Associate Professor
J. Cesar Cardenas is a Medical Technologist in Morphophysiopathology and Cytodiagnosis and a PhD in Biomedical Sciences, both obtained at the University of Chile. He then completed a postdoc with Dr. Clara Franzini-Armstrong at the University of Pennsylvania (UPENN), determining the nuclear localization of the 1,4,5-trisphosphate-sensitive Ca2+ channel, InsP3R, using high-resolution electron microscopy and cryofracture. Motivated to better understand the physiological role of InsP3R, he joined the laboratory of Dr. Kevin Foskett also at UPENN, where he demonstrated for the first time that InsP3R-dependent basal Ca2+ signaling were essential for maintaining mitochondrial function.
PUBLICATIONS
2015-pres
RESEARCH LINES
Mechanisms that regulate cell metabolism are a fundamental requirement for cell viability. Normal differentiated cells rely primarily on mitochondrial oxidative phosphorylation to generate the energy needed for cellular processes. In tumor cells, it has historically been assumed that mitochondrial metabolism is significantly diminished while aerobic glycolysis is enhanced so that it becomes the major ATP source to fuel cancer cell proliferation, a phenomenon known as the Warburg effect. Nevertheless, recent studies have shown that the mitochondrial tricarboxylic acid (TCA) cycle is both functional and essential for tumor growth, because provide the cells, in addition to energy, building blocks for the synthesis of macromolecules (proteins, lipids and nucleotides), and reducing equivalent which among other functions, regulate the redox state of the cell. Therefore, we focus our research in understand how mitochondrial activity is regulate and how we can modulate it in cancer cells. We discover that Ca2+ transfer from the endoplasmic reticulum (ER) mediate trough the inositol trisphosphate receptor (InsP3R) channel (InsP3R) to mitochondria maintain normal mitochondrial activity and the absence of this signal generate a bioenergetic crisis that induce selective cancer cell death. We demonstrate that Ca2+ transfer to mitochondria is essential to maintain the activity of pyruvate, α-ketoglutarate and isocitrate dehydrogenases, key rate limiting enzymes of the TCA cycle. In this scenario, we hypothesize that in the absence of Ca2+, tumor cells are unable to use glutamine and the TCA cycle to generate the building blocks needed to proliferate and maintain homeostasis. We expect that a deeper understanding of the regulation of mitochondria bioenergetics by InsP3R-released Ca2+ will result in the identification of new therapeutic targets.
By 2050, close to one fifth of the Chilean population will be over 60 years old, making Chile one of the countries with the highest number of elderly people. Aging is one of the main risk factors for cancer, heart and neurodegenerative diseases. Cellular senescence, an irreversible cell cycle arrest, play a big role in the decline of the regenerative potential and function of tissues, inflammation, and tumorigenesis in aged organisms. Thus, the identification, characterization, and pharmacological elimination of senescent cells have gained attention in the field of aging. Since cellular senescence is accompanied by change in metabolism and Ca2+ homeostasis, we aim to understand the role of mitochondria in the generation and maintenance of senescence cells and determine if the modulation of it activity can be use as a therapeutical tool.
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and the most frequent cause of dementia, affecting millions of people worldwide and still incurable. It is characterized clinically as a decline of intellectual and cognitive functions and irreversible memory loss as major features. Altered Ca2+ signaling and mitochondrial dysfunction are observed early in the development of the disease, long before the onset of measurable histopathology or cognitive deficits. However, the involvement of exaggerated Ca2+ signaling on mitochondrial dysfunction remain poorly understood. A molecular mechanism underlying exaggerated Ca2+ signaling is mediated in part by Ca2+ release from the endoplasmic reticulum (ER) through inositol 1,4,5-trisphosphate receptors (IP3R). IP3R are in close proximity with the mitochondrial Ca2+ uniporter (MCU), the ion channel responsible for sequestering Ca2+ into the mitochondrial matrix. We aim to study the relation InsP3R-MCU in an AD context and determine weather the normalization of Ca2+ signaling by decreasing IP3R activity will restore or prevent mitochondrial crisis and synaptic dysfunction in AD models.
The dysferlinopathies include different muscular dystrophy phenotypes; all of which are autosomal recessive, and are consequence of mutations in the dysferlin gene (DYSF). Miyoshi’s distal myopathy (MM) and limb girdle muscular dystrophy 2B (LGMD2B), are the two more common dysferlinopathy phenotypes, and correspond to allelic disorders. The functionality of dysferlin in muscle cells is under active investigation. Pathogenesis of dysferlinopahy is attributed to impaired calcium-mediated muscle-membrane repair after normal stress injury. Abnormal mitochondria have been observed in myophaties like Pompe and Danon’s disease. Accumulation of damaged mitochondria usually reflects an autophagy malfunction, which generates a bioenergetic crisis sensed by AMPK, the master energy regulator of the cell. In the dysferlinopathies context is unknow weather the mitochondria are functional or not and which is the bioenergetic state of the cells. Thus, we aim to explore the signal pathway that regulate cellular bioenergetic in this pathophysiological context and determine is potential as a therapeutical target.
PROJECTS
Active:
2024-2026: ECOS-FONDECYT (France-Chile exchange grant) “Role of inositol 1,4,5-trisphosphate receptors in celular senescence” ECOS230006. (Principal Investigator)
2024-2027: FONDECYT (similar to a NIH R01) “IP3R disengagement from mitochondrial-endoplasmic reticulum contact sites (MERCS) activate mitochondrial retrograde signals that initiate the therapy induce senescence program”. N° 1240807. (Principal Investigator).
2020-2025: FONDAP (similar to a center grant) “Geroscience Center for Brain Health and Metabolism” N° 15150012. (Principal Investigator).
Completed:
2020-2023: FONDECYT “Constitutive InsP3R-mediated calcium transfer to the mitochondria as a specific vulnerability of senescent cells; effect on cancer relapse” N° 1200255. (Principal Investigator).
2022-2023: The Jain Foundation Inc grant “Ketosis ameliorates dysferlinopathy phenotype in bla/j mice by promoting mitochondrial function” (Principal Investigator).
2020-2022: The Jain Foundation Inc grant “Ketogenic diet ameliorates dysferlinopathy phenotype by promoting mitochondrial function in in vitro and in vivo models of the disease” (Principal Investigator).
2018-2021: FONDECYT “New mitochondria-targeted anti-tumor compounds: Synthesis of anti-proliferative and anti-migratory phosphonium and pyridinium salts derived from acylpolyphenols” N° 1180069 (Co- Investigator).
2016-2019: FONDECYT “Mitochondrial uptake of constitutive InsP3R-released Ca2+ is essential to maintain mitochondrial metabolism and sustain breast cancer cell migration, invasion and metastasis”. N°1160332. (Principal Investigator).
2015-2018: FONDECYT “Autophagy as a possible pathophysiological mechanism in dysferlinopathy” N° 1151383. (Co- Investigator)
2014-2017: FONDECYT “Regulation of skeletal muscle atrophy and autophagy by polycystin 2” N° 1140908. (Co-Investigator).
2014-2017: Supporting the development of research projects between Chile and the United States “Gene therapy strategy to target the unfolded protein response (UPR) in ALS”. N° USA2013-0003. ( Co-Investigator).
2012-2015: FONDECYT “Mitochondrial Ca2+ uptake mediated by InsP3 receptors is required to maintain cancer cell bioenergetics. Its inhibition results in selective cancer cell death.” N° 1120443. (Principal Investigator).
2012: FONDEQUIP “Cellular Bioenergetics” N°EQM120032. (Principal Investigator).
TEAM
Andrea Puebla-Huerta, , Lab Manager.
Osman Diaz, Research Assistant.
Loreto Araos, Research Assistant.
Donato Garrido, Research Assistant.
Sergio Linsambarth, Postdoc.
Hernan Huerta, Postdoc.
Pablo Morgado, PhD student in Biochemistry from Universidad de Chile.
Cesar Casanova PhD student in Neurobiology from Universidad Mayor.
Alejandra Lopez-Moroni, PhD student in Neurobiology from Universidad Mayor.
NETWORK
Nacional
Dr. Jorge Bevilacqua, Hospital Jose Joaquin Aguirre, Universidad de Chile, Santiago Chile
Dr. Felipe Salech, School of Medicine, Universidad de Chile, Santiago Chile
Dr. Ute Woehlbier, Center for Integrative Biology, Universidad Mayor, Santiago, Chile
Dr. Daniela Sauma, School of Science, Universidad de Chile, Santiago Chile
Dr. Patricia Luz-Crawford, Centro de Investigación e Innovación Biomédica, Facultad de Medicina, Universidad de los Andes
Dr. Diego Garcia, School of Medicine, Universidad de Chile, Santiago Chile
Dr. Alejandro Godoy, CEBICEM, Universidad San Sebastian
Dr. Juan Garcia-Huidobro, Facultad de Quimica y Biologia, Usach.
Internacional
Dr. Kevin Foskett, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA.
Dr. Armen Zakarian, Department of Chemistry, University of California, Santa Barbara, USA.
Dr. Mariano Viapiano, Neuroscience and Physiology department, Upstate Medical University. USA.
Dr. David Bernard, Cancer Research Centre of Lyon, University of Lyon. France.
Dr Paola Pizzo, department of Biomedical Science, University of Padova.
Dr. Tito Cali, department of Biomedical Science, University of Padova.
Dr. Amalia Dolga, Faculty of Science and Engineering, Groningen University, Groningen, Netherland
Dr. Jordi Molgo, Institute de Neurobiologie Alfred Fessard, CNRS, Gif-sur-Yvette, France
Dr. Jimmy Crott, USDA Human Nutrition Research Center on Aging, Tufts University, Boston, USA