Pyroptosis and mitochondrial function participated in miR-654-3p-protected against myocardial infarction.

Myocardial infarction (MI) is one of the leading causes of heart failure with highly complicated pathogeneses. miR-654-3p has been recognized as a pivotal regulator of controlling cell survival. However, the function of miR-654-3p in cardiomyocytes and MI has yet to be reported. This study aimed to identify the role of miR-654-3p in the regulation of myocardial infarction. To understand the contribution of miR-654-3p on heart function, we generated cardiac-specific knockdown and overexpression mice using AAV9 technology in MI injury. Mechanically, we combined cellular and molecular techniques, pharmaceutical treatment, RNA sequencing, and functional testing to elucidate the potential pathological mechanisms. We identified that mice subjected to MI decreased the expression of miR-654-3p in the border and infarcted area. Mice lacking miR-654-3p in the heart showed some inflammation infiltration and myocardial fibrosis, resulting in a mild cardiac injury. Furthermore, we found a deficiency of miR-654-3p in cardiomyocytes resulted in pyroptotic cell death but not other programmed cell death. Intriguingly, miR-654-3p deficiency aggravated MI-induced cardiac dysfunction, accompanied by higher myocardial fibrosis and cardiac enzymes and augmented pyroptosis activation. Cardiac elevating miR-654-3p prevented myocardial fibrosis and inflammation infiltration and decreased pyroptosis profile, thereby attenuating MI-induced cardiac damage. Using RNA sequence and molecular biological approaches, we found overexpression of miR-654-3p in the heart promoted the metabolic ability of the cardiomyocytes by promoting mitochondrial metabolism and mitochondrial respiration function. Our finding identified the character of miR-654-3p in protecting against MI damage by mediating pyroptosis and mitochondrial metabolism. These findings provide a new mechanism for miR-654-3p involvement in the pathogenesis of MI and reveal novel therapeutic targets. miR-654-3p expression was decreased after MI. Mice lacking miR-654-3p in the heart showed some inflammation infiltration and myocardial fibrosis, resulting in a mild cardiac injury. The deficiency of miR-654-3p in cardiomyocytes resulted in pyroptotic cell death. miR-654-3p deficiency aggravated MI-induced cardiac dysfunction, accompanied by higher myocardial fibrosis and cardiac enzymes and augmented pyroptosis activation. Overexpression of miR-654-3p prevented myocardial fibrosis and inflammation infiltration and decreased pyroptosis profile, thereby attenuating MI-induced cardiac damage. Overexpression of miR-654-3p in the heart promoted the metabolic ability of the cardiomyocytes by promoting mitochondrial metabolism and mitochondrial respiration function.

Respiratory syncytial virus infection of microglia exacerbates SH-SY5Y neuronal cell injury by inducing the secretion of inflammatory cytokines: A Transwell in vitro study.

OBJECTIVES: To elucidate the mechanism of Respiratory Syncytial Virus (RSV) infection and central neuronal disease and to understand the role of microglia in neuronal injuries during RSV infection. MATERIALS AND METHODS: The effects of RSV and the cytokines produced by RSV-infected CHME-5 microglial cells on SY5Y neuronal cells were evaluated based on an in vitro Transwell coculture system. Five treatment groups were established in this study, including the normal control SY5Y group, RSV+SY5Y infection group, (cytokine+CHME-5)+SY5Y Transwell group, (RSV+CHME-5)+SY5Y Transwell group, and (RSV+cytokine+CHME-5)+SY5Y Transwell group. The morphological and physical alterations in SY5Y cells and their synapses were analyzed by confocal microscopy. The mRNA and protein expression levels of TLR3/RIG-I, as well as the expression of Hv1, in microglia were measured by qRT-PCR and Western blot assays. In addition, the apoptosis ratio of neuronal cells was determined by flow cytometry. RESULTS: RSV infection activated the protein expression of Hv1 protein in microglia in vitro (P<0.05), induced morphological changes in SY5Y cells, lengthened synapses (73.36±0.12 µm vs 38.10±0.11 µm), simultaneously activated TLR3 and RIG-I protein expression (P<0.05), upregulated the secretion of the inflammatory cytokines TNF-α, IL-6, and IL-8 (P<0.01), and increased the apoptosis rate of SY5Y cells (P<0.01). CONCLUSION: The results demonstrate that RSV infection of microglia can induce SY5Y neuronal cell injury and stimulate apoptosis through inflammatory cytokine release.

Cerebral venous collaterals: A new fort for fighting ischemic stroke?

Stroke therapy has entered a new era highlighted by the use of endovascular therapy in addition to intravenous thrombolysis. However, the efficacy of current therapeutic regimens might be reduced by their associated adverse events. For example, over-reperfusion and futile recanalization may lead to large infarct, brain swelling, hemorrhagic complication and neurological deterioration. The traditional pathophysiological understanding on ischemic stroke can hardly address these occurrences. Accumulating evidence suggests that a functional cerebral venous drainage, the major blood reservoir and drainage system in brain, may be as critical as arterial infusion for stroke evolution and clinical sequelae. Further exploration of the multi-faceted function of cerebral venous system may add new implications for stroke outcome prediction and future therapeutic decision-making. In this review, we emphasize the anatomical and functional characteristics of the cerebral venous system and illustrate its necessity in facilitating the arterial infusion and maintaining the cerebral perfusion in the pathological stroke content. We then summarize the recent critical clinical studies that underscore the associations between cerebral venous collateral and outcome of ischemic stroke with advanced imaging techniques. A novel three-level venous system classification is proposed to demonstrate the distinct characteristics of venous collaterals in the setting of ischemic stroke. Finally, we discuss the current directions for assessment of cerebral venous collaterals and provide future challenges and opportunities for therapeutic strategies in the light of these new concepts.

Orientia tsutsugamushi infection in rodents in Anhui Province of China.

We conducted an investigation of Orientia tsutsugamushi infection among rodents in non-endemic areas in Anhui Province. Fifty-six (56) rodents including 44 Apodemus agrarius and 12 Niviventer niviventer were trapped and captured in autumn in the fields of three counties in Anhui Province. DNA samples were amplified and sequenced for the 56kDa protein gene of Orientia tsutsugamushi. The overall infection rate in the rodents was 23.2%(13/56). The rate of detection of O. tsutsugamushi in Apodemus agrarius and Niviventer niviventer were 27.3% and 8.3% respectively. Moreover, we identified two genotypes (Karp and Gilliam strains) of Orientia tsutsugamushi in rodents. Our study demonstrated that Apodemus agrarius is the main host for O. tsutsugamushi pathogen and this is the first report of Karp and Gilliam strains in these non-endemic areas in Anhui Province.

[Thrombus length evaluated by CT perfusion imaging and its value in prediction of recanalization after intravenous thrombolysis therapy].

OBJECTIVE: To evaluate the thrombus length on CT perfusion imaging and to assess its predictive value for recanalization and clinical outcome after intravenous thrombolysis therapy (IVT). METHODS: Fifty-six consecutive acute ischemic stroke patients with proximal middle cerebral artery (M1 segment) occlusion underwent CT perfusion imaging examination before IVT between June 2009 and May 2015. The onset-to needle time was (214.3 ± 82.0) min, and the pretreatment NIHSS score of patients was 13 (IQR 8-17). The thrombus length was determined as the distance between the proximal and distal thrombus end delineated on dynamic angiography, which was reconstructed from CT perfusion source images. Recanalization was evaluated according to Arterial Occlusive Lesion (AOL) scale, and functional outcome was based on modified Rankin scale (mRS) 3 months after IVT. Logistic regression model was used to investigate the relationship between thrombus length and recanalization, and the optimal cut-off points were determined by receiver operating characteristic curve (ROC). RESULTS: Among 56 patients, 42 (75%) achieved recanalization 24 h after IVT with mean thrombus length of (9.0 ± 4.7) mm; and 14 (25%) patients remained occlusion with mean thrombus length of (10.0 ± 5.4) mm. Logistic regression analysis demonstrated that thrombus length was an independent predictor for both recanalization (OR=0.869; 95% CI:0.764-0.987; P=0.031) and unfavorable outcome (OR=1.180;95% CI:1.023-1.362; P=0.023). Thrombus length of 11.3 mm was identified as the optimal cut-off value for recanalization (AUC=0.697, sensitivity 71.4%, specificity 76.2%), while thrombus length of 9.9 mm was the optimal cut-off value for unfavorable functional outcome (AUC=0.689, sensitivity 64.7%, specificity 71.4%). CONCLUSION: The thrombus length evaluated on CT perfusion imaging is an effective predictor for recanalization and unfavorable outcome after IVT in acute ischemic stroke patients with middle cerebral artery occlusion.