Project description:Two of the most prominent organ systems, the nervous and the cardiovascular systems, are intricately connected to maintain homeostasis in mammals. Recent years have shown tremendous efforts toward therapeutic modulation of cardiac contractility and electrophysiology by electrical stimulation. Neuronal innervation and cardiac ganglia regulation are often overlooked when developing in vitro models for cardiac devices, but it is likely that peripheral nervous system plays a role in the clinical effects. We developed an in vitro neurocardiac coculture (ivNCC) model system to study cardiac and neuronal interplay using human induced pluripotent stem cell (hiPSC) technology. We demonstrated significant expression and colocalization of cardiac markers including troponin, α-actinin, and neuronal marker peripherin in neurocardiac coculture. To assess functional coupling between the cardiomyocytes and neurons, we evaluated nicotine-induced β-adrenergic norepinephrine effect and found beat rate was significantly increased in ivNCC as compared to monoculture alone. The developed platform was used as a nonclinical model for the assessment of cardiac medical devices that deliver nonexcitatory electrical pulses to the heart during the absolute refractory period of the cardiac cycle, that is, cardiac contractility modulation (CCM) therapy. Robust coculture response was observed at 14 V/cm (5 V, 64 mA), monophasic, 2 ms pulse duration for pacing and 20 V/cm (7 V, 90 mA) phase amplitude, biphasic, 5.14 ms pulse duration for CCM. We observed that the CCM effect and kinetics were more pronounced in coculture as compared to cardiac monoculture, supporting a hypothesis that some part of CCM mechanism of action can be attributed to peripheral nervous system stimulation. This study provides novel characterization of CCM effects on hiPSC-derived neurocardiac cocultures. This innervated human heart model can be further extended to investigate arrhythmic mechanisms, neurocardiac safety, and toxicity post-chronic exposure to materials, drugs, and medical devices. We present data on acute CCM electrical stimulation effects on a functional and optimized coculture using commercially available hiPSC-derived cardiomyocytes and neurons. Moreover, this study provides an in vitro human heart model to evaluate neuronal innervation and cardiac ganglia regulation of contractility by applying CCM pulse parameters that closely resemble clinical setting. This ivNCC platform provides a potential tool for investigating aspects of cardiac and neurological device safety and performance.

Project description:Because of the epidemic rise of obesity worldwide, the identification of novel target genes for pharmacological treatment of obesity and related disorders is becoming of high importance. IFRD1 and IFRD2 are members of a novel transcriptional regulators family. Intestinal over-expression of mouse homologue of IFRD1 promoted intestinal triglyceride uptake and induced whole body adiposity in mice. To further elucidate the role of IFRD1 and IFRD2 in vivo, we generated mice lacking both mouse homologues of IFRD1 (TIS7) and IFRD2 (SKMc15) genes. Here, we report that mice deficient in TIS7 and SKMc15 genes, despite normal calorie intake had severely reduced amount of adipose tissue, were resistant to diet-induced obesity and displayed high glucose tolerance. Lower dietary fat entry into the circulation suggested that this phenotype resulted from impaired intestinal lipid transport. We identified down-regulation of CD36, a fatty acid transporter, both on RNA and protein levels. Reporter assays indicated that TIS7 and SKMc15 transcriptionally regulated CD36 expression and CD36 overexpression partially restored fatty acid uptake in vitro. Hence, our study suggested that TIS7 and SKMc15 play an important role in the regulation of the lipid metabolism and might represent a novel strategy for treatment of disorders caused by excess fat intake. To determine whether decreased intestinal lipid absorption might be caused by changes in expression of lipid processing and transport molecules, we performed Affymetrix microarray analyses of total RNA samples isolated from the jejunum of HFD-fed WT type and dKO animals. The moderated t-test was used to calculate p-values for significance of differential gene expression between 3 dKO and 3 wild type mice. These raw p-values were adjusted for multiple hypothesis testing using the method from Benjamini and Hochberg for a strong control of the false discovery rate (FDR) and genes with thus adjusted p-values < 0.05 were considered significant. Age-matched (7-10 week old) male wild type and TIS7 (Ifrd1) SKMc15 (Ifrd2) double knock out mice (C57Bl6 background) were caged individually and maintained from 3 weeks up to 8 weeks on a synthetic high saturated fat (HFD) diet (Ssniff). Small intestines (jejunum) were harvested for total RNA isolation. RNAs from 3 WT and 3 dKO mice were subjected to Affymetrix based whole genome gene expression analysis (Mouse 430.2 GeneChip).

Project description:Because of the epidemic rise of obesity worldwide, the identification of novel target genes for pharmacological treatment of obesity and related disorders is becoming of high importance. IFRD1 and IFRD2 are members of a novel transcriptional regulators family. Intestinal over-expression of mouse homologue of IFRD1 promoted intestinal triglyceride uptake and induced whole body adiposity in mice. To further elucidate the role of IFRD1 and IFRD2 in vivo, we generated mice lacking both mouse homologues of IFRD1 (TIS7) and IFRD2 (SKMc15) genes. Here, we report that mice deficient in TIS7 and SKMc15 genes, despite normal calorie intake had severely reduced amount of adipose tissue, were resistant to diet-induced obesity and displayed high glucose tolerance. Lower dietary fat entry into the circulation suggested that this phenotype resulted from impaired intestinal lipid transport. We identified down-regulation of CD36, a fatty acid transporter, both on RNA and protein levels. Reporter assays indicated that TIS7 and SKMc15 transcriptionally regulated CD36 expression and CD36 overexpression partially restored fatty acid uptake in vitro. Hence, our study suggested that TIS7 and SKMc15 play an important role in the regulation of the lipid metabolism and might represent a novel strategy for treatment of disorders caused by excess fat intake. To determine whether decreased intestinal lipid absorption might be caused by changes in expression of lipid processing and transport molecules, we performed Affymetrix microarray analyses of total RNA samples isolated from the jejunum of HFD-fed WT type and dKO animals. The moderated t-test was used to calculate p-values for significance of differential gene expression between 3 dKO and 3 wild type mice. These raw p-values were adjusted for multiple hypothesis testing using the method from Benjamini and Hochberg for a strong control of the false discovery rate (FDR) and genes with thus adjusted p-values < 0.05 were considered significant.

Project description:In this work, we studied the intestinal absorption of a peptide with a molecular weight of 4353 Da (MEDI7219) and a protein having a molecular weight of 11 740 Da (PEP12210) in the rat intestinal instillation model and compared their absorption to fluorescein isothiocyanate (FITC)-labeled dextrans of similar molecular weights (4 and 10 kDa). To increase the absorption of the compounds, the permeation enhancer sodium caprate (C10) was included in the liquid formulations at concentrations of 50 and 300 mM. All studied compounds displayed an increased absorption rate and extent when delivered together with 50 mM C10 as compared to control formulations not containing C10. The time period during which the macromolecules maintained an increased permeability through the intestinal epithelium was approximately 20 min for all studied compounds at 50 mM C10. For the formulations containing 300 mM C10, it was noted that the dextrans displayed an increased absorption rate (compared to 50 mM C10), and their absorption continued for at least 60 min. The absorption rate of MEDI7219, on the other hand, was similar at both studied C10 concentrations, but the duration of absorption was extended at the higher enhancer concentration, leading to an increase in the overall extent of absorption. The absorption of PEP12210 was similar in terms of the rate and duration at both studied C10 concentrations. This is likely caused by the instability of this molecule in the intestinal lumen. The degradation decreases the luminal concentrations over time, which in turn limits absorption at time points beyond 20 min. The results from this study show that permeation enhancement effects cannot be extrapolated between different types of macromolecules. Furthermore, to maximize the absorption of a macromolecule delivered together with C10, prolonging the duration of absorption appears to be important. In addition, the macromolecule needs to be stable enough in the intestinal lumen to take advantage of the prolonged absorption time window enabled by the permeation enhancer.

Dataset Information

New In Vitro Coculture Model for Evaluating Intestinal Absorption of Different Lipid Nanocapsules.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets