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Awad Alshahrani,1–3 Mohammed AlDubayee,1–3 Mahmoud Zahra,3 Firas M Alsebayel,3 Nawaf Alammari,3 Faisal Alsudairy,3 Muath Almajed,3 Ahmad Aljada4 1Department of Medicine, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Kingdom of Saudi Arabia; 2King Abdullah International Medical Research Centre (KAIMRC), Riyadh, Kingdom of Saudi Arabia; 3College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi Arabia; 4Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Kingdom of Saudi ArabiaCorrespondence: Ahmad AljadaDepartment of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, P.O. Box 50927, Riyadh 11533, Kingdom of Saudi ArabiaTel +966 112158 834Email aaljada@alfaisal.eduBackground: Interactions between environmental factors, such as diet and lifestyle, and metabolic pathways are pivotal in understanding aging mechanisms. hNAA40, Nicotinamide phosphoribosyltransferase (NAMPT), and NAD-dependent protein deacetylase sirtuin-1 (SIRT-1) have been shown to exert important biological processes, including stress response and aging.Methods: hNAA40, NAMPT, and SIRT-1 mRNA expression in peripheral blood mononuclear cells (PBMC) were quantitated in 30 lean adult volunteers of normal weight, 30 obese, 20 drug-naïve obese Type 2 diabetes mellitus (T2DM), and 30 obese T2DM on Metformin. Similarly, hNAA40, NAMPT, and SIRT-1 expression in PBMC were quantitated in 36 normal healthy adults randomly assigned to three different groups (Glucose or Whey proteins or lipids; 300 kcal). Blood samples were obtained at 1, 2, and 3 hrs after the macronutrient intake.Results: There was an increase in hNAA40 and a decrease in NAMPT and SIRT-1 expression in PBMC from T2DM. Metformin treatment reverted hNAA40, NAMPT, and SIRT-1 expression levels to normal levels. Glucose intake resulted in a significant increase in expression of hNAA40 at 1 hr and decreased significantly at 3 hrs post intake. Lipid intake resulted in an increase in expression of hNAA40 at 2 hr post intake and returned to normal levels at 3 hrs. Neither glucose nor lipid intake resulted in a significant change in NAMPT or SIRT-1 expression. Whey proteins resulted in significantly lower expression of NAMPT at 3 hrs and did not alter the expression levels of SIRT-1 significantly.Conclusion: hNAA40, NAMPT, and SIRT-1 pathway could play a role in the determination of the healthy life-span. Metformin modulates this pathway.Keywords: hNAA40, nicotinamide phosphoribosyltransferase, NAMPT, sirtuin-1, T2DM, obesity, senescence

Mohammed Al Dubayee,1– 3 Awad Alshahrani,1– 3 Dana Aljada,4 Mahmoud Zahra,5 Ahmed Alotaibi,1 Ibrahim Ababtain,1 Malik Alnaim,1 Ali Alahmari,1 Abdullah Aljarallah,1 Muhammad Affan Elahi,5 Hana MA Fakhoury5 1College of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Riyadh, Saudi Arabia; 2King Abdullah International Medical Research Center (KAIMRC), Riyadh, Saudi Arabia; 3Department of Medicine, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia; 4College of Liberal Arts and Sciences, Hofstra University, Hempstead, NY, USA; 5Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi ArabiaCorrespondence: Mohammed Al DubayeeCollege of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), P.O. Box 22490, Riyadh, Saudi ArabiaTel +966 11 801 1111 ext: 53551Email ALDUBAYEEMO@ngha.med.saIntroduction: Insulin resistance in obesity and type 2 diabetes mellitus (T2DM) is associated with cardiovascular complications such as atherosclerosis. On the other hand, the reduction of apoptosis in macrophages has been linked with accelerated atherosclerosis. Apoptosis is controlled by a different family of proteins including Bcl-2 and caspases.Methods: To examine apoptosis in insulin resistance, we assessed the mRNA expression by qRT-PCR of several Bcl-2 family members, as well as caspase-3, − 7, − 8, and − 9 in peripheral blood mononuclear cells (PBMCs) isolated from lean, obese, diabetic, and diabetic on metformin individuals.Results: PBMCs of diabetic individuals exhibited reduced expression of caspase-7 and increased expression of Bcl-10, Bad, Bax, Bid, and caspase-3. T2DM on metformin group had significantly higher Bad, Bax, and caspase-7 expression.Discussion: The moderate up-regulation of pro-apoptotic Bcl-10, Bax, Bad, Bid, and the effector caspase-3 coupled with inhibition of caspase-7 in circulating PBMCs of T2DM could be the result of increased inflammation in T2DM. Metformin treatment significantly inhibited the expression of Bcl-10, Bid, and caspase-3 and upregulated Bad/Bax/caspase-7 pathway suggesting the activation of Bad/Bax/caspase-7 apoptotic pathway. Further studies are warranted to elicit the underlying apoptotic pathways of PBMCs in T2DM and following metformin treatment.Keywords: apoptosis, T2DM, peripheral blood mononuclear cells, PBMC, caspase, BCl-10, BCl-2