BACKGROUND:Wound healing is crucial for tissue repair, with inflammatory regulation being a key determinant of recovery. While Allicin exhibits multifunctional therapeutic properties, its mechanistic basis for anti-inflammatory protection during wound healing requires elucidation. METHODS:In vitro, we established an inflammatory model by stimulating HaCaT cells with lipopolysaccharide (LPS). In vivo, experiments employed a standardized full-thickness excisional wound model (1 cm diameter) in mice. Cellular responses were evaluated using CCK-8 assays and scratch tests. Protein expression of inflammatory markers (IL-6, TNF-α), proliferative indicators (PCNA), and PI3K/AKT/NF-κB pathway components (including phosphorylation status) were analyzed through western blotting and immunofluorescence. Pathway specificity was confirmed via PI3K inhibitor (LY294002) pretreatment. Tissue morphology and collagen deposition were assessed using hematoxylin-eosin (H&E) and Masson's trichrome staining. RESULTS:In vitro, Allicin dose-dependently suppressed HaCaT cell within 24 h, regardless of LPS stimulation. In vivo, Allicin treatment significantly enhanced wound closure rates (P < 0.05) and promoted collagen deposition and re-epithelialization. Significantly reduced protein levels of IL-6, TNF-α, PCNA, PI3K, AKT, and NF-κB (including phosphorylation status) were observed in Allicin group versus LPS-treated group or Injury group (P < 0.05) in both Western blotting and immunofluorescence. CONCLUSION:Allicin accelerates wound healing by modulating PI3K/AKT/NF-κB signaling to suppress inflammation and abnormal proliferation.
The limited and backward diagnostic approaches elicit high mortality associated with pulmonary fibrosis (PF) because they fail to identify injury phase of PF. Developing a precisely theranostic nanoplatform presents a promising shortcut to reverse PF. Herein, a specific molecular nanotheranostic (Casp-GNMT), which is triggered by endogenous cysteinyl aspartate specific proteinase-3 (caspase-3), boosts antifibrotic efficacy through bioimaging synergistic with chemotherapy at molecular level, facilitating by ionizable lipid and reactive oxygen species sensitive lipid for precise and manageable therapy. The activation of molecular imaging probe (pCY-pairs) by consumption of endogenous caspase-3 initiates fluorescence resonance energy transfer-guided theranostic pattern, aiming to restore mitochondrial dysfunction-induced oxidative stress and inflammatory responses in alveolar epithelial cells II (AECs II). This process sequentially resists the expression of interleukin-1β and vascular endothelial growth factor receptor through combined with nintedanib, further suppressing abnormal injury of AECs II and persistent migration and proliferation of inflammatory cells. Especially, the homeostasis of injured AECs II diminishes excessive accumulation of transforming growth factor-β to restrain myofibroblasts proliferation and collagen deposition, thereby amplifying the possibility of reversing PF. This theranostic nanoplatform is proposed to provide a prompt and exact approach to enhance diagnostic authenticity and treating efficiency through harnessing endogenous indicator for PF reversal.
Spinal Cord Injury (SCI) is a severe condition that often leads to substantial neurological impairments. This study aimed to explore the role of Aquaporin-4 (AQP4) in regulating astrocyte autophagy and neuroinflammation post-SCI, as well as to evaluate the therapeutic potential of AQP4 inhibition using the specific inhibitor TGN-020. Using Western blot, CCK8 assays, immunofluorescence staining, histopathological assessments, and behavioral analyses, we investigated the effects of TGN-020 on SCI-induced alterations in autophagy, neuroinflammation, astrocyte proliferation, neuronal damage, and motor function recovery in both rat and astrocyte models. Our findings indicate that TGN-020 significantly enhances astrocyte autophagy, reduces neuroinflammation, thereby leading to mitigated astrocyte activation by suppressing AQP4 expression. These beneficial effects are associated with the activation of the peroxisome proliferator-activated receptor-γ/mammalian target of rapamycin (PPAR-γ/mTOR) signaling pathway. Notably, the introduction of the PPAR-γ specific inhibitor GW9662 abrogated the positive regulatory effects of TGN-020 on SCI-induced autophagy and neuroinflammation. Collectively, our in vivo and in vitro experiments demonstrate that TGN-020, by down-regulating AQP4, activates the PPAR-γ/mTOR pathway, ameliorates astrocyte autophagy, diminishes neuroinflammation, and ultimately enhances motor function recovery.
Spinal cord injury (SCI) is a devastating neurological disorder characterized by high morbidity and disability. However, there is still a lack of effective treatments for it. The identification of drugs that promote autophagy and inhibit apoptosis in neurons is critical for improving patient outcomes following SCI. Previous studies have shown that increasing the activity of silent information regulator 1 (SIRT1) and downstream protein AMP-activated protein kinase (AMPK) in rat models of SCI is highly neuroprotective. Oxymatrine (OMT), a quinolizidine alkaloid, has exhibited neuroprotective effects in various central nervous system (CNS) diseases. However, its explicit effect and molecular mechanism in SCI are still unclear. Herein, we aimed to investigate the therapeutic effects of OMT and explore the potential role of autophagy regulation following SCI in rats. A modified compressive device (weight 35 g, time 5 min) was applied to induce moderate SCI in all groups except the sham group. After treatment with drugs or vehicle (saline), our results indicated that OMT treatment significantly reduced the lesion size, promoted survival of motor neurons, and subsequently attenuated motor dysfunction following SCI in rats. OMT significantly enhanced autophagy activity, inhibited apoptosis in neurons, and increased SIRT1 and p-AMPK expression levels. Interestingly, these effects of OMT on SCI were partially prevented by co-treatment with SIRT1 inhibitor EX527. Furthermore, combining OMT with the potent autophagy inhibitor chloroquine (CQ) could effectively abolish its promotion of autophagic flux. Taken together, these data revealed that OMT exerts a neuroprotective role in functional recovery against SCI in rats, and these effects are potentially associated with OMT-induced activation of autophagy via the SIRT1/AMPK signaling pathway.
Spinal cord injury (SCI) is a severe traumatic event, but without any established effective treatment because of the irreversible neuronal death. Here, we investigated the role of miR-222-3p in neuronal apoptosis following SCI. Rat SCI models and neuron hypoxia models were accordingly established. The Bbc3, Bim, Bcl-2, Bax, cleaved-caspase 3, cleaved-caspase 9, Cytochrome c, and miR-222-3p expression levels were examined by Western blotting and real-time reverse transcription polymerase chain reaction (RT-qPCR). The possible association between miR-222-3p and Bbc3/Bim was analyzed by dual-luciferase assay. The neuron viability was assessed by Cell Counting Kit-8 assay and Nissl's staining. Live cell staining was performed to detect the mitochondrial membrane potential and neuronal apoptosis. Rat locomotor function was assessed using the Basso-Beattie-Bresnahan scores. Cytochrome c was outflowed from the mitochondria after SCI or hypoxia treatment, and Bbc3, Bim, Bax, cleaved-caspase 9, and cleaved-caspase 3 were significantly upregulated, while Bcl-2 and miR-222-3p were decreased remarkably. Meanwhile, neuronal cell viability was significantly inhibited. Treatment of miR-222-3p significantly suppressed the Cytochrome c efflux and neuronal apoptosis and improved neuronal cell viability and motor function in SCI rats. Moreover, we found that Bbc3 and Bim were the direct targets of miR-222-3p. Overall, our data suggest that miR-222-3p could alleviate the mitochondrial pathway-mediated apoptosis and motor dysfunction in rats after SCI by targeting Bbc3 and Bim.
AIMS:This work investigates the effects and mechanisms of inhibiting TRPC6 (a non-selective cation channel) downregulation on rat astrocyte activation and proliferation following spinal cord injury (SCI) by suppressing AQP4 expression. We used HYP9 (TRPC6-specific agonist) and TGN-020 (AQP4-specific inhibitor) to explore the relationship between TRPC6 and AQP4 and their probable protective effects on SCI.METHODS:In a rat SCI model, we randomly assigned female Sprague-Dawley rats into the following four groups: Sham, SCI, SCI+HYP9, and SCI+TGN-020. Western blotting and immunofluorescence staining were used to determine protein expression among groups following SCI. TUNEL and immunofluorescence staining were used to identify changes in the rate of apoptosis and the fraction of surviving neurons after SCI. The Basso-Beattie-Bresnahan open-field locomotor scale was used to identify changes in motor function after SCI. In vitro astrocyte scratch model, we first used the CCK8 assay to test the effects of varying doses of HYP9 or TGN-020 on astrocytes and then split the astrocytes into four groups: Con, Scratch, Scratch+HYP9, and Scratch+TGN-020. Western blotting and immunofluorescence were used to identify changes in the expression of target proteins.RESULTS:In vivo and in vitro models, SCI dramatically decreased TRPC6 while considerably upregulating AQP4, glial fibrillary acidic protein (GFAP), and proliferating cell nuclear antigen (PCNA) expression. However, HYP9 or TGN-020 significantly suppressed activation of astrocytes, promoted neurons survival in the anterior horn of the spinal cords, and benefited the recovery of motor function in the hind limbs of rats following SCI. Interestingly, TRPC6 agonists dramatically suppressed AQP4 overexpression, indicating that the probable mechanism of HYP9 benefiting alleviation of SCI may be connected to AQP4 inhibition and astrocyte activation and proliferation reduction.CONCLUSION:we discovered for the first time that HYP9 inhibits astrocyte activation and proliferation by inhibiting AQP4 in SCI rats in vivo and in vitro models and that it preserves neuronal survival and functional recovery after SCI.
The extracellular signal-regulated kinase (ERK) pathway has been reported to play a pivotal role in mediating spinal cord injury (SCI) progression. The present study aimed to investigate the effects of phosphorylated ERK1/2 (p-ERK1/2) inhibition on SCI-induced astrocyte activation and inflammation and its possible mechanism in rats. Here, female Sprague-Dawley rats were randomly assigned to four groups: (1) Sham group, (2) SCI group, (3) TGN-020 group (aquaporin-4, AQP4, blocking agent), (4) PD98059 group (ERK blocking agent). A well SCI model was established by compressing the thoracic vertebra 10 level (weight 35 g, time 5 min) in rats. Western blotting and immunofluorescence staining were used to measure the expression of associated proteins after SCI. HE staining and Nissl staining were performed to detect the morphological changes of spinal cords and the number of surviving neurons following SCI, respectively. The Basso-Beattie-Bresnahan open-field rating scale was used to evaluate functional locomotor recovery following SCI in rats. Our results demonstrated that SCI significantly induced the upregulation of aquaporin-4, p-ERK1/2, glial fibrillary acidic protein, proliferating cell nuclear antigen, and proinflammatory cytokines (tumor necrosis factor-α, interleukin-6 and interleukin-1β). However, treatment with TGN-020 or PD98059 could effectively inhibit astrocyte proliferation and proinflammatory cytokine release, preserve the number of surviving ventral horn neurons, and subsequently improve the locomotor function of rats after SCI. Interestingly, the SCI-induced elevation of AQP4 expression was downregulated by p-ERK1/2 inhibition, suggesting that blocking ERK1/2 phosphorylation could attenuate astrocyte activation and inflammatory processes through negative regulation of AQP4. Therefore, p-ERK1/2 blockade may be employed as a therapeutic target for SCI.
Skin defects, soft tissue damage, and fractures often occur simultaneously in severe trauma. Under current medical technology, fractures can be quickly fixed by internal or external repair techniques, and early functional exercises can be performed. However, skin defects heal over a long time and can even be difficult to heal. Functional exercise may cause cutting of fresh granulation to break and impair wound healing. Functional exercise and wound healing seem to contradict each other. In this study, an alginate hydrogel was developed. With self-healing characteristics, the hydrogel tightly adhered to the wound and could self-heal breaks in the gel caused by functional exercises. These characteristics enable this hydrogel to be used in complex clinical situations to solve sports rehabilitation and skin defect repair problems. In addition, this hydrogel can slowly release strontium ions, promote angiogenesis and collagen deposition in the wound, and quickly heal the wound.
Objective:To detect the effects of metformin(MET)on ER stress and apoptosis after spinal cord injury(SCI)in rats.Methods:Adult female SD rats were randomly divided into three groups:sham group(Sham group),spinal cord injury group(SCI group)and MET intervention group(50g/kg/day).SCI rat model was established at T10 section by Allen's weight drop method.Spinal cord tissues were harvested 7 days after spinal cord injury.Real-time quantitative PCR was used to detect the expressions of GRP78,CHOP,and caspase-12 mRNA.The expression of GRP78,CHOP,caspase-12,and active caspase-3 was detected by Western blotting and immunofluorescence labeling technique.The fluorescent TUNEL staining was used to detect apoptosis.The BBB score was used to detect the recovery of hindlimb motor function in rats.Results:Compared with sham group,the mRNA and protein levels of GRP78,CHOP,and caspase-12 were significantly increased and so were the protein levels of active caspase-3 and the number of apoptosic cells,while the BBB scores were decreased significantly in SCI group.Compared with SCI group,the mRNA and protein levels GRP78,CHOP,and caspase-12,and the protein levels of active caspase-3 were significantly reduced,and the apoptosis had the same trend;however,BBB scores were increased significantly in MET group.Conclusion:Metformin may inhibit the apoptosis,and promote the recovery of hindlimb motor function by inhibiting endoplasmic reticulum stress after spinal cord injury in rats.
AIMS:Identifying drugs that inhibit edema and glial scar formation and increase neuronal survival is crucial to improving outcomes after spinal cord injury (SCI). Here, we used 2-(nicotinamide)-1,3,4-thiadiazole (TGN-020), a potent selective inhibitor of aquaporin 4 (AQP4), to investigate the effects of TGN-020 on SCI in Sprague-Dawley rats.MAIN METHODS:We compressed the spinal cord at T10 using a sterile impounder (35 g, 5 min), to induce moderate injury. TGN-020 (100 mg/kg) or an equal volume of 10% dimethyl sulfoxide was then administered via intraperitoneal injection. Neurological function was evaluated using the Basso-Beattie-Bresnahan open-field locomotor scale 1, 3, 7, 14, 21, and 28 days after SCI. The degree of edema was assessed via determination of the precise spinal cord water content 3 days after SCI. Expression levels of AQP4, glial fibrillary acidic protein (GFAP), proliferating cell nuclear antigen (PCNA), and growth-associated protein-43 (GAP-43) were determined via western blotting and immunofluorescence staining 3 days after SCI and 4 weeks after SCI. Numbers of surviving neurons and glial scar sizes were determined using Nissl and hematoxylin-eosin staining, respectively.KEY FINDINGS:Our results showed that TGN-020 promoted functional recovery at days 3, 7, 14, 21, and 28, as well as reduced the degree of edema and inhibited the expression of AQP4, GFAP, PCNA at days 3 after SCI. Furthermore, observations 4 weeks after SCI revealed that TGN-020 inhibited the glial scar formation and upregulated GAP-43 expression.SIGNIFICANCE:TGN-020 can alleviate spinal cord edema, inhibit glial scar formation, and promote axonal regeneration, conferring beneficial effects on recovery in rats.
Epidural spinal cord stimulation (ESCS) markedly improves motor and sensory function after spinal cord injury (SCI), but the underlying mechanisms are unclear. Here, we investigated whether ESCS affects oligodendrocyte differentiation and its cellular and molecular mechanisms in rats with SCI. ESCS improved hindlimb motor function at 7 days, 14 days, 21 days, and 28 days after SCI. ESCS also significantly increased the myelinated area at 28 days, and reduced the number of apoptotic cells in the spinal white matter at 7 days. SCI decreased the expression of 2′,3′-cyclic-nucleotide 3′-phosphodiesterase (CNPase, an oligodendrocyte marker) at 7 days and that of myelin basic protein at 28 days. ESCS significantly upregulated these markers and increased the percentage of Sox2/CNPase/DAPI-positive cells (newly differentiated oligodendrocytes) at 7 days. Recombinant human bone morphogenetic protein 4 (rhBMP4) markedly downregulated these factors after ESCS. Furthermore, ESCS significantly decreased BMP4 and p-Smad1/5/9 expression after SCI, and rhBMP4 reduced this effect of ESCS. These findings indicate that ESCS enhances the survival and differentiation of oligodendrocytes, protects myelin, and promotes motor functional recovery by inhibiting the BMP4-Smad1/5/9 signaling pathway after SCI.
目的 检测水通道蛋白4(aquaporin 4,AQP4)特异性抑制剂TGN-020对大鼠脊髓损伤(spinal cord injury,SCI)后继发性水肿和星形胶质细胞增生相关指标的影响,为SCI后水肿与星形细胞增生之间的关系研究提供重要依据.方法 成年雌性SD大鼠72只,体质量180~220 g,随机分为假手术组(Sham组)、单纯脊髓损伤组(SCI组)、TGN-020干预组(TGN-020组),每组24只.采用改良后的动脉夹挤压脊髓建立SCI模型,Sham组仅行椎板切除术.术后TGN-020组腹腔内注射TGN-020(5 mg/kg,ip)处理,Sham组和SCI组予以等体积的二甲基亚砜(dimethyl sul-foxide,DMSO)各组于术后3 d收集标本,分别采用干湿重法检测含水量变化,采用蛋白印记、免疫荧光检测AQP4、胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)、增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)蛋白表达.结果 术后3 d,与Sham组相比,SCI组和TGN-020组脊髓损伤区含水量明显升高(P<0.01),与SCI组相比,TGN-020组脊髓损伤区含水量减少(P<0.05);SCI组和TGN-020组AQP4、GFAP、PCNA的表达较Sham组明显升高(P<0.01),TGN-020组AQP4、GFAP、PCNA的表达较SCI组降低(P<0.05).结论 TGN-020可以通过下调大鼠脊髓损伤后AQP4的表达减轻继发性水肿,抑制星形胶质细胞增生,从而促进大鼠急性损伤后的功能恢复.
Evidences have supported the neuroprotective potential of berberine (BBR) in brain ischemia and injury. This study aimed to investigating whether BBR has neuroprotective effects on SCI and its mechanisms. Adult male Sprague-Dawley rats (220-250 g) were randomly divided into Sham, SCI, SCI + BBR (40 mg/kg/day), and SCI + BBR (40 mg/kg/day) + Compound C groups. The BBB score showed BBR improved functional recovery obviously 7 days later after SCI. Spinal cord tissue samples were harvested three days after SCI. Apoptotic neurons were assessed by TUNEL assay, and the expression levels of p-AMPK, AMPK, CHOP, cleaved caspase-12, Bcl-2, Bax, and cleaved caspase-3 were determined via Western blot. Furthermore, the influence of BBR on p-AMPK, caspase-12 and CHOP expression was determined via immunofluorescence. Neuronal cell apoptosis after SCI was significantly attenuated by BBR (P<0.01). Moreover, Western blot demonstrated that the expressions of cleaved caspase-12, CHOP, Bax, and caspase-3, which were linked to endoplasmic reticulum stress (ERS) associated apoptosis pathways, were significantly increased after SCI and were inhibited by BBR (P<0.01). However, the expressions of p-AMPK and Bcl-2 were significantly decreased after SCI and ameliorated by BBR (P<0.01). Immunofluorescence analysis indicated that BBR increased p-AMPK positive neurons number, reduced caspase-12 and CHOP positive neurons number following SCI (P<0.01). However, the protective effect of BBR on ERS-related protein expression was abolished by Compound C (P>0.05). Thus, BBR attenuates neuronal apoptosis and improves functional recovery in rats with SCI, and these neuroprotective effects may be associated with ERS inhibition and AMPK activation.
Spinal cord injury (SCI) is a common and devastating central nervous system insult which lacks efficient treatment. Our previous experimental findings indicated that dynamin-related protein 1 (Drp1) mediates mitochondrial fission during SCI, and inhibition of Drp1 plays a significant protective effect after SCI in rats. Dynasore inhibits GTPase activity at both the plasma membrane (dynamin 1, 2) and the mitochondria membrane (Drp1). The aim of the present study was to investigate the beneficial effects of dynasore on SCI and its underlying mechanism in a rat model. Sprague–Dawley rats were randomly assigned to sham, SCI, and 1, 10, and 30 mg dynasore groups. The rat model of SCI was established using an established Allen’s model. Dynasore was administered via intraperitoneal injection immediately. Results of motor functional test indicated that dynasore ameliorated the motor dysfunction greatly at 3, 7, and 10 days after SCI in rats (P < 0.05). Results of western blot showed that dynasore has remarkably reduced the expressions of Drp1, dynamin 1, and dynamin 2 and, moreover, decreased the Bax, cytochrome C, and active Caspase-3 expressions, but increased the expressions of Bcl-2 at 3 days after SCI (P < 0.05). Notably, the upregulation of proliferating cell nuclear antigen (PCNA) and glial fibrillary acidic protein (GAFP) are inhibited by dynasore at 3 days after SCI (P < 0.05). Results of immunofluorescent double labeling showed that there were less apoptotic neurons and proliferative astrocytes in the dynasore groups compared with SCI group (P < 0.05). Finally, histological assessment via Nissl staining demonstrated that the dynasore groups exhibited a significantly greater number of surviving neurons compared with the SCI group (P < 0.05). This neuroprotective effect was dose-dependent (P < 0.05). To our knowledge, this is the first study to indicate that dynasore significantly enhances motor function which may be by inhibiting the activation of neuronal mitochondrial apoptotic pathway and astrocytic proliferation in rats after SCI.
Changes in mitochondrial morphology and function play an important role in secondary damage after acute spinal cord injury. We recorded the time representation of mitochondrial morphology and function in rats with acute spinal cord injury. Results showed that mitochondria had an irregular shape, and increased in size. Mitochondrial cristae were disordered and mitochondrial membrane rupture was visible at 2-24 hours after injury. Fusion protein mitofusin 1 expression gradually increased, peaked at 8 hours after injury, and then decreased to its lowest level at 24 hours. Expression of dynamin-related protein 1, amitochondrial fission protein, showed the opposite kinetics. At 2-24 hours after acute spinal cord injury, malondialdehyde content, cytochrome c levels and caspase-3 expression were increased, but glutathione content, adenosine triphosphate content, Na+-K+-ATPase activity and mitochondrial membrane potential were gradually reduced. Furthermore, mitochondrial morphology altered during the acute stage of spinal cord injury. Fusion was important within the first 8 hours, but fission played a key role at 24 hours. Oxidative stress was inhibited, biological productivity was diminished, and mitochondrial membrane potential and permeability were reduced in the acute stage of injury. In summary, mitochondrial apoptosis is activated when the time of spinal cord injury is prolonged.
After spinal cord injury (SCI), astrocytes become hypertrophic and proliferative, forming a dense network of astroglial processes at the site of the lesion. This constitutes a physical and biochemical barrier to axonal regeneration. Mitochondrial fission regulates cell cycle progression; inhibiting the cell cycle of astrocytes can reduce expression levels of axon growth-inhibitory molecules as well as astroglial scar formation after SCI. We therefore investigated how an inhibitor of mitochondrial fission, Mdivi-1, would affect astrocyte proliferation, astroglial scar formation, and axonal regeneration following SCI in rats. Western blot and immunofluorescent double-labeling showed that Mdivi-1 markedly reduced the expression of the astrocyte marker glial fibrillary acidic protein (GFAP), and a cell proliferation marker, proliferating cell nuclear antigen, in astrocytes 3 days after SCI. Moreover, Mdivi-1 decreased the expression of GFAP and neurocan, a chondroitin sulfate proteoglycan. Notably, immunofluorescent labeling and Nissl staining showed that Mdivi-1 elevated the production of growth-associated protein-43 and increased neuronal survival at 4 weeks after SCI. Finally, hematoxylin-eosin staining and behavioral evaluation of motor function indicated that Mdivi-1 also reduced cavity formation and improved motor function 4 weeks after SCI. Our results confirm that Mdivi-1 promotes motor function after SCI, and indicate that inhibiting mitochondrial fission using Mdivi-1 can inhibit astrocyte activation and astroglial scar formation and contribute to axonal regeneration after SCI in rats.
Objective To observe the effects of acetyl-l-carnitine (ALC) on autophagy, apoptosis and motor function after acute spinal cord injury (ASCI) in rats. Methods Thirty-six adult female Sprague-Dawley rats were randomly divided into sham operation group (Sham group, n=12), simple spinal cord injury group (SCI group, n=12), ALC treatment group (ALC group, n=12). Spinal cord injury model at the level of T10 segment was established using Allen's method. They were assessed with Basso-Beattle-Bresnahan (BBB) scale three days after injury. Then the rats were sacrificed, and the expression of microtubule associated protein 1 light chain 3 (LC3)-II in spinal cord was detect-ed with Western blotting and immunofluorescent labeling, and the number of apoptotic cells were assessed with TUNEL staining. Results The expression of LC3-II and the number of apoptotic cells increased in SCI group compared with those in Sham group (P<0.01), while the BBB score decreased (P<0.001). The expression of LC3-II increased and the number of apoptotic cells decreased in ALC group compared with those in SCI group (P<0.001), while the BBB score increased (P<0.01). Conclusion ALC may promote autophagy, and inhibit apopto-sis to improve the locomotor function after ASCI.
Autophagy occurs prior to apoptosis and plays an important role in cell death regulation during spinal cord injury (SCI). This study aimed to determine the effects and potential mechanism of the glucagon-like peptide-1 (GLP-1) agonist extendin-4 (Ex-4) in SCI. Seventy-two male Sprague Dawley rats were randomly assigned to sham, SCI, 2.5 μg Ex-4, and 10 μg Ex-4 groups. To induce SCI, a 10-g iron rod was dropped from a 20-mm height to the spinal cord surface. Ex-4 was administered via intraperitoneal injection immediately after surgery. Motor function evaluation with the Basso Beattie Bresnahan (BBB) locomotor rating scale indicated significantly increased scores (p < 0.01) in the Ex-4-treated groups, especially 10 μg, which demonstrated the neuroprotective effect of Ex-4 after SCI. The light chain 3-II (LC3-II) and Beclin 1 protein expression determined via western blot and the number of autophagy-positive neurons via immunofluorescence double labeling were increased by Ex-4, which supports promotion of autophagy (p < 0.01). The caspase-3 protein level and neuronal apoptosis via transferase UTP nick end labeling (TUNEL)/NeuN/DAPI double labeling were significantly reduced in the Ex-4-treated groups, which indicates anti-apoptotic effects (p < 0.01). Finally, histological assessment via Nissl staining demonstrated the Ex-4 groups exhibited a significantly greater number of surviving neurons and less cavity (p < 0.01). To our knowledge, this is the first study to indicate that Ex-4 significantly enhances motor function in rats after SCI, and these effects are associated with the promotion of autophagy and inhibition of apoptosis.
Objective To investigate the effects of hydrogen sulfide on autophagy and the apoptosis after acute spinal cord injury in rats. Methods Thirty-six adult male SD rats (250-300 g) were randomly divided into three groups (n=12 for each group):sham operation group (Sham group), spinal cord injury group (Model group) and hydrogen sulfide pre-treatment group (H2S group). Allen’s method was used to establish the rat model of spinal cord injury. Rats of sham operation group re?ceived only laminectomy. Rats of H2S group received sodium hydrosulphide injection intraperitoneally (50μmol/kg) 1h after spinal cord injury, and Model group was given the same amount of saline solution. Rats in the three groups were sacrificed 24 h after spinal cord injury, then the spinal cord was removed. The expressions of LC3, p70S6K and Cleaved caspase-3 were detected by Western blot assay. The expression of LC3 was also detected by immunofluorescence. The cell apoptosis was as?sessed by TUNEL stain. Results Compared with Sham group, the expression levels of LC3Ⅱ/LC3Ⅰand Cleaved caspase-3 were increased in Model group, but the expression of p70S6K decreased and cell apoptosis increased in Model group (P<0.01). Compared with Model group, the expression levels of LC3Ⅱ/LC3Ⅰand Cleaved caspase-3 were decreased significant?ly, while the expression of p70S6K increased and cell apoptosis decreased significantly in H2S group (P < 0.01). Conclu?sion Hydrogen sulfide can inhibit autophagy and reduce cell apoptosis after acute spinal cord injury in rats.