Dias, E. S. | Search bioRxiv

bioRxiv2023

The protein-bound uremic solute 3-carboxy-4-methyl-5-propyl-2-furanpropionate (CMPF) increases erythrocyte osmotic fragility through interaction with the mechanosensitive channel Piezo1.

Jedi1, a chemical activator of the mechanosensitive cation channel Piezo1, shares structural similarities with the uremic solute 3-carboxy-4-methyl-5-propyl-2-furanpropionate (CMPF). We explored the hypothesis that CMPF at a concentration seen in uremia activates Piezo1 located on red blood cells (RBC). We incubated RBC from five healthy individuals with either Jedi1 or CMPF (both 87 M), with or without the Piezo1 inhibitor GsMTx-4 (2 M), and quantified the cells osmotic fragility. Our results indicate that compared to controls (i.e., RBC incubated with buffer), both Jedi1 and CMPF increase the osmotic fragility of RBC (i.e., reduce their resistance to osmotic stress). Effects of Jedi1 and CMPF were reversed to the control level by GsMTx-4. These results indicate a role of Piezo1 in augmenting RBC osmotic fragility and modulation of this effect by Jedi1 and CMPF. Our findings open the possibility that CMPF may act as an endogenous chemical activator of Piezo1.

cell biology↗

bioRxiv2023

Litter Matters: The Importance of Decomposition Products for Soil Bacterial Diversity and abundance of key groups of the N cycle in Tropical Areas

This study investigated the contribution of soil organic layers to bacterial diversity evaluations. We used a forest in the eastern Amazon and an adjacent pasture as model systems. Distinct organic and organo-mineral layers were identified in the forest and pasture floors, including the litter, partially and wholly decomposed organic material, and the mineral and rhizospheric soils. DNA was extracted, and 16S rRNA gene sequencing and qPCR were performed to assess bacterial community structure and the abundance of critical groups of the N cycle. We observed a clear vertical gradient in bacterial community composition. Species followed a log-normal distribution, with the highest richness and diversity observed in transitional organic layers of both land uses. Generally, critical groups of the N cycle were more abundant in these transitional layers, especially in the pastures fragmented litter and in the forests partially decomposed organic material. Considering the organic layers increased diversity estimates significantly, with the highest alpha and gamma bacterial diversity observed on the pasture floor and the highest beta diversity on the forest floor. The results show that organic layers harbor significant bacterial diversity in natural and anthropized systems and suggest that they can be crucial for maintaining the N cycle in these ecosystems, highlighting the need to consider them when studying soil bacterial diversity.

microbiology↗