Targeting PERK mediated endoplasmic reticulum stress attenuates neuroinflammation and alleviates lipopolysaccharide-induced depressive-like behavior in male mice.

Neuroinflammation plays a key role in the development of depression-like behaviors.Endoplasmic reticulum (ER) stress,defined as accumulation of unfolded proteins in the ER,is suggested tocollaboratewithinflammation process to drive sustained neuroinflammation. Protein kinase R-like endoplasmic reticulum kinase (PERK) is ofparticularly attractive target because it plays key rolein the regulation of ER stress-induced neuroinflammation, however, little isknown whether PERKmediatedER stress is implicated in LPS-induced depression-like behaviors.Thus, we aimed to evaluate the induction of PERK pathwayin mice with depression-like behaviors induced by LPS, as well as the alterations in depression-like behaviorsfollowing the blocking of PERK pathway.We found that LPS challenges resulted in enhanced PERK in the hippocampus, with no alteration in the prefrontal cortex. Importantly, we found that PERKinhibitorISRIB reducedthe proinflammatory responsesof microglia in the context of acute LPS-induced brain inflammation, and subsequent the preserved hippocampal neurogenesis, and improvement in depression-like behavioroutcomes following LPS challenges.It was also worth mentioning thatISRIB treatmentreduced the peripheral pro-inflammatory cytokines includingIL-1ß, IL-6 and IL-18. Thus, targetingPERK mediated Endoplasmic reticulum stress may be a promising antidepressant and anti-inflammatory candidate drug for the alleviation of neuroinflammationmediated depression, and PERKinhibitorISRIBmay havebenefits for combating major depressive disorder.

Roles of physical exercise in neurodegeneration: reversal of epigenetic clock.

The epigenetic clock is defined by the DNA methylation (DNAm) level and has been extensively applied to distinguish biological age from chronological age. Aging-related neurodegeneration is associated with epigenetic alteration, which determines the status of diseases. In recent years, extensive research has shown that physical exercise (PE) can affect the DNAm level, implying a reversal of the epigenetic clock in neurodegeneration. PE also regulates brain plasticity, neuroinflammation, and molecular signaling cascades associated with epigenetics. This review summarizes the effects of PE on neurodegenerative diseases via both general and disease-specific DNAm mechanisms, and discusses epigenetic modifications that alleviate the pathological symptoms of these diseases. This may lead to probing of the underpinnings of neurodegenerative disorders and provide valuable therapeutic references for cognitive and motor dysfunction.

Endocrine Dysfunction Following Stroke.

Endocrine dysfunction is known to occur after traumatic brain injury. The purpose of this study was to examine the incidence of various endocrine dysfunctions after a stroke. The Taiwan National Health Insurance Research Database (NHIRD) was searched from 2001 to 2011 for patients with a diagnosis of stroke. Stroke patients were matched by diagnosis date, age, and sex to patients without a stroke. Cox proportional hazards regression analyses were performed to compare the incidence of goiter, acquired hypothyroidism, thyroiditis, pituitary dysfunction, and disorders of the adrenal glands between stroke and non-stroke patients. There were 131,951 patients in the stroke group, and 131,951 in the matched non- stroke group (mean age 66.1 ± 14.9 years). Stroke patients had significantly higher risk of acquired hypothyroidism (crude hazard ratio [cHR] = 1.65, 95% confidence interval [CI]: 1.44, 1.90; adjusted hazard ratio [aHR] = 1.65, 95% CI: 1.42, 1.91), pituitary dysfunction (cHR = 2.32, 95% CI: 1.79, 2.99; aHR = 1.92, 95% CI: 1.46, 2.52), and disorders of the adrenal glands (cHR = 1.79, 95% CI: 1.52, 2.12; aHR =1.62, 95% CI: 1.36, 1.92) than non-stroke patients. Pituitary dysfunction and disorders of the adrenal glands were found in both hemorrhagic stroke and ischemic stroke patients, while hypothyroidism was seen in ischemic stroke patients only. No significant association was found for goiter and thyroiditis. In conclusions, stroke survivors have an approximately 2-fold increased risk of developing acquired hypothyroidism, pituitary dysfunction, or disorders of the adrenal glands. These risks should be taken into account in the management of patients who have ischemic or hemorrhagic strokes. Graphical Abstract.

Expression of vimentin and glial fibrillary acidic protein in central nervous system development of rats.

OBJECTIVE: To investigate the distribution and contents of vimentin (Vim) and glial fibrillary acidic protein (GFAP) immunoreactivities in the central nervous system (CNS) of normal newborn, adult and aged rats. METHODS: In this study, thirty healthy and normal Sprague-Dawley rats were simply classified into three groups: Newborn (7 days aged), adult (5 months aged) and aged (24 months aged) rats. Brains and spinal cord were dissected and cut into frozen sections. The expression of Vim and GFAP in CNS were detected by confocal immunofluorescence. RESULTS: In each group, Vim was expressed in all the regions of CNS including the hippocampal, cerebral cortex, the third ventricle and spinal cord, and the expression was highest in neuron-like cell of newborn rats, while Vim was mainly expressed in cell bodies in adult and aged rats. GFAP was expressed in all the regions of CNS including the hippocampal, cerebral cortex, the third ventricle and spinal cord, and the expression was in astrocytes of aged rats. In the third ventricle, Vim was detected in all groups, and only observed in neuron-like cells of newborn. Meanwhile, the GFAP expression showed no significant differences between adult and aged rats in this region. The co-localization of Vim and GFAP were mainly observed in hippocampus and cerebral cortex of newborn, but this co-localization was found in the third ventricle of the rats in all groups. CONCLUSION: Our data demonstrate for the first time that the expression of Vim and GFAP in the rat's CNS during development. This data may provide a foundation for the further mechanistic studies of these two main intermediate filaments during development of CNS.

Effect of shunting of collateral flow into the venous system on arteriogenesis and angiogenesis in rabbit hind limb.

The aim of this study was to characterize the vascular remodeling in the external iliac artery (EIA) and the lower leg muscles in a rabbit shunt model created between the distal stump of the occluded femoral artery and the accompanying vein. Histology and immunoconfocal microscopy were used in this study. We found that: 1) both endothelial nitric oxide synthase (eNOS) and phosphorylated eNOS (P-eNOS) proteins were significantly increased in the shunt-side EIA; 2) matrix metalloproteinase-2 (MMP-2) expression was 5.5 times in shunt side EIA over that in normal EIA; 3) intercellular adhension molecule-1 (ICAM-1) expression was strongly induced in endothelial cells (EC) and vascular adhension molecule-1 (VCAM-1) expression was significantly increased in both EC and the adventitia of the shunt-side EIA; 4) augmentation of cell proliferation and extracellular proteolysis by macrophage infiltration was observed in shunt-side EIA; 5) cell proliferation was active in shunt side EIA, but quiet in shunt side lower leg's arterial vessels; 6) capillary density in shunt side lower leg muscles was 2 times over that in normal side. In conclusion, our data demonstrate the paradigm that the power of shear stress takes the reins in arteriogenesis, whereas ischemia in angiogenesis, but not in arteriogenesis.

Comparative proteome analysis of 3T3-L1 adipocyte differentiation using iTRAQ-coupled 2D LC-MS/MS.

Adipose tissue is critical in obesity and type II diabetes. Blocking of adipocyte differentiation is one of the anti-obesity strategies targeting on strong rise in fat storage and secretion of adipokine(s). However, the molecular basis of adipocyte differentiation and its regulation remains obscure. Therefore, we exposed 3T3-L1 cell line to appropriate hormonal inducers as adipocyte differentiation model. Using iTRAQ-coupled 2D LC-MS/MS, a successfully exploited high-throughput proteomic technology, we nearly quantitated 1,000 protein species and found 106 significantly altered proteins during adipocyte differentiation. The great majority of differentially expressed proteins were related to metabolism enzymes, structural molecules, and proteins involved in signal transduction. In addition to previously reported differentially expressed molecules, more than 20 altered proteins previously unknown to be involved with adipogenic process were firstly revealed (e.g., HEXB, DPP7, PTTG1IP, PRDX5, EPDR1, SPNB2, STEAP3, TPP1, etc.). The partially differential proteins were verified by Western blot and/or real-time PCR analysis. Furthermore, the association of PCX and VDAC2, two altered proteins, with adipocyte conversion was analyzed using siRNA method, and the results showed that they could contribute considerably to adipogenesis. In conclusion, our data provide valuable information for further understanding of adipogenesis.

Collateral vessel growth induced by femoral artery ligature is impaired by denervation.

Innervation plays an important role in development and remodeling of blood vessels. However, very little is known whether innervation is involved in arteriogenesis. In the present study, we tested the hypothesis that innervation may contribute to the process of arteriogenesis induced by ligature of femoral artery in rat/rabbit hind limb with or without denervation. We found that: (1) angiography showed more collateral vessels in the ligature side than that in ligature plus denervation side; (2) collateral vessels in denervation side was characterized by an inward remodeling; (3) in both collateral vessels (CVs) from only femoral ligature side as well as the ligature plus denervation side, ICAM-1 and VCAM-1 expression was up-regulated but increased VCAM-1 was more evident in the adventitia of collateral vessels of only femoral ligature side; (4) 7 days after surgery, in CVs from the femoral ligature side only, numerous macrophages (RAM11 positive cells) and high cell proliferation ratio (ki67 positive cells) were detected, but they were less in the denervation side. In conclusion, our data demonstrate for the first time that neural regulation is one of the factors that contributes to collateral vessel growth in rat/rabbit hind limb ischemic model by showing collateral vessel growth induced by femoral artery ligature is impaired by denervation.