Biology subjects

Coman, C.

Publications and source records attributed to Coman, C..

4 recordsLinked to original sources

bioRxiv2025

GPR27 mediates adrenergic ligands-induced transinhibition of EGFR

1.G-protein coupled receptor 27 (GPR27) is part of the "Super Conserved Receptors Expressed in Brain" (SREB) family, alongside GPR85 and GPR173. While the endogenous ligands and functions of SREB receptors are still unknown, GPR27 has been implicated in insulin secretion and tumorigenesis. Here, we show that substituting GPR27s C-terminus domain with that of the {beta}1 adrenergic receptor ({beta}1AR) yields a chimera with {beta}1AR-like ligand selectivity and cellular functions. Interestingly, adrenergic ligands stimulation of GPR27 inhibited EGF-induced serum-responsive element (SRE) activation, independently of G-proteins and {beta}-arrestins, through dephosphorylation of c-Src and EGFR proteins. This unique response was exclusive to GPR27, as GPR85 and GPR173 showed no similar effects. These findings suggest that GPR27 is a receptor responding to adrenergic ligands to transinhibit EGFR through an atypical signaling mechanism.

cell biology↗

bioRxiv2024

Adenosine signaling in glia modulates metabolic state-dependent behavior in Drosophila

An animals metabolic state strongly influences its behavior. Hungry animals prioritize food seeking and feeding behaviors, while sated animals suppress these behaviors to engage in other activities. Additionally, neuronal activity and synaptic transmission are among the most energy expensive processes. Yet neurons do not uptake nutrients from the circulation. Instead, glia fulfill this highly evolutionary conserved function. Recent studies have shown that glia can modulate neuronal activity and behavior. However, how different glia subtypes sense metabolic state and modulate neurons and behavior is incompletely understood. Here, we unravel two types of glia-mediated modulation of metabolic state-dependent behavior. In food-deprived flies, astrocyte-like and perineurial glia promote foraging and feeding, respectively, while cortex glia suppress these behaviors. We further show that adenosine and adenosine receptor modulate intracellular calcium levels in these glia subtypes, which ultimately controls behavior. This study reveals a new mechanism how different glia subtypes sense the metabolic state of the animal and modulate its behavior accordingly.

neuroscience↗

bioRxiv2023

Tradeoffs of increasing temperatures for the spread of antimicrobial resistance in river biofilms

River microbial communities regularly act as the first defense barrier against the spread of antimicrobial resistance genes (ARG) that enter environmental microbiomes through wastewaters. However, how the invasion dynamics of wastewater-born ARGs into river biofilm communities will shift due to increasing average and peak temperatures worldwide through climate change remains unknown. Here we aimed at elucidating the effects of increasing temperatures on both, the natural river biofilm resistome, as well as the river biofilms invadability by foreign, wastewater-born ARGs. To achieve this, natural biofilms were grown in a pristine German river and transferred to artificial laboratory recirculation flume systems at three different temperatures (20{degrees}C, 25{degrees}C, 30{degrees}C). Already after one week of acclimatization to the temperatures, significant increases in the abundance of most naturally occurring ARGs were detected in the biofilms exposed to the highest temperature. Thereafter, biofilms were exposed to a single pulse of wastewater and the invasion dynamics of wastewater-born ARGs were analyzed over a period of two weeks. While initially after one day ARGs were able to invade all biofilms successfully and in equal proportions, the foreign invading ARGs were lost at a far increased rate at 30{degrees}C over time. ARG levels dropped to the initial natural levels at 30{degrees}C after 14 days. Contrary at the lower temperatures ARGs remained far elevated and certain ARGs were able to establish themselves in the biofilms. Overall, we here demonstrate tradeoffs of increasing temperature between increases in naturally occurring and faster loss dynamics of invading ARGs.

microbiology↗

bioRxiv2023

Microbiome diversity: A barrier to the environmental spread of antimicrobial resistance?

BackgroundIn the environment, microbial communities are constantly exposed to invasion by antimicrobial resistant bacteria (ARB) and their associated antimicrobial resistance genes (ARGs) that were enriched in the anthroposphere. A successful invader has to overcome the biotic resilience of the habitat, which is more difficult with increasing biodiversity. The capacity to exploit resources in a given habitat is enhanced when communities exhibit greater diversity, reducing opportunities for invaders, leading to a lower persistence. In the context of antimicrobial resistance (AMR) dissemination, exogenous ARB reaching a natural community may persist longer if the biodiversity of the autochthonous community is low, increasing the chance of ARGs to transfer to community members. Reciprocally, high microbial diversity could serve as a natural long-term barrier towards invasion by ARB and ARGs. ResultsTo test this hypothesis, a sampling campaign across seven European countries was carried out to obtain 172 environmental samples from sites with low anthropogenic impact. Samples were collected from contrasting environments: stationary structured forest soils, or dynamic river biofilms and sediments. Microbial diversity and relative abundance of 27 ARGs and 5 mobile genetic element marker genes were determined. In soils, higher diversity, evenness and richness were all significantly negatively correlated with the relative abundance of the majority (>85%) of ARGs. Furthermore, the number of detected ARGs per sample was inversely correlated with diversity. However, no such effects were found for the more dynamic, regularly mixed rivers. Conclusions: In conclusion, we demonstrate that diversity can serve as barrier towards AMR dissemination in the environment. This effect is mainly observed in stationary, structured environments, where long-term, diversity-based resilience against invasion can evolve. Such barrier effects can in the future be exploited to limit the environmental proliferation of AMR.

microbiology↗