bims-polyam 2023-01-01 papers

Issue of 2023–01–01
two papers selected by
Sebastian J. Hofer, University of Graz

Mol Cells. 2022 Dec 31. 45(12): 963-975

SLC3A2 and SLC7A2 Mediate the Exogenous Putrescine-Induced Adipocyte Differentiation.

Jin Eom, Juhyun Choi, Sung-Suk Suh, Jong Bae Seo.

Exogenous polyamines are able to induce life span and improve glucose homeostasis and insulin sensitivity. However, the effects of exogenous polyamines on adipocyte differentiation and which polyamine transporters mediate them have not been elucidated yet. Here, we identified for the first time that exogenous polyamines can clearly stimulate adipocyte differentiation through polyamine transporters, solute carrier family 3 member A2 (SLC3A2) and SLC7A1. Exogenous polyamines markedly promote 3T3-L1 adipocyte differentiation by increasing the intracellular lipid accumulation and the expression of both adipogenic and lipogenic genes in a concentration-dependent manner. In particular, exogenous putrescine mainly regulates adipocyte differentiation in the early and intermediate stages. Moreover, we have assessed the expression of polyamine transporter genes in 3T3-L1 preadipocytes and adipocytes. Interestingly, the putrescine-induced adipocyte differentiation was found to be significantly suppressed in response to a treatment with a polyamine transporter inhibitor (AMXT-1501). Furthermore, knockdown experiments using siRNA that specifically targeted SLC3A2 or SLC7A2, revealed that both SLC3A2 and SLC7A2 act as important transporters in the cellular importing of exogenous putrescine. Thus, the exogenous putrescine entering the adipocytes via cellular transporters is involved in adipogenesis through a modulation of both the mitotic clonal expansion and the expression of master transcription factors. Taken together, these results suggest that exogenous polyamines (such as putrescine) entering the adipocytes through polyamine transporters, can stimulate adipogenesis.

Keywords: adipocyte; adipogenesis; differentiation; polyamine; putrescine

DOI: https://doi.org/10.14348/molcells.2022.0123

J Pediatr Gastroenterol Nutr. 2023 Jan 01. 76(1): 59-65

Plasma Biomarkers and Fractional Exhaled Nitric Oxide in the Diagnosis of Eosinophilic Esophagitis.

Rohit Josyabhatla, Cristoniel Abrenica, Tu Mai, Syed Shahrukh Hashmi, Yuying Liu, Ricardo Mosquera, Melissa Van Arsdall, Fernando Navarro, Amanda Tchakarov, Nina Tatevian, Guoyao Wu, Jon Marc Rhoads.

OBJECTIVES: Eosinophilic esophagitis (EoE) is a chronic disease which requires endoscopy with biopsies for diagnosis and monitoring. We aimed to identify a panel of non-invasive markers that could help identify patients with active EoE.
METHODS: In this prospective cohort study, we enrolled 128 children aged 5-18 years old, scheduled for endoscopy for suspected esophageal or peptic disease. On the day of the endoscopy, fractionated exhaled nitric oxide (FeNO) was measured; and blood was collected for peripheral absolute eosinophil count (AEC), plasma amino acids, and plasma polyamine analysis. Patients were grouped into controls (n = 91), EoE in remission (n = 16), or active EoE (n = 21), based on esophageal eosinophilia and history of EoE.
RESULTS: AEC was not statistically significant different among the groups compared ( P = 0.056). Plasma amino acids: citrulline (CIT), β-alanine (β-ALA), and cysteine (CYS) were higher in active EoE compared to controls ( P < 0.05). The polyamine spermine was lower in active EoE versus controls ( P < 0.05). Receiver operator characteristic (ROC) curve to assess the predictive capability of a combined score made of FeNO, β-ALA, CYS, and spermine had an area under curve (AUC) of 0.90 (95% CI: 0.80-0.96) in differentiating active EoE from controls and 0.87 (95% CI: 0.74-1.00) when differentiating active EoE from EoE in remission.
CONCLUSION: A panel comprising FeNO, 2 plasma amino acids (β-ALA, CYS) and the polyamine spermine can be used as a non-invasive tool to differentiate active EoE patients from controls.

DOI: https://doi.org/10.1097/MPG.0000000000003634