Glycogen Deposition Research Articles

Sleep restriction exacerbates cardiac dysfunction in diabetic mice by causing cardiomyocyte death and fibrosis through mitochondrial damage.

Diabetic cardiomyopathy (DCM) is a cardiovascular complication of diabetes mellitus with a poor prognosis and is the leading cause of death in diabetic patients. Sleep deficiency is not only recognized as an important risk factor for the development of type 2 DM, but is also associated with increased morbidity and mortality of cardiovascular disease. The underlying role and mechanisms of sleep restriction (SR) in DCM are far from clear. The KK/Upj-Ay mouse model of T2 DM was used as a study subject, and the small animal ultrasound imaging system was used to detect the function of the heart; immunopathological staining was used to clarify the histo-structural pathological alterations of the heart; and TUNEL staining, qPCR, transmission electron microscopy (TEM), and ELISA kits were used to detect apoptosis, oxidative stress, inflammation, and mitochondrial damage, and related molecular alterations. SR led to a significant increase in mortality, cardiac hypertrophy, necrosis, glycogen deposition and fibrosis further deteriorated in DM KK mice. SR increased cardiomyocyte death in KK mice through the Bax/Bcl2 pathway. In addition to this, SR not only exacerbated the inflammatory response, but also aggravated mitochondrial damage and promoted oxidative stress in KK mice through the PRDM16-PGC-1α pathway. Overall, SR exacerbates structural alterations and dysfunction through inflammation, oxidative stress, and apoptosis in DM KK mice, increasing the risk of death. Clinicians and diabetic patients are prompted to pay attention to sleep habits to avoid accelerating the transition of DCM to heart failure and inducing death due to poor sleep habits.

Astragaloside IV and cycloastragenol promote liver regeneration through regulation of hepatic oxidative homeostasis and glucose/lipid metabolism

BackgroundThe regenerative capacity of the liver is pivotal for mitigating various forms of liver injury and requires the rapid proliferation of hepatocytes. Aquaporin-9 (AQP9) provides vital support for hepatocyte proliferation by preserving hydrogen peroxide (H2O2) oxidative balance and glucose/lipid metabolism equilibrium within hepatocytes. Our previous study demonstrated that Radix Astragali (RA) decoction promotes liver regeneration by upregulating hepatic expression of AQP9, possibly via two major active constituents: astragaloside IV (AS-IV) and cycloastragenol (CAG). PurposeTo verify that upregulated AQP9 expression in hepatocytes maintains liver oxidative balance and glucose/lipid metabolism homeostasis, and is the main pharmacological mechanism by which AS-IV and CAG promote liver regeneration. Study Design/MethodsEffects of AS-IV and CAG on liver regeneration were scrutinized using a mouse model of 70 % partial hepatectomy (PHx). AQP9-targeted liver regeneration mediated by AS-IV and CAG was verified using AQP9 gene knockout mice (AQP9−/−). The AQP9 protein expression pattern in hepatocytes was determined using tdTomato-tagged AQP9 transgenic mice (AQP9-RFP). Potential mechanisms of AS-IV and CAG on liver regeneration were studied using real-time quantitative PCR, immunoblotting, staining with hematoxylin and eosin, oil red O, and periodic acid-Schiff, and immunofluorescence, immunohistochemistry, HyPerRed fluorescence, and biochemical analyses. ResultsAS-IV and CAG promoted substantial liver regeneration and increased hepatic AQP9 expression in wild-type mice (AQP9+/+) following 70 % PHx, but had no discernible benefits in AQP9−/- mice. Both saponin compounds also helped maintain oxidative homeostasis by reducing levels of oxidative stress markers (reactive oxygen species [ROS], H2O2, and malondialdehyde) and elevating levels of ROS scavengers (glutathione and superoxide dismutase) in AQP9+/+ mice post-70 % PHx. This further activated the PI3K-AKT and insulin signaling pathways, thereby fostering liver regeneration. Furthermore, AS-IV and CAG both promoted hepatocyte glycerol uptake, increased gluconeogenesis, facilitated lipolysis, reduced glycolysis, and inhibited glycogen deposition, thus ensuring the energy supply required for liver regeneration. ConclusionThis research is the first to demonstrate AS-IV and CAG as major active ingredients of RA that promote liver regeneration by upregulating hepatocyte AQP9 expression, improving hepatocyte glucose/lipid metabolism, and reducing oxidative stress damage, constituting a crucial pharmacological mechanism underlying the liver-protective effects of RA. The augmentation of hepatocyte AQP9 expression underscores an important aspect of the Qi-tonifying effect of RA. This study establishes AQP9 as an effective target for regulation of liver regeneration and provides a universal strategy for clinical drug intervention aimed at enhancing liver regeneration.

8193 Mauriac Syndrome Uncovered, The Insulin Access Impact in Type 1 Diabetes Mellitus

Abstract Disclosure: D.H. Sacoto: None. R. Belokovskaya: None. K. Gebran: None. K. Madani: None. A. De Rosairo: None. D. Patel: None. A.A. Franco-Akel: None. Introduction: Mauriac syndrome is a rare complication of poorly controlled type 1 diabetes mellitus (T1DM). It is reversible with appropriate glycemic control; however, factors affecting healthcare access to insulin are leading to its re-emergence. We present a case of Mauriac syndrome as a complication of uncontrolled T1DM due to insulin access. Case: A 22-year-old Hispanic female with a history of T1DM presented to the emergency department with a two-day history of abdominal pain. She was diagnosed with diabetic ketoacidosis (DKA) (blood glucose: 802 mg/dL; pH 7.14; bicarbonate: 7 mmol/L; anion gap: 34; positive serum ketones). Incidental transaminitis was noted. R factor showed a cholestatic pattern of 0.6 (AST: 136 U/L, ALT: 49 U/L, alkaline phosphatase:286 U/L). US liver revealed an enlarged liver (craniocaudal: 16.5 cm) without biliary obstruction. Her phenotype consisted of short stature (4.8 feet) with a moon face and a protuberant abdomen. Her records revealed a normal karyotype 46 XX, with a bone age of 4 years, pubertal delay, low insulin-like growth factor-1 levels (58 ng/mL), and long-standing hyperlipidemia. Over the years, she experienced multiple DKA episodes in the context of uncontrolled T1DM (hemoglobin A1c:11-13 %). The main problem identified included difficulty with insulin access, specifically related to insurance coverage as well as managing her disease. Glycemic control has significantly improved with continuous glucose monitoring and updated insurance status. Discussion: Mauriac syndrome is characterized by hepatomegaly, transaminitis, delayed pubertal maturation, growth failure, and cushingoid features. Hyperglycemia leads to intrahepatic glycogen deposition and the lack of insulin to lipolysis and ketosis, leading to high cortisol levels and growth delay. Factors leading to uncontrolled T1DM include lack of insulin access. The high cost is considered a major barrier, with an average price per millimeter of insulin tripled from 231 to 736 US dollars. Even patients with insurance tend to have high co-pays and deductibles, with a 61% chance of delay or denial due to pre-approval requirements. Lower socioeconomic status, lack of access to devices such as insulin pumps, migratory status, social support, and ethnic background are other factors related to glycemic control. Our patient belongs to a family of immigrants with low socioeconomic status, which might have contributed to the development of Mauriac syndrome. Since clinical and laboratory abnormalities are reversible with appropriate glycemic control, advocating for policies that facilitate better insulin access is paramount. Presentation: 6/2/2024

Glial alterations in the glutamatergic and GABAergic signaling pathways in a mouse model of Lafora disease, a severe form of progressive myoclonus epilepsy.

Lafora disease (LD; OMIM#254780) is a rare form of progressive myoclonus epilepsy characterized by the accumulation of insoluble deposits of aberrant glycogen (polyglucosans), named Lafora bodies (LBs), in the brain but also in peripheral tissues. It is assumed that the accumulation of LBs is related to the appearance of the characteristic pathological features of the disease. In mouse models of LD, we and others have reported an increase in the levels of reactive astrocytes and activated microglia, which triggers the expression of the different pro-inflammatory mediators. Recently, we have demonstrated that the TNF and IL-6 inflammatory signaling pathways are the main mediators of the neuroinflammatory phenotype associated with the disease. In this work, we present evidence that the activation of these pathways produces a dysregulation in the levels of different subunits of the excitatory ionotropic glutamatergic receptors (phopho-GluN2B, phospho-GluA2, GluK2) and also an increase in the levels of the GABA transporter GAT1 in the hippocampus of the Epm2b-/- mice. In addition, we present evidence of the presence of activated forms of the Src and Lyn protein kinases in this area. These effects may increase the excitatory glutamatergic signaling and decrease the inhibitory GABAergic tone, leading to hyper-excitability. More importantly, the enhanced production of these subunits occurs in non-neuronal cells such as activated microglia and reactive astrocytes, pointing out a key role of glia in the pathophysiology of LD.

Mas receptor blockade impairs exercise-induced cardiac hypertrophy

Exercise training leads to physiological cardiac hypertrophy and the protective axis of the renin-angiotensin system composed of angiotensin-converting enzyme 2, angiotensin-(1–7), and Mas receptor seems involved in this process. However, the role of the basal activity of the Mas receptor in exercise-induced physiological cardiac hypertrophy is still unclear. We evaluated the effects of the Mas receptor blockade on the left ventricular structure and function of rats submitted to running training. Rats were assigned to 4 groups: sedentary (S), sedentary + A-779 (Mas receptor antagonist, 120 µg/kg/day, i.p.; SA), trained (60-minute treadmill running sessions, five days a week, 8 weeks; T), and trained + A-779 (TA). Systolic blood pressure was higher in sedentary and trained rats treated with A-779 at the end of the experimental period. The A-779 treatment prevented the left ventricular hypertrophy evoked by physical exercise and increased collagen deposition in sedentary and trained rats. Cardiomyocytes from the SA group presented increased length and thickness of the sarcomeres, elongated mitochondria, glycogen deposits, and enlarged cisterns of the sarcoplasmic reticulum. TA group presented a reduced sarcomere thickness and cytoplasm with a degenerative aspect. These findings show that the basal activity of the Mas receptor is essential for the proper turnover of the extracellular matrix in the myocardium and the maintenance of the sarcomeric structure of cardiomyocytes.

PI3KR1 and AKT1 in largemouth bass (Micropterus salmoides): molecular cloning, characterization, and its involvement in the alleviation of hepatic glycogen deposition caused by insulin inclusion in vitro.

In this study, the full-length cDNA sequences of the phosphatidylinositol-3-kinase p85 alpha (PI3KR1) and serine/threonine kinase 1 (AKT1) genes in largemouth bass (Micropterus salmoides) were obtained using the rapid amplification of cDNA ends (RACE) method. Sequence analysis revealed that the cloned sequences of PI3KR1 and AKT1 are 4170 bp and 3672 bp in length, with open reading frames (ORFs) of 1389 bp and 1422 bp encoding 462 and 473 amino acids, respectively. Sequence alignment and evolutionary tree analysis indicated their close relationship to other teleosts, especially those with similar feeding habits. Tissue distribution demonstrated widespread distribution of both genes in various tissues, with the highest abundance in the liver. Further results found that the upregulation of the expression of p-PI3KR1, p-AKT1, p-FoxO1, and GLUT2 proteins by insulin, while suppressing the expression of the total FoxO1 protein, effectively triggers a significant activation of the PI3KR1-AKT1 insulin signaling pathway. Meanwhile, the mRNA levels of the key glycolytic genes, including glucokinase (gk), pyruvate kinase (pk), and phosphofructokinase liver type (pfkl), have been enhanced evidently. In contrast, the expression of gluconeogenic genes such as phosphoenolpyruvate carboxykinase (pepck), glucose-6-phosphatase catalytic subunit (g6pc), and fructose-1,6-bisphosphatase-1 (fbp1) has been notably down-regulated. In addition, insulin treatment promoted the phosphorylation of glycogen phosphorylase (PYGL) and the dephosphorylation of glycogen synthase (GS), and the glycogen content in the insulin-treated group was remarkably reduced compared to the control group. Overall, our study indicates that the activation of PI3KR1-AKT1 insulin signaling pathway represses the hepatic glycogen deposition via the regulation of glycolysis and gluconeogenesis, which provides some new insights into nutritional strategy to effectively regulate the glucose metabolism in carnivorous fish.

N-acetylcysteine combined with insulin therapy can reduce myocardial injury induced by type 1 diabetes through the endoplasmic reticulum pathway

With the development of Type 1 diabetes mellitus (T1DM), various complications can be caused. Hyperglycemia affects the microenvironment of cardiomyocytes, changes endoplasmic reticulum homeostasis, triggers unfolding protein response and eventually promotes myocardial apoptosis. However, insulin therapy alone cannot effectively combat the complications caused by T1DM. Forty adult beagles were randomly divided into five groups: control group, diabetes mellitus group, insulin group, insulin combined with NAC group, and NAC group. 24-hour blood glucose, 120-day blood glucose, 120-day body weight, and serum FMN content were observed, furthermore, hematoxylin-eosin staining, Periodic acid Schiff reagent staining, and Sirius red staining of the myocardium were evaluated. The protein expressions of GRP78, ATF6, IRE1, PERK, JNK, CHOP, caspase 3, Bcl2, and Bax were detected. Results of the pathological section of myocardial tissue indicated that insulin combined with NAC therapy could improve myocardial pathological injury and glycogen deposition. Additionally, insulin combined with NAC therapy down-regulates the expression of GRP78, ATF6, IRE1, PERK, JNK, CHOP, caspase3, and Bax. These findings suggest that NAC has a phylactic effect on myocardial injury in beagles with T1DM, and the mechanism may be related to the improvement of endoplasmic reticulum stress-induced apoptosis.

Current Clinical Guidelines for the Management of Patients with Glycogen Storage Disease

Glycogen storage disease refers to hereditary pathologies of carbohydrate metabolism, its cause is mutations of various genes encoding enzymes responsible for the synthesis and breakdown of glycogen. Due to enzyme defects, excessive glycogen deposition occurs in cells of various tissues, mainly in the liver and muscles. The authors present modern epidemiological data and features of the etiopathogenesis of glycogen storage disease, and give clinical characteristics of various types of this nosology. In accordance with the developed clinical guidelines, information is provided on laboratory, instrumental and morphological signs of glycogen storage disease in children, as well as on methods of treatment of glycogen storage disease. Due to the variety of clinical forms of glycogenosis, the article provides up-to-date information on three types of pathology that occur with predominant liver damage.

Liraglutide alleviates high-fat diet-induced kidney injury in mice by regulating the CaMKKβ/AMPK pathway

Objective Liraglutide, a glucagon-like peptide-1 receptor agonist, has been shown to regulate blood sugar and control body weight, but its ability to treat obesity-related nephropathy has been poorly studied. Therefore, this study was designed to observe the characteristics and potential mechanism of liraglutide against obesity-related kidney disease. Methods Thirty-six C57BL/6J male mice were randomly divided into six groups (n = 6 per group). Obesity-related nephropathy was induced in mice by continuous feeding of high-fat diet (HFD) for 12 weeks. After 12 weeks, liraglutide (0.6 mg/kg) and AMP-activated protein kinase (AMPK) agonists bortezomib (200 μg/kg) were injected for 12 weeks, respectively. Enzyme-linked immunosorbent assay was employed to detect the levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol, blood urea nitrogen, creatinine in serum, as well as urinary protein in urine. Besides, hematoxylin–eosin staining and periodic acid-Schiff staining were used to observe the pathological changes of kidney tissue; immunohistochemistry, western blot, and real-time quantitative PCR to assess the calmodulin-dependent protein kinase kinase beta (CaMKKβ)/AMPK signaling pathway activation. Results Liraglutide significantly reduced serum lipid loading, improved kidney function, and relieved kidney histopathological damage and glycogen deposition in the mouse model of obesity-related kidney disease induced by HFD. In addition, liraglutide also significantly inhibited the CaMKKβ/AMPK signaling pathway in kidney tissue of HFD-induced mice. However, bortezomib partially reversed the therapeutic effect of liraglutide on HDF-induced nephropathy in mice. Conclusions Liraglutide has a therapeutic effect on obesity-related kidney disease, and such an effect may be achieved by inhibiting the CaMKKβ/AMPK signaling pathway in kidney tissue.

Moderate chronic sleep perturbation impairs glucose and lipid homeostasis in rats.

Sleep deprivation is a potential risk factor for metabolic diseases, including obesity and type 2 diabetes. We evaluated the impacts of moderate chronic sleep deprivation on glucose and lipid homeostasis in adult rats. Wistar rats (both sexes) were sleep-perturbed daily for 2 hours at the early (06:00-08:00) and the late light cycle (16:00-18:00) five days a week (except weekends) for 4 weeks. Sleep perturbation (SP) resulted in reduced body weight gain in both sexes, associated with altered food intake and reduced adiposity. SP did not alter the short- or long-term memories or cause anxiogenic behavior. No major changes were observed in the plasma insulin, leptin, triacylglycerol, non-esterified fatty acids, and blood glucose upon SP. After SP, females exhibited a transitory glucose intolerance, while males became glucose intolerant at the end of the experimental period. Male rats also developed higher insulin sensitivity at the end of the SP protocol. Morphometric analyses revealed no changes in hepatic glycogen deposition, pancreatic islet mass, islet-cell distribution, or adrenal cortex thickness in SP rats from both sexes, except for lower adipocyte size compared with controls. We did not find homogeneous changes in the relative expression of circadian and metabolic genes in muscle or hepatic tissues from the SP rats. Moderate chronic SP reduces visceral adiposity and causes glucose intolerance with a more pronounced impact on male rats, reinforcing the metabolic risks of exposure to sleep disturbances.

Mice with NOP2/sun RNA methyltransferase 5 deficiency die before reaching puberty due to fatal kidney damage

Background NOP2/Sun RNA methyltransferase 5 (NSUN5) is an RNA methyltransferase that has a broad distribution and plays critical roles in various biological processes. However, our knowledge of the biological functions of NSUN5 in mammals is very limited. Therefore, in this study, we investigate the role of NSUN5 in mice. Methods In the present research, we built a mouse model (Nsun5-/- ) using the CRISPR/Cas9 system to investigated the specific role of NSUN5. Results We observed that Nsun5-/- mice had a reduced body weight compared to wild-type mice. Additionally, their survival rate gradually decreased to 20% after postnatal day (PD) 21. Further examination revealed the Nsun5-/- mice had multiple organ damage, with the most severe damage occurring in the kidneys. Moreover, we observed glycogen deposition and fibrosis, along with a notable shorting of the primary foot processes of glomeruli in Nsun5-/- kidneys. Furthermore, we found that the kidneys of Nsun5-/- mice showed increased expression of the apoptotic signal Caspase-3 and accumulated stronger DNA damage at PD 21. Conclusions In our study, we found that mice lacking NSUN5 died before puberty due to kidney fatal damage caused by DNA damage and cell apoptosis. These results suggest that NSUN5 plays a vital role in preventing the accumulation of DNA damage and cell apoptosis in the kidney.

A case study of a liver transplant-treated patient with glycogen storage disease type Ia presenting with multiple inflammatory hepatic adenomas: an analysis of clinicopathologic and genetic data

BackgroundGlycogen storage disease (GSD) is a disease caused by excessive deposition of glycogen in tissues due to genetic disorders in glycogen metabolism. Glycogen storage disease type I (GSD-I) is also known as VonGeirk disease and glucose-6-phosphatase deficiency. This disease is inherited in an autosomal recessive manner, and both sexes can be affected. The main symptoms include hypoglycaemia, hepatomegaly, acidosis, hyperlipidaemia, hyperuricaemia, hyperlactataemia, coagulopathy and developmental delay.Case presentationHere, we present the case of a 13-year-old female patient with GSD Ia complicated with multiple inflammatory hepatic adenomas. She presented to the hospital with hepatomegaly, hypoglycaemia, and epistaxis. By clinical manifestations and imaging and laboratory examinations, we suspected that the patient suffered from GSD I. Finally, the diagnosis was confirmed by liver pathology and whole-exome sequencing (WES).WES revealed a synonymous mutation, c.648 G > T (p.L216 = , NM_000151.4), in exon 5 and a frameshift mutation, c.262delG (p.Val88Phefs*14, NM_000151.4), in exon 2 of the G6PC gene. According to the pedigree analysis results of first-generation sequencing, heterozygous mutations of c.648 G > T and c.262delG were obtained from the patient's father and mother.Liver pathology revealed that the solid nodules were hepatocellular hyperplastic lesions, and immunohistochemical (IHC) results revealed positive expression of CD34 (incomplete vascularization), liver fatty acid binding protein (L-FABP) and C-reactive protein (CRP) in nodule hepatocytes and negative expression of β-catenin and glutamine synthetase (GS). These findings suggest multiple inflammatory hepatocellular adenomas. PAS-stained peripheral hepatocytes that were mostly digested by PAS-D were strongly positive.This patient was finally diagnosed with GSD-Ia complicated with multiple inflammatory hepatic adenomas, briefly treated with nutritional therapy after diagnosis and then underwent living-donor liver allotransplantation.After 14 months of follow-up, the patient recovered well, liver function and blood glucose levels remained normal, and no complications occurred.ConclusionThe patient was diagnosed with GSD-Ia combined with multiple inflammatory hepatic adenomas and received liver transplant treatment. For childhood patients who present with hepatomegaly, growth retardation, and laboratory test abnormalities, including hypoglycaemia, hyperuricaemia, and hyperlipidaemia, a diagnosis of GSD should be considered. Gene sequencing and liver pathology play important roles in the diagnosis and typing of GSD.

Exploring the dietary strategies of phenylalanine: Improving muscle nutraceutical quality as well as muscle glycogen and protein deposition in adult grass carp (Ctenopharyngodon idella)

Muscle is the main edible part of bony fish. The purpose of this study was to investigate the influences of phenylalanine (Phe) on muscle quality, amino acid composition, fatty acid composition, glucose metabolism, and protein deposition in adult grass carp. The diets at 2.30, 4.63, 7.51, 10.97, 13.53, and 17.07 g/kg Phe levels were fed for 9 weeks. The results manifested that Phe (10.97–13.53 g/kg) increased the pH of the fillets and decreased muscle cooking loss and lactic acid content; Phe (7.51–17.07 g/kg) improved the composition of the fillets in terms of flavor (free) amino acids, bound amino acids (especially EAA), and fatty acids (especially EPA and DHA); Phe (7.51–13.53 g/kg) increased muscle glycogen content (possibly related to the AMPK signaling pathway) and muscle protein deposition (possibly related to IGF-1/4EBP1/TOR and AKT/FOXOs signaling pathways). In conclusion, a diet with appropriate Phe levels could improve fillet quality.

MiR-141/200c contributes to ethanol-mediated hepatic glycogen metabolism

ObjectiveHepatic glucose metabolism is profoundly perturbed by excessive alcohol intake. miR-141/200c expression is significantly induced by chronic ethanol feeding. This study aimed at identifying the role of miR-141/200c in glucose homeostasis during chronic ethanol exposure. MethodsWT and miR-141/200c KO mice were fed a control or an ethanol diet for 30 days, followed by a single binge of maltose dextrin or ethanol, respectively. Untargeted metabolomics analysis of hepatic primary metabolites was performed along with analyses for liver histology, gene expression, intracellular signaling pathways, and physiological relevance. Primary hepatocytes were used for mechanistic studies. ResultsmiR-141/200c deficiency rewires hepatic glucose metabolism during chronic ethanol feeding, increasing the abundance of glucose intermediates including G6P, an allosteric activator for GS. miR-141/200c deficiency replenished glycogen depletion during chronic ethanol feeding accompanied by reduced GS phosphorylation in parallel with increased expression of PP1 glycogen targeting subunits. Moreover, miR-141/200c deficiency prevented ethanol-mediated increases in AMPK and CaMKK2 activity. Ethanol treatment reduced glycogen content in WT-hepatocytes, which was reversed by dorsomorphin, a selective AMPK inhibitor, while KO-hepatocytes displayed higher glycogen content than WT-hepatocytes in response to ethanol treatment. Furthermore, treatment of hepatocytes with A23187, a calcium ionophore activating CaMKK2, lowered glycogen content in WT-hepatocytes. Notably, the suppressive effect of A23187 on glycogen deposition was reversed by dorsomorphin, demonstrating that the glycogen depletion by A23187 is mediated by AMPK. KO-hepatocytes exhibited higher glycogen content than WT-hepatocytes in response to A23187. Finally, miR-141/200c deficiency led to improved glucose tolerance and insulin sensitivity during chronic ethanol feeding. ConclusionsmiR-141/200c deficiency replenishes ethanol-mediated hepatic glycogen depletion through the regulation of GS activity and calcium signaling coupled with the AMPK pathway, improving glucose homeostasis and insulin sensitivity. These results underscore miR-141/200c as a potential therapeutic target for the management of alcohol intoxication.

Starvation in Mice Induces Liver Damage Associated with Autophagy.

Anorexia nervosa (AN) induces organ dysfunction caused by malnutrition, including liver damage leading to a rise in transaminases due to hepatocyte damage. The underlying pathophysiology of starvation-induced liver damage is poorly understood. We investigate the effect of a 25% body weight reduction on murine livers in a mouse model and examine possible underlying mechanisms of starvation-induced liver damage. Female mice received a restricted amount of food with access to running wheels until a 25% weight reduction was achieved. This weight reduction was maintained for two weeks to mimic chronic starvation. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured spectrophotometrically. Liver fat content was analyzed using an Oil Red O stain, and liver glycogen was determined using a Periodic acid-Schiff (PAS) stain. Immunohistochemical stains were used to investigate macrophages, proliferation, apoptosis, and autophagy. Starvation led to an elevation of AST and ALT values, a decreased amount of liver fat, and reduced glycogen deposits. The density of F4/80+ macrophage numbers as well as proliferating KI67+ cells were decreased by starvation, while apoptosis was not altered. This was paralleled by an increase in autophagy-related protein staining. Increased transaminase values suggest the presence of liver damage in the examined livers of starved mice. The observed starvation-induced liver damage may be attributed to increased autophagy. Whether other mechanisms play an additional role in starvation-induced liver damage remains to be investigated.

Esters of Quinoxaline-7-Carboxylate 1,4-di-N-Oxide as Potential Inhibitors of Glycolytic Enzymes of Entamoeba histolytica: In silico Approach.

Esters of quinoxaline-7-carboxylate 1,4-di-N-oxide (7-carboxylate QdNOs) derivatives are compounds that inhibit the growth of Entamoeba histolytica</i>, the causative agent of amebiasis. Although these compounds cause changes in the redistribution of glycogen deposits within the parasite, it is unknown whether these compounds interact with enzymes of the glycolytic pathway. The aim of this study was to test the binding affinity of these compounds to pyrophosphate- dependent phosphofructokinase (PPi-PFK), triosephosphate isomerase (TIM), and pyruvate phosphate dikinase (PPDK) from E. histolytica</i> as a possible mechanism of action. The molecular docking study of the 7-carboxylate QdNOs derivatives and the proteins was performed using AutoDock/Vina software. Molecular dynamics simulation was performed for 100 ns. Among all the selected compounds, T-072 exhibited the best binding affinity to EhPPi- PFK and EhTIM proteins, while T-006 interacted best with EhPPDK. ADMET analysis revealed that T-072 was non-toxic, while T-006 could become harmful to the host. In addition, molecular dynamics showed that T-072 has stable interaction with EhPPi-PFK and EhTIM. Including all aspects, these data indicated that these compounds might inhibit the activity of key enzymes in energy metabolism leading to parasite death. Furthermore, these compounds may be a good starting point for the future development of new potent antiamebic agents.

Effect of nattokinase on the pathological conditions in streptozotocin induced diabetic rats

Nattokinase (NK), also known as subtilisin NAT (EC 3.4.21.62), is a serine protease produced by Bacillus subtilis natto that has anti-inflammatory and fibrinolytic properties. To study whether NK prevents the progression of pathological changes in diabetes as an inflammatory disease, we examined the effect of NK on pathological conditions in streptozotocin (STZ)-induced diabetic rats using the following parameters: fasting blood glucose (glucose), total plasma protein (TP), creatinine, histopathology of renal corpuscles and tubules, advanced glycation end products (AGEs), and C-reactive protein (CRP). STZ-administered rats were maintained on a basic diet (CE-2) as control, low-NK diet (containing 0.2 mg NK/g diet), and high-NK diet (0.6 mg NK/g diet) for 14 days. High-dose NK significantly inhibited both glycogen deposition in the renal tubules and increase in the circulating AGE levels without downregulating glucose levels. Compared with the control group, the group treated with the high-NK diet presented a significant inhibition of the increase in the circulating CRP level on day 7 after the beginning of the treatment. However, the CRP level in the NK-H group reached the same level as that in the control group on Day 14. AGEs are known to induce CRP expression in hepatocytes, but the increase in CRP levels in our animal model was independent on the circulating AGE levels. In contrast, low-dose NK did not suppress changes in these parameters. Our present study suggests that NK suppresses glycogen deposition in renal tubules in a dose-dependent manner by the downregulation of AGE formation under hyperglycaemia in the rats with STZ-induced short-term diabetes. However, it is unclear whether this downregulation is caused by intact NK or peptides derived from NK during its digestion in the digestive tract.

Abstract 6286: Metabolic abnormalities are early predictors of liver metastasis in patients with ER+ breast tumors

Abstract Approximately 70% of human breast cancers express estrogen receptor alpha (ERα), providing a potential for targeted endocrine therapy for patients. Unfortunately, 30-40% of ER+ patients still experience recurrence and metastasis, with a 5-year relative overall survival rate of just 24% for patients with metastatic disease. In our preliminary analysis of the data from a large cohort of ER+ MBC patients, liver metastases were associated with reduced overall survival compared to other sites, while on the standard of care estrogen receptor antagonist, Fulvestrant (Fulv). This supports data from previous clinical trials showing that patients with liver metastases are less responsive to estrogen receptor alpha (ERα) targeting endocrine therapies compared to patients with bone or lung metastases. However, the factors underlying site-specific responses of MBC to ER antagonists are unknown. In this study, we investigated the concept that response of liver metastatic tumors is impacted by systemic glucose metabolism and the presence of liver metastatic tumors in turn will affect glucose homeostasis in the body. In our preliminary studies, metastatic liver tumors upregulated expression of enzymes that increased glycogen deposition in tumor cells in response to Fulv. Further analysis showed that a ketogenic diet restored Fulv response of metastatic liver tumors. Based on these results, we investigated if there was a relationship between metastatic site and response to endocrine therapy and if the metabolic status related to glucose homeostasis impacts metastatic disease response. We also searched if glucose homeostasis abnormalities can be indicators of liver metastasis. We obtained electronic health records from 192 patients with stage IV estrogen receptor positive breast cancer and analyzed glucose metabolism and liver panel markers including ALT, AST and ALP. Our results showed that more than 85% of patients with liver metastases have another accompanying metastasis and these patients are at a higher risk of diabetes diagnosis compared to other metastatic site patients. A higher % of patients with liver metastasis were deceased. We also observed increased levels of ALT, AST and ALP with liver metastasis and our preliminary analysis indicates that these blood biomarkers along with metabolic disease status (diabetes, hypertension, lipidemia) are good predictors of liver metastasis. Detecting early changes in markers of glucose metabolism may provide an easy diagnostic tool for early detection of liver metastases as well as assessment of treatment response. This may lead to accurate adjustment of treatment choices with improved outcome of patients with liver metastases from breast cancer. Citation Format: Ayca Nazli Mogol, Mahima Goel, Audrey Lam, Debapriya Dutta, Betsy Barnick, Maria Grosse Perdekamp, Zeynep Madak Erdogan. Metabolic abnormalities are early predictors of liver metastasis in patients with ER+ breast tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6286.

A kidney-targeted chitosan-melanin nanoplatform for alleviating diabetic nephropathy through modulation of blood glucose and oxidative stress

Diabetic nephropathy (DN) is a serious complication in patients with diabetes, whose expansion process is closely related to oxidative stress caused by hyperglycemia. Herein, we report a chitosan-targeted dagliflozin-loaded melanin nanoparticle (CSMDNPs) that can selectively accumulate in injured kidneys, reduce blood glucose, and alleviate the oxidative stress-induced damage. CSMDNPs possess good dispersion and physiological stability, responsive release at acidic pH, and strong scavenging activities for various reactive oxygen and reactive nitrogen radicals. Moreover, in vitro experiments confirm that CSMDNPs have good biocompatibility, enable targeted uptake in NRK-52E renal tubular cells, and also well alleviate high glucose-induced oxidative stress. In the STZ-induced DN model, CSMDNPs exhibit high targeting distribution and retention in the damaged kidneys of DN mice according to photoacoustic imaging. At the end of CSMDNPs treatment, DN mice show a decrease in fasting blood glucose and a return to near-normal urine and blood indices. H&E, PAS, and masson pathological staining also indicates that CSMDNPs significantly inhibit the expansion of renal interstitium, glycogen, and collagen deposition, showing excellent therapeutic effects. In addition, melanin acts as both drug carrier and antioxidant without exogenous carrier introduction, exhibiting better biosafety and translational prospects.

Characteristics, clinical laboratory, histopathology, and outcomes of glycogenic hepatopathy in children.

Glycogenic hepatopathy (GH) is a rare complication of type I diabetes mellitus (DM1), resulting in abnormal deposition of glycogen in the liver due to poor glycemic control. Clinical characteristics and natural history of GH are not completely understood in children. In this study, we investigated clinical, biochemical, histologic parameters and outcomes in children with GH. This was a retrospective review of patients less than 18 years old diagnosed with GH and DM. GH was confirmed on liver biopsy. Medical records were reviewed for clinical presentation, laboratory tests, and clinical outcomes. Liver biopsy findings were reviewed by a pediatric pathologist (I. A. G.). Nine children were diagnosed with GH and type 1 DM. The median age at diagnosis of GH was 16 (IQR 14.5-17) years. Duration of diagnosis of DM until GH diagnosis was 7 (IQR 5-11) years. The median frequency of diabetic ketoacidosis before GH diagnosis was three times (IQR 2-5.25). Peak Aspartate transaminase (AST) and Alanine transaminase (ALT) ranged from 115 to 797, and 83-389 units/L, respectively. Only two children had mild fibrosis. Seven of nine had steatosis without steatohepatitis. There was no correlation between glycosylated hemoglobin (HbA1c), or other laboratory tests and liver fibrosis on biopsy. HbA1c was 11.2 (IQR 10.2-12.8) at GH diagnosis and 9.8 (IQR 9.5-10.8) with normalization of liver enzymes. GH appears to be related to poor glycemic control in teenagers with long-term diabetes. GH presents with high to very high aminotransferase especially AST > ALT and resolves with modestly improved glycemic control. Diffuse hepatocyte swelling, steatosis, minimal fibrosis without hepatocyte ballooning or lobular inflammation are most common histological features.