Biology subjects

Rodriguez, M. C.

Publications and source records attributed to Rodriguez, M. C..

3 recordsLinked to original sources

bioRxiv2024

L-Type calcium channels and TRPC3 channels shape brain pericyte calcium signaling and hemodynamics throughout the arteriole to capillary network in vivo

Pericytes play a crucial role in regulating cerebral blood flow (CBF) through processes like vasomotion and neurovascular coupling (NVC). Recent work has identified different pericyte types at distinct points in the cerebrovascular network, such as the arteriole-capillary transition zone (ACT) and distal capillaries, sparking debate about their functional roles in blood flow control. Part of this discussion has comprised the possible mechanisms that may regulate pericyte Ca2+ signaling. Using in vivo two-photon Ca2+ imaging and a pharmacological approach with Ca2+ channel blockers (nimodipine and Pyr3), we assessed the contribution of L-type voltage-gated Ca2+ channels (VGCC) and transient receptor potential canonical 3 (TRPC3) channels to Ca2+ signaling in different pericyte types, ensheathing and capillary pericytes. We also measured local hemodynamics such as vessel diameter, blood cell velocity and flux during vasomotion, and following somatosensory stimulation to evoke NVC. We report that VGCC and TRPC3 channels underlie spontaneous fluctuations in ensheathing pericyte Ca2+ that trigger vasomotor contractions, but the contribution of each of these mechanisms to vascular tone depends on the specific branch of the ACT. Distal capillary pericytes also express L-type VGCCs and TRPC3 channels and they mediate spontaneous Ca2+ signaling in these cells. However, only TRPC3 channels maintain resting capillary tone, possibly by a receptor-operated Ca2+ entry mechanism. By applying the Ca2+ channel blockers during NVC, we found a significant involvement of L-type VGCCs in both pericyte types, influencing their ability to dilate during functional hyperemia. These findings provide new evidence of VGCC and TRPC3 activity in pericytes in vivo and establish a clear distinction between brain pericyte types and their functional roles, opening avenues for innovative strategies to selectively target their Ca2+ dynamics for CBF control. Significance StatementAlthough brain pericytes contribute to the regulation of CBF, there is uncertainty about how different types of pericytes are involved in this process. Ca2+ signaling is believed to be important for the contractility and tone of pericytes, but there is a limited understanding of the Ca2+ pathways in specific pericyte types. Here, we demonstrate that both VGCC and TRPC3 channels are active in distinct types of pericytes throughout the cerebrovascular network, but have different roles in pericyte tone depending on the pericyte location. This has important implications for how pericytes influence vasomotion and neurovascular coupling, which are central processes in CBF regulation. This work also provides the first evidence of TRPC3 channel activity in pericytes in vivo, furthering our understanding of the diverse signaling pathways within these brain mural cells.

neuroscience↗

bioRxiv2021

Multi-omic analysis reveals the biochemical changes underpinning the varied phenotypes of the Arabidopsis long-period mutant rve 4 6 8

Plants are able to sense changes in their light environments, such as the onset of day and night, as well as anticipate these changes in order to adapt and survive. Central to this ability is the plant circadian clock, a molecular circuit that precisely orchestrates plant cell processes over the course of a day. REVEILLE proteins (RVEs) are recently discovered members of the plant circadian circuitry that activate the evening complex and PRR genes to maintain regular circadian oscillation. The RVE 8 protein and its two homologs, RVE 4 and 6, have been shown to limit the length of the circadian period, with rve 4 6 8 triple-knockout plants possessing an elongated period along with increased leaf surface area, biomass, cell size and delayed flowering relative to wild-type Col-0 plants. Here, using a multi-omics approach consisting of phenomics, transcriptomics, proteomics, and metabolomics we draw novel connections between RVE8-like proteins and a number of core plant cell processes. In particular, we reveal that loss of RVE8-like proteins results in altered carbohydrate, organic acid and lipid metabolism, including a starch excess phenotype at dawn. We further demonstrate that rve 4 6 8 plants have lower levels of 20S proteasome subunits and possess significantly reduced proteasome activity, potentially explaining the increase in cell-size observed in RVE8-like mutants. Overall, this robust, multi-omic dataset, provides substantial new insights into the far reaching impact RVE8-like proteins have on the diel plant cell environment.

plant biology↗

bioRxiv2020

Quantitative proteome and PTMome analysis of Arabidopsis thaliana root responses to persistent osmotic and salinity stress.

Abiotic stresses such as drought result in large annual economic losses around the world. As sessile organisms, plants cannot escape the environmental stresses they encounter, but instead must adapt to survive. Studies investigating plant responses to osmotic and/or salt stress have largely focused on short-term systemic responses, leaving our understanding of intermediate to longer-term adaptation (24 h - days) lacking. In addition to protein abundance and phosphorylation changes, evidence suggests reversible lysine acetylation may also be important for abiotic stress responses. Therefore, to characterize the protein-level effects of osmotic and salt stress, we undertook a label-free proteomic analysis of Arabidopsis thaliana roots exposed to 300 mM Mannitol and 150 mM NaCl for 24 h. We assessed protein phosphorylation, lysine acetylation and changes in protein abundance, detecting significant changes in 245, 35 and 107 total proteins, respectively. Comparison with available transcriptome data indicates that transcriptome- and proteome-level changes occur in parallel, while PTMs do not. Further, we find significant changes in PTMs and protein abundance involve different proteins from the same networks, indicating a multifaceted regulatory approach to prolonged osmotic and salt stress. In particular, we find extensive protein-level changes involving sulphur metabolism under both osmotic and salt conditions as well as changes in protein kinases and transcription factors that may represent new targets for drought stress signaling. Collectively, we find that protein-level changes continue to occur in plant roots 24 h from the onset of osmotic and salt stress and that these changes differ across multiple proteome levels.

plant biology↗