live-images-glut4-protein-trafficking-mouse-primary-hypothalamic

Live Images of GLUT4 Protein Trafficking in Mouse Primary Hypothalamic Neurons Using Deconvolution Microscopy

Type 2 diabetes mellitus (T2DM) is a global health crisis which is characterized by insulin signaling impairment and chronic inflammation in peripheral ...

studying-hypothalamic-insulin-signal-to-peripheral-glucose

Studying the Hypothalamic Insulin Signal to Peripheral Glucose Intolerance with a Continuous Drug Infusion System into the Mouse Brain

Insulin regulates systematic metabolism in the hypothalamus and the peripheral insulin response. An inflammatory reaction in peripheral adipose tissues ...

Taipei Medical University and National Health Research

Taipei Medical University

The accumulation of reactive oxygen species (ROS) have implicated the pathogenesis of several human diseases including neurodegenerative disorders, stroke, and traumatic brain injury, hence protecting neurons against ROS is very important. In this study, we focused on sigma-1 receptor (Sig-1R), a chaperone at endoplasmic reticulum, and investigated its protective functions. Using hydrogen peroxide (H2O2)-induced ROS accumulation model, we verified that apoptosis-signaling pathways were elicited by H2O2 treatment. However, the Sig-1R agonists, dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS), reduced the activation of apoptotic pathways significantly. By performing protein-protein interaction assays and shRNA knockdown of Sig-1R, we identified the brain Zinc finger protein 179 (Znf179) as a downstream target of Sig-1R regulation. The neuroprotective effect of Znf179 overexpression was similar to that of DHEAS treatment, and likely mediated by affecting the levels of antioxidant enzymes. We also quantified the levels of peroxiredoxin 3 (Prx3) and superoxide dismutase 2 (SOD2) in the hippocampi of wild-type and Znf179 knockout mice, and found both enzymes to be reduced in the knockout versus the wild-type mice. In summary, these results reveal that Znf179 plays a novel role in neuroprotection, and Sig-1R agonists may be therapeutic candidates to prevent ROS-induced damage in neurodegenerative and neurotraumatic diseases.

The sigma-1 receptor-zinc finger protein 179 pathway protects against hydrogen peroxide-induced cell injury.

Traumatic brain injury (TBI) is a global health concern that typically causes emotional disturbances and cognitive dysfunction. Secondary pathologies following TBI may be associated with chronic neurodegenerative disorders and an enhanced likelihood of developing dementia-like disease in later life. There are currently no approved drugs for mitigating the acute or chronic effects of TBI.

Pomalidomide mitigates neuronal loss, neuroinflammation, and behavioral impairments induced by traumatic brain injury in rat.

Erratum to: Pomalidomide mitigates neuronal loss, neuroinflammation, and behavioral impairments induced by traumatic brain injury in rat.

Many neurodegenerative diseases are accompanied by metabolic disorders. CCL5/RANTES, and its receptor CCR5 are known to contribute to neuronal function as well as to metabolic disorders such as type 2 diabetes mellitus, obesity, atherosclerosis and metabolic changes after HIV infection. Herein, we found that the lack of CCR5 or CCL5 in mice impaired regulation of energy metabolism in hypothalamus. Immunostaining and co-immunoprecipitation revealed the specific expression of CCR5, associated with insulin receptors, in the hypothalamic arcuate nucleus (ARC). Both ex vivo stimulation and in vitro tissue culture studies demonstrated that the activation of insulin, and PI3K-Akt pathways were impaired in CCR5 and CCL5 deficient hypothalamus. The inhibitory phosphorylation of insulin response substrate-1 at Ser302 (IRS-1(S302)) but not IRS-2, by insulin was markedly increased in CCR5 and CCL5 deficient animals. Elevating CCR5/CCL5 activity induced GLUT4 membrane translocation and reduced phospho-IRS-1(S302) through AMPKα-S6 Kinase. Blocking CCR5 using the antagonist, (Met)CCL5, abolished the de-phosphorylation of IRS-1(S302) and insulin signal activation. In addition, intracerebroventricular delivery of (Met)CCL5 interrupted hypothalamic insulin signaling and elicited peripheral insulin responsiveness and glucose intolerance. Taken together, our data suggest that CCR5 regulates insulin signaling in hypothalamus which contributes to systemic insulin sensitivity and glucose metabolism.

CCL5/RANTES contributes to hypothalamic insulin signaling for systemic insulin responsiveness through CCR5.

Recently, a novel substrate known as an electrospun polylactic acid (PLLA) microtube array membrane (MTAM) was successfully developed as a cell coculture platform. Structurally, this substrate is made up of one-to-one connected, ultrathin, submicron scale fibers that are arranged in an arrayed formation. Its unique structure confers several key advantages which are beneficial in a cell coculture system. In this study, the interaction between rat fetal neural stem cells (NSC) and astrocytes was examined by comparing the outcome of a typical Transwell-based coculture system and that of an electrospun PLLA MTAM-based coculture system. Compared to tissue culture polystyrene (TCP) and Transwell coculture inserts, a superior cell viability of NSC was observed when cultured in lumens of electrospun PLLA MTAM (with supportive immunostaining images). Reverse transcription polymerase chain reaction revealed a strong interaction between astrocytes and NSC through a higher expression of doublecortin and a lower expression of nestin. These data demonstrate that MTAM is clearly a better coculture platform than the traditional Transwell system.

Szu-Yi Chou

The Ph.D. Program for Neural Regenerative Medicine,
College of Medical Science and Technology,
The Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology

Taipei Medical University and National Health Research

Live Images of GLUT4 Protein Trafficking in Mouse Primary Hypothalamic Neurons Using Deconvolution Microscopy

Studying the Hypothalamic Insulin Signal to Peripheral Glucose Intolerance with a Continuous Drug Infusion System into the Mouse Brain

Szu-Yi Chou

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}The Ph.D. Program for Neural Regenerative Medicine,College of Medical Science and Technology,The Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology

Taipei Medical University and National Health Research

Live Images of GLUT4 Protein Trafficking in Mouse Primary Hypothalamic Neurons Using Deconvolution Microscopy

Studying the Hypothalamic Insulin Signal to Peripheral Glucose Intolerance with a Continuous Drug Infusion System into the Mouse Brain

The Ph.D. Program for Neural Regenerative Medicine,
College of Medical Science and Technology,
The Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology