Effect of Siphon Morphology on the Risk of C7 Segment Aneurysm Formation : A Case-control CFD Study.

PURPOSE: Tortuosity of the internal carotid artery (ICA) is associated with intracranial aneurysms (IAs). The siphon is the most curved segment of the ICA, but its morphology has controversial effects on IAs. This study aimed to explore the morphometric features of the siphon and the potential hemodynamic mechanisms that may affect C7 aneurysm formation. METHODS: In this study 32 patients with C7 aneurysms diagnosed at Xiangya Hospital between 2019 and 2021 and 32 control subjects were enrolled after propensity score matching. Computed tomography angiography (CTA) images were acquired to measure morphologic features, and then, by combining clinical data, simplified carotid siphon models were constructed, and computational fluid dynamics (CFD) analysis was performed. RESULTS: The presence of C7 aneurysms was associated with the height of the C4-C6 curved arteries (odds ratio [OR] 0.028, 95% confidence interval [CI] 0.003-0.201; P < 0.001). The heights of the C4-C6 curved arteries in the aneurysm group were significantly shorter than those in the control group. The CFD analysis revealed that shorter C4-C6 bends led to greater blood velocity and pressure in the C7 segment arteries. CONCLUSION: A shorter C4-C6 bend was associated with distal C7 aneurysm formation, and an elaborate hemodynamic mechanism may underlie this association.

MicroRNA miR-34a-5p inhibition restrains oxidative stress injury of macrophages by targeting MDM4.

OBJECTIVE: Atherosclerosis is a chronic cardiovascular disease associated with oxidative stress damage, which is caused by excessive oxidation of low-density lipoprotein (ox-LDL). The role of microRNA miR-34a-5p on oxidative stress in ox-LDL-treated macrophages was investigated in this study. METHODS: Flow cytometry was prepared for assessing THP1-derived macrophage apoptosis. The protein and expression levels of miR-34a-5p and MDM4 were examined by Western blot and RT-qPCR, respectively. We also measured the levels of total cholesterol (TC) and triglyceride to determine the lipid accumulation. Subsequently, the activities of superoxide dismutase, malondialdehyde, and reactive oxygen species revealed the level of oxidative stress injury after miR-34a-5p and MDM4 knockdown. RESULTS: After ox-LDL treatment, cell apoptosis of macrophages increased in a dose-dependent and time-dependent manner. With the increase of ox-LDL treatment and the prolongation of treatment time, the expression level of miR-34a-5p was upregulated. Next, interfering with miR-34a-5p inhibited lipid accumulation and oxidative stress injury in ox-LDL-stimulated macrophages. MDM4 was a target gene of miR-34a-5p and was upregulated in ox-LDL-stimulated macrophages. With the increase of ox-LDL treatment and the prolongation of treatment time, the expression level of MDM4 was downregulated. Importantly, MDM4 knockdown partially counteracted the inhibitory effect of miR-34a-5p on oxidative stress injury. CONCLUSION: MicroRNA miR-34a-5p knockdown suppressed oxidative stress injury via MDM4 in ox-LDL-treated macrophages.

Molecular feature of arterial remodeling in the brain arteriovenous malformation revealed by arteriovenous shunt rat model and RNA sequencing.

PURPOSE: Morphological research suggested the feeding artery of brain arteriovenous malformation (bAVM) had vascular remodeling under the high blood flow; however, the underlying molecular mechanisms were unclear. METHODS: We constructed 32 simplified AVM rat models in four groups: the control group (n = 6), 1-week high-blood-flow group (n = 9), 3-week high-blood-flow group (n = 7) and 6-week high-blood-flow group (n = 10). The circumference, blood velocity, blood flow, pressure, and wall shear of the feeding artery were measured or calculated. The arterial wall change was observed by Masson staining. RNA sequencing (RNA-seq) of feeding arteries was performed, followed by bioinformatics analysis to detect the potential molecular mechanism for bAVM artery remodeling under the high blood flow. RESULTS: We observed hemodynamic injury and vascular remodeling on the feeding artery under the high blood flow. RNA-seq showed immune/inflammation infiltration and vascular smooth muscle cell (VSMC) phenotype transformation during remodeling. Weighted gene co-expression network analysis (WGCNA) and time series analysis further identified 27 key genes and pathways involved in remodeling. Upstream miRNA and molecular drugs were predicted targeting these key genes. CONCLUSIONS: We depicted molecular change of bAVM arterial remodeling via RNA-seq in high-blood-flow rat models. Twenty-seven key genes may regulate immune/inflammation infiltration and VSMC phenotype transform in bAVM arterial remodeling.

The dynamic changes of Nrf2 mediated oxidative stress, DNA damage and base excision repair in testis of rats during aging.

Accumulation of oxidative stress, DNA damage and impaired DNA repair appear to play critical roles in the decline of testicular function with aging. However, when those factors begin to lose control in testis during aging has not yet been well understood. This study was designed to assess the changes of oxidative stress and DNA damage status, and DNA repair capacity in testis during aging. Thus, male Sprague-Dawley rats at 3, 9, 15 and 24 months of age were used to delineate the dynamic changes in testicular weight and index, testosterone concentration, testicular histology, Nrf2-mediated oxidative stress, DNA damage, DNA repair and apoptosis. Results showed that testicular weight and index, testosterone concentration and spermatid number progressively declined from 9 to 24 months of age. Similarly, seminiferous tubule diameters and seminiferous epithelium heights gradually diminished with aging. Nrf2-mediated antioxidant defense ability was significantly impaired in testis with increasing age including decreased the activity of SOD and the expression levels of Nrf2, HO-1 and NQO-1, and increased the contents of MDA. In addition, DNA damage including DNA single-strand breaks (SSBs) and DNA double-strand breaks (DSBs) also progressively increased accompanied by increased levels of 8-hydroxydeoxyguanosine (8-OHdG) and γ-H2AX, and activated ATM/Chk2 and ATR/Chk1 pathway. Consistent with the results of Nrf2 pathway, the expression levels of APE1, OGG1 and XRCC1 involved in base excision DNA repair (BER) pathway increased from 3 to 9 months of age, and then gradually decreased after 9 months of age. Finally, TUNEL and Western blot results further confirmed germ cell apoptosis progressively increased from 3 to 24 months of age as evidenced by decreased ratio of Bcl-2/Bax and levels of Bcl-2 expression, and increased Bax expression levels. Taken together, our results suggest that downregulation of antioxidant ability mediated by Nrf2 pathway and impairment of BER capacity might correlate with increased DNA damage, and then induce declining testicular function during aging after adult.

Oleanolic acid rejuvenates testicular function through attenuating germ cell DNA damage and apoptosis via deactivation of NF-κB, p53 and p38 signalling pathways.

OBJECTIVES: Inflammation can cause degenerative changes of reproductive function. Oleanolic acid (OA), the effective component from Ligustrum lucidum Ait., exhibits significantly anti-inflammation and antiageing activity. However, whether OA restores testicular dysfunction via inhibition of inflammation with ageing is unclear. Here, in a natural ageing rat model, we investigated the protection effects of OA and its mechanism of action. METHODS: Eighteen-month-old Sprague Dawley (SD) rats were randomly divided into ageing control group and two OA-treated groups (5 and 25 mg/kg). Nine-month-old SD rats were used as adult controls. All rats were received either vehicle or OA for 6 months. Then, histomorphology, weight and index of testis, protein expression and immunohistochemistry were examined. KEY FINDINGS: Oleanolic acid significantly restored testicular morphology and improved testicular weight and index. Moreover, OA significantly inhibited phospho-NF-κB p65 and its downstream proinflammatory cytokines' expressions, including IL-1ß, COX-2 and TNF-α in testis tissues. Similarly, OA remarkably inhibited IL-1ß and TNF-α production. OA significantly attenuated germ cells' DNA damage and apoptosis. Such changes were accompanied by downregulation of γH2AX, p-P53 and Bax expressions, and upregulation of Bcl-2 and Bcl-2/Bax ratio. In addition, OA remarkably inhibited p38 signalling. CONCLUSIONS: Oleanolic acid effectively rejuvenates testicular function via attenuating germ cell DNA damage and apoptosis through deactivation of NF-κB, p53 and p38 signalling pathways.

[Protective Effect of Wuzi Yanzong Prescription on Apoptosis in Germ Cells of Mice Induced by Cyclophosphamide].

Objective: To investigate the protective effect and mechanism of Wuzi Yanzong prescription on apoptosis in germ cell of adult male mice induced by cyclophosphamide( CTX). Methods: Male Balb / C mice were randomly divided into normal control group,model group,the low-,medium- and high- dose of Wuzi Yanzong prescription groups( 100 mg / kg,200 mg / kg and 400 mg / kg),with 10 mice in each group. The mice were injected intraperitoneally with CTX( 200 mg / kg) from 4th day,and gave drug once a week,and executed for 4 weeks. Three doses of Wuzi Yanzong prescription were intragastrically administered every day. For normal control group,the same procedure was performed with intraperitoneal normal saline. Twelve hours after giving CTX at last time, all mice were weighed and sacrificed by cervical dislocation. The testis was immediately dissected and weighed, and then calculated the testis index. The pathological changes of testis were observed by HE staining,the apoptosis of germ cells were detected by TUNEL, the expression of apoptosis-related protein Caspase-3,BAX,BCL-2 in testis were examined by Western blot. Results: Compared with normal control group, the body weight, testis weight,testis index,and the expression of BCL-2 protein levels in testis of model control group were significantly decreased, the expression of BAX,Caspase-3 protein levels and apoptosis in testis of model control group were significantly increased. Wuzi Yanzong prescription significantly increased the body weight,testis weight,testis index,the expression of BCL-2 protein, while decreased the levels of BAX and Caspase-3 protein expression, and then led to the reduction in apoptosis of testis. Conclusion: Wuzi Yanzong prescription can effectively protect the apoptosis of germ cell induced by CTX, and its mechanism may be associated with downregulating protein expression of BAX and Caspase-3,and increasing the protein expression of BCL-2.