Background: High-fat diet (HFD) that contributes to obesity is one of the pivotal risk factors for metabolic syndrome and cancers. The dietary pattern can shape the intestinal bacterial community and influence the physiological parameters. This study aimed to investigate whether the short-term dietary pattern shift from HFD to a balanced chow diet (CD) could correct HFD-induced colonic dysbiosis and reverse adverse health effects and identify the specific bacteria that changed by dietary patterns. Results: C57BL/6 mice fed with an HFD for 10 months, followed by a CD for 3 months, served as the dietary shift model. Stool samples were collected for bacterial analysis. Physiological parameters, such as serum adipokines, blood lipid levels, and hepatic function, were monitored in control and dietary shift groups. HFD-induced weight gain was mitigated by the dietary shift. A highly similar structure at the phylum, genus, and species levels was observed in the beta diversity of colonic bacteria in mice that underwent the dietary shift as compared to those in the control group. Notably, the abundance of Peptococcaceae and Akkermansiaceae in HFD-fed mice reduced after the dietary shift; whereas the diminished amount of probiotic Lachnospiraceae NK4A136 group in HFD-fed mice was restored to the level comparable to those in controls after the dietary shift. Conclusions: Our finding suggests that a dietary switch from a long-term HFD to a short-term balanced diet has the potential to correct colonic dysbiosis and restore physiological homeostasis. The Lachnospiraceae NK4A136 group has the potential to be a probiotic.

Reporter proteins have broad applications in visualizing molecular events at the cellular, tissue and whole‐body levels. Transmembrane transporters recognizing specific molecular domains are of particular interest because they enable the migration of signal‐source molecules from the extracellular space to the cytoplasm for subsequent application in multimodality imaging. Organic anion‐transporting polypeptides (OATPs) have demonstrated their MRI reporter efficacy. We further expanded their use as a dual‐modality reporter in MRI and noninvasive in vivo imaging system (IVIS). We overexpressed OATP1B3 in the HT‐1080 sarcoma cell line. Both Gd‐EOB‐DTPA, an MRI contrast agent, and indocyanine green (ICG), a near‐infrared fluorescent dye that provides better deep‐tissue detection because of its long wavelength, could be delivered to the intracellular space and imaged in a tumor‐bearing nude mouse model. Our in vivo dual‐imaging reporter system achieved high sensitivity in MRI and observation periods lasting as long as 96 h in IVIS. Because of the superior temporal and spatial resolutions and the clinical availability of both ICG and Gd‐EOB‐DTPA, this dual‐imaging OATP1B3 system will find biomedical use in tumor biology, stem cell trafficking, and tissue engineering.—Wu, M.‐R., Liu, H.‐M., Lu, C.‐W., Shen, W.‐H., Lin, I.‐J., Liao, L.‐W., Huang, Y.‐Y., Shieh, M.‐J., Hsiao, J.‐K. Organic anion‐transporting polypeptide 1B3 as a dual reporter gene for fluorescence and magnetic resonance imaging. FASEB J. 32,1705‐1715 (2018). www.fasebj.org

Normal pregnancy is supported by increased levels of progesterone (P4), which is secreted from ovarian luteal cells via enzymatic steps catalyzed by P450scc (CYP11A1) and HSD3B. The development and maintenance of corpora lutea during pregnancy, however, are less well understood. Here we used Cyp11a1 transgenic mice to delineate the steps of luteal cell differentiation during pregnancy. Cyp11a1 in a bacterial artificial chromosome was injected into mouse embryos to generate transgenic mice with transgene expression that recapitulated endogenous Cyp11a1 expression. Cyp11a1 transgenic females displayed reduced pregnancy rate, impaired implantation and placentation, and decreased litter size in utero, although they produced comparable numbers of blastocysts. The differentiation of transgenic luteal cells was delayed during early pregnancy as shown by the delayed activation of genes involved in steroidogenesis and cholesterol availability. Luteal cell mitochondria were elongated, and their numbers were reduced, with morphology and numbers similar to those observed in granulosa cells. Transgenic luteal cells accumulated lipid droplets and secreted less progesterone during early pregnancy. The progesterone level returned to normal on Gestation Day 9 but was not properly withdrawn at term, leading to delayed stillbirth. P4 supplementation rescued the implantation rates but not the ovarian defects. Thus, overexpression of Cyp11a1 disrupts normal development of the corpus luteum, leading to progesterone insufficiency during early pregnancy. Misregulation of the progesterone production in Cyp11a1 transgenic mice during pregnancy resulted in aberrant implantation, anomalous placentation, and delayed parturition.

Myocardial infarction (MI) is a life-threatening disease, often leading to heart failure. Defining therapeutic targets at an early time point is important to prevent heart failure. MicroRNA screening was performed at early time points after MI using paired samples isolated from the infarcted and remote myocardium of pigs. We also examined the microRNA expression in plasma of MI patients and pigs. For mechanistic studies, AAV9-mediated microRNA knockdown and overexpression were administrated in mice undergoing MI. MicroRNAs let-7a and let-7f were significantly downregulated in the infarct area within 24 h post-MI in pigs. We also observed a reduction of let-7a and let-7f in plasma of MI patients and pigs. Inhibition of let-7 exacerbated cardiomyocyte apoptosis, induced a cardiac hypertrophic phenotype, and resulted in worsened left ventricular ejection fraction. In contrast, ectopic let-7 overexpression significantly reduced those phenotypes and improved heart function. We then identified TGFBR3 as a target of let-7, and found that induction of Tgfbr3 in cardiomyocytes caused apoptosis, likely through p38 MAPK activation. Finally, we showed that the plasma TGFBR3 level was elevated after MI in plasma of MI patients and pigs. Together, we conclude that the let-7-Tgfbr3-p38 MAPK signalling plays an important role in cardiomyocyte apoptosis after MI. Furthermore, microRNA let-7 and Tgfbr3 may serve as therapeutic targets and biomarkers for myocardial damage. FUND: Ministry of Science and Technology, National Health Research Institutes, Academia Sinica Program for Translational Innovation of Biopharmaceutical Development-Technology Supporting Platform Axis, Thematic Research Program and the Summit Research Program, Taiwan.

Molecular and cellular imaging in living organisms have ushered in an era of comprehensive understanding of intracellular and intercellular events. Currently, more efforts have been focused on the infrared fluorescent dyes that facilitate deeper tissue visualization. Both sodium taurocholate cotransporting polypeptide (NTCP) and organic-anion-transporting polypeptide 1B3 (OATP1B3) are capable of carrying indocyanine green (ICG) into the cytoplasm. We compared the feasibility of NTCP and OATP1B3 as reporter genes in combination with ICG. NTCP and OATP1B3 were transduced into HT-29 cells. Genetically modified HT-29 cells were inoculated into nude mice. ICG was administered in vitro and in vivo and the signals were observed under confocal microscopy, flow cytometry, multimode microplate reader, and an in vivo imaging system. Both NTCP- and OATP1B3-expressing cells and xenografts had higher ICG intensities. The OATP1B3-expressing xenograft has a higher ICG uptake than the NTCP-expressing xenograft. NTCP or OATP1B3 combined with ICG could serve as a noninvasive imaging modality for molecular and cellular imaging. OATP1B3 outperforms NTCP in terms of in vivo imaging.