Loss of SARM1 ameliorates secondary thalamic neurodegeneration after cerebral infarction.

Ischemic stroke causes secondary neurodegeneration in the thalamus ipsilateral to the infarction site and impedes neurological recovery. Axonal degeneration of thalamocortical fibers and autophagy overactivation are involved in thalamic neurodegeneration after ischemic stroke. However, the molecular mechanisms underlying thalamic neurodegeneration remain unclear. Sterile /Armadillo/Toll-Interleukin receptor homology domain protein (SARM1) can induce Wallerian degeneration. Herein, we aimed to investigate the role of SARM1 in thalamic neurodegeneration and autophagy activation after photothrombotic infarction. Neurological deficits measured using modified neurological severity scores and adhesive-removal test were ameliorated in Sarm1-/- mice after photothrombotic infarction. Compared with wild-type mice, Sarm1-/- mice exhibited unaltered infarct volume; however, there were markedly reduced neuronal death and gliosis in the ipsilateral thalamus. In parallel, autophagy activation was attenuated in the thalamus of Sarm1-/- mice after cerebral infarction. Thalamic Sarm1 re-expression in Sarm1-/- mice increased thalamic neurodegeneration and promoted autophagy activation. Auotophagic inhibitor 3-methyladenine partially alleviated thalamic damage induced by SARM1. Moreover, autophagic initiation through rapamycin treatment aggravated post-stroke neuronal death and gliosis in Sarm1-/- mice. Taken together, SARM1 contributes to secondary thalamic neurodegeneration after cerebral infarction, at least partly through autophagy inhibition. SARM1 deficiency is a potential therapeutic strategy for secondary thalamic neurodegeneration and functional deficits after stroke.

Risk factors for pharmacotherapy for storage symptoms after transurethral resection of the prostate in patients with benign prostatic hyperplasia.

OBJECTIVES: Postoperative persistence of storage symptoms after transurethral resection of the prostate (TURP) is bothersome, and evidence of its cause is sparse. We sought to analyze risk factors for using antimuscarinics or beta-3 agonists after TURP in benign prostatic hyperplasia (BPH) patients. METHODS: BPH patients who underwent TURP and were followed up for >6 months after surgery were retrospectively enrolled. Postoperative pharmacotherapy for storage symptoms was defined as the prescription of antimuscarinics or beta-3 agonists within 3 months after TURP for >3 months. Preoperative and perioperative variables were evaluated for their effect on the postoperative prescription of antimuscarinics or beta-3 agonists. RESULTS: Of the 376 patients, 45 (12.0%) received postoperative pharmacotherapy for storage symptoms. Patients who underwent bipolar TURP were significantly more likely to receive postoperative pharmacotherapy than those who underwent monopolar TURP (15.7% vs 6.9%; P = 0.01). Significantly more patients with intravesical prostatic protrusions >1 cm used postoperative pharmacotherapy than those with protrusions of ≤1 cm (14.4% vs 5.2% respectively; P = 0.02). Multivariate logistic regression analysis revealed age >75 years (odds ratio [OR] 3.04; 95% CI 1.29-7.16; P = 0.011), intravesical prostatic protrusion >1 cm (OR, 3.48; 95% CI, 1.32-9.15; P = 0.012), and bipolar transurethral resection (OR 4.25; 95% CI 1.53-11.80; P = 0.005) as significant risk factors for postoperative pharmacotherapy. CONCLUSIONS: Advanced age, intravesical prostatic protrusion, and bipolar TURP were significantly associated with postoperative pharmacotherapy for storage symptoms after TURP in BPH patients. Therefore, patients with these risk factors might be informed about the risk of postoperative storage symptoms that may require medications after TURP.

Schisandrin B displays a protective role against primary pulmonary hypertension by targeting transforming growth factor ß1.

Pulmonary arterial smooth muscle cells (PASMCs) in the medial layer of the vessel wall are involved in vessel homeostasis, but also for pathologic vascular remodeling in diverse diseases, such as pulmonary arterial hypertension (PAH). Pulmonary vascular remodeling in PAH results in vascular disorders, but its underlying molecular mechanisms are still not to be fully disclosed. In this study, we investigated the expression and function of the transforming growth factor (TGF)-ß1 in human PASMC cultured under the condition of hypoxia and elucidated the effect of schisandra chinensis and its active ingredients on proliferation, migration, and apoptosis in human PASMCs. We demonstrated that schisandrin B (Sch.B) alleviated the severity of PAH in PASMCs cultured under the condition of hypoxia. Significant upregulation of TGF-ß1 was observed in hypoxia-induced human PASMCs. Interestingly, administration of Sch.B substantially attenuated TGF-ß1 level in these PASMCs. In order to elucidate Sch.B function, the hypoxia-induced human PASMC was stimulated with Sch.B or cotreatment with TGF-ß1 in vitro. In agreement with its TGF-ß1-reducing effect, Sch B relieved human PASMCs migration and promoted the apoptosis of human PASMCs, by activation of TGF-ß1 downstream signal pathways in PASMCs. In contrast, co-treatment with TGF-ß1 promoted human PASMC proliferation and migration and inhibited the apoptosis of human PASMC, which can attenuate the protective role of Sch.B in human PASMC. Taken collectively, these findings suggest that the vascular relaxation evoked by Sch.B was mediated by direct effect on vascular smooth muscle cell via TGF-ß1 downstream signal pathways.

Dehydroabietic acid isolated from Commiphora opobalsamum causes endothelium-dependent relaxation of pulmonary artery via PI3K/Akt-eNOS signaling pathway.

Commiphora opobalsamum is a Traditional Chinese Medicine used to treat traumatic injury, mainly by relaxing blood vessels. In this study, two diterpenes, dehydroabietic acid (DA) and sandaracopimaric acid (SA) were obtained from it by a bioassay-guided approach using isolated rat pulmonary artery rings. The structures of the two compounds were elucidated by spectroscopic methods (IR, 1H- and 13C-NMR, HR-ESI-MS). Both DA and SA reduced the contraction of phenylephrine-induced pulmonary arteries in a concentration-dependent manner, and endothelium contributed greatly to the vasodilatory effect of DA. This effect of DA was attenuated by NG-Nitro-L-arginine methyl ester (L-NAME, an eNOS inhibitor). Meanwhile, DA increased nitric oxide (NO) production, along with the increase of phosphorylation level of eNOS and Akt in endothelial cells. LY294002 (a PI3K inhibitor) could reverse this effect, which suggested the endothelial PI3K/Akt pathway involved in the mechanism underlying DA-induced relaxation of pulmonary artery. This work provided evidence of vasorelaxant substances in Commiphora opobalsamum and validated that PI3K/Akt-eNOS pathway was associated with DA-induced pulmonary artery vasodilation.

Cerebrolysin reduces amyloid-ß deposits, apoptosis and autophagy in the thalamus and improves functional recovery after cortical infarction.

Focal cerebral infarction causes amyloid-ß (Aß) deposits and secondary thalamic neuronal degeneration. The present study aimed to determine the protective effects of Cerebrolysin on Aß deposits and secondary neuronal damage in thalamus after cerebral infarction. At 24h after distal middle cerebral artery occlusion (MCAO), Cerebrolysin (5 ml/kg) or saline as control was once daily administered for consecutive 13 days by intraperitoneal injection. Sensory function and secondary thalamic damage were assessed with adhesive-removal test, Nissl staining and immunofluorescence at 14 days after MCAO. Aß deposits, activity of ß-site amyloid precursor protein-cleaving enzyme 1 (BACE1), apoptosis and autophagy were determined by TUNEL staining, immunofluorescence and immunoblot. The results showed that Cerebrolysin significantly improved sensory deficit compared to controls (p<0.05). Aß deposits and BACE1 were obviously reduced by Cerebrolysin, which was accompanied by decreases in neuronal loss and astroglial activation compared to controls (all p < 0.05). Coincidently, Cerebrolysin markedly inhibited cleaved caspase-3, conversion of LC3-II, downregulation of Bcl-2 and upregulation of Bax in the ipsilateral thalamus compared to controls (all p<0.05). These findings suggest that Cerebrolysin reduces Aß deposits, apoptosis and autophagy in the ipsilateral thalamus, which may be associated with amelioration of secondary thalamic damage and functional recovery after cerebral infarction.

Autophagosomes accumulation is associated with ß-amyloid deposits and secondary damage in the thalamus after focal cortical infarction in hypertensive rats.

Focal cerebral cortical infarction after distal middle cerebral artery occlusion causes ß-amyloid deposition and secondary neuronal degeneration in the ipsilateral ventroposterior nucleus of the thalamus. Several studies suggest that autophagy is an active pathway for ß-amyloid peptide generation. This study aimed to investigate the role of autophagy in thalamic ß-amyloid deposition and neuronal degeneration after cerebral cortical infarction in hypertensive rats. At 7 and 14days after middle cerebral artery occlusion, neuronal death and ß-amyloid deposits were evident in the ipsilateral ventroposterior nucleus, and the activity of ß-site amyloid precursor protein (APP)-cleaving enzyme 1, required for ß-amyloid peptide generation, was elevated in the thalamus. In correlation, both the number of cells showing punctate microtubule-associated protein 1A light chain 3 fluorescence and levels of light chain 3-II protein, an autophagosome marker, were markedly increased. Notably, most of the cells that over-expressed ß-site APP-cleaving enzyme 1 displayed punctate light chain 3 staining. Furthermore, the inhibition of autophagy with 3-methyladenine significantly reduced the thalamic neuronal damage, ß-amyloid deposits, and ß-site APP-cleaving enzyme 1 activity. These results suggest that autophagosomes accumulate within thalamic cells after cerebral cortical infarction, which is associated with thalamic ß-amyloid deposition and secondary neuronal degeneration via elevation of ß-site APP-cleaving enzyme 1 level.

Beclin 1 knockdown inhibits autophagic activation and prevents the secondary neurodegenerative damage in the ipsilateral thalamus following focal cerebral infarction.

Cerebral infarction can cause secondary degeneration of thalamus and delay functional recovery. However, the mechanisms underlying secondary degeneration are unclear. The present study aimed to determine the occurrence and contribution of autophagy to the thalamic degeneration after cerebral infarction. Focal cerebral infarction was induced by distal middle cerebral artery occlusion (MCAO). Autophagic activation, Beclin 1 expression and amyloid ß (Aß) deposits were determined by immunofluorescence, immunoblot and electron microscopy. Secondary damage to thalamus was assessed with Nissl staining and immunofluorescence analysis. Apoptosis was determined using TUNEL staining. The contribution of autophagy to the secondary damage was evaluated by shRNA-mediated downregulation of Beclin 1 and the autophagic inhibitor, 3-methyladenine (3-MA). The potential role of Aß in autophagic activation was determined with N-[N-(3, 5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT). The results showed that the conversion of LC3-II, the formation of autophagosomes, and the levels of activated cathepsin B and Beclin 1 were significantly increased in the ipsilateral thalamus at 7 and 14 days after MCAO (p < 0.05 or 0.01). Both Beclin 1 knockdown and 3-MA treatment significantly reduced LC3-II conversion and autophagosome formation, which were accompanied by obvious decreases in neuronal loss, gliosis and apoptosis in the ipsilateral thalamus (p < 0.05 or 0.01). Additionally, DAPT treatment markedly reduced Aß deposits, which coincided with decreases in LC3-II conversion and autophagosome formation (p < 0.01). These results suggest that inhibition of autophagy by Beclin 1 knockdown can attenuate the secondary thalamic damage after focal cerebral infarction. Furthermore, Aß deposits may be involved in the activation of autophagy.

Decrease of tight junction integrity in the ipsilateral thalamus during the acute stage after focal infarction and ablation of the cerebral cortex in rats.

1. Whether damage to the blood-brain barrier (BBB) occurs in remote areas after a focal cortical lesion remains unknown. The present study investigated tight junction-related proteins and tight junction microstructure in the ipsilateral thalamus during the acute stage after middle cerebral artery occlusion (MCAO) and cortical aspiration lesion (CAL) in rats. 2. Thirty-six hypertensive and normotensive rats were subjected to MCAO or CAL; another 18 rats in each group were submitted to sham operation. Zonula Occluden (ZO)-1, occludin and albumin were detected by western blotting 12 and 24 h after surgery. Tight junction microstructure was evaluated using electron microscopy, whereas albumin location in the ipsilateral thalamus was determined using double immunostaining for albumin and occludin or albumin and neuronal nuclei (NeuN) 24 h after surgery. 3. Twenty-four hours after MCAO or CAL, occludin expression was reduced to 78.4% and 81.3%, respectively, compared with control. A reduction in ZO-1 expression in the ipsilateral thalamus (to 79%) was seen only after CAL (P < 0.05). Membrane contact at the tight junction was discontinuous in the ipsilateral thalamus in both MCAO and CAL rats. Albumin levels were 23.2% and 82.5% higher in the ipsilateral thalamus after MCAO and CAL, respectively (P < 0.05). The percentage of the albumin-positive area that coincided with the occludin-positive area in the MCAO and CAL groups was 76.8% and 64.6%, respectively, indicating that albumin was mainly localized around the microvessels. 4. The results of the present study suggest that tight junction integrity decreases during the acute stage in the ipsilateral thalamus after MCAO and CAL in rats.