VEGFD/VEGFR3 signaling contributes to the dysfunction of the astrocyte IL-3/microglia IL-3Rα cross-talk and drives neuroinflammation in mouse ischemic stroke.

Astrocyte-derived IL-3 activates the corresponding receptor IL-3Rα in microglia. This cross-talk between astrocytes and microglia ameliorates the pathology of Alzheimer's disease in mice. In this study we investigated the role of IL-3/IL-3Rα cross-talk and its regulatory mechanisms in ischemic stroke. Ischemic stroke was induced in mice by intraluminal occlusion of the right middle cerebral artery (MCA) for 60 min followed by reperfusion (I/R). Human astrocytes or microglia subjected to oxygen-glucose deprivation and reoxygenation (OGD/Re) were used as in vitro models of brain ischemia. We showed that both I/R and OGD/Re significantly induced decreases in astrocytic IL-3 and microglial IL-3Rα protein levels, accompanied by pro-inflammatory activation of A1-type astrocytes and M1-type microglia. Importantly, astrocyte-derived VEGFD acting on VEGFR3 of astrocytes and microglia contributed to the cross-talk dysfunction and pro-inflammatory activation of the two glial cells, thereby mediating neuronal cell damage. By using metabolomics and multiple biochemical approaches, we demonstrated that IL-3 supplementation to microglia reversed OGD/Re-induced lipid metabolic reprogramming evidenced by upregulated expression of CPT1A, a rate-limiting enzyme for the mitochondrial ß-oxidation, and increased levels of glycerophospholipids, the major components of cellular membranes, causing reduced accumulation of lipid droplets, thus reduced pro-inflammatory activation and necrosis, as well as increased phagocytosis of microglia. Notably, exogenous IL-3 and the VEGFR antagonist axitinib reestablished the cross-talk of IL-3/IL-3Rα, improving microglial lipid metabolic levels via upregulation of CPT1A, restoring microglial phagocytotic function and attenuating microglial pro-inflammatory activation, ultimately contributing to brain recovery from I/R insult. Our results demonstrate that VEGFD/VEGFR3 signaling contributes to the dysfunction of the astrocyte IL-3/microglia IL-3Rα cross-talk and drives pro-inflammatory activation, causing lipid metabolic reprogramming of microglia. These insights suggest VEGFR3 antagonism or restoring IL-3 levels as a potential therapeutic strategy for ischemic stroke.

Valproic Acid Inhibits Glial Scar Formation after Ischemic Stroke.

INTRODUCTION: Cerebral ischemia induces reactive proliferation of astrocytes (astrogliosis) and glial scar formation. As a physical and biochemical barrier, the glial scar not only hinders spontaneous axonal regeneration and neuronal repair but also deteriorates the neuroinflammation in the recovery phase of ischemic stroke. OBJECTIVES: Previous studies have shown the neuroprotective effects of the valproic acid (2-n-propylpentanoic acid, VPA) against ischemic stroke, but its effects on the ischemia-induced formation of astrogliosis and glial scar are still unknown. As targeting astrogliosis has become a therapeutic strategy for ischemic stroke, this study was designed to determine whether VPA can inhibit the ischemic stroke-induced glial scar formation and to explore its molecular mechanisms. METHODS: Glial scar formation was induced by an ischemia-reperfusion (I/R) model in vivo and an oxygen and glucose deprivation (OGD)-reoxygenation (OGD/Re) model in vitro. Animals were treated with an intraperitoneal injection of VPA (250 mg/kg/day) for 28 days, and the ischemic stroke-related behaviors were assessed. RESULTS: Four weeks of VPA treatment could markedly reduce the brain atrophy volume and improve the behavioral deficits in rats' I/R injury model. The results showed that VPA administrated upon reperfusion or 1 day post-reperfusion could also decrease the expression of the glial scar makers such as glial fibrillary acidic protein, neurocan, and phosphacan in the peri-infarct region after I/R. Consistent with the in vivo data, VPA treatment showed a protective effect against OGD/Re-induced astrocytic cell death in the in vitro model and also decreased the expression of GFAP, neurocan, and phosphacan. Further studies revealed that VPA significantly upregulated the expression of acetylated histone 3, acetylated histone 4, and heat-shock protein 70.1B in the OGD/Re-induced glial scar formation model. CONCLUSION: VPA produces neuroprotective effects and inhibits the glial scar formation during the recovery period of ischemic stroke via inhibition of histone deacetylase and induction of Hsp70.1B.

ALDH2 Gene rs671 Polymorphism May Decrease the Risk of Essential Hypertension.

Aldehyde dehydrogenase-2 (ALDH2) rs671 G>A polymorphism can influence the activity of ALDH2 and may be associated with the risk of essential hypertension (EH). Although many previous studies have explored such a relationship, the conclusion is still controversial.The PubMed, Embase, and China National Knowledge Infrastructure databases were searched on the ALDH2 gene and EH. We used the Newcastle-Ottawa Scale to evaluate the quality of the study. Then we calculated the strength of relationship between ALDH2 rs671 mutation and EH by utilizing odds ratios and 95% confidence intervals. Besides, subgroup analysis and sensitivity analysis were performed and the publication bias was assessed.There were 12 studies containing 8153 cases and 10,162 controls. Our meta-analysis showed significant association between ALDH2 rs671 polymorphism and EH in four genetic models (the allele model, the homozygote model, the heterozygote model, and the dominant model), whereas it did not indicate this connection in the recessive model. However, a trend of decreased risk still could be seen. Furthermore, we also found an obvious association between rs671 mutation and the risk of EH in the male group than in the female group in all five genetic models.We concluded that ALDH2 rs671 G>A polymorphism may decrease the risk of EH. Furthermore, susceptibility to EH reduced in males but not in females. As a variant in ALDH2, rs671 G>A could be an attractive candidate for genetic therapy of EH. In addition, more case-control studies should be conducted to strengthen our conclusion and evaluate the gene-gene and gene-environment interactions between the ALDH2 gene and EH.

Coordination of Autophagy and Other Cellular Activities.

Conventionally, autophagy (=self-eating) is thought to be a catabolic cellular process that is responsible for regulating cell homeostasis. However, the newly evidence have expanded the range of the impact of autophagy in biology. Autophagy interplays with endocytosis through shared factors such as phosphatidylinositol 3 kinase complex (PI(3)K complex), autophagy associated gene (Atg), and lysosome. Autophagy and phagocytosis orchestrate in maintaining homeostasis, in MHC class II antigen processing, in the removal of pathogens, in cell death, immunity, and inflammation. There are numerous cross talks of autophagy with biosynthetic processes such as conventional and unconventional secretion of biologically active cargo and trafficking of integral membrane proteins, as well as the exosome secretion. There are also links between autophagy and trafficking events from plasma membrane, including lateral plasma membrane proteins connexins, cell connections, and ciliogenesis.

The brain protection of MLKL inhibitor necrosulfonamide against focal ischemia/reperfusion injury associating with blocking the nucleus and nuclear envelope translocation of MLKL and RIP3K.

Mixed lineage kinase like protein (MLKL) is a key mediator of necroptosis. While previous studies highlighted the important role of MLKL as one of the central regulators of brain damage against acute ischemic neuronal injury, how the activation of MLKL mediates brain injuries and cell death remains unclear, especially in astrocytes. In a transient middle cerebral artery occlusion (tMCAO) rat model in vivo, and an oxygen-glucose deprivation and reoxygenation (OGD/Re) injury model in both primary cultured astrocytes and human astrocytes, we show that necrosulfonamide (NSA), a MLKL specific inhibitor, reduces infarction volume and improves neurological deficits in tMCAO-treated rats. In addition, NSA treatment, as well as RIP1K inhibitor Nec-1 or RIP3K inhibitor GSK-872 treatment, decreases the OGD/Re-induced leakage of LDH in both primary cultured astrocytes and human astrocytes. NSA treatment also reduces the number of propidium iodide (PI)-positive cells, and prevents the upregulation of necroptotic biomarkers such as MLKL/p-MLKL, RIP3K/p-RIP3K, and RIP1K/p-RIP1K in ischemic penumbra of cerebral cortex in tMCAO-treated rats or in OGD/Re-treated human astrocytes. Importantly, NSA treatment blocks both the nucleus and nuclear envelope localization of MLKL/p-MLKL and RIP3K/p-RIP3K in ischemic cerebral cortex induced by tMCAO. Similarly, Co-immunoprecipitation assay shows that NSA treatment decreases tMCAO- or OGD/Re- induced increased combination of MLKL and RIP3K in nuclear envelope of ischemic penumbra of cerebral cortex or of primary cultured astrocytes, respectively. RIP3K inhibitor GSK-872 also reduces tMCAO-induced increased combination of MLKL and RIP3K in nuclear envelope of ischemic penumbra of cerebral cortex. These data suggest NSA exerts protective effects against focal ischemia/reperfusion injury via inhibiting astrocytic necroptosis through preventing the upregulation of necroptotic kinases as well as blocking both the nucleus and nuclear envelope co-localization of p-MLKL and p-RIP3K. The translocation of p-MLKL, along with p-RIP3K, to the nuclear envelope and the nucleus may play a crucial role in MLKL-mediated necroptosis under ischemic conditions.

The Key Regulator of Necroptosis, RIP1 Kinase, Contributes to the Formation of Astrogliosis and Glial Scar in Ischemic Stroke.

Necroptosis initiation relies on the receptor-interacting protein 1 kinase (RIP1K). We recently reported that genetic and pharmacological inhibition of RIP1K produces protection against ischemic stroke-induced astrocytic injury. However, the role of RIP1K in ischemic stroke-induced formation of astrogliosis and glial scar remains unknown. Here, in a transient middle cerebral artery occlusion (tMCAO) rat model and an oxygen and glucose deprivation and reoxygenation (OGD/Re)-induced astrocytic injury model, we show that RIP1K was significantly elevated in the reactive astrocytes. Knockdown of RIP1K or delayed administration of RIP1K inhibitor Nec-1 down-regulated the glial scar markers, improved ischemic stroke-induced necrotic morphology and neurologic deficits, and reduced the volume of brain atrophy. Moreover, knockdown of RIP1K attenuated astrocytic cell death and proliferation and promoted neuronal axonal generation in a neuron and astrocyte co-culture system. Both vascular endothelial growth factor D (VEGF-D) and its receptor VEGFR-3 were elevated in the reactive astrocytes; simultaneously, VEGF-D was increased in the medium of astrocytes exposed to OGD/Re. Knockdown of RIP1K down-regulated VEGF-D gene and protein levels in the reactive astrocytes. Treatment with 400 ng/ml recombinant VEGF-D induced the formation of glial scar; conversely, the inhibitor of VEGFR-3 suppressed OGD/Re-induced glial scar formation. RIP3K and MLKL may be involved in glial scar formation. Taken together, these results suggest that RIP1K participates in the formation of astrogliosis and glial scar via impairment of normal astrocyte responses and enhancing the astrocytic VEGF-D/VEGFR-3 signaling pathways. Inhibition of RIP1K promotes the brain functional recovery partially via suppressing the formation of astrogliosis and glial scar.

Mechanism and consequences for avoidance of superparasitism in the solitary parasitoid Cotesia vestalis.

A parasitoid's decision to reject or accept a potential host is fundamental to its fitness. Superparasitism, in which more than one egg of a given parasitoid species can deposit in a single host, is usually considered sub-optimal in systems where the host is able to support the development of only a single parasitoid. It follows that selection pressure may drive the capacity for parasitoids to recognize parasitized hosts, especially if there is a fitness cost of superparasitism. Here, we used microsatellite studies of two distinct populations of Cotesia vestalis to demonstrate that an egg laid into a diamondback moth (Plutella xylostella) larva that was parasitized by a conspecific parasitoid 10 min, 2 or 6 h previously was as likely to develop and emerge successfully as was the first-laid egg. Consistent with this, a naive parasitoid encountering its first host was equally likely to accept a healthy larva as one parasitized 10 min prior, though handling time of parasitized hosts was extended. For second and third host encounters, parasitized hosts were less readily accepted than healthy larvae. If 12 h elapsed between parasitism events, the second-laid egg was much less likely to develop. Discrimination between parasitized and healthy hosts was evident when females were allowed physical contact with hosts, and healthy hosts were rendered less acceptable by manual injection of parasitoid venom into their hemolymph. Collectively, these results show a limited capacity to discriminate parasitized from healthy larvae despite a viability cost associated with failing to avoid superparasitism.

[CT scan findings of primary pulmonary non-Hodgkin's lymphoma and their relation to pathological features].

OBJECTIVE: To investigate the CT scan findings of primary pulmonary non-Hodgkin's lymphoma (PPNHL) and their relation to pathological features. METHODS: The CT scan findings of 17 PPNHL cases confirmed pathologically from August 1992 to June 2007 were analyzed in relation to their pathological foundation. RESULT: In 17 cases the CT findings showed: 1) Five were single mass or nodule, including 3 with air-bronchograms, 1 with straddling-lobe distribution and 3 with slight enhancement; 2) One was multi-nodules with air-bronchograms; 3) Six were consolidation with air bronchogram,including 3 with straddling-lobe distribution and 3 with slight enhancement; 4) Five were combined changes, including 5 with air-bronchograms, 2 with straddling-lobe distribution and 4 with slight enhancement. The CT features of PPNHL corresponded to their pathological process and pathological features. CONCLUSION: Primary pulmonary non-Hodgkin's lymphoma should be considered when CT scan shows variety of images found in one patient, middle lobe of right lung involved, air-bronchograms and straddling-lobe distribution in consolidation with slight enhancement.

Inhibition of autophagy blocks cathepsins-tBid-mitochondrial apoptotic signaling pathway via stabilization of lysosomal membrane in ischemic astrocytes.

Our previous study and others have demonstrated that autophagy is activated in ischemic astrocytes and contributes to astrocytic cell death. However, the mechanisms of ischemia-induced autophagy remain largely unknown. In this study, we established a rat's model of permanent middle cerebral artery occlusion (pMCAO) and an in vitro oxygen and glucose deprivation (OGD) model. Autophagy was inhibited by either pharmacological treatment with 3-methyladenine (3-MA) and wortmannin (Wort) or genetic treatment with knockdown of Atg5 in primary cultured astrocytes and knockout of Atg5 in mouse embryonic fibroblast (MEF) cells, respectively. We found that pharmacological or genetic inhibition of autophagy reversed pMCAO or OGD-induced increase in LC3-II, active cathepsin B and L, tBid, active caspase-3 and cytoplastic cytochrome c (Cyt-c), and suppressed the injury-induced reduction in mitochondrial Cyt-c in ischemic cortex, in injured astrocytes and MEF cells. Immunofluorescence analysis showed that 3-MA or Wort treatment reversed OGD-induced release of cathepsin B and L from the lysosome to the cytoplasm and activation of caspase-3 in the astrocytes. Furthermore, treatment of 3-MA or Wort decreased OGD-induced increase in lysosomal membrane permeability and enhanced OGD-induced upregulation of lysosomal heat shock protein 70.1B (Hsp70.1B) in astrocytes. Inhibition of autophagy by 3-MA or Wort reduced infarction volume in rats and protected OGD-induced astrocytic cell injury. A non-selective caspase inhibitor z-VAD-fmk or a specific caspase-3 inhibitor Q-DEVD-OPh also rescued OGD-induced astrocytic cell injury. In conclusion, our presenting data suggest that inhibition of autophagy blocks cathepsins-tBid-mitochondrial apoptotic signaling pathway via stabilization of lysosomal membranes, possibly due to upregulation of the lysosomal Hsp70.1B in ischemic astrocytes.

Evaluation of selective hepatic angiography and embolization in patients with massive hemobilia.

BACKGROUND: Massive hemobilia is a rare but potentially life-threatening cause of upper gastrointestinal hemorrhage. Transarterial embolization is considered the first line of intervention to stop the bleeding for most causes of hemobilia. This study was conducted to evaluate selective hepatic angiography and embolization in the diagnosis and treatment of patients with massive hemobilia. METHODS: The clinical data of 16 patients with massive hemobilia were analyzed retrospectively. These patients underwent emergency celiac and selective right or left hepatic artery angiography and treated by embolization using Gelfoam particles and/or coils. RESULTS: Hepatic artery angiography revealed hepatic artery pseudoaneurysms in 6 patients, cystic artery pseudoaneurysms in 2, diffuse hemorrhage of hepatic artery branches in 5, and right hepatic artery-bile duct fistulae in 3. The patients were diagnosed rapidly by angiography and treated successfully by embolization of the hepatic artery branch proximal to the bleeding point, and hemorrhage was stopped immediately. Two patients were embolized the second time for rebleeding. Neither recurrence of bleeding nor serious complication was found during the follow-up for 3 months to 2 years. The other 2 patients whose hemorrhage failed to be controlled died several days later. CONCLUSION: Being safe, reliable and minimally invasive, selective hepatic artery angiography and embolization are effective in the diagnosis and treatment of massive hemobilia.

Role of CT-guided percutaneous lung biopsy in diagnosis of pulmonary fungal infection in patients with hematologic diseases.

The goal of our study is to evaluate the efficiency and safety of CT-guided percutaneous lung biopsy for the diagnosis of pulmonary fungal infection in patients with hematologic disease. Medical records were retrospectively reviewed for 16 patients with hematologic diseases, who were initially suspected to have pulmonary fungal infection clinically and underwent further diagnostic methods including blood culture, sputum culture and percutaneous lung biopsy. Of the 16 patients, 10 were diagnosed fungal infection (8 aspergillus, 2 mold fungus), 4 chronic organizing pneumonitis, 1 tuberculosis, and 1 Pneumocystis carinii through histological examination after percutaneous lung biopsy. However, the results of blood culture and sputum culture were negative. CT-guided biopsy showed 100% overall accuracy and 62.5% (10/16) fungal infection rate. The biopsy-induced complications encountered were pneumothorax in 3/16 (18.75%) and hemoptysis in 1/16 (6.25%). No serious complication was found in this series. In conclusion, CT-guided percutaneous lung biopsy is an effective and safe method for the diagnosis of pulmonary fungal infection in patients with hematologic diseases.