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The role of astrocytes in major depressive disorder has received great attention. Increasing evidence indicates that decreased astrocyte numbers in the hippocampus may be associated with depression, but the role of necroptosis in depression is unknown. Here, in a chronic unpredictable mild stress (CUMS) mouse model and a corticosterone (Cort)-induced human astrocyte injury model in vitro , we found that mice treated with chronic unpredictable mild stress for 3–5 weeks presented depressive-like behaviors and reduced body weight gain, accompanied by a reduction in astrocytes and a decrease in astrocytic brain-derived neurotropic factors (BDNF), by activation of necroptotic kinases, including RIPK1 (receptor-interacting protein kinase 1)/p-RIPK1, RIPK3 (receptor-interacting protein kinase 3)/p-RIPK3 and MLKL (mixed lineage kinase domain-like protein)/p-MLKL, and by upregulation of inflammatory cytokines in astrocytes of the mouse hippocampus. In contrast, necroptotic kinase inhibitors suppressed Cort-induced necroptotic kinase activation, reduced astrocytes, astrocytic necroptosis and dysfunction, and decreased Cort-mediated inflammatory cytokines in astrocytes. Treatment with fluoxetine (FLX) for 5 weeks improved chronic unpredictable mild stress-induced mouse depressive-like behaviors; simultaneously, fluoxetine inhibited depression-induced necroptotic kinase activation, reversed the reduction in astrocytes and astrocytic necroptosis and dysfunction, decreased inflammatory cytokines and upregulated brain-derived neurotropic factors and 5-HT1A levels. Furthermore, fluoxetine had no direct inhibitory effect on receptor-interacting protein kinase 1 phosphorylation. The combined administration of fluoxetine and necroptotic kinase inhibitors further reduced corticosterone-induced astrocyte injury. In conclusion, the reduction in astrocytes caused by depressive-like models in vivo and in vitro may be associated with the activation of necroptotic kinases and astrocytic necroptosis, and fluoxetine exerts an antidepressive effect by indirectly inhibiting receptor-interacting protein kinase 1-mediated astrocytic necroptosis.

Hyperhomocysteinemia (HHcy) is an independent risk factor of atherosclerosis and other cardiovascular diseases. Unfortunately, Hcy-lowering strategies were found to have limited effects in reducing cardiovascular events. The underlying mechanisms remain unclear. Increasing evidence reveals a role of inflammation in the pathogenesis of HHcy. Homocysteine (Hcy) is a precursor of hydrogen sulfide (H2S), which is formed via the transsulfuration pathway catalyzed by cystathionine β-synthase and cystathionine γ-lyase (CSE) and serves as a novel modulator of inflammation. In the present study, we showed that methionine supplementation induced mild HHcy in mice, associated with the elevations of TNF-α and IL-1β in the plasma and reductions of plasma H2S level and CSE expression in the peritoneal macrophages. H2S-releasing compound GYY4137 attenuated the increases of TNF-α and IL-1β in the plasma of HHcy mice and Hcy-treated raw264.7 cells while CSE inhibitor PAG exacerbated it. Moreover, the in vitro study showed that Hcy inhibited CSE expression and H2S production in macrophages, accompanied by the increases of DNA methyltransferase (DNMT) expression and DNA hypermethylation in cse promoter region. DNMT inhibition or knockdown reversed the decrease of CSE transcription induced by Hcy in macrophages. In sum, our findings demonstrate that Hcy may trigger inflammation through inhibiting CSE-H2S signaling, associated with increased promoter DNA methylation and transcriptional repression of cse in macrophages.

Sporadic hemiplegic migraine is a rare form of migraine headache with aura. We herein report a case of visual impairment, dizziness, and motor weakness in a patient who had experienced recurrent headache attacks with aura including flickering spots and blurred vision for 20 years, Electroencephalography, cerebrospinal fluid analysis, and brain imaging findings were normal. The patient gradually recovered after treatment with nonsteroidal anti-inflammatory drugs and flunarizine.

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 β-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.

POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes) syndrome is rare, with polyneuropathy and monoclonal plasma cell disorder generally considered as essential diagnostic symptoms. We report two cases of POEMS syndrome without monoclonal protein expression. The first case was a 72-year-old man who had experienced recurrent edema of the lower limbs for 2 years and abdominal distention for 2 months. The other case was a 62-year-old man with a 5-year history of recurrent numbness of the extremities and muscle weakness, which had become serious over the preceding 3 months. Both patients had various symptoms that matched those of POEMS syndrome, but neither had monoclonal protein expression. However, a diagnosis of POEMS syndrome was made in each case. Both patients were treated with lenalidomide and dexamethasone, after which their symptoms improved and laboratory test results normalized. The findings in these two cases suggest the possibility that POEMS syndrome may occur without monoclonal protein expression. The diagnostic criteria of POEMS syndrome may thus need further investigation.

Receptor-interacting protein kinase 1 (RIPK1) contributes to necroptosis. Our previous study showed that pharmacological or genetic inhibition of RIPK1 protects against ischemic stroke-induced astrocyte injury. In this study, we investigated the molecular mechanisms underlying RIPK1-mediated astrocyte injury in vitro and in vivo. Primary cultured astrocytes were transfected with lentiviruses and then subjected to oxygen and glucose deprivation (OGD). In a rat model of permanent middle cerebral artery occlusion (pMCAO), lentiviruses carrying shRNA targeting RIPK1 or shRNA targeting heat shock protein 70.1B (Hsp70.1B) were injected into the lateral ventricles 5 days before pMCAO was established. We showed that RIPK1 knockdown protected against OGD-induced astrocyte damage, blocked the OGD-mediated increase in lysosomal membrane permeability in astrocytes, and inhibited the pMCAO-induced increase in astrocyte lysosome numbers in the ischemic cerebral cortex; these results suggested that RIPK1 contributed to the lysosomal injury in ischemic astrocytes. We revealed that RIPK1 knockdown upregulated the protein levels of Hsp70.1B and increased the colocalization of Lamp1 and Hsp70.1B in ischemic astrocytes. Hsp70.1B knockdown exacerbated pMCAO-induced brain injury, decreased lysosomal membrane integrity and blocked the protective effects of the RIPK1-specific inhibitor necrostatin-1 on lysosomal membranes. On the other hand, RIPK1 knockdown further exacerbated the pMCAO- or OGD-induced decreases in the levels of Hsp90 and the binding of Hsp90 to heat shock transcription factor-1 (Hsf1) in the cytoplasm, and RIPK1 knockdown promoted the nuclear translocation of Hsf1 in ischemic astrocytes, resulting in increased Hsp70.1B mRNA expression. These results suggest that inhibition of RIPK1 protects ischemic astrocytes by stabilizing lysosomal membranes via the upregulation of lysosomal Hsp70.1B; the mechanism underlying these effects involves decreased Hsp90 protein levels, increased Hsf1 nuclear translocation and increased Hsp70.1B mRNA expression.

Multiple myeloma (MM) is an incurable hematopoietic malignancy, although many novel therapeutic agents have been explored. In the present study, we showed that 4-chlorobenzoyl berbamine (BBD9), a novel derivative of berbamine, inhibited the growth of 4 MM cell lines (U266, RPMI 8226, MM1.R and MM1.S). After a 24-h treatment with BBD9, the half maximal inhibitory concentration (IC50) values were 1.8, 2.3, 1.5 and 2.4 μg/ml, respectively, using MTT assays. In BBD9-treated U266 and RPMI 8226 cells, Annexin V (AV)-propidium iodide (PI) staining and FACS analysis demonstrated that apoptosis was involved in this inhibition. This was confirmed by western blot analysis indicating activation and cleavage of caspase-3, -8, -9 and PARP. BBD9 also induced G2/M phase cell cycle arrest in these cells. To investigate the mechanisms responsible for BBD9-induced apoptosis, U266 cells were incubated with 0, 1 or 2 μg/ml of BBD9 combined with 0 or 150 ng/ml of interleukin (IL)-6. MTT assays showed that IL-6 partially abrogated the BBD9-induced cell growth inhibition. Furthermore, BBD9 inhibited autocrine IL-6 production, and downregulated membrane IL-6 receptor (IL-6R) expression. Crucial proteins downstream of the IL-6 signaling pathway, including AKT and STAT3, were inactivated in BBD9-treated U266 cells, although exogenous IL-6 did not abrogate this effect. Forkhead transcription factor class 3a (FOXO3a), a nuclear transcription factor downstream from AKT, was upregulated in the nuclei of BBD9-treated U266 cells. Bim, the target gene of FOXO3a, was upregulated at both the protein and mRNA levels, as shown by western blot analysis and quantitative PCR. These results suggest that BBD9 induces apoptosis in MM cells through the inhibition of the IL-6 signaling pathway, leading to FOXO3a activation and upregulation of pro-apoptotic Bim.

The peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of aggressive neoplasms that account for <15% of all non-Hodgkin's lymphoma cases in adults. Angioimmunoblastic T-cell lymphoma (AITL) is a specific subtype of PTCL. The tumor is frequently aggressive and there is currently no general consensus regarding an effective treatment strategy. The present study reports a case in which bortezomib combined with dexamethasone was used to treat refractory AITL. A 63-year-old woman was admitted to Sir Run Run Shaw Hospital, Zhejiang University School of Medicine (Zhejiang, China) on August 17, 2013. The patient had been diagnosed with AITL for 4 months and had experienced a relapse of symptoms for the 4 days prior to admission. The patient demonstrated fever and dyspnea, accompanied by severe edema in the face and lower limbs, which later spread to the right upper limb. The patient was treated with bortezomib plus dexamethasone, which rapidly relieved the symptoms. The patient was subsequently administered an additional 2 cycles of bortezomib-based chemotherapy and survived for an additional 4 months, prior to succumbing to the disease. Only a small number of studies have reported the use of bortezomib in the treatment of T-cell lymphoma. The present study suggested that bortezomib-based treatment may be a reliable, safe and effective alternative for the treatment of relapsed/refractory PTCL. The efficacy of bortezomib as a treatment for PTCL requires additional evaluation in future studies.

Casticin, a component from Vitex rotundifolia , widely used as an anti-inflammatory agent in Chinese traditional medicine, was reported to have anti-tumor activities. This study aims to examine the anti-leukemic activity of casticin on leukemia cells and its molecular mechanism. Cell viability was measured by MTT method; apoptosis and cell cycle arrest were determined by flow cytometry, AV-PI assay, and DNA fragmentation assay. Western blot were performed to measure the protein expression level. The cell morphology alteration was detected with immunofluorescent analysis and DAPI nuclear staining. Our results showed that the proliferation of leukemia cells, including K562, Kasumi-1, and HL-60, were inhibited by casticin in a time- and dose-dependent manner. The IC50, determined after 48 h incubation, was 5.95 μM, 4.82 μM, and 15.56 μM for K562, HL-60, and Kasumi-1, respectively. The cell cycle analysis demonstrated casticin treatment resulted in a significant G2/M accumulation, concomitant with upregulation of P21waf1 and P27kip1. The percentage of cells in G2/M increased with time of exposure and reached to its climax (75.3%) at 12 h after casticin treatment, and subsequently declined to 27% at 48 h. We found that casticin treatment induced remarkable apoptosis, evidenced by increased percentage of AV-positive PI-negative cells as well as the cleavage of PARP and caspase 3. In addition, DNA fragmentation assay showed the typical apoptotic DNA ladder in casticin-treated K562 cells. Mitotic catastrophe and decreased polymeric tubulin can also be observed in casticin-treated K562 cells. In addition, we found that PI3K/AKT pathway was activated; Ly294002, a PI3K/AKT specific inhibitor, can enhance the anti-leukemic effect of casticin. Taken together, these results demonstrated that casticin induced leukemic cell death via apoptosis and mitotic catastrophe, and could synergize with PI3K/AKT inhibitor, suggesting that casticin could be a promising therapeutic agent against leukemia.