26 research outputs found
TRPA1 channel activation induces cholecystokinin release via extracellular calcium
AbstractTRPA1 channels are non-selective cation channels activated by plant derived pungent products including allyl isothiocyanate (AITC) from mustard. Therefore, possible intestinal secretory functions of these channels were investigated. We detected TRPA1 mRNA in mouse and human duodenal mucosa and in intestinal mouse neuroendocrine STC-1 cells. Stimulation of STC-1 cells with AITC increased intracellular calcium ([Ca2+]i) and significantly stimulated cholecystokinin secretion by 6.7-fold. AITC induced cholecystokinin release was completely blocked by TRPA1 antagonist ruthenium red and depletion of extracellular calcium and reduced by 36% by nimodipine and nifedipine. This suggests that spices in our daily food might stimulate digestive functions
The Circadian Clock Protein CRY1 Is a Negative Regulator of HIF-1 alpha
The circadian clock and the hypoxia-signaling pathway are regulated by an integrated interplay of positive and negative feedback limbs that incorporate energy homeostasis and carcinogenesis. We show
that the negative circadian regulator CRY1 is also a negative regulator of hypoxia-inducible factor
(HIF). Mechanistically, CRY1 interacts with the basic-helix-loop-helix domain of HIF-1a via its tail region. Subsequently, CRY1 reduces HIF-1a half-life and binding of HIFs to target gene promoters.
This appeared to be CRY1 specific because genetic disruption of CRY1, but not CRY2, affected the
hypoxia response. Furthermore, CRY1 deficiency could induce cellular HIF levels, proliferation, and
migration, which could be reversed by CRISPR/Cas9- or short hairpin RNA-mediated HIF knockout.
Altogether, our study provides a mechanistic explanation for genetic association studies linking a
disruption of the circadian clock with hypoxia-associated processes such as carcinogenesis
Causal Relationship between Obesity and Vitamin D Status: Bi-Directional Mendelian Randomization Analysis of Multiple Cohorts
M.-L. Lokki työryhmÀn Genetic Invest Anthropometric Trai jÀsen.Peer reviewe
Ghrelin stimulates synaptic formation in cultured cortical networks in a dose-dependent manner
Ghrelin was initially related to appetite stimulation and growth hormone secretion. These findings suggest that ghrelin may provide a novel therapeutic strategy for the treatment of disorders related to synaptic impairment
Influence of the position of the side chain on crystallization and solar cell performance of DPP-based small molecules
Three isomeric p-conjugated molecules based on diketopyrrolopyrrole and bithiophene (DPP2T) substituted with hexyl side chains in different positions are investigated for use in solution-processed organic solar cells. Efficiencies greater than 3% are obtained when a mild annealing step is used. The position of the side chains on the DDP2Ts has a major influence on the optical and electronic properties of these molecules in thin semicrystalline films. By combining optical absorption and fluorescence spectroscopy, with microscopy (AFM and TEM) and scattering techniques (GIWAXS and electron diffraction), we find that the position of the side chains also affects the morphology and crystallization of these DPP2Ts when they are combined with a C70 fullerene derivative in a thin film. The study demonstrates that changing the side chain position is an additional, yet complex, tool to influence behavior of conjugated molecules in organic solar cells
Novel Delivery Systems for Improving the Clinical Use of Peptides
Peptides have long been recognized as a promising group of therapeutic substances to treat various diseases. Delivery systems for peptides have been under development since the discovery of insulin for the treatment of diabetes. The challenge of using peptides as drugs arises from their poor bioavailability resulting from the low permeability of biological membranes and their instability. Currently, subcutaneous injection is clinically the most common administration route for peptides. This route is cost-effective and suitable for self-administration, and the development of appropriate dosing equipment has made performing the repeated injections relatively easy; however, only few clinical subcutaneous peptide delivery systems provide sustained peptide release. As a result, frequent injections are needed, which may cause discomfort and additional risks resulting from a poor administration technique. Controlled peptide delivery systems, able to provide required therapeutic plasma concentrations over an extended period, are needed to increase peptide safety and patient compliancy. In this review, we summarize the current peptidergic drugs, future developments, and parenteral peptide delivery systems. Special emphasis is given to porous silicon, a novel material in peptide delivery. Biodegradable and biocompatible porous silicon possesses some unique properties, such as the ability to carry exceptional high peptide payloads and to modify peptide release extensively. We have successfully developed porous silicon as a carrier material for improved parenteral peptide delivery. Nanotechnology, with its different delivery systems, will enable better use of peptides in several therapeutic applications in the near future.PharmacologyBiopharmaceutic