Biology subjects

Guerrero, C.

Publications and source records attributed to Guerrero, C..

9 recordsLinked to original sources

bioRxiv2026

Acetylated PLIN2 coordinates the innate immune system and oxylipin synthesis on lipid droplets to propagate inflammation

Research has implicated lipid droplets (LDs) and their associated proteins in inflammation and the innate immune response. The key LD protein Perilipin 2 (PLIN2) is tightly correlated with lipid storage and inflammation, but little is known about the mechanisms underlying its proinflammatory effects. Here, we show that PLIN2 is required for the inflammatory response to mitogens and the recruitment of pro-inflammatory proteins to the surface of LDs. PLIN2 directly binds arachidonic acid and interacts with key oxylipin synthetic enzymes such as PLA2 and COX2 to promote LD-localized oxylipin synthesis and propagate inflammatory signaling. Moreover, LPS induces PLIN2 hyperacetylation, and acetylation-dead PLIN2 mutants lose their proinflammatory properties in the presence of an inflammatory stimulus, as if PLIN2 were ablated. Thus, acetylated PLIN2 forms a key metabolon on LDs that is essential for the response and amplification of proinflammatory signaling.

immunology↗

bioRxiv2026

Plasma metabolomics reveals lipid-predominant metabolic disruptions in virologically suppressed people with HIV

People with HIV (PWH) on antiretroviral therapy (ART) experience excess morbidity and mortality from comorbidities including cardiovascular and metabolic disease, yet the biological mechanisms underlying these outcomes in virally suppressed PWH (VS-PWH) remain incompletely understood. We applied high-dimensional targeted plasma metabolomics to quantify 254 small molecules and 750 lipids across 49 classes in viremic PWH (Vi-PWH), VS-PWH, and people without HIV (PWoH), analyzed alongside multiple T cell metrics and plasma cytokine concentrations. Globally, the plasma metabolome of VS-PWH was indistinguishable from PWoH, while Vi-PWH exhibited substantial metabolic disruption characterized by depletion of phosphatidylcholines, sphingomyelins, and hexosylceramides alongside triglyceride accumulation, dysregulation of the tryptophan-kynurenine and arginine-citrulline axes, and elevations in diacetylated polyamines and N4-acetylcytidine. Ordinal trend analysis identified subtle but consistent residual alterations in VS-PWH, particularly within phosphatidylcholine and sphingomyelin classes, that correlated with elevated TNF and reduced CD4+ T cell counts and CD4/CD8 ratio. Together, these findings indicate that residual TNF-associated inflammation and incomplete T cell recovery continue to shape the plasma metabolome in treated HIV, identifying candidate biomarkers for further mechanistic and clinical investigation.

microbiology↗

bioRxiv2026

Multi-omics links microbial dysbiosis, systemic inflammation and metabolomic disruptions to SNAE risk in treated HIV

Serious non-AIDS events (SNAEs), including non-AIDS malignancies, cardiovascular disease, and hepatic complications, remain major causes of mortality in treated HIV infection. These outcomes are driven by persistent immune activation, systemic inflammation, and metabolic dysfunction despite effective viral suppression with antiretroviral therapy (ART). To investigate mechanisms underlying SNAE pathogenesis, we performed a cross-site multi-omic analysis integrating plasma proteins, plasma metabolites, and mucosal microbiomes (ileum and rectum) in 82 ART-treated people with HIV (PWH) and 10 people without HIV (PWoH) from the United States and Mexico. Geography was the dominant source of variation, particularly across lipid classes. However, individuals at high risk for SNAEs, defined by low CD4 T cell counts and low CD4/CD8 ratios, shared a consistent signature of systemic inflammation, mitochondrial dysfunction, and microbial dysbiosis including elevated plasma IL-6, {omega}-oxidation products (adipic and suberic acids), and depletion of short-chain fatty acid-producing commensals in the gut mucosa, including Akkermansia muciniphila, Bacteroides uniformis, and Ruminococcus. Notably, A. muciniphila abundance correlated with lower IL-6 levels, fewer HIV RNA-producing cells in lymph nodes, and higher CD4/CD8 ratios. Together, these findings identify a shared inflammatory and metabolic phenotype in PWH and implicate A. muciniphila as a potential microbiome-based target to mitigate immune activation and SNAE risk in treated HIV.

immunology↗

bioRxiv2025

Impaired Lung BCAA Metabolism Promotes Ferroptosis and Resultant Pulmonary Arterial Hypertension-Associated Hepatopathy

BackgroundDysregulated branched chain amino acid (BCAA) homeostasis occurs in pulmonary arterial hypertension (PAH) as BCAA metabolites accumulate and cause metabolic alterations in pulmonary artery smooth muscle cells (PASMC). In other cells, altered BCAA metabolism promotes ferroptosis, a PAH-inducing metabolic pathway. However, the interplay between BCAAs, lung ferroptosis, and PAH is unexplored, as is the impact of PAH severity on liver molecular regulation, a key unknown as recent clinical data highlight the importance of the lung-right heart-liver axis in PAH outcomes. MethodsHuman metabolomic and transcriptomic studies examined BCAA metabolism and ferroptosis pathways. The relationship between BCAAs and ferroptotic-phenotypes in PASMCs was evaluated. Multi-omics and physiological analyses evaluated how modulation of BCAA catabolism impacted preclinical PAH multi-organ physiology. Confocal microscopy and proteomic analyses assessed hepatic alterations in human PAH. ResultsMetabolomic analyses identified alterations in BCAA metabolites across multiple physiological gradients in patients with pulmonary vascular disease. RNA sequencing demonstrated deficits in the BCAA catabolic and ferroptosis pathways in PAH lungs and smooth muscle cells. In vitro, excess BCAAs induced mitochondrial fragmentation, reactive oxygen species generation, and lipid peroxidation in PASMC. Moreover, BCAAs promoted PASMC death, which ferrostatin-1, a ferroptosis antagonist, rescued. BT2, a small-molecule inducer of BCAA catabolism, reduced PAH severity, improved RV function, and enhanced maximal exercise capacity in monocrotaline rats. BT2 blunted pro-ferroptotic changes in lung metabolites and proteins, and combatted peri-vascular complement deposition. In the liver, BT2 blocked mechanical shear stress phenotypes including hepatocyte nuclear expansion and restructured mitochondrial protein regulation and the metabolomic signature. Additionally, a low BCAA diet modestly combatted preclinical PAH severity. Finally, human PAH livers exhibited increased hepatocyte nuclear size and derangements in liver metabolic regulation. ConclusionsImpaired BCAA metabolism promotes PAH via ferroptosis. PAH severity is associated with hepatic pathological shear stress phenotypes and metabolic alterations, which are combatted by a BCAA-targeted therapy. Graphical Abstract/Summary Figure O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=152 SRC="FIGDIR/small/672819v1_ufig1.gif" ALT="Figure 1"> View larger version (55K): org.highwire.dtl.DTLVardef@1649980org.highwire.dtl.DTLVardef@199c40aorg.highwire.dtl.DTLVardef@1586fdorg.highwire.dtl.DTLVardef@15166c1_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2025

Proteomic and Metabolomic Profiling Nominates Druggable Targets and Biomarkers forPulmonary Arterial Hypertension-Associated Myopathy and Exercise Intolerance

BackgroundPulmonary arterial hypertension (PAH) is a rare but debilitating condition that causes exercise intolerance and ultimately death. Skeletal muscle derangements contribute to depressed exercise capacity in PAH, but the mechanisms underlying muscle dysfunction including the changes in muscle biology based on fiber type are understudied. MethodsWe evaluated exercise capacity, muscle histopathology, mitochondrial density, mitochondrial proteomics, and metabolomics/lipidomics of quadriceps (predominately fast fibers) and soleus (predominately slow fibers) muscles in the monocrotaline (MCT) rat model of PAH. ResultsMCT rats exhibited impaired exercise capacity. Surprisingly, there were divergent atrophic and metabolic remodeling in the quadriceps and soleus muscles of MCT rats. In the quadriceps, there was a mild atrophic response only in type II fibers. In contrast, both type I and II fibers atrophied in the soleus. Both muscles exhibited fibrotic infiltration, but mitochondrial density was reduced in the quadriceps only. Mitochondrial proteomics and tissue metabolomics/lipidomics profiling demonstrated the two muscles exhibited distinct responses as the quadriceps had impairments in oxidative phosphorylation/fat metabolism and storage of triacylglycerides. However, the soleus showed signs of proteasome deficiencies and alterations in phosphatidylcholine/phosphatidylethanolamine homeostasis. Finally, profiling of metabolites/lipids in the serum identified potential novel biomarkers of exercise intolerance in PAH including the dimethylarginine pathway, cysteine, and triacylglycerides. ConclusionOur data suggests differential cachectic and metabolic responses occur in PAH-induced myopathy. We nominate mitochondrial biogenesis and proteasome activation as potential druggable targets for PAH-myopathy.

systems biology↗

bioRxiv2024

NK cells mediate preventive efficacy of intravenous BCG against lung metastasis in mice

Lung metastases frequently arise from primary tumors, including bladder cancer, and represent a critical negative prognostic factor. Natural Killer (NK) cells have shown to play a vital role in controlling metastasis. Consequently, tumor cells have evolved specific mechanisms to evade NK cell-mediated immune surveillance, promoting metastasis and resistance to immunotherapy. In this study, we investigated the prophylactic and therapeutic potential of intravenous Bacillus Calmette-Guerin (BCG) in preventing lung metastases from bladder cancer cells using a murine model. We demonstrated that prophylactic BCG administration significantly reduced tumor burden and prolonged survival, largely through NK cell activation. However, BCG treatment was ineffective when administered over established tumors, likely due to tumor-driven immune evasion mechanisms. Our results revealed the contribution of interferon-gamma (IFN-{gamma}) to tumor resistance. Tumor cells exposed to IFN-{gamma} upregulated were more resistant to BCG in vivo, which correlated with the overexpression of immune checkpoint molecules, whereas disruption of the IFN-{gamma} signaling pathway in tumor cells partially restored the therapeutic efficacy of BCG. Our findings highlight the importance of understanding tumor immune escape mechanisms and suggest that BCG could be a promising treatment for preventing lung metastases in bladder cancer.

immunology↗

bioRxiv2023

SARS-CoV-2 infection is associated with intestinal permeability, systemic inflammation, and microbial dysbiosis in hospitalized COVID-19 patients

Coronavirus disease 2019 (COVID-19) and associated severity has been linked to uncontrolled inflammation and may be associated with changes in the microbiome of mucosal sites including the gastrointestinal tract and oral cavity. These sites play an important role in host-microbe homeostasis and disruption of epithelial barrier integrity during COVID-19 may potentially lead to exacerbated inflammation and immune dysfunction. Outcomes in COVID-19 are highly disparate, ranging from asymptomatic to fatal, and the impact of microbial dysbiosis on disease severity is unclear. Here, we obtained plasma, rectal swabs, oropharyngeal swabs, and nasal swabs from 86 patients hospitalized with COVID-19 and 12 healthy volunteers. We performed 16S rRNA sequencing to characterize the microbial communities in the mucosal swabs and measured circulating cytokines, markers of gut barrier integrity, and fatty acids in the plasma samples. We compared these plasma concentrations and microbiomes between healthy volunteers and the COVID-19 patients who had survived or unfortunately died by the end of study enrollment, and between severe disease and healthy controls, as well as performed a correlation analysis between plasma variables and bacterial abundances. The rectal swabs of COVID-19 patients had reduced abundances of several commensal bacteria including Faecalibacterium prausnitsii, and an increased abundance of the opportunistic pathogens Eggerthella lenta and Hungatella hathewayi. Furthermore, the oral pathogen Scardovia wiggsiae was more abundant in the oropharyngeal swabs of COVID-19 patients who died. The abundance of both H. hathewayi and S. wiggsiae correlated with circulating inflammatory markers including IL-6, highlighting the possible role of the microbiome in COVID-19 severity, and providing potential therapeutic targets for managing COVID-19.

microbiology↗

bioRxiv2022

Crk proteins activate the Rap1 guanine nucleotide exchange factor C3G by segregated adaptor-dependent and -independent mechanisms

C3G is a guanine nucleotide exchange factor (GEF) that activates Rap1 to promote cell adhesion. Resting C3G is autoinhibited and the GEF activity is released by stimuli that signal through tyrosine kinases. Tyrosine phosphorylation of C3G and interaction with Crk adaptor proteins, whose expression is increased in multiple human cancers, participate in C3G activation. However, the molecular details of C3G activation and the interplay between C3G phosphorylation and Crk interaction are poorly understood. Here, we combine biochemical, biophysical, and cell biology approaches to elucidate the mechanisms of C3G activation. CrkL interacts through its SH3N domain with the proline-rich motifs P1 and P2 of inactive C3G in vitro and in Jurkat and HEK293T cells, and these sites are necessary to recruit C3G to the plasma membrane. However, direct stimulation of the GEF activity requires binding of Crk proteins to the P3 and P4 sites. P3 is occluded in resting C3G and is essential for activation, while P4 contributes secondarily towards complete stimulation. Tyrosine phosphorylation of C3G alone causes marginal activation. Instead, phosphorylation primes C3G lowering the concentration of Crk proteins required for activation and increasing the maximum activity. Unexpectedly, optimal activation also requires the interaction of CrkL-SH2 domain with phosphorylated C3G. Phosphorylation and Crk-binding form a two-factor mechanism that ensures tight control of C3G activation. The simultaneous SH2 and SH3N interaction of CrkL with C3G, required for the activation, reveals a novel adaptor-independent function of Crk proteins relevant to understanding their role in physiological signaling and their deregulation in diseases.

molecular biology↗

bioRxiv2022

Upregulation of TLR4/MyD88 pathway in alcohol-induced Wernicke's encephalopathy: findings in preclinical models and in a postmortem human case

Wernickes encephalopathy (WE) is a neurologic disease caused by vitamin B1 or thiamine deficiency (TD), being the alcohol use disorder (AUD) its main risk factor. WE patients present limiting motor, cognitive and emotional alterations related to a selective cerebral vulnerability. Neuroinflammation has been proposed as one of the phenomena contributing to brain damage. Our previous studies provide evidence for the involvement of the innate immune receptor Toll-like (TLR) 4 in the inflammatory response induced in the frontal cortex and cerebellum in TD animal models (animals fed with TD diet and receiving pyrithiamine). However, the effects of the combination of chronic alcohol consumption and TD on TLR4 and their specific contribution to the pathogenesis of WE are currently unknown. Additionally, no studies on TLR4 have been conducted on WE patients since brains from these patients are difficult to achieve. Here, we used rat models of chronic alcohol (CA; 9 months of forced consumption of 20% (w/v) alcohol), TD hit (TDD; TD diet + daily 0.25 mg/kg i.p. pyrithiamine during 12 days), or a combined treatment (CA+TDD) to check the activation of the proinflammatory TLR4/MyD88 pathway and related markers in the frontal cortex and the cerebellum. In addition, we characterized for the first time the TLR4 and its co-receptor MyD88 signature, along with other markers of this proinflammatory signaling such as phospo-NF{kappa}B p65 and I{kappa}B, in the post-mortem human frontal cortex and cerebellum (gray and white matter) of an alcohol-induced WE patient, comparing it with negative (no disease) and positive (aged brain with Alzheimers disease) control subjects for neuroinflammation. We found an increase in the cortical TLR4 and its adaptor molecule MyD88, together with an upregulation of the proinflammatory signaling molecules p-NF-B and IB in the CA+TDD animal model. In the patient diagnosed with alcohol-induced WE we observed cortical and cerebellar upregulation of the TLR4/MyD88 pathway. Thus, our findings provide evidence, both in the animal model and the human postmortem brain, of the upregulation of the TLR4/MyD88 proinflammatory pathway in WE related to alcohol consumption.

neuroscience↗