the setting of KD, and hypothesized that pyroptosis may play a central role in its pathophysiology. In vivo experiments of patients with KD demonstrated that serum levels of pyroptosis-related proteins, including ASC, caspase-1, IL-1ß, IL-18, GSDMD and lactic dehydrogenase (LDH), were significantly increased in KD compared with healthy controls (HCs). Moreover, western blot analysis showed that the expression of GSDMD and mature IL-1ß was notably elevated in KD sera. In vitro, exposure of human umbilical vein endothelial cells (HUVECs) to KD sera-treated THP1 cells resulted in the activation of NLRP3 inflammasome and subsequent pyroptosis induction, as evidenced by elevated expression of caspase-1, GSDMD, cleaved p30 form of GSDMD, IL-1ß and IL-18, and increased LDH release and TUNEL and propidium iodide (PI)-positive cells. Furthermore, our results showed that NLRP3-dependent endothelial cell pyroptosis was activated by HMGB1/RAGE/cathepsin B signaling. These findings were also recapitulated in a mouse model of KD induced by Candida albicans cell wall extracts (CAWS). Together, our findings suggest that endothelial cell pyroptosis may play a significant role in coronary endothelial damage in KD, providing novel evidence that further elucidates its pathophysiology.

Trehalose promotes the survival of random-pattern skin flaps by TFEB mediated autophagy enhancement.

Random-pattern skin flaps are commonly used and valuable tools in reconstructive surgery, however, post-operative random skin flap necrosis remains a major and common complication. Previous studies have suggested that activating autophagy, a major pathway for degradation of intracellular waste, may improve flap survival. In this study, we investigated whether trehalose, a novel and potent autophagy activator, improves random skin flap viability. Our results demonstrated that trehalose significantly improves viability, augments blood flow, and decreases tissue edema. Furthermore, we found that trehalose leads to increased angiogenesis, decreased apoptosis, and reduced oxidative stress. Using immunohistochestry and western blot, we demonstrated that trehalose augments autophagy, and that inhibition of autophagy augmentation using 3MA significantly blunted the aforementioned benefits of trehalose therapy. Mechanistically, we showed that trehalose's autophagy augmentation is mediated by activation and nuclear translocation of TFEB, which may be due to inhibition of Akt and activation of the AMPK-SKP2-CARM1 signaling pathway. Altogether, our results established that trehalose is a potent agent capable for significantly increasing random-pattern skin flap survival by augmenting autophagy and subsequently promoting angiogenesis, reducing oxidative stress, and inhibiting cell death.

Stabilization of Hypoxia Inducible Factor-1α by Dimethyloxalylglycine Promotes Recovery from Acute Spinal Cord Injury by Inhibiting Neural Apoptosis and Enhancing Axon Regeneration.

Spinal cord injury (SCI) is a devastating neurological disorder that usually leads to a loss of motor and sensory function in patients. The expression of hypoxia inducible factor-1α (HIF-1α) is increased, and exerts a protective role after traumatic SCI. However, the endogenous activity of HIF-1α is insufficient for promoting functional recovery. The present study tested the potential effect of the sustained activation of HIF-1α by the prolylhydroxylase (PHD) inhibitor dimethyloxalylglycine (DMOG) on anti-apoptotic process and the regulation of axonal regeneration after SCI. Here, we found that treatment with DMOG significantly increased the expression of HIF-1α and that the stabilization of HIF-1α induced by DMOG not only decreased the expression of apoptotic proteins to promote neural survival, but also enhanced axonal regeneration by regulating microtubule stabilization in vivo and in vitro. In addition, we found that DMOG promoted neural survival and axonal regeneration by activating autophagy, which is induced by the HIF-1α/BNIP3 signaling pathway, and that the inhibition of HIF-1α or autophagy abrogated the protective effect of DMOG, as expected. Taken together, our results demonstrate that treatment with DMOG improves functional recovery after SCI and that DMOG may serve as a potential candidate for treating SCI.

Therapeutic potential of pravastatin for random skin flaps necrosis: involvement of promoting angiogenesis and inhibiting apoptosis and oxidative stress.

Background: Random skin flap is frequently used in plastic and reconstructive surgery, but its distal part often occurs ischemia and necrosis. Pravastatin (Prava) with bioactivities of pro-angiogenesis, anti-apoptosis and anti-oxidative stress, may be beneficial for flap survival. Materials and methods: A modified McFarlane flap model was performed in Sprague-Dawley rats. The animals were divided into the Control and Prava groups and treated as follows: the Prava group was injected intraperitoneally with 2 mg/kg Prava for consecutive 7 days, and the Control group received an equal volume of vehicle daily. On day 7, the necrosis skin flaps were observed, while visualization of blood flow below the tissue surface was performed by Laser Doppler blood flow imaging (LDBFI). Then animals were euthanized, and levels of angiogenesis, apoptosis and oxidative stress were analyzed. Results: Prava decreased necrosis and edema of skin flaps compared with the Control group, with more blood flow in the flap under LDBFI. Prava treatment increased the mean vessels density, elevated the expression levels of angiogenic proteins (matrix metallopeptidase 9, vascular endothelial growth factor, Cadherin5) and antioxidant proteins (superoxide dismutase 1 (SOD1), endothelial nitric oxide synthase, heme oxygenase), and decreased the expression of apoptotic factors (BAX, CYC, Caspase3). In addition, malondialdehyde content was reduced, and glutathione level and SOD activity were increased in the skin flaps after treatment with Prava. Conclusion: Prava promotes survival of random skin flap through induction of angiogenesis, and inhibition of apoptosis and oxidative stress.

Protective effects of resveratrol on random-pattern skin flap survival: an experimental study.

Random-pattern skin flap transplantation is a common procedure in plastic surgery, but its distal area usually incurs ischemia and necrosis. Resveratrol (Rev), a natural polyphenol primarily found in peanuts, grapes, and red wine, which exerts multi-bioactivity. In this study, forty-eight rats with the modified "McFarlane flap" model were divided into Control and Rev groups, which were treated with vehicle Control and Rev, respectively. After 7 days of continuous treatment and observation, ischemic flap tissues were harvested to evaluate angiogenesis, apoptosis, oxidative stress, and autophagy. It was observed a greater survival area of flaps, accompanied with reduced water content and stronger blood supply, in the Rev group than in the Control group. In addition, Rev upregulated the expression of MMP9, VEGF, and Cadherin5, indicating that Rev promotes angiogenesis in ischemic flaps. Moreover, Rev decreased the levels of Bax, CYC, and Caspase3, suggesting that it inhibits apoptosis. Besides, Rev increased the expression of SOD1, eNOS, HO1, the activities of SOD and GSH, and reduced the levels of MDA, which uncovers that it depresses oxidative stress in ischemic flaps. Finally, it increased the expression of Beclin1, LC3II, VPS34, and CTSD, and decreased SQSTM1/p62 levels, which reveals that it activates autophagy in the flaps. These results suggest that Rev promotes random skin flap survival through proangiogenic, antiapoptotic, and antioxidative effects; moreover, autophagy is activated in the process, which might be another underlying mechanism for the flap survival.