ST2, amemberoftheinterleukin(IL)1receptorfamily,anditsligandIL-33playcriticalrolesinimmuneregulationandinflammatoryresponses. This study explores the roles of endogenous IL-33/ST2 signaling in ischemic brain injury and elucidates the underlying mechanisms of action. The expression of IL-33 rapidly increased in oligodendrocytes and astrocytes after 60 min transient middle cerebral artery occlusion (tMCAO). ST2 receptor deficiency exacerbated brain infarction 3 d after tMCAO as well as distal permanent MCAO. ST2 deficiency also aggravated neurologicaldeficitsupto7daftertMCAO.Conversely,intracerebroventricularinfusionsofIL-33aftertMCAOattenuatedbraininfarction.Flow cytometry analyses demonstrated high levels of ST2 expression on microglia, and this expression was dramatically enhanced after tMCAO. The absence of ST2 enhanced the expression of M1 polarization markers on microglia/macrophages, and impaired the expression of M2 polarization markers after tMCAO. In vitro studies on various types of cultures and coculture systems confirmed that IL-33/ST2 signaling potentiated expression of IL-10 and other M2 genes in primary microglia. The activation of ST2 on microglia led to a protective phenotype that enhanced neuronal survival against oxygen glucose deprivation. Further in vitro studies revealed that IL-33-activated microglia released IL-10, and that this was critical for their neuroprotective effects. Similarly, intracerebroventricular infusions of IL-33 into IL-10 knockout mice failed to provide neuroprotection against tMCAO in vivo. These results shed new light on the IL-33/ST2 axis as an immune regulatory mechanism that serves as a natural brake on the progression of ischemic brain injury.
White matter (WM) occupies a large volume of the human cerebrum and is mainly composed of myelinated axons and myelin-producing glial cells. The myelinated axons within WM are the structural foundation for efficient neurotransmission between cortical and subcortical areas. Similar to neuron-enriched gray matter areas, WM undergoes a series of changes during the process of aging. WM malfunction can induce serious neurobehavioral and cognitive impairments. Thus, age-related changes in WM may contribute to the functional decline observed in the elderly. In addition, aged WM becomes more susceptible to neurological disorders, such as stroke, traumatic brain injury (TBI), and neurodegeneration. In this review, we summarize the structural and functional alterations of WM in natural aging and speculate on the underlying mechanisms. We also discuss how age-related WM changes influence the progression of various brain disorders, including ischemic and hemorrhagic stroke, TBI, Alzheimer’s disease, and Parkinson’s disease. Although the physiology of WM is still poorly understood relative to gray matter, WM is a rational therapeutic target for a number of neurological and psychiatric conditions.
Panoramic video provides immersive and interactive experience by enabling humans to control the field of view (FoV) through head movement (HM). Thus, HM plays a key role in modeling human attention on panoramic video. This paper establishes a database collecting subjects' HM in panoramic video sequences. From this database, we find that the HM data are highly consistent across subjects. Furthermore, we find that deep reinforcement learning (DRL) can be applied to predict HM positions, via maximizing the reward of imitating human HM scanpaths through the agent's actions. Based on our findings, we propose a DRL-based HM prediction (DHP) approach with offline and online versions, called offline-DHP and online-DHP. In offline-DHP, multiple DRL workflows are run to determine potential HM positions at each panoramic frame. Then, a heat map of the potential HM positions, named the HM map, is generated as the output of offline-DHP. In online-DHP, the next HM position of one subject is estimated given the currently observed HM position, which is achieved by developing a DRL algorithm upon the learned offline-DHP model. Finally, the experiments validate that our approach is effective in both offline and online prediction of HM positions for panoramic video, and that the learned offline-DHP model can improve the performance of online-DHP.
SAPHO syndrome is predominant in middle-age women, characterized by dermatological and osteoarticular manifestations with unknown aetiology. CT scan and bone scintigraphy are useful for diagnosis. There is still no standard treatment to control the disease.
Understanding the molecular mechanisms involved in the response of tumors to fractionated exposures to ionizing radiation is important for improving radiotherapy and/or radiochemotherapy. In the present study, we examined the expression of stress-related genes in an MCF-7 cell population (MCF-IR20) that has been derived through treatment with fractionated irradiation (2 Gy per fraction with a total dose of 40 Gy). MCF-IR20 cells showed a 1.6-fold increase in sensitization with dose at 10% isosurvival in a clonogenic assay, and a reduced growth delay ( approximately 15 h compared to approximately 27 h), compared to the parental MCF-7 cells treated with a single dose of 5 Gy. To determine which effector genes were altered in the MCF-IR20 cells, the expression of stress-related effector genes was measured using a filter with 588 genes (Clontech) that included major elements involved in cell cycle control, DNA repair, and apoptosis. Compared to MCF-7 cells that were not exposed to fractionated radiation, 19 genes were up- regulated (2.2-5.1-fold) and 4 were down-regulated (2.7-3.4- fold) in the MCF-IR20 cells. In agreement with the array results, 6 up-regulated genes tested by RT-PCR showed elevated expression. Also, activities of the stress-related transcription factors NFKB, TP53 and AP1 showed a 1.2-4.5-fold increase after a single dose of 5 Gy in MCF-IR20 cells compared with parental MCF-7 cells. However, when the radioresistant MCF-IR20 cell were cultured for more than 12 passages after fractionated irradiation (MCF-RV), radioresistance was lost, with the radiosensitivity being the same as the parental MCF- 7 cells. Interestingly, expression levels of CCNB1, CD9 and CDKN1A in MCF-RV cells returned to levels expressed by the parental cells, whereas the expression levels of three other genes, MSH2, MSH6 and RPA remained elevated. To determine if any of the changes in gene expression could be responsible for the induced radioresistance, CCNB1 and CDKN1A, both of which were up-regulated in MCF-IR20 cells and down-regulated in MCF-RV cells, were studied further by transfection with antisense oligonucleotides. Antisense of CCNB1 significantly reduced the clonogenic survival of MCF- IR20 cells at doses of 5 and 10 Gy, from 42% to 26% and from 5.7% to 1.0%, respectively. Antisense of CDKN1A, however, had no effect on radiation survival of MCF-IR20 cells. In summary, these results suggest that stress-related effector genes are altered in cells after treatment with fractionated irradiation, and that up-regulation of CCNB1 is responsible, at least in part, for radioresistance after fractionated irradiation.
Hepatocellular carcinoma (HCC) is the most prevalent liver cancer, characterized by a high rate of recurrence and heterogeneity. Liver cancer stem cells (CSCs) may well contribute to both of these pathological properties, but the mechanism underlying their self-renewal maintenance is poorly understood. Here, we identified a long noncoding RNA (lncRNA) termed HAND2-AS1 that is highly expressed in liver CSCs. Human HAND2-AS1 and its mouse ortholog lncHand2 display a high level of conservation. HAND2-AS1 is required for the selfrenewal maintenance of liver CSCs to initiate HCC development. Mechanistically, HAND2-AS1 recruits the INO80 chromatin-remodeling complex to the promoter of BMPR1A, thereby inducing its expression and leading to the activation of BMP signaling. Importantly, interfering with expression of HAND2-AS1 by antisense oligonucleotides (ASOs) and BMPR1A by siRNAs has synergistic antitumorigenic effects on humanized HCC models. Moreover, knockout of lncHand2 or Bmpr1a in mouse hepatocytes impairs BMP signaling and suppresses the initiation of liver cancer. Our findings reveal that HAND2-AS1 promotes the self-renewal of liver CSCs and drives liver oncogenesis, offering a potential new target for HCC therapy. The EMBO JournalYanying Wang et al to promote BMPR1A expression and activates BMP signaling for increasing self-renewal of liver CSCs. Moreover, the addition of ASOs of HAND2-AS1 along with siRNA against BMPR1A has potent therapeutic effect on HCC.
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