rt of tryptophan, phenylalanine and tyrosine, each localized at the apical Akt2 Storage & Stability membrane of enterocytes. Precisely the same pattern of expression was observed for SLC3A1 and SLC7A9, that are involved within the influx transport of L-DOPA. In contrast, the enzymes DDC, SULT1A1/2/3, MAOA, MAOB and CYP2D6 harbored a cytoplasmic staining pattern. Also anticipated, the L-DOPA efflux transporters SLC3A2 and SLC7A8 had been detected in the basolateral membrane of enterocytes. A low and diffuse staining pattern was observed for SLC16A10. Finally, no TH staining might be detected (Figure S1), in accordance with genomics analyses. Determined by these mined data, a scheme summarizing the predicted dopamine/trace amines metabolic pathways taking place in human enterocytes is shown in Figure two.Int. J. Mol. Sci. 2021, 22,metabolism of dopamine and/or trace amines. This observation suggests that regionalization rather than cell specificity may well dictate the expression of such genes. At the protein level, a survey on the immunohistochemical analyses gathered inside the Human Protein Atlas confirmed that enterocytes on the modest intestine robustly express ACE2, SLC6A19 as well as the 12 other proteins we identified as molecules of interest resulting from their involvement inside the 5 of 16 metabolism of dopamine and/or trace amines (Figure 1). Additional details regarding antibodies and tissues are presented in Section 4.Figure 1. Expression by human enterocytes of important molecules involved in dopamine/trace amines metabolic pathways: A by human enterocytes of crucial molecules involved in dopamine/trace amines metabolic pathways: survey on the Human Protein Atlas (proteinatlas.org/ (accessed on 24 24 September 2021)) allowed extractA survey of the Human Protein Atlas (proteinatlas.org/ (accessed on September 2021)) allowed extracting ing immunohistochemical information obtained on human tiny intestine for the following candidate molecules: angiotensinconverting enzyme two (ACE2), solute carrier family six member 19 (SLC6A19), solute carrier household 3 member 1 (SLC3A1), solute carrier family members 7 member 9 (SLC7A9), dopa-decarboxylase (DDC), mAChR1 site sulfotransferase family members 1A member 1 (SULT1A1), sulfotransferase household 1A member two (SULT1A2), sulfotransferase household 1A member three (SULT1A3), cytochrome P450 household two subfamily D member 6 (CYP2D6), monoamine oxidase A (MAOA), monoamine oxidase B (MAOB), solute carrier loved ones 3 member two (SLC3A2), solute carrier family members 7 member eight (SLC7A8) and solute carrier household six member ten (SLC16A10). Scale bar: 25 .2.two. Assessment of Co-Expression Links between ACE2 and Essential Genes with the Dopamine/Trace Amines Metabolic Pathways in SARS-CoV2-Infected Human Intestinal Organoids We then sought to determine irrespective of whether, in SARS-CoV2-infected human enterocytes, ACE2 co-regulates with DDC and/or crucial genes involved in the dopamine/trace amines metabolic pathways. To this aim, we re-assessed a recently published RNA-seq dataset obtained in the evaluation of manage vs. SARS-CoV2-infected human intestinal organoids [34]. In these experiments, the expression of ACE2 exhibited a peculiar kinetics characterized, at 24 h post-infection, by a dramatic drop of mRNA levels (by a aspect ten in two independent experiments; Figure S2), followed by a return to baseline levels at 60 h post-infection (Figure S2). Among the genes of interest that we focused on, a equivalent silencing impact of SARS-CoV2 was observed at 24 h post-infection for SLC6A19 (the gene encoding the neutral amino acid transporter that physically interacts with
