Anil Yadav

Background: Prolonged postoperative mechanical ventilation (PPMV) after pediatric liver transplantation is frequently associated with increased morbidity and mortality. Identifying the causes and associated risk factors will help improve the perioperative management and outcomes. The primary objective of this original retrospective cohort study was to evaluate the incidence, risk factors, and postoperative impact of PPMV in pediatric living-donor liver transplant recipients at a tertiary-care centre in India (April 2012–March 2022). Results: Sixty-four patients were included for the final analysis. The incidence of PPMV was 31.2% ( n = 20). Elevated serum lactate at the end of surgery (≥ 4.4 mmol/L) was the only independent predictor (OR 2.81, 95% CI 1.06–7.45, p = 0.038) of PPMV. Patients in the PPMV group had significantly longer ICU stay (26.3 ± 7.9 vs. 17.3 ± 2.2 days, p = 0.030) and hospital stay (57.8 ± 14.7 vs. 36.4 ± 10.2 days, p < 0.001). These patients also had higher rates of tracheostomy (30% vs. 0.4%, p = 0.004), re-exploration (60% vs. 18.2%, p < 0.001), and graft dysfunction (15% vs. 0%, p = 0.009). Mortality at 28 days was significantly higher in this group (45% vs. 11.4%). Conclusion: PPMV was found in nearly one-third of pediatric liver transplant recipients and was associated with unfavorable postoperative outcomes. Lactate ≥ 4.4 mmol/L was independently associated with PPMV and may serve as a useful marker for identifying children at increased risk. Trial registration: ClinicalTrials.gov NCT05825703.

Aim: Sarcopenia is a significant predictor of postoperative morbidity and mortality in liver transplant recipients. Traditional assessment tools such as computed tomography (CT) and bioelectrical impedance analysis have limitations in clinical use. This study aimed to evaluate the utility of ultrasonography (USG) in assessing abdominal muscle thickness as a marker of sarcopenia. Material and methods: This prospective observational study was conducted at a tertiary liver transplant center between September 2023 and May 2024. USG was used to measure the thickness of the external oblique (EO), internal oblique, and transversus abdominis (TA) muscles in 41 liver transplant recipients and 41 healthy donors. Sarcopenia was also assessed using CT-based L3 skeletal muscle index (L3-SMI) and hand grip strength. Correlations with disease severity (Model for End-Stage Liver Disease, Child-Turcotte-Pugh (CTP)), postoperative outcomes, and ascitic fluid volume were analyzed. Results: Abdominal muscle thickness was significantly lower in recipients compared to donors (EO: 2.9 ± 1.0 mm vs. 4.5 ± 1.8 mm; TA: 2.2 ± 0.7 mm vs. 3.2 ± 1.0 mm; p <0.001). Sarcopenia prevalence was 78% by L3-SMI and 82.9% by hand grip strength. ROC analysis demonstrated that EO <3.6 mm and TA <2.55 mm predicted sarcopenia in males with high sensitivity and specificity. Muscle thinning correlated with higher CTP scores, greater ascitic fluid volume, and prolonged intensive care unit stay. Conclusions: USG-derived abdominal muscle thickness, especially EO <3.6 mm and TA <2.55 mm in males, is a reliable, non-invasive marker for sarcopenia in liver transplant candidates. It correlates with disease severity and postoperative morbidity, supporting its utility in pre-transplant risk stratification.

Disclosure: K.A. de Oliveira: None. F.D. Andrade: None. M. Ozgul-Onal: None. A. Yadav: None. T. Onal: None. L. Jin: None. S. Sengupta: None. R. Clarke: None. Endocrine therapy can lead to cellular nutrient deprivation by reducing glucose and glutamine uptake and total cellular ATP production in breast cancer cells. The ability to bypass this metabolic stress is fundamental to how breast cancer cells regulate growth and acquire endocrine resistance. SIRT3, which can be activated by calorie restriction, modulates mitochondrial adaptation to low energy input. It has a key role in mitochondrial integrity and function, regulating cell survival, death, and metabolism, regulating the shift to amino-acid and fatty-acid catabolism. SIRT3 can maintain ROS levels at the appropriate levels for sustaining a proliferative phenotype, preventing apoptosis and promoting carcinogenesis. A role of SIRT3 in epigenetic regulation has also been reported. The ability of SIRTs to sense and respond to changes in energy, coupled with their intrinsic deacetylase/deacylase functions, could provide a mechanism for the cell to rewire signaling and maintain a newly acquired drug-resistant phenotype. Using antiestrogen sensitive (LCC1) and cross-resistant (LCC9) breast cancer cells, we confirmed higher expression of SIRT3 in LCC9, compared with LCC1 cells. Upregulation of SIRT3 expression within 24 hrs of Fulvestrant (ICI 1 µM) treatment (p=0.0176) in LCC1 was shown, whereas no effect was observed in LCC9 cells. Inhibition of SIRT3 activity, using the inhibitor LC0296 (15 µM), reduced growth rate in both LCC1 and SIRT3-silenced LCC9 cells under treatment with ICI (pPresentation: Thursday, June 15, 2023

Endocrine therapy can lead to nutrient deprivation by reducing glucose and glutamine uptake and total cellular ATP production. The ability of cells to bypass this metabolic stress is fundamental to how they regulate BC growth and acquire endocrine resistance. Sirtuins (SIRTs) are NAD+-dependent deacylases and regulate a widerange of intracellular processes including metabolism. SIRT3, activated by calorie restriction, modulates mitochondrial adaptation to low energy input. It has a key role in mitochondrial integrity and function, regulating cell survival, death and metabolic pathways, regulating the shift to amino-acid and fatty-acid catabolism. SIRT3 can maintain ROS levels at the appropriate levels for sustaining a proliferative phenotype, preventing apoptosis and promoting carcinogenesis. A role of SIRT3 in epigenetic regulation has also been reported. We used Differential Dependency Network analysis to compare the wiring of the SIRTs and key metabolism-related genes in matched antiestrogen- sensitive vs. resistant breast cancer (BC) cells, which identified several novel signaling hubs including CDKN2A (p16), linking SIRT3 to cell proliferation. The ability of SIRTs to sense and respond to changes in energy, coupled with their deacetylase/deacylase functions, could provide a mechanism for the cell to rewire signaling and maintain a newly acquired drug-resistant phenotype. Using endocrine sensitive (LCC1) and resistant (LCC9) BC cells, we confirmed the higher expression of SIRT3 in LCC9, compared to LCC1 cells. Upregulation of SIRT3 expression within 24 hrs of Fulvestrant (ICI 1 µM) treatment (p=0.0176) in LCC1 was shown, but no effect was observed in LCC9 cells. Conversely, treatment with 17β-estradiol (E2- 10 nM) did not significantly affect SIRT3 expression in either LCC1 or LCC9 cells. Inhibition of SIRT3 acitivity, using the LC0296 inhibitor (15 µM), reduced growth rate in LCC1 and SIRT3-silenced LCC9 cells under treatment with ICI (1 nM and 1 µM, respectively) (p< 0.0001, p< 0.001 respectively). Treatment with SIRTUIN 3 inhibitor and ICI induced apoptosis in LCC1 and SIRT3-silenced LCC9 cells compared to the untreated control and ICI only treated cells (p< 0.001). The combination SIRT3 inhibitor (15 µM) plus ICI (0.5 µM) increased ROS production in LCC9-SIRT3 silenced cells in 24 hours of treatment compared to the untreated control and ICI only treated cells (p< 0.001). SIRT3 inhibitor (15 µM) decreased LCC1 cell spheroid formation (p< 0.05), however it didn’t show additive effect to the effect of ICI (0.5 µM) in the same conditions. The combination of SIRT3 inhibitor (15 µM) and ICI (1 µM) reduced the growth of LCC9 SIRT3-silenced cells in detached condition compared to untreated control and ICI only treated cells (p< 0.001). The results show that SIRT3 may have a role in Fulvestrant response in BC cells; the mechanism is under investigation in our laboratory. Citation Format: Karla Andrade de Oliveira, Surojeet Sengupta, Lu Jin, Fabia de Oliveira Andrade, Melike Ozgu-Onal, Anil Yadav, Robert Clarke. Inhibition of Sirtuin 3 Sensitizes Breast Cancer Cells to Fulvestrant [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-11-08.

AlaskOmega® Omega 7 500, also known as Omega‑7 fatty acid or 7‑MEGA™, is a highly concentrated palmitoleic acid (C16:1). Little is known about how 7‑MEGA regulates skin inflammation and wrinkle formation in cultured skin cells. The present study aimed to investigate the effects of 7‑MEGA on the expression of cyclooxygenase‑2 (COX‑2), matrix metallopeptidase (MMP)‑1/3 and type 1 procollagen, which are markers of skin inflammation and wrinkle formation, in ultraviolet B (UVB)‑irradiated human dermal fibroblasts (HDFs) and keratinocytes (HaCaT). No toxicity was observed upon treatment of HDFs and HaCaT cells with 0.5‑2.5 µl/ml 7‑MEGA. The exposure of HaCaT cells to 10 mJ/cm2 UVB for 6 h resulted in increased protein and/or mRNA expression of COX‑2 and MMP‑3. Treatment of HaCaT cells with 2.5 µl/ml 7‑MEGA suppressed the UVB‑induced expression of COX‑2 and MMP‑3 in these cells. In addition, treatment with 2.5 µl/ml 7‑MEGA attenuated the UVB‑induced expression and phosphorylation levels of c‑Fos and c‑Jun, two components of the activator protein‑1 (AP‑1) transcription factor, in HaCaT cells. Exposure of HDFs to 60 mJ/cm2 UVB for 6 h significantly decreased the expression of type 1 procollagen protein, whereas treatment with 2.5 µl/ml 7‑MEGA partially reversed the effects of UVB on the expression of type 1 procollagen protein. These results demonstrated for the first time that 7‑MEGA regulated the expression of COX‑2, MMP‑3 and type 1 procollagen in UVB‑irradiated skin cells. The present study suggested that 7‑MEGA may serve as a novel agent against UVB‑induced skin inflammation and damage.