4 results
548 Metformin normalizes impaired renal and cardiac function in a rat model of transient undernutrition
- Part of
- Branka Stanic, Aline M.A de Souza, Hong Ji, Kyle Korolowicz, Kathryn Sandberg, Carolyn M. Ecelbarger
-
- Journal:
- Journal of Clinical and Translational Science / Volume 8 / Issue s1 / April 2024
- Published online by Cambridge University Press:
- 03 April 2024, p. 164
-
- Article
-
- You have access Access
- Open access
- Export citation
-
OBJECTIVES/GOALS: In the U.S., over 4 million people including children experience transient periods of undernutrition annually. Cardio-metabolic and renal diseases are more prevalent in this population. We are investigating therapeutic strategies to reverse the long-term risk of these diseases in a rat model of transient undernutrition followed by refeeding. METHODS/STUDY POPULATION: Thirty six female Fischer rats (3-months of age) were initially divided into 2 groups. Half were fed regular chow (CT) while the other half were severely food restricted (sFR) by 60% from 0-2 weeks (wks) followed by refeeding from 2-14 wks (sFR-Refed). These 2 groups were then subdivided and treated ± metformin (Met) from wk 7 to wk 12 (n=9/group). High precision ultrasound was conducted on live rats to assess heart and kidney function immediately after the sFR period ended (wk 2) and at the end of the study (wk 14). At the conclusion of the experiment, the rats were sacrificed and the histology of the kidney and heart tissues were analyzed in hematoxylin and eosin-stained sections. The protein to DNA ratio was also calculated in homogenates from these tissues. RESULTS/ANTICIPATED RESULTS: In sFR-Refed rats, cardiac output (CO), heart rate (HR) and renal artery blood flow (RBF) were decreased by 11 ± 1.5%#, 7.0 ± 6.0% and 22 ± 0.6%#, respectively, compared to control (CT) rats; #p<0.05. Mean glomerular diameter was reduced in the kidneys of sFR-refed rats compared to CT and this effect was attenuated by metformin treatment [(µm): CT, 406 ± 31; sFR-Refed, 383 ± 11, p<0.06; CT+Met, 393 ± 18; sFR-Refed+Met, 407 ± 18*]. Furthermore, the mean cardiomyocyte thickness was reduced in sFR-Refed rats compared to controls while metformin treatment prevented this effect [(µm): CT, 16.4 ± 3.6; sFR-Refed, 11.5 ± 2.3#; CT+Met, 16.4 ± 3.6; sFR-Refed+Met, 15.9 ± 3.2*]. #p<0.05 vs. CT, same treatment; *p<0.05 vs. Met, same diet; two-way ANOVA. DISCUSSION/SIGNIFICANCE: These findings have promising implications for metformin use to mitigate long-term impairments in heart and kidney structure and function in individuals who have experienced bouts of undernutrition earlier in life for either voluntarily (e.g., very low calorie dieting) or involuntary (e.g., very low food security) reasons.
395 Systemic Administration of miR-451 Improves Autophagy Response in an Accelerated Mouse Model of Diabetic Kidney Disease
- Part of
- Sadaf Ghaderzadeh, Baiyeendang Agbor-Baiyee, Chidera Obiwuma, Neal Mohit, Kanwal K. Gambhir, Carolyn M. Ecelbarger, Maurice B. Fluitt
-
- Journal:
- Journal of Clinical and Translational Science / Volume 8 / Issue s1 / April 2024
- Published online by Cambridge University Press:
- 03 April 2024, p. 118
-
- Article
-
- You have access Access
- Open access
- Export citation
-
OBJECTIVES/GOALS: Diabetic Kidney Disease (DKD) is a common diabetes complication, often linked to end-stage renal disease in the United States (US). While autophagy and miRNAs are pivotal, miR-451’s specific role remains understudied. Our study explores its renoprotective effects in an accelerated DKD mouse model. METHODS/STUDY POPULATION: We assessed the effect of miR-451 mimic treatment on Diabetic Kidney Disease (DKD) in BTBR ob/ob mice, known for their rapid DKD-like renal lesions. Mice were divided into four groups: WT (wild-type), BTBR ob/ob, WT+miR-451 (wild-type with miR-451 mimic), and BTBR ob/ob+miR-451 (BTBR ob/ob with miR-451 mimic). MiR-451 mimics were administered at 2mg/kg body weight once weekly for three consecutive weeks. We collected spot urine and monitored blood glucose levels at each time point. After the treatment period, mice were euthanized for kidney and blood samples. Western blot analysis assessed autophagy-related protein markers. Statistical analysis included Student’s t-test and ANOVA (p<0.05). RESULTS/ANTICIPATED RESULTS: The study assessed the impact of miR-451 mimic treatment in BTBR ob/ob mice. Albumin:creatinine ratio increased fourfold (p=0.01) in BTBR ob/ob mice at 5 weeks. MiR-451 mimic treatment had no impact on body weight. Blood glucose levels were notably higher in both treated and untreated BTBR ob/ob mice at 12 (425±33.1 mg/dL; p=0.04) and 13 weeks (383±25.3 mg/dL; p=0.007). However, a significant drop occurred from week 13 (554.7±10.8 mg/dL) to week 14 (289±13.3 mg/dL; p=0.0002) in BTBR ob/ob miR-451 treated mice. Western blot analysis in whole kidney homogenates showed a 91% reduction (p=0.02) in YWHAZ, a predicted miR-451 target, in treated BTBR ob/ob mice and a 95% reduction (p=0.01) in WT mice. Furthermore, miR-451 mimic treatment led to a 68% increase (p=0.01) in ATG101 and a 44% increase in Beclin-1 in BTBR ob/ob mice. DISCUSSION/SIGNIFICANCE: The study uncovers miR-451-based interventions as a promising avenue to counter Diabetic Kidney Disease by modulating autophagy, potentially introducing novel therapies for at-risk individuals. However, practical DKD treatments will require further research and rigorous clinical validation to harness the full potential of these insights.
396 Brain pathophysiology in SARS-CoV-2 disease
- Branka Milicic Stanic, Aline M.A. de Souza, Hong Ji, Xie Wu, Robert C. Speth, Nisha K. Duggal, Carolyn A. Ecelbarger, Juan M. Saavedra, Dexter L. Lee, Kathryn Sandberg
-
- Journal:
- Journal of Clinical and Translational Science / Volume 6 / Issue s1 / April 2022
- Published online by Cambridge University Press:
- 19 April 2022, pp. 74-75
-
- Article
-
- You have access Access
- Open access
- Export citation
-
OBJECTIVES/GOALS: The SARS-CoV-2 (Severe Acute Respiratory Syndrome CoronaVirus-2), which underlies the current COVID-19 pandemic, among other tissues, also targets the central nervous system (CNS). The goal of this study is to investigate mechanisms of neuroinflammation in Lipopolysaccharides (LPS)-treated mouse model and SARS-CoV-2-infected hamsters. METHODS/STUDY POPULATION: In this research I will assay vascular reactivity of cerebral vessels to assess vascular dysfunction within the microcirculation. I will determine expression of proinflammatory cytokines, coagulation factors and AT1 receptors (AT1R) in isolated microvessels from the circle of Willis to assess inflammation, thrombosis and RAS activity in the microvasculature. LPS and SARS-CoV-2, are both associated with coagulopathies and because of that I will measure concentration of PAI-1, von Willebrand Factor, thrombin and D-dimer to assess the thrombotic pathway in the circulation. Histology and immunohistochemistry will assess immune cell type infiltration into the brain parenchyma, microglia activation and severity of neuroinflammation and neural injury. RESULTS/ANTICIPATED RESULTS: We hypothesize that under conditions of reduced ACE2 (e.g., SARS-CoV-2 infection), AT1R activity is upregulated in the microvasculature. In the presence of an inflammatory insult, these AT1Rs promote endothelialitis and immunothrombosis through pro-thrombotic pathways and pro-inflammatory cytokine production leading to endothelial dysfunction in the microvasculature, blood brain barrier (BBB) injury, deficits in cognition and increased anxiety. We will test this hypothesis through 2 aims: Aim 1: Determine the role of the pro-injury arm of the RAS in the pathophysiology of the brain in animal models of neuroinflammation and COVID-19. Aim 1: Determine the role of the protective arm of the RAS in the pathophysiology of the brain in animal models of neuroinflammation and COVID-19. DISCUSSION/SIGNIFICANCE: This study will provide insights that will complement on-going clinical trials on angiotensin type 1 receptor (AT1R) blockers (ARBs) in COVID-19. This research is a necessary first step in understanding mechanisms of brain pathogenesis that can set the groundwork for future studies of more complex models of disease.
2466 MicroRNA-451: A potential key player in the development of diabetic nephropathy in an insulin resistant mouse model
- Maurice B Fluitt, Lijun Li, Narayan Shivapurkar, Carolyn Ecelbarger
-
- Journal:
- Journal of Clinical and Translational Science / Volume 2 / Issue S1 / June 2018
- Published online by Cambridge University Press:
- 21 November 2018, p. 20
-
- Article
-
- You have access Access
- Open access
- Export citation
-
OBJECTIVES/SPECIFIC AIMS: MicroRNAs (miRNA) affect transcription of a number of genes involved in the development and progression of diabetic nephropathy (DN), and have become attractive therapeutic targets and biomarkers. Elevated renal gluconeogenesis, fibrosis, and albuminuria are early markers of incipient DN. Recent studies report that renal miRNA-451 may protect against DN and reduce renal gluconeogenesis in rodent models. MiRNA-451 is thought to act by targeting select factors resulting from disrupted insulin and growth factor signaling and the mechanistic-target of rapamycin (mTOR) in early DN. This study aimed to elucidate the role of miRNA-451 in the development and progression of DN. METHODS/STUDY POPULATION: To further elucidate the role of miRNA-451 in DN, we placed male insulin-resistant, TALLYHO/Jng mice on a high-fat diet (60% kCal). The mice were divided into 2 treatment groups and received 8 consecutive weekly intraperitoneal injections of locked nucleic acid (LNA) miR-451-inhibitor or LNA-scrambled compound (2 mg/kg·bw; n=8/treatment). Mice were euthanized after 12 weeks (4 weeks sans injections) and kidneys, liver, pancreas and abdominal adipose tissue were harvested for analysis. RESULTS/ANTICIPATED RESULTS: Renal homogenate expression of miRNA-451 was drastically reduced in inhibitor-treated mice (~6-fold) in comparison with scramble-treated mice. Western blotting of cortex homogenates for indicators of fibrosis and targets of miRNA-451 revealed a significant reduction in collagen IV (marker of epithelial integrity) in inhibitor-treated mice. In addition, metalloproteinase type 9 (MMP9, a known type IV collagenase), YWHAZ (a scaffolding protein and known target of miR-451), mTOR, and fructose bisphosphatase (FBP1, a rate-limiting gene in gluconeogenesis) were significantly increased in this group in comparison to scramble-treated mice. However, no differences were found in protein levels for glucose-6-phosphatase (G-6-Pase) or phosphoenolpyruvate (PEPCK), 2 additional gluconeogenic rate-limiting genes. MiRNA-451 antagonist did not significantly affect final body weight or blood glucose; however, mean blood sodium concentrations were slightly, but significantly higher (2%) in the LNA-inhibitor treated group (when compared with the scramble-treated group). No differences in blood potassium or chloride were found. Anion gap was 90% higher in the LNA-inhibitor treated group when compared with scramble-treated mice. No differences in urinary albumin to creatinine ratio were found between the two treatment groups. However, Masson Trichrome scoring revealed a 59% increase in fibrosis in inhibitor-treated mice. DISCUSSION/SIGNIFICANCE OF IMPACT: Collectively, these findings support a potentially protective role of miRNA-451 in attenuating signaling via mTOR that may alter both renal gluconeogenic potential (contributing to the diabetic phenotype) and activation and progression of renal fibrosis. Therapies to enhance miRNA-451 signaling may be beneficial to reduce renal pathology associated with DN.