Chlorinated paraffins (CPs) are environmental pollutants extensively used in industries. While the use of short-chain chlorinated paraffins (SCCPs) has been restricted since 2017, the use of medium-chain chlorinated paraffins (MCCPs) has risen as their replacement. Due to lipophilic character, it can be expected that CPs enter the cells; however, the in vitro accumulation potential of CPs remains poorly understood. In this study, we aimed to explore the ability of SCCPs and MCCPs to accumulate in fat cells. We utilized an in vitro model of mouse 3T3-L1 preadipocytes and adipocytes. Using gas chromatography coupled with high-resolution mass spectrometry operated in negative chemical ionization mode, we determined the intracellular amounts of CPs. These compounds accumulated at rates of 8.5 ± 0.1 µg/gcells/h for SCCPs and 7.8 ± 0.3 µg/gcells/h for MCCPs when an initial concentration of 120 ng/ml was present in the medium. This rate increased approximately tenfold when the concentration of CPs was raised to 1200 ng/ml. CPs content in adipocytes steadily increased over 5 days, whereas preadipocytes accumulated 15-20 times less CPs. This highlights the importance of cellular lipid content, which was about 12 times higher in adipocytes. Furthermore, we found that the level of chlorine content in the CPs molecules significantly influenced their accumulation. Our results demonstrate that MCCPs exhibit a similar accumulation potential to SCCPs, with lipid content playing a crucial role. As with SCCPs, restrictions on the use of MCCPs in industry should be considered to mitigate their environmental and health impacts.

• Keywords
• 3T3-L1 cells, Adipocytes, Chlorinated paraffins, Persistent organic pollutants,
• MeSH
• 3T3-L1 Cells MeSH
• Hydrocarbons, Chlorinated * metabolism   toxicity   MeSH
• Halogenation MeSH
• Environmental Pollutants * metabolism   toxicity   MeSH
• Lipids analysis   MeSH
• Lipid Metabolism * drug effects   MeSH
• Mice MeSH
• Paraffin * metabolism   toxicity   chemistry   MeSH
• Gas Chromatography-Mass Spectrometry MeSH
• Adipocytes * metabolism   drug effects   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Hydrocarbons, Chlorinated * MeSH
• Environmental Pollutants * MeSH
• Lipids MeSH
• Paraffin * MeSH

Type 2 diabetes mellitus represents a major health problem with increasing prevalence worldwide. Limited efficacy of current therapies has prompted a search for novel therapeutic options. Here we show that treatment of pre-diabetic mice with mitochondrially targeted tamoxifen, a potential anti-cancer agent with senolytic activity, improves glucose tolerance and reduces body weight with most pronounced reduction of visceral adipose tissue due to reduced food intake, suppressed adipogenesis and elimination of senescent cells. Glucose-lowering effect of mitochondrially targeted tamoxifen is linked to improvement of type 2 diabetes mellitus-related hormones profile and is accompanied by reduced lipid accumulation in liver. Lower senescent cell burden in various tissues, as well as its inhibitory effect on pre-adipocyte differentiation, results in lower level of circulating inflammatory mediators that typically enhance metabolic dysfunction. Targeting senescence with mitochodrially targeted tamoxifen thus represents an approach to the treatment of type 2 diabetes mellitus and its related comorbidities, promising a complex impact on senescence-related pathologies in aging population of patients with type 2 diabetes mellitus with potential translation into the clinic.

• MeSH
• Diabetes Mellitus, Type 2 * complications   drug therapy   MeSH
• Diabetes Mellitus, Experimental * complications   drug therapy   MeSH
• Glucose metabolism   MeSH
• Humans MeSH
• Mice MeSH
• Obesity complications   drug therapy   metabolism   MeSH
• Aged MeSH
• Tamoxifen pharmacology   therapeutic use   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Aged MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Glucose MeSH
• Tamoxifen MeSH

(1) Background: empagliflozin, sodium-glucose co-transporter 2 (SGLT-2) inhibitor, is an effective antidiabetic agent with strong cardio- and nephroprotective properties. The mechanisms behind its cardio- and nephroprotection are still not fully clarified. (2) Methods: we used male hereditary hypertriglyceridemic (hHTG) rats, a non-obese model of dyslipidaemia, insulin resistance, and endothelial dysfunction fed standard diet with or without empagliflozin for six weeks to explore the molecular mechanisms of empagliflozin effects. Nuclear magnetic resonance (NMR)-based metabolomics; quantitative PCR of relevant genes involved in lipid and glucose metabolism, or senescence; glucose and palmitic acid oxidation in isolated tissues and cell lines of adipocytes and hepatocytes were used. (3) Results: empagliflozin inhibited weight gain and decreased adipose tissue weight, fasting blood glucose, and triglycerides and increased HDL-cholesterol. It also improved insulin sensitivity in white fat. NMR spectroscopy identified higher plasma concentrations of ketone bodies, ketogenic amino acid leucine and decreased levels of pyruvate and alanine. In the liver, adipose tissue and kidney, empagliflozin up-regulated expression of genes involved in gluconeogenesis and down-regulated expression of genes involved in lipogenesis along with reduction of markers of inflammation, oxidative stress and cell senescence. (4) Conclusion: multiple positive effects of empagliflozin, including reduced cell senescence and oxidative stress, could contribute to its long-term cardio- and nephroprotective actions.

• Keywords
• cell senescence, empagliflozin, hereditary hypertriglyceridemic rat model, hypertriglyceridemia, insulin sensitivity, metabolic syndrome,
• MeSH
• Administration, Oral MeSH
• Benzhydryl Compounds administration & dosage   MeSH
• 3T3-L1 Cells MeSH
• Hep G2 Cells MeSH
• Down-Regulation drug effects   MeSH
• Dyslipidemias drug therapy   MeSH
• Sodium-Glucose Transporter 2 Inhibitors administration & dosage   MeSH
• Gluconeogenesis drug effects   genetics   MeSH
• Glucosides administration & dosage   MeSH
• Weight Gain drug effects   MeSH
• Hypertriglyceridemia drug therapy   metabolism   MeSH
• Hypoglycemic Agents administration & dosage   MeSH
• Insulin Resistance MeSH
• Liver metabolism   MeSH
• Rats MeSH
• Kidney metabolism   MeSH
• Humans MeSH
• Lipogenesis drug effects   genetics   MeSH
• Disease Models, Animal MeSH
• Mice MeSH
• Oxidative Stress drug effects   MeSH
• Cellular Senescence drug effects   MeSH
• Adipose Tissue metabolism   MeSH
• Up-Regulation drug effects   MeSH
• Cell Survival drug effects   MeSH
• Treatment Outcome MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Humans MeSH
• Male MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Benzhydryl Compounds MeSH
• empagliflozin MeSH Browser
• Sodium-Glucose Transporter 2 Inhibitors MeSH
• Glucosides MeSH
• Hypoglycemic Agents MeSH

Nicotinamide phosphoribosyltransferase (NAMPT) is located in both the nucleus and cytoplasm and has multiple biological functions including catalyzing the rate-limiting step in NAD synthesis. Moreover, up-regulated NAMPT expression has been observed in many cancers. However, the determinants and regulation of NAMPT's nuclear transport are not known. Here, we constructed a GFP-NAMPT fusion protein to study NAMPT's subcellular trafficking. We observed that in unsynchronized 3T3-L1 preadipocytes, 25% of cells had higher GFP-NAMPT fluorescence in the cytoplasm, and 62% had higher GFP-NAMPT fluorescence in the nucleus. In HepG2 hepatocytes, 6% of cells had higher GFP-NAMPT fluorescence in the cytoplasm, and 84% had higher GFP-NAMPT fluorescence in the nucleus. In both 3T3-L1 and HepG2 cells, GFP-NAMPT was excluded from the nucleus immediately after mitosis and migrated back into it as the cell cycle progressed. In HepG2 cells, endogenous, untagged NAMPT displayed similar changes with the cell cycle, and in nonmitotic cells, GFP-NAMPT accumulated in the nucleus. Similarly, genotoxic, oxidative, or dicarbonyl stress also caused nuclear NAMPT localization. These interventions also increased poly(ADP-ribosyl) polymerase and sirtuin activity, suggesting an increased cellular demand for NAD. We identified a nuclear localization signal in NAMPT and amino acid substitution in this sequence (424RSKK to ASGA), which did not affect its enzymatic activity, blocked nuclear NAMPT transport, slowed cell growth, and increased histone H3 acetylation. These results suggest that NAMPT is transported into the nucleus where it presumably increases NAD synthesis required for cell proliferation. We conclude that specific inhibition of NAMPT transport into the nucleus might be a potential avenue for managing cancer.

• Keywords
• GFP fusion, NAMPT, cancer, epigenetics, nicotinamide adenine dinucleotide (NAD), nuclear localization, pre–B cell colony enhancing factor (PBEF), sirtuin, visfatin,
• MeSH
• Acrylamides pharmacology   MeSH
• Active Transport, Cell Nucleus MeSH
• Cell Nucleus metabolism   MeSH
• 3T3-L1 Cells MeSH
• Hep G2 Cells MeSH
• Cytoplasm metabolism   MeSH
• Histones metabolism   MeSH
• Cell Cycle Checkpoints MeSH
• Humans MeSH
• Mutagenesis, Site-Directed MeSH
• Mice MeSH
• NAD metabolism   MeSH
• Nicotinamide Phosphoribosyltransferase chemistry   genetics   metabolism   MeSH
• Oxidative Stress MeSH
• Piperidines pharmacology   MeSH
• Poly(ADP-ribose) Polymerases metabolism   MeSH
• Cell Proliferation MeSH
• Recombinant Fusion Proteins chemistry   genetics   metabolism   MeSH
• Sirtuins metabolism   MeSH
• Cell Survival drug effects   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Acrylamides MeSH
• Histones MeSH
• N-(4-(1-benzoylpiperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide MeSH Browser
• NAD MeSH
• Nicotinamide Phosphoribosyltransferase MeSH
• Piperidines MeSH
• Poly(ADP-ribose) Polymerases MeSH
• Recombinant Fusion Proteins MeSH
• Sirtuins MeSH