Specific role of NAD+ biosynthesis reduction mediated mitochondrial dysfunction in vascular endothelial injury induced by chronic intermittent hypoxia.

OBJECTIVE: Cardiovascular diseases (CVD) are prevalent among those with obstructive sleep apnea (OSA) and are the leading cause of death in these individuals. However, due to clinical confounders, the mechanism by which OSA induces CVD is still unclear. Previous studies have shown that chronic intermittent hypoxia (CIH) and high cholesterol diet (HCD) induce distinct characteristics of atherosclerotic plaques, highlighting the specific mechanisms involved in CIH-induced vascular endothelial injury. MATERIALS AND METHODS: This study aims to investigate whether nicotinamide adenine dinucleotide (NAD+) biosynthesis reduction-mediated mitochondrial dysfunction is responsible for vascular endothelial injury induced by CIH and to elucidate its specific role in this process. Models were established to stimulate human umbilical vein endothelial cells (HUVECs) with CIH and oxidized low-density lipoprotein (ox-LDL), and the NAD+ biosynthesis-related indicators, such as NAD+ levels and nicotinamide phosphoribosyltransferase (NAMPT) enzyme activity, were measured in this model. Additionally, interventions were performed by supplementing NAD+ levels with nicotinamide mononucleotide (NMN), inhibiting NAD+ synthesis with FK866, and evaluating mitochondrial function, oxidative stress status, vascular constriction and dilation function, and endothelial adhesion function in these models. A comparative study was conducted to assess the effects of these interventions. RESULTS: We found that under CIH conditions, NAMPT enzyme activity was inhibited, leading to a reduction in NAD+ biosynthesis and a decrease in NAD+/NADH ratio. At the same time, CIH caused mitochondrial dysfunction in HUVECs, including a decrease in adenosine triphosphate (ATP) content and mitochondrial membrane potential, as well as the activity of respiratory chain complex I and III, induced an increase in oxidative stress levels in endothelial cells, impaired vascular constriction and dilation function, and significantly increased expression of adhesion factors. The impact of CIH on endothelial cell-related mitochondrial function and endothelial function was restored by supplementing NMN. Although ox-LDL also causes multi-level endothelial injury, it does not involve the NAD+ pathway, as there were no significant changes in the related indicators, and the impaired endothelial function under ox-LDL conditions was not restored by supplementing NMN. CONCLUSIONS: CIH-induced vascular endothelial injury may be associated with NAD+ biosynthesis reduction-mediated mitochondrial dysfunction. Supplementing NAD+ precursors to increase its levels may be a potential intervention to ameliorate CIH-induced vascular endothelial injury, while it does not have a significant effect on endothelial injury caused by ox-LDL.

Efficacy and safety of neoadjuvant Folfirinox and Gemcitabine plus Nab-Paclitaxel for borderline resectable and locally advanced pancreatic cancer: a systematic review and meta-analysis.

OBJECTIVE: Multi-agent regimens such as Folfirinox and gemcitabine plus nab-paclitaxel have shown significant improvements compared with single-agent gemcitabine as neoadjuvant chemotherapy for patients with borderline resectable or locally advanced pancreatic cancer. However, the efficacy and safety of Folfirinox and GNP as NAC for BRPC and LAPC is still controversial. MATERIALS AND METHODS: The eligible studies including prospective, retrospective, and randomized controlled trial related to Folfirinox and GNP as NAC for patients with BRPC or LAPC up to March 2022 were searched and assessed. Pooled analysis for chemotherapy response rate, resection rate, R0 resection rate, progress free survival, overall survival, and grade 3/4 events of toxicity were performed in the study. RESULTS: Eight studies were included in this meta-analysis. Compared with GNP, Folfirinox had higher resection rate (HR=0.82; 95% CI 0.59-1.14) and R0 resection rate (HR=0.77; 95% CI 0.60-0.97), better PFS (HR=0.78; 95% CI 0.55-1.12) and OS (HR=0.68; 95% CI 0.46-0.99), and without increasing severe toxicity rate (HR=0.95; 95% CI 0.71-1.28). There are no differences in rate of stable disease (HR=1.06; 95% CI 0.92-1.22) and partial/complete regression (HR=0.85; 95% CI 0.59-1.23) between two groups. CONCLUSIONS: Higher resection and R0 resection rate and better PFS and OS results were obtained in Folfirinox group compared with GNP group for patients with BRPC and LAPC. There was no increased severe toxicity rate for Folfirinox compared with GNP.

[Influence of Toll-like receptor 7 on CD8(+) T lymphocytes in patients with breast cancer].

Objective: To investigate the effect of Toll-like receptor 7 (TLR7) in CD8(+) T cells activity from patients with breast cancer. Methods: Thirty-three patients with breast cancer, twenty-three patients with benign breast tumor, and twenty healthy individuals were collected from The First Affiliated Hospital of Xinxiang Medical University between December 2017 and March 2018. Peripheral blood mononuclear cells (PBMCs) were isolated, and CD8(+) T cells were purified. TLR7 protein and mRNA relative expression in CD8(+) T cells was measured using flow cytometry and real-time PCR, respectively. mRNA relative expressions corresponding to perforin, granzyme B, and FasL in CD8(+) T cells were measured in response to TLR7 agonist stimulation. Direct/indirect contact co-culture system of CD8(+) T cells and breast cancer cell line MCF-7 was also used to assess cytolytic and noncytolytic function in response to TLR7 agonist CL097 stimulation. Results: The mean fluorescence intensity corresponding to TLR7 protein in CD8(+) T cells from breast cancer patients was 124.0±15.32, which was significantly down-regulated in comparison with benign breast tumor patients (255.5±54.91) and healthy individuals (261.9±68.65) (P<0.000 1). TLR7 mRNA relative level was also remarkably reduced in CD8(+) T cells from breast cancer patients (1.97±1.18) in comparison with benign breast tumor patients (4.84±1.01) and healthy individuals (4.75±1.40) (P<0.000 1). TLR7 agonist CL097 stimulation notably increased mRNA relative levels of perforin and granzyme B mRNA in CD8(+) T cells (P<0.01), but not elevated FasL mRNA (P>0.05).Furthermore, TLR7 agonist CL097 stimulation enhanced the cytolytic and noncytolytic function of CD8(+) T cells to MCF-7 cells, which presented as the elevation of target cell death and increase of interferon-γ production in direct and indirect contact co-culture system. Conclusion: TLR7 agonist promoted CD8(+) T cells function from breast cancer patients.

Linc00261 suppresses growth and metastasis of non-small cell lung cancer via repressing epithelial-mesenchymal transition.

OBJECTIVE: Long non-coding RNAs (lncRNAs) have been identified to participate in the development and progression of various types of cancers, including non-small cell lung cancer (NSCLC). However, the expression and function of linc00261 in NSCLC has not been studied yet. We aim to explore the role and potential of linc00261 in NSCLC tumorigenesis. PATIENTS AND METHODS: The expression level of linc00261 in 71 paired of NSCLC tissues and matched normal tissues, was detected using quantitative Real-time polymerase chain reaction (qRT-PCR). Linc00261 expression in NSCLC cells was also measured. NSCLC cells were transfected with pcDNA3.1 or siRNA linc00261 to upregulate or downregulate linc00261 expression, respectively. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and colony formation assay were utilized for examining the proliferative ability of NSCLC cells. Wound-healing and transwell assays were performed for detecting the metastatic ability of NSCLC cells. Protein levels of epithelial-mesenchymal transition markers were detected by Western blot. Furthermore, in vivo function of linc00261 was evaluated using the nude mice. RESULTS: Linc00261 expressed significantly lower in NSCLC tissues and cell lines than that in the adjacent normal tissues or control cell line. Over-expression of linc00261 significantly inhibited proliferation, invasion and migration of NSCLC cells. On the contrast, knockdown of linc00261 promoted cell growth and metastasis of NSCLC cells. Furthermore, linc00261 inhibited the epithelial-mesenchymal transition of NSCLC via downregulating Snail. Linc00261 could slow down the growth of xenograft of NSCLC in vivo. CONCLUSIONS: We demonstrated that linc00261 was lowly expressed in NSCLC tissues and cells. It inhibited cell proliferation and metastasis by downregulating Snail expression via EMT. This might provide a novel sight for the biological treatment for NSCLC.

[The protective effect of puerarin on cultured rat cerebral cortical astrocytes].

AIM: To study the effects of puerarin (Pue) on impairment of rat astrocytes in primary cell culture induced by oxygen-glucose deprivation (OGD) or sodium glutamate (Glu). METHODS: Astrocyte damage induced by (OGD), Glu or (+/-)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (trans-ACPD), as well as the action of Pue was measured by determining the intracellular water space (as measured by 3-O-methyl-[1- 3H]D-glucose uptake) of astrocytes and the leakage of lactate dehydrogenase (LDH) from astrocytes. RESULTS: Following the exposure to OGD for 5 h, 0.5 mmol/L Glu or 1 mmol/L trans-ACPD for 1 h, the astrocyte volume and LDH leakage from astrocytes were increased. 0.1 mmol/L Pue, when co-incubated with OGD, Glu or trans-ACPD, reduced astrocytic swelling and the LDH leakage. CONCLUSION: Pue had protective effects on astrocytes damaged by OGD, Glu or trans-ACPD.

Effects of puerarin against glutamate excitotoxicity on cultured mouse cerebral cortical neurons.

AIM: To study the effects of puerarin (Pue) against injury of cultured neurons by sodium glutamate (Glu). METHODS: Neuronal damage induced by Glu, N-methyl-D-asparate (NMDA), and kainic acid (KA), as well as the actions of Pue and some excitatory amino acid antagonists (EAAA), were measured by determining the leakage of lactate dehydrogenase (LDH) from nerve cells. RESULTS: The 24-h leakage of LDH was increased from cells exposed either to Glu 100 and 500 mumol.L-1 for 15 min (from 20 +/- 4 kU/g protein in control group to 35 +/- 3 kU/g protein in Glu 100 mumol.L-1 group and to 46 +/- 6 kU/g protein in Glu 500 mumol.L-1 group) or to NMDA 500 mumol.L-1 or KA 500 mumol.L-1 for 45 min (from 19 +/- 4 kU/g protein in control group to 27 +/- 3 kU/g protein in NMDA group and to 30 +/- 5 kU/g protein in KA group). Pre and post-treatment with Pue (100 mumol.L-1) decreased the leakage of LDH, which was similar to the effects of EAAA kynurenic acid (from 35 +/- 3 kU/g protein in Glu 100 mumol.L-1 to 20 +/- 5 kU/g protein in kynurenic acid group and to 22 +/- 3 kU/g protein in Pue group), DL-2-amino-5-phosphonovaleric acid (APV) (from 27 +/- 3 kU/g protein in NMDA damaged group to 183 kU/g protein in APV group and to 19 +/- 5 kU/g protein in Pue group) or 6,7-dinitroquinoxaline-2,3(1H,4H)-diane (DNQX) (from 30 +/- 5 kU/g protein in KA damaged control to 22 +/- 5 kU/g protein in DNQX group and to 20 +/- 4 kU/g protein in Pue group). Post-treatment with Pue (100 mumol.L-1) was able to reduce 24-h leakage of LDH from neurons expos ed to Glu 100 mumol.L-1 for 15 min (from 35 +/- 3 kU/g protein to 27 +/- 4 kU/g protein). CONCLUSION: Pue had protective effects on neurons damaged by Glu, NMDA, or KA.

[Effects of carbamazepine on hypoxic and ischemic brain damage in mice].

When carbamazepine (Car) was injected ip 13.0-50.0 mg.kg-1 30 min before inhaling 96% N2 + 4% O2, the survival time of mice was prolonged (from 54 +/- 8 s in control group to 119 +/- 35 s). The survival time of mice subjected to bilateral carotid artery ligation was markedly prolonged by Car (25.0-50.0 mg.kg-1), medians were 4, 6, and 15 min, respectively. Car (25.5-70.0 mg.kg-1) alleviated the reduction of ATP (from 1.0 +/- 0.3 mumol.g-1 in control group to 1.9 +/- 0.5 mumol.g-1) and phosphocreatine (PC) contents (from 0.8 +/- 0.2 mumol.g-1 in control group to 1.2 +/- 0.3 mumol.g-1) and the accumulation of lactic acid (LA) (from 9.6 +/- 1.3 mumol.g-1 in control group to 6.7 +/- 0.7 mumol.g-1) in mouse brain 30 s after decapitation. These results indicated that Car was effective against hypoxia and brain ischemia in mice.

[Effect of mexiletine on energy metabolism of ischemic brain in mice].

After 30 s ischemia induced by decapitation, the contents of ATP and phosphocreatine (PC) in mouse brain reduced, while that of lactic acid (LA) increased. When mexiletine (3.1-50 mg.kg-1) was injected ip 30 min before decapitation, the brain ATP and PC reduction, and LA accumulation were both alleviated in a dose-dependent manner. These findings suggested that mexiletine was effective in ameliorating the energy exhaustion in the ischemic brain.