The Effect of a Western Diet on Hepatic Autophagy in Age Accelerated SAMP8 Mice

Non-alcoholic steatohepatitis (NASH) is characterized as a dysregulation of hepatic lipid metabolism and a chronic inflammatory state. It is hypothesized the link between lipid dysregulation and inflammation may be due in part to defective hepatic autophagy and reduced mitochondrial capacity to oxidize fatty acids. It remains to be determined; however, the effects of a Western diet on hepatic autophagy and mitochondrial function during aging. PURPOSE: The purpose of this study was to determine the effect of a high-fat high fructose diet (HFF) on markers of hepatic autophagy and mitochondrial function in an age accelerated mouse model. METHODS: Twenty week old, male and female, SAMP8 mice (n=49) were randomly assigned, matching for gender, to either a standard chow (SC) or HFF (45% fat, 24% fructose) diet for 32 weeks. Liver tissue was analyzed for mRNA expression of autophagic (BNIP3, Beclin 1, p62, and Atg7) and mitochondrial (PGC1α and COXIV) genes. Differences between gender and dietary groups were identified by a 2 x 2 ANOVA and statistical significance was set at p\u3c0.05. RESULTS: Following 32 weeks of feeding, male mice fed the HFF diet were significantly heavier than male mice in the SC group (31.6 g vs 26.5 g; p=0.001); however, no difference was observed between diet groups for female mice. The HFF diet resulted in higher autophagic activity as observed by Beclin 1 (+36%; p=0.001) and BNIP3 (+40%; P=0.003) expression. Despite the higher autophagic activity, p62 was higher (+31%; p\u3c0.001) in the HFF compared to the SC group, suggesting impaired autophagic flux. In addition, mitochondrial COXIV expression was elevated (+43%; P\u3c0.001) in the HFF group compared to the SC group suggesting increased β-oxidation. Overall, the expression of all autophagic and mitochondrial markers was higher in male compared to female mice; however, both sexes responded similarly to the HFF diet. CONCLUSION: Despite the higher expression of autophagic and mitochondrial genes, elevated expression of p62 suggests an impaired autophagic flux in age accelerated mice following a Western diet

Omega-3-Fatty Acids Hold Therapeutic Potential for the Prevention and Treatment of Diabetic Neuropathy

Diabetic neuropathy is a debilitating complication of diabetes, affecting over 50% of diabetic patients. Overweight humans display manifestations of diabetic neuropathy before developing overt diabetes and mice fed a high fat diet exhibit signs of neuropathy including mechanical hindpaw hypersensitivity and neuronal inflammation, suggesting fat diet-induced inflammation may play a role in the development of neuropathy. Omega-3 (n-3) fatty acids have anti-inflammatory properties and may hold therapeutic potential as a preventative treatment for prediabetic and diabetic patients at risk for neuropathy. PURPOSE: Investigate the impact of diet composition on signs of neuropathy. We hypothesized that a diet rich in n-3 fatty acids would attenuate hindpaw hypersensitivity during prolonged feeding of a high fat diet. METHODS: C57BL/6 mice were randomized into four diet groups (n = 12/group) for 32 weeks: 10% low fat-fish oil (LFFO), 41% high fat-fish oil (HFFO), 10% low fat-lard (LFL), or 41% high fat-lard (HFL). Neuropathy was characterized at baseline and every other week thereafter using the von Frey behavioral test for hindpaw mechanical sensitivity. A glucose tolerance test was performed at end study, and total area under the curve (AUC) was calculated using the trapezoidal method. RESULTS: At end study, body weight was greater in HFL compared to all other groups. Body weight was also greater in HFFO compared to LFFO. Fasting glucose and glucose AUC were higher in HFL compared to LFFO and HFFO. Following the same pattern as body weight, fasting glucose was higher in HFFO compared to LFFO. Although percent paw withdrawal was greater in HFL compared to HFFO and LFFO, there were no significant differences for LF vs. HF for fish oil or lard. CONCLUSION: A HFL diet induced signs of neuropathy including hindpaw hypersensitivity, whereas a fish oil diet was protective against hindpaw hypersensitivity. Moreover, omega-3-fatty acids may hold therapeutic potential for neuropathy prevention in nondiabetic and diabetic patients

Regulation of Liver Regeneration by Hepatocyte O-GlcNAcylation in Mice

A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author's publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Background & Aims The liver has a unique capacity to regenerate after injury in a highly orchestrated and regulated manner. Here, we report that O-GlcNAcylation, an intracellular post-translational modification regulated by 2 enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), is a critical termination signal for liver regeneration following partial hepatectomy (PHX). Methods We studied liver regeneration after PHX on hepatocyte specific OGT and OGA knockout mice (OGT-KO and OGA-KO), which caused a significant decrease (OGT-KO) and increase (OGA-KO) in hepatic O-GlcNAcylation, respectively. Results OGA-KO mice had normal regeneration, but the OGT-KO mice exhibited substantial defects in termination of liver regeneration with increased liver injury, sustained cell proliferation resulting in significant hepatomegaly, hepatic dysplasia, and appearance of small nodules at 28 days after PHX. This was accompanied by a sustained increase in expression of cyclins along with significant induction in pro-inflammatory and pro-fibrotic gene expression in the OGT-KO livers. RNA-sequencing studies revealed inactivation of hepatocyte nuclear 4 alpha (HNF4α), the master regulator of hepatic differentiation and a known termination signal, in OGT-KO mice at 28 days after PHX, which was confirmed by both Western blot and immunohistochemistry analysis. Furthermore, a significant decrease in HNFα target genes was observed in OGT-KO mice, indicating a lack of hepatocyte differentiation following decreased hepatic O-GlcNAcylation. Immunoprecipitation experiments revealed HNF4α is O-GlcNAcylated in normal differentiated hepatocytes. Conclusions These studies show that O-GlcNAcylation plays a critical role in the termination of liver regeneration via regulation of HNF4α in hepatocytes

Stigma and Differences of Sex Development: A Scoping Review

Scoping Review ProtocolN/Ahttp://deepblue.lib.umich.edu/bitstream/2027.42/167691/1/Scoping Review Protocol_Stigma.pdfDescription of Scoping Review Protocol_Stigma.pdf : Stigma in DSD Scoping Review ProtocolSEL

Neuronal Inflammation: A Potential Contributing Mechanism to High Fat Diet-Induced Neuropathy

Neuropathy, a debilitating complication of diabetes, has primarily been attributed to poor glycemic control, but has recently been associated with obesity and the metabolic syndrome in nondiabetic individuals. A robust body of evidence indicates that a high-fat diet can induce signs of neuropathy in mice but the pathogenesis of high fat diet-induced neuropathy remains unknown. PURPOSE: To determine if neuronal inflammation is a potential initiating mechanism for the development of mechanical hypersensitivity and nerve fiber changes (signs of neuropathy) in high fat fed mice. METHODS: Male C57Bl/6 mice were randomized to a standard (Std, 15% kcal from fat) or high fat diet (HF, 54% kcal from fat) for 2, 4, or 8 wks (n = 11-12 per group). Lumbar dorsal root ganglia were harvested and inflammatory mediators (IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-17, MCP-1, IFN-γ, TNF-α, MIP-1α, GMCSF, RANTES) were quantified using a Multiplex ELISA and normalized to total protein. Neuropathy was characterized by the von Frey test for mechanical sensitivity at wk 0 and every other week thereafter. Hindpaw foot pad skin was harvested at end study and used to quantify intraepidermal nerve fiber density (IENFD) and pain-sensing (TrkA) nerve fibers via immunohistochemistry. RESULTS: After 8 wks, HF had greater bodyweight (33.3 ± 1.0 vs. 26.7 ± 0.5 g, p < 0.001), fasting blood glucose (160.3 ± 9.4 vs. 138.5 ± 3.4 mg/dl, p < 0.05) and insulin (3.58 ± 0.46 vs. 0.82 ± 0.14 ng/ml, p < 0.001) compared to Std. IL-1α, RANTES and IL-5 were higher in HF compared to Std after 2 wks and 4 wks, respectively (IL-1α: 4.8 ± 1.3 vs. 2.9 ± 0.6 pg/mg, p < 0.05; RANTES: 19.6 ± 2.2 vs. 13.3 ± 1.2 pg/mg p < 0.05; IL-5: 5.8 ± 0.7 vs. 3.1 ± 0.5 pg/mg, p < 0.05 ). IENFD and TrkA fiber density were also higher in HF vs. Std after 4 wks (IENFD: 39.4 ± 1.2 vs. 32.2 ± 1.3 fibers/mm, p < 0.001; TrkA: 30.4 ± 1.8 vs. 22.4 ± 1.3 fibers/mm). There were no significant differences in hindpaw sensitivity for Std vs. HF at any time point. CONCLUSION: Increased inflammatory mediators preceded and accompanied an increase in a specific population of pain sensing nerve fibers (TrkA) in the hindpaw footpad of high fat fed mice. Diets high in fat may increase neuronal inflammation and initiate nerve fiber changes responsible for painful neuropathy in nondiabetic and diabetic individuals

Role of Pyroptosis in Acetaminophen-Induced Hepatotoxicity

Acetaminophen (APAP) is a widely used pain reliever that can cause liver injury or liver failure in response to an overdose. Understanding the mechanisms of APAP-induced cell death is critical for identifying new therapeutic targets. In this respect it was hypothesized that hepatocytes die by oncotic necrosis, apoptosis, necroptosis, ferroptosis and more recently pyroptosis. The latter cell death is characterized by caspase-dependent gasdermin cleavage into a C-terminal and an N-terminal fragment, which forms pores in the plasma membrane. The gasdermin pores can release potassium, interleukin-1β (IL-1β), IL-18, and other small molecules in a sublytic phase, which can be the main function of the pores in certain cell types such as inflammatory cells. Alternatively, the process can progress to full lysis of the cell (pyroptosis) with extensive cell contents release. This review discusses the experimental evidence for the involvement of pyroptosis in APAP hepatotoxicity as well as the arguments against pyroptosis as a relevant mechanism of APAP-induced cell death in hepatocytes. Based on the critical evaluation of the currently available literature and understanding of the pathophysiology, it can be concluded that pyroptotic cell death is unlikely to be a relevant contributor to APAP-induced liver injury

GROCS Collection for Noteworks 2007-2008

Collection of artifacts from the Noteworks GROCS project in 2008.We propose to design and implement a computer application that enables users to create sound experiences and musical compositions in a completely new way. In particular, our software will enable users to design dynamic temporal networks in which the nodes correspond to sound clips, and directed edges represent time and other relationships between nodes. Furthermore, we will embed functionality in the application so as to enable different instances of our software to interact with other musicians’ networks so as to create a truly interactive, collaborative music experience. We will also release our software to any interested parties so they can extend it as they see fit (and set up their own musical networks at home).GROCS: GRant Opportunities [collaborative spaces], a Digital Media Commons program to fund student research on the use of rich media in collaborative learning.http://deepblue.lib.umich.edu/bitstream/2027.42/62445/11/grocs_proposal_noteworks.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/62445/10/setup.AVIhttp://deepblue.lib.umich.edu/bitstream/2027.42/62445/9/NW Design Review 2.1.08.mp3http://deepblue.lib.umich.edu/bitstream/2027.42/62445/8/noteworks_screenshot.pnghttp://deepblue.lib.umich.edu/bitstream/2027.42/62445/7/noteworks_screencast.avihttp://deepblue.lib.umich.edu/bitstream/2027.42/62445/6/noteworks_melancholy.mp4http://deepblue.lib.umich.edu/bitstream/2027.42/62445/5/noteworks_logo.pnghttp://deepblue.lib.umich.edu/bitstream/2027.42/62445/4/noteworks.ziphttp://deepblue.lib.umich.edu/bitstream/2027.42/62445/3/Noteworks Demo April 5.movhttp://deepblue.lib.umich.edu/bitstream/2027.42/62445/2/michigan.AVIhttp://deepblue.lib.umich.edu/bitstream/2027.42/62445/1/bedtime.av

Stigma and Differences of Sex Development: Search Strategies

http://deepblue.lib.umich.edu/bitstream/2027.42/192640/2/DSDSTIG_Search_Documentation.pdfDescription of DSDSTIG_Search_Documentation.pdf : Document containing search strateigies associated with this scoping review.SEL