PI3K/AKT mediated De novo fatty acid synthesis regulates RIG-1/MDA-5-dependent type I IFN responses in BVDV-infected CD8+T cells.

Bovine viral diarrhea virus (BVDV) has caused massive economic losses in the cattle business worldwide. Fatty acid synthase (FASN), a key enzyme of the fatty acid synthesis (FAS) pathway, has been shown to support virus replication. To investigate the role of fatty acids (FAs) in BVDV infection, we infected CD8+T lymphocytes obtained from healthy cattle with BVDV in vitro. During early cytopathic (CP) and noncytopathic (NCP) BVDV infection in CD8+ T cells, there is an increase in de novo lipid biosynthesis, resulting in elevated levels of free fatty acids (FFAs) and triglycerides (TG). BVDV infection promotes de novo lipid biosynthesis in a dose-dependent manner. Treatment with the FASN inhibitor C75 significantly reduces the phosphorylation of PI3K and AKT in BVDV-infected CD8+ T cells, while inhibition of PI3K with LY294002 decreases FASN expression. Both CP and NCP BVDV strains promote de novo fatty acid synthesis by activating the PI3K/AKT pathway. Further investigation shows that pharmacological inhibitors targeting FASN and PI3K concurrently reduce FFAs, TG levels, and ATP production, effectively inhibiting BVDV replication. Conversely, the in vitro supplementation of oleic acid (OA) to replace fatty acids successfully restored BVDV replication, underscoring the impact of abnormal de novo fatty acid metabolism on BVDV replication. Intriguingly, during BVDV infection of CD8+T cells, the use of FASN inhibitors prompted the production of IFN-α and IFN-ß, as well as the expression of interferon-stimulated genes (ISGs). Moreover, FASN inhibitors induce TBK-1 phosphorylation through the activation of RIG-1 and MDA-5, subsequently activating IRF-3 and ultimately enhancing the IFN-1 response. In conclusion, our study demonstrates that BVDV infection activates the PI3K/AKT pathway to boost de novo fatty acid synthesis, and inhibition of FASN suppresses BVDV replication by activating the RIG-1/MDA-5-dependent IFN response.

Metformin Improves Functional Recovery After Spinal Cord Injury via Autophagy Flux Stimulation.

Spinal cord injury (SCI) is a severe neurological disease with few efficacious drugs. Autophagy is a cellular process to confront with stress after SCI and considered to be a therapeutic target of SCI. In this study, we investigated the therapeutic effect of metformin on functional recovery after SCI and its underlying mechanism of autophagy regulation. Using a rat model of traumatic SCI, we found improved function recovery which was paralleled by a reduction of apoptosis after metformin treatment. We further examined autophagy via detecting autophagosomes by transmission electron microscopy and immunofluorescence, as well as autophagy markers by western blot in each groups. The results showed that the number of autophagosomes and expression of autophagy markers such as LC3 and beclin1 were increased in SCI group, while autophagy substrate protein p62 as well as ubiquitinated proteins were found to accumulate in SCI group, indicating an impaired autophagy flux in SCI. But, metformin treatment attenuated the accumulation of p62 and ubiquitinated proteins, suggesting a stimulative effect of autophagy flux by metformin. Blockage of autophagy flux by chloroquine partially abolished the apoptosis inhibition and functional recovery effect of metformin on SCI, which suggested that the protective effect of metformin on SCI was through autophagy flux stimulation. Activation of AMPK as well as inhibition of its downstream mTOR signaling were detected under metformin treatment in vivo and in vitro; inhibition of AMPK signaling by compound C suppressed autophagy flux induced by metformin in vitro, indicating that AMPK signaling was involved in the effect of metformin on autophagy flux regulation. Together, these results illustrated that metformin improved functional recovery effect through autophagy flux stimulation and implied metformin to be a potential drug for SCI therapy.

Reversing effect of exogenous WWOX gene expression on malignant phenotype of primary cultured lung carcinoma cells.

BACKGROUND: Whether WW domain containing oxidoreductase (WWOX) gene is a tumor-suppressor is still controversial. Some researchers found that the transcription of the WWOX gene was lacking not only in tumor tissues but also in non-tumorous tissues and sometimes in normal tissues. Hence it is important to explore the role of the expression of the exogenous WWOX gene in the proliferation and apoptosis of primary cultured lung carcinoma cells. METHODS: Lipofection technique was used to determine primary cultured lung carcinoma cells containing the highly expressed exogenous WWOX gene and primary cultured cells with vectors as controls. An animal model of lung cancer was made by subcutaneous implantation of tumor cells into nude mice. RT-PCR, Western blotting, flow cytometry, and TUNEL were used to detect the transcription, expression of the exogenous gene and the effect of the expression of targeted genes on the proliferation and apoptosis of the primary cultured lung carcinoma cells. RESULTS: The growth, clone formation rate (CFR) ((5.33 +/- 1.53)%) of the primary lung cancer cells transfected with the WWOX gene, tumor size and weight were significantly lower than those of the non-transfected lung cancer cells (CFR: (14.33 +/- 1.53)%) and the primary lung cancer cells transfected with blank plasmids (CFR: (11.00 +/- 1.73)%, P < 0.05). The apoptosis level of primary lung cancer cells transfected with the WWOX gene ((40.72 +/- 5.20)%) was significantly higher than that of the non-transfected lung cancer cells ((2.76 +/- 0.02)%) and the primary lung cancer cells transfected with blank plasmids ((2.72 +/- 0.15)%, P < 0.05). CONCLUSION: The expression of the exogenous WWOX gene can significantly inhibit the proliferation of lung cancer cells and induce their apoptosis, suggesting that the WWOX gene possesses tumor-suppressing effect.

[The diagnosis and surgical treatment for 56 cases with pulmonary and pleural aspergillosis].

OBJECTIVE: To summarize the experience of diagnosis and surgical treatment for pulmonary and pleural aspergillosis. METHODS: The clinical data of cases with pulmonary and pleural aspergillosis were analyzed retrospectively between September 1972 and June 2003. There were 53 cases with pulmonary aspergillosis and 3 cases with pleural aspergillosis. Aspergillus was found preoperatively in 8 patients by sputum culture (5 cases) or needle biopsy of the lung (2 cases) or fibro-bronchoscopic biopsy (1 case). All patients were treated with surgical procedures following X-ray film or CT scan. RESULTS: Of 53 cases with pulmonary aspergillosis, 42 lobectomies, 3 segment-Pneumonectomies, and 8 wedge resections were performed. Of three cases with pleural aspergillosis following eliminating their diseased foci in residual pleural space, two underwent thoracoplasty, one underwent postoperative closed chest drainage for one and an half month with fluconazole injected into residual pleural space repeatedly for 1 month (200 mg/100 ml, 1 time per 2 or 3 days). No operative death and major postoperative complications occurred. None of the patients had recurrent symptoms at follow-up. CONCLUSION: We recommend aggressive surgical resection for pulmonary and pleural aspergillosis, and the surgical result is excellent.