Biology subjects

Velez, M.

Publications and source records attributed to Velez, M..

3 recordsLinked to original sources

bioRxiv2023

Investigating Metabolic Trends in the Oral Cavity to Identify Novel Metabolites

The human oral microbiome typically contains over 700 different microbial species. These interactions between the microorganisms within this community can shape the microenvironment throughout the human body, as these interactions are paramount to maintaining oral and overall systemic health. Recent advances in technology, such as next-generation sequencing (NGS), have revealed the complexities of the oral microbiome, linking dysbiosis of the oral microbiome with several chronic ailments such as cardiovascular disease, diabetes, and inflammatory bowel disease. However, the role of microbial secondary metabolites in oral and systemic disease progression remains poorly understood. Here, we conducted a metabolomics study on the human salivary secondary metabolome during the induction of gingival inflammation (gingivitis), the precursor to periodontal disease. In this study, we sought to assess the changes in the oral secondary metabolome during disease progression by emulating dysbiosis of the oral microbiome through a twenty-one-day induction of gingivitis in twenty human participants. We identified secondary metabolites, cyclo(L-Tyr-L-Pro) with regulatory properties for quorum sensing and inflammatory marker secretion, indicating a specialized role for secondary metabolites in oral health maintenance. Surprisingly, we also uncovered a previously unknown metabolic lag that occurs during dysbiosis recovery of the oral cavity, which indicates a lingering presence of signaling molecules for pathogenic microbe proliferation or a total oral metabolome modification following microenvironmental stress in the oral cavity. This work represents a high-resolution metabolomic landscape for understanding oral health during gingivitis that opens new opportunities for combating progressive periodontal diseases and sepsis due to the translocation of oral microbes in the human body.

molecular biology↗

bioRxiv2023

Kappa Opioid Receptor Antagonism Rescues Genetic Perturbation of Dopamine Homeostasis: Molecular, Physiological and Behavioral Consequences

Aberrant dopamine (DA) signaling is implicated in schizophrenia, bipolar disorder (BPD), autism spectrum disorder (ASD), substance use disorder, and attention-deficit/hyperactivity disorder (ADHD). Treatment of these disorders remains inadequate, as exemplified by the therapeutic use of d-amphetamine and methylphenidate for the treatment of ADHD, agents with high abuse liability. In search for an improved and non-addictive therapeutic approach for the treatment of DA-linked disorders, we utilized a preclinical mouse model expressing the human DA transporter (DAT) coding variant DAT Val559, previously identified in individuals with ADHD, ASD, or BPD. DAT Val559, like several other disease-associated variants of DAT, exhibits anomalous DA efflux (ADE) that can be blocked by d-amphetamine and methylphenidate. Kappa opioid receptors (KORs) are expressed by DA neurons and modulate DA release and clearance, suggesting that targeting KORs might also provide an alternative approach to normalizing DA-signaling disrupted by perturbed DAT function. Here we demonstrate that KOR stimulation leads to enhanced surface trafficking and phosphorylation of Thr53 in wildtype DAT, effects achieved constitutively by the Val559 mutant. Moreover, these effects can be rescued by KOR antagonism of DAT Val559 in ex vivo preparations. Importantly, KOR antagonism also corrected in vivo DA release as well as sex-dependent behavioral abnormalities observed in DAT Val559 mice. Given their low abuse liability, our studies with a construct valid model of human DA associated disorders reinforce considerations of KOR antagonism as a pharmacological strategy to treat DA associated brain disorders.

neuroscience↗

bioRxiv2022

Driving forces behind remorin nanodomain formation in anionic lipid membranes

Remorins are a family of multigenic phosphoproteins of the plasma membrane, involved in biotic and abiotic plant interaction mechanisms, partnering in molecular signaling cascades. Signaling activity of remorins depends on their phosphorylation states and subsequent clustering into nano-sized membrane domains. The presence of a coiled-coil domain and a C-terminal domain is crucial to anchor remorins to negatively charged membrane domains, however the exact role of the N-terminal intrinsically disordered domain (IDD) on protein clustering and lipid interactions is largely unknown. Here we combine chemical biology and imaging approaches to study the partitioning of group 1 remorin into anionic model membranes mimicking the inner leaflet of the plant plasma membrane. Using reconstituted membranes containing a mix of saturated and unsaturated PhosphatidylCholine (PC), PhosphatidylInositol Phosphates (PIPs), and sterol, we investigate the clustering of remorins to the membrane and monitor the formation of nano-sized membrane domains. REM1.3 promoted membrane nanodomain organization on the exposed external leaflet of both spherical lipid vesicles and flat supported lipid bilayers. Our results reveal that REM1.3 drives a mechanism allowing lipid reorganization, leading to the formation of remorin-enriched nanodomains. Phosphorylation of the N-terminal IDD by the calcium protein kinase CPK3 influences this clustering and can lead to the formation of smaller and more disperse domains. Our work reveals the phosphate-dependent involvement of the N-terminal IDD in the remorin-membrane interaction process by driving structural rearrangements at lipid-water interfaces. Summary headingUsing reconstituted membranes, we demonstrated the clustering of the plant protein remorins StREM1.3 to the lipid bilayer external leaflet and monitor the formation of nanodomains of the protein.

plant biology↗