Low-dose lipopolysaccharide protects nerve cells against spinal cord injury via regulating the PI3K-AKT-Nrf2 signaling pathway.

This study explored the molecular mechanism behind the protective effects from low-dose lipopolysaccharide (LPS) on an in-vitro model of spinal cord injury (SCI). For this, PC12 cells were treated with different concentrations of LPS and the cell counting kit-8 assay was used to measure the toxicity of LPS to the cells. Next, we used immunofluorescence to measure nuclear translocation of Nrf2 in PC12 cells. PC12 cells were then treated with IGF-1 (PI3K agonist) and LY294002 (PI3K inhibitor). An in-vitro model of SCI was then established via oxygen-glucose deprivation/reoxygenation. Rates of apoptosis were measured using flow cytometry and the TUNEL assay. Low-dose LPS increased the expression levels of Nrf2, p-PI3K/PI3K, and p-AKT/AKT, and facilitated nuclear translocation of Nrf2. The activation of PI3K-AKT signaling by IGF-1 significantly increased the expression of Nrf2, whereas inhibition of PI3K-AKT signaling significantly decreased the expression of Nrf2. Low-dose LPS reduced the apoptotic ratio of PC12 cells, decreased the expression levels of caspase 3 and caspase 9, and increased the expression levels of HO-1, NQO1, and γ-GCS. Low-dose LPS also reduced the rate of apoptosis and oxidative stress by activating the PI3K-AKT-Nrf2 signaling pathway. Collectively, the results indicate that PI3K-AKT-Nrf2 signaling participates in the protective effects from low-dose LPS in an in-vitro PC12 cell model of SCI.

Low-dose Lipopolysaccharide Alleviates Spinal Cord Injury-induced Neuronal Inflammation by Inhibiting microRNA-429-mediated Suppression of PI3K/AKT/Nrf2 Signaling.

This study investigated the impact of low-dose lipopolysaccharide (LPS) on spinal cord injury (SCI) and the potential molecular mechanism. Rats were randomly assigned to four groups: Sham, SCI, SCI + LPS, and SCI + LPS + agomir. Allen's weight-drop method was used to establish an in vivo SCI model. The Basso Bcattie Bresnahan rating scale was employed to monitor locomotor function. An in vitro SCI model was constructed by subjecting PC12 cells to oxygen and glucose deprivation/ reoxygenation (OGD/R). Enzyme-linked immunosorbent assay (ELISA) was applied for the determination interleukin (IL)-1ß and IL-6. The dual luciferase reporter assay was used to validate the targeting of microRNA (miR)-429 with PI3K. Immunohistochemical staining was used to assess the expression of PI3K, phosphorylated AKT and Nrf2 proteins. The Nrf2-downstream anti-oxidative stress proteins, OH-1 and NQO1, were detected by western blot assay. MiR-429 expression was detected by fluorescence in situ hybridization and real-time quantitative reverse transcription PCR. In vitro, low-dose LPS decreased miR-429 expression, activated PI3K/AKT/Nrf2, inhibited oxidative stress and inflammation, and attenuated SCI. MiR-429 was found to target and negatively regulate PI3K. Inhibition of miR-429 suppressed low-dose LPS-mediated oxidative stress and inflammation via activation of the PI3K/AKT/Nrf2 pathway. In vivo, miR-429 was detectable in neurons. Inhibition of miR-429 blocked low-dose LPS-mediated oxidative stress and inflammation via activation of the PI3K/AKT/Nrf2 pathway. Overall, low-dose LPS was found to alleviate SCI-induced neuronal oxidative stress and inflammatory response by down-regulating miR-429 to activate the PI3K/AKT/Nrf2 pathway.

Application of transverse tibial bone transport and microcirculation reconstruction in the treatment of diabetic foot ulcer: a case report.

Diabetic foot ulcer (DFU) is a common complication in the advanced stages of diabetes mellitus. DFU in these individuals cannot heal properly over time due to microcirculatory changes that hinder and stagnate the healing process. There is a wide range of therapeutic strategies for DFU, but only minimal efficacy has been found in limited published studies. Transverse tibial bone transport (TTBT) is a new strategy for DFU, which based on Ilizarov technology. We present a case of a 45-year-old female with longstanding type 2 diabetes complicated with slowly expanding ulceration to her right foot. According to the symptoms, signs, and medical history, she was diagnosed as DFU with osteomyelitis. After sufficient preoperative preparation, including tight blood glucose control, wound dressing, and anti-infection therapy, the ulcer was treated with Ilizarov TTBT. Under these interventions, the ulcer gradually improved. The patient's foot ulcer was completely healed seven months after surgery, and foot function was well preserved. No complications were observed during the follow-up. For patients with refractory DFU, TTBT should be considered a promising treatment option for maintaining the foot's shape and function. The present study's findings indicate that further studies should focus on the mechanism of microcirculation reconstruction for the treatment of DFU.

Curcumin promotes functional recovery and inhibits neuronal apoptosis after spinal cord injury through the modulation of autophagy.

Objective: The study was aimed to investigate whether the neuroprotective role of curcumin is associated with regulation of autophagy.Methods: Rat spinal cord injury (SCI) models were established according to Allen's weight-drop trauma method. Curcumin was administered 30 min after the contusion and continued weekly. At 3, 7, 14, 21, and 28 days after SCI, functional recovery was evaluated using the Basso, Beattie and Bresnahan (BBB) scoring and the oblique plate test, following which, spinal cord tissues were obtained. Histological changes and apoptosis were then measured with H&E staining and TUNEL assay. Glia activation, inflammatory infiltration, inflammatory factor release, and myelination were observed through immunohistochemical (IHC) staining and ELISA. Autophagy and Akt activation were detected by western blotting. After autophagy was inhibited by injection of chloroquine, TUNEL, inflammatory factor release, myelin basic protein (MBP) IHC staining and functional recovery evaluation were performed again.Results: Curcumin treatment promoted functional recovery after SCI and reduced neuron apoptosis, improved spinal cord integrity, recovery, and re-myelination, and suppressed the inflammatory response. Autophagy was enhanced and Akt/mTOR pathway was inhibited by curcumin. Autophagy inhibition partially eliminated the protective effect of curcumin on SCI.Conclusion: Curcumin may exert its therapeutic effect on SCI through the enhancement of autophagy, in which, inhibition of the Akt/mTOR signaling pathway may be also involved.

MiR-374a Activates Wnt/ß-Catenin Signaling to Promote Osteosarcoma Cell Migration by Targeting WIF-1.

MiR-374a was proved to take part in the initiation and development of several cancers. However, the molecular mechanism of miR-374a in osteosarcoma (OS) cells remains unclear. The aim of our research was to investigate the role of miR-374a in OS cells migration and clarify the potential mechanisms. Quantitative real-time PCR (qRT-PCR) and western blot analysis were applied to evaluate the expression of miR-374a and Wnt inhibitory factor-1 (WIF-1). Bioinformatical methods and luciferase reporter assay were carried out to predict and confirm the combination of miR-374a and WIF-1. Transwell and wound healing assays were performed to detect the migration capacity of OS cells. Lithium chloride (LiCl) was used to investigate the role of LiCl-activated Wnt/ß-catenin signaling pathway in regulating cell migration. Our studies revealed that miR-374a was up-regulated whereas WIF-1 was down-regulated in OS cells. Besides, WIF-1 was the target of miR-374a by performing luciferase reporter assay. By transfection of miR-374a inhibitor and/or WIF-1 siRNA to OS cells, we found that miR-374a promoted the migration of OS cells. In addition, the inhibition of WIF-1 abolished the miR-374a inhibitor-induced migration suppression of OS cells. LiCl experiment revealed that miR-374a promoted OS cells migration by regulating Wnt/ß-catenin signaling. In conclusion, miR-374a promotes OS cells migration by activating Wnt/ß-catenin signaling pathway via targeting WIF-1.

Endovascular treatment of a ruptured thoracic aortic pseudoaneurysm secondary to Pott disease during a spine surgery: A case report and a literature review.

RATIONALE: The coexistence of a tuberculous aortic pseudoaneurysm and Pott disease in patients with a history of tuberculosis (TB) is relatively rare, and the treatment strategies remain still controversial. PATIENT CONCERNS: A 57-year-old female patient with a history of primary pulmonary TB presented with symptoms of breathlessness, chest pain, weight loss, and fever. Magnetic resonance imaging (MRI) and computed tomography (CT) showed a thoracic aortic pseudoaneurysm secondary to Pott disease at T11/12 level. DIAGNOSES: Tuberculous pseudoaneurysm at the descending thoracic aorta associated with tuberculous vertebral osteomyelitis. INTERVENTIONS: We originally planned a combined surgery consisting of posterior spine stabilization, anterior excision of the infected field, and aortic reconstruction. When we surgically stabilized the posterior spine, unexpectedly, the pseudoaneurysm ruptured. Immediately, we terminated the surgery and appropriately placed an endovascular stent graft, which successfully rescued the patient. OUTCOMES: When the patient's conditions were stable, we anteriorly debrided all infected tissues and then performed a spinal fusion by grafting autologous iliac bone. After the debridement and spinal fusion, we arranged a 1-year anti-tuberculous chemotherapy for this patient and performed a 24-month follow-up. This patient had no signs of recurrent infection during the follow-up. LESSONS: For the patients with tuberculous aortic aneurysm(s) complicated with vertebral osteomyelitis, the endovascular repair of an aneurysm(s) should be considered a conventional therapy before the spine surgery, lowering the risk of aortic aneurysm rupture. Meanwhile, minimally invasive endovascular stent graft combined with anti-tuberculosis drugs may be considered one of the therapeutic regimens for the patients whose conditions are not suitable for open surgery, such as age, weakness, or severe organ failure.

Lipopolysaccharide-induced preconditioning protects against traumatic spinal cord injury by upregulating Nrf2 expression in rats.

AIMS: Lipopolysaccharide (LPS)-induced preconditioning protects neurons against traumatic spinal cord injury (TSCI) in rats. This study sought to test whether Nrf2, a transcription factor, mediated LPS-induced preconditioning. MAIN METHODS: The TSCI model was established using a standardized NYU impactor on adult female rats. Rats were pretreated with LPS (0.2mg/kg, IP; 72h before injury). Nrf2 was silenced by injecting a lentivirus encoding RNAi against Nrf2 into injured spinal cords. Neurologic function was assessed by Basso, Beattie and Bresnahan (BBB) scores 6h, 12h, 24h, 48h, 72h, 7d and 14d after TSCI. Neuronal apoptosis was measured by a TUNEL staining. Ultrastructure was observed using transmission electron microscope (TEM). The protein expression of HO-1, NQO1 and GCLC was examined using immunohistochemistry and immunoblotting. KEY FINDINGS: The injection of a lentivirus effectively transfected GFP into injured spinal cords. The expression of Nrf2 was significantly decreased in spinal cords receiving a lentivirus encoding RNAi against Nrf2. BBB scores showed that TSCI markedly impaired nervous function, which was markedly preserved by LPS pretreatment. Nrf2 knockdown significantly suppressed LPS pretreatment-induced protection of nervous function. TEM images and TUNEL staining showed an increase in apoptotic cells when Nrf2 was silenced. Moreover, immunohistochemistry and immunoblotting analysis exhibited that LPS pretreatment significantly upregulated the expression of anti-oxidative proteins including HO-1, NQO1 and GCLC, which was suppressed when Nrf2 expression was silenced in injured spinal cords. SIGNIFICANCE: LPS preconditioning effectively alleviates TSCI-induced impairment and preserves nervous function in a Nrf2-dependent manner.