Kevin Perez

University of Lausanne | UNIL

Over the last decades, several premature aging mouse models have been developed to study aging and identify interventions that can delay age-related diseases. Yet, it is still unclear whether these models truly recapitulate natural aging. Here, we analyzed DNA methylation in multiple tissues of four previously reported mouse models of premature agi...

Aging is accompanied by a loss of muscle mass and function, termed sarcopenia, which causes numerous morbidities and economic burdens in human populations. Mechanisms implicated in age-related sarcopenia or frailty include inflammation, muscle stem cell depletion, mitochondrial dysfunction, and loss of motor neurons, but whether there are key drive...

Aging is characterized by a progressive loss of brain volume at an estimated rate of 5% per decade after age 40. While these morphometric changes, especially those affecting gray matter and atrophy of the temporal lobe, are predictors of cognitive performance, the strong association with aging obscures the potential parallel, but more specific role...

The dedifferentiation of somatic cells into a pluripotent state by cellular reprogramming coincides with a reversal of age-associated molecular hallmarks. Although transcription factor induced cellular reprogramming has been shown to ameliorate these aging phenotypes in human cells and extend health and lifespan in mice, translational applications...

The establishment of aging clocks based on DNA methylation highlighted the strong link between epigenetic alterations and aging. However, the connection between DNA methylation changes at clock sites and their effect on cellular function remains unclear. We hypothesize that chromatin accessibility, a readout that integrates many epigenetic mechanis...

The induction of cellular reprogramming by forced expression of the transcription factors OCT4, SOX2, KLF4, and C-MYC (OSKM) has been shown to allow the dedifferentiation of somatic cells and ameliorate age-associated phenotypes in multiple tissues and organs. Yet to date, the benefits of in vivo reprogramming are limited by the occurrence of detri...

Background and aims: Ileocolonic resection is frequently needed in the course of Crohn's disease (CD) and post-operative recurrence is extremely common. Our main objective was to analyze gene expression in the mucosa of CD patients at time of surgery and post-operative endoscopy, in order to identify predictors and mechanisms of early endoscopic r...

Cellular senescence is a driver of many age-related pathologies. There is an active search for pharmaceuticals termed senolytics that can mitigate or remove senescent cells in vivo by targeting genes that promote the survival of senescent cells. We utilized single-cell RNA sequencing to identify CRYAB as a robust senescence-induced gene and potenti...

Background T resident memory (Trm) cells in the intestinal mucosa and in particular subpopulations expressing phenotypic markers such as alphaE-beta7 or NKG2D have been associated with chronic inflammatory bowel disease (IBD) activity. We hypothesize that these populations may have a direct deleterious impact on the intestinal epithelium in IBD. M...

Background Inflammatory bowel diseases (IBDs) are characterized by chronic inflammation and tissue damages in limited segments of the digestive tract. Pathogenesis in the tissue and mucosal inflammation probably differs according to disease location. Our aim was to further analyze transcriptomic profiles in different locations of IBD, differentiati...

Skeletal muscle mass and function can decline with aging, resulting in a syndrome known as sarcopenia. This decline is linked to functional alterations in critical cell types within mature muscle, including fibro-adipogenic progenitors (FAPs) and satellite cells (SCs), driven in part by cellular senescence. We utilized single-cell RNA sequencing an...

Significance Chronic inflammation contributes to morbidity and mortality in aging, but whether similar mechanisms underlie dysfunction in infection-associated chronic inflammation is unclear. Using a multicohort systems immunology approach, we identified signatures of immune dysfunction that are shared in aging and chronic viral infections, namely...

Aging is accompanied by a loss of muscle mass and function, termed sarcopenia, which causes numerous morbidities and economic burdens in human populations. Mechanisms implicated in age-related sarcopenia include inflammation, muscle stem cell depletion, mitochondrial dysfunction and loss of motor neurons, but whether there are key drivers of sarcop...

Background: The coronavirus disease 2019 (COVID-19) pandemic continues to ravage and burden hospitals around the world. The epidemic started in Wuhan, China was recognized by the World Health Organization (WHO) as an international public health emergency and declared the outbreak a pandemic in March 2020. Since then, the scale of disruptions cause...

BACKGROUND The COVID-19 pandemic continues to ravage and burden hospitals around the world. The epidemic started in Wuhan, China, and was subsequently recognized by the World Health Organization as an international public health emergency and declared a pandemic in March 2020. Since then, the disruptions caused by the COVID-19 pandemic have had an...

The coronavirus disease 2019 (COVID-19) pandemic, caused by Severe Acute Respiratory Syndrome (SARS)-CoV-2, continues to burden medical institutions around the world by increasing total hospitalization and Intensive Care Unit (ICU) admissions. A better understanding of symptoms, comorbidities and medication used for pre-existing conditions in patie...

Background A dysregulated T-cell response is involved in the pathophysiology of inflammatory bowel diseases (IBD). T cells expressing the NKG2D activation receptor are implicated. Here, we investigated changes in intestinal T lymphocyte subsets overtime in patients treated by biotherapy for active disease. Methods In this prospective single-centre...

T cell clonal expansions are present in the inflamed mucosa of patients with Crohn’s disease (CD) and may be implicated in postoperative recurrence after ileocolonic resection. Methods T cell receptor (TCR) analysis was performed in 57 patients included in a prospective multicentre cohort. Endoscopic recurrence was defined by a Rutgeerts score >i0....

T cell clonal expansions are present in the inflamed mucosa of patients with Crohn’s disease (CD) and may be implicated in postoperative recurrence after ileocolonic resection. Methods T cell receptor (TCR) analysis was performed in 57 patients included in a prospective multicentre cohort. Endoscopic recurrence was defined by a Rutgeerts score >i0...

Background and aims N-acyl homoserine lactones (AHLs), which are autoinducer quorum-sensing molecules involved in the bacterial communication network, also interact with eukaryotic cells. Searching for these molecules in the context of inflammatory bowel disease (IBD) is appealing. The aims of our study were to look for AHL molecules in faecal samp...

Background: Patients with primary sclerosing cholangitis associated with inflammatory bowel disease (PSC-IBD) have a very high risk of developing colorectal neoplasia. Alterations in the gut microbiota and/or gut bile acids could account for the increase in this risk. However, no studies have yet investigated the net result of cholestasis and a po...

Background: The comparative efficacy of adalimumab (ADA) and infliximab (IFX) in Crohn's disease, and the benefit of initial combotherapy with an immunomodulator, are debated. Aim: To assess the best anti-TNF treatment regimens in Crohn's disease. Methods: We included 906 biologic-naïve Crohn's disease patients [median age, 31 years (24-41)] a...