Ceramide and ceramide 1-phosphate in health and disease

Sphingolipids are essential components of cell membranes, and many of them regulate vital cell functions. In particular, ceramide plays crucial roles in cell signaling processes. Two major actions of ceramides are the promotion of cell cycle arrest and the induction of apoptosis. Phosphorylation of ceramide produces ceramide 1-phosphate (C1P), which has opposite effects to ceramide. C1P is mitogenic and has prosurvival properties. In addition, C1P is an important mediator of inflammatory responses, an action that takes place through stimulation of cytosolic phospholipase A2, and the subsequent release of arachidonic acid and prostaglandin formation. All of the former actions are thought to be mediated by intracellularly generated C1P. However, the recent observation that C1P stimulates macrophage chemotaxis implicates specific plasma membrane receptors that are coupled to Gi proteins. Hence, it can be concluded that C1P has dual actions in cells, as it can act as an intracellular second messenger to promote cell survival, or as an extracellular receptor agonist to stimulate cell migration

Implication of Ceramide Kinase/C1P in Cancer Development and Progression

Cancer cells rewire their metabolic programs to favor biological processes that promote cell survival, proliferation, and dissemination. Among this relevant reprogramming, sphingolipid metabolism provides metabolites that can favor or oppose these hallmarks of cancer. The sphingolipid ceramide 1-phosphate (C1P) and the enzyme responsible for its biosynthesis, ceramide kinase (CERK), are well established regulators of cell growth and survival in normal, as well as malignant cells through stress-regulated signaling pathways. This metabolite also promotes cell survival, which has been associated with the feedback regulation of other antitumoral sphingolipids or second messengers. C1P also regulates cancer cell invasion and migration of different types of cancer, including lung, breast, pancreas, prostate, or leukemia cells. More recently, CERK and C1P have been implicated in the control of inflammatory responses. The present review provides an updated view on the important role of CERK/C1P in the regulation of cancer cell growth, survival, and disseminationWork in AGM lab is supported by ‘Departamento de Educación, Universidades e Investigación del Gobierno Vasco’, Basque Country, Spain (Grant IT1106-16). The work of A. Carracedo is supported by the Basque Department of Industry, Tourism and Trade (Elkartek), the Department of Education (IKERTALDE IT1106-16) and Health (RIS3), the MICINN (PID2019-108787RB-I00 (FEDER/EU), Severo Ochoa Excellence Accreditation SEV-2016-0644, Excellence Networks RED2018-102769-T), the AECC (GCTRA18006CARR), La Caixa Foundation (ID 100010434), under the agreement LCF/PR/HR17/, and the European Research Council (Consolidator Grant 819242). CIBERONC was co-funded with FEDER funds and funded by ISCIII

Lysophosphatidic Acid Signaling Axis Mediates Ceramide 1-Phosphate-Induced Proliferation of C2C12 Myoblasts.

Sphingolipids are not only crucial for membrane architecture but act as critical regulators of cell functions. The bioactive sphingolipid ceramide 1-phosphate (C1P), generated by the action of ceramide kinase, has been reported to stimulate cell proliferation, cell migration and to regulate inflammatory responses via activation of different signaling pathways. We have previously shown that skeletal muscle is a tissue target for C1P since the phosphosphingolipid plays a positive role in myoblast proliferation implying a role in muscle regeneration. Skeletal muscle displays strong capacity of regeneration thanks to the presence of quiescent adult stem cells called satellite cells that upon trauma enter into the cell cycle and start proliferating. However, at present, the exact molecular mechanism by which C1P triggers its mitogenic effect in myoblasts is lacking. Here, we report for the first time that C1P stimulates C2C12 myoblast proliferation via lysophosphatidic acid (LPA) signaling axis. Indeed, C1P subsequently to phospholipase A2 activation leads to LPA1 and LPA3 engagement, which in turn drive Akt (protein kinase B) and ERK1/2 (extracellular signal-regulated kinases 1/2) activation, thus stimulating DNA synthesis. The present findings shed new light on the key role of bioactive sphingolipids in skeletal muscle and provide further support to the notion that these pleiotropic molecules might be useful therapeutic targets for skeletal muscle regeneration

Unraveling the potential of endothelial progenitor cells as a treatment following ischemic stroke

Angiogénesis; Células progenitoras endoteliales; IctusAngiogènesi; Cèl·lules progenitores endotelials; IctusAngiogenesis; Endothelial progenitor cells; StrokeIschemic stroke is becoming one of the most common causes of death and disability in developed countries. Since current therapeutic options are quite limited, focused on acute reperfusion therapies that are hampered by a very narrow therapeutic time window, it is essential to discover novel treatments that not only stop the progression of the ischemic cascade during the acute phase, but also improve the recovery of stroke patients during the sub-acute or chronic phase. In this regard, several studies have shown that endothelial progenitor cells (EPCs) can repair damaged vessels as well as generate new ones following cerebrovascular damage. EPCs are circulating cells with characteristics of both endothelial cells and adult stem cells presenting the ability to differentiate into mature endothelial cells and self-renew, respectively. Moreover, EPCs have the advantage of being already present in healthy conditions as circulating cells that participate in the maintenance of the endothelium in a direct and paracrine way. In this scenario, EPCs appear as a promising target to tackle stroke by self-promoting re-endothelization, angiogenesis and vasculogenesis. Based on clinical data showing a better neurological and functional outcome in ischemic stroke patients with higher levels of circulating EPCs, novel and promising therapeutic approaches would be pharmacological treatment promoting EPCs-generation as well as EPCs-based therapies. Here, we will review the latest advances in preclinical as well as clinical research on EPCs application following stroke, not only as a single treatment but also in combination with new therapeutic approaches.This study was partially supported by grants from the Xunta de Galicia (PH, JC, and TS: IN607A2018/3, TS: IN607D 2020/09, AC: IN606A-2021/015), the Science Ministry of Spain (TS: RTI2018-102165-B-I00 and RTC2019-007373-1), and the Instituto de Salud Carlos III (AR: PI19/00186 and RD21/0006/0007). Furthermore, this study was also supported by grants from the INTERREG Atlantic Area (LF and TS: EAPA_791/2018_ NEUROATLANTIC Project), INTER-REG V A España Portugal (POCTEP) (LF and TS: 0624_2IQBIONEURO_6_E), the European Regional Development Fund (ERDF), the PT2020 program (LF: FEDER, project LABEL: POCI-01-0247-FEDER-049268), and the Fundação para a Ciência e Tecnologia (LF: project ENDEAVOUR: EXPL/BTM-ORG/1348/2021). Moreover, DR-S (CD21/00166), MA-N (IFI18/00008), and TS (CPII17/00027) are recipients of Sara Borrell, iPFIS, and Miguel Servet contracts, respectively, from the Instituto de Salud Carlos III. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript

FORTIS: a Live-Cell Assay to Monitor AMPA Receptors Using pH-Sensitive Fluorescence Tags

The real-time live fluorescent monitoring of surface AMPA receptors (AMPARs) could open new opportunities for drug discovery and phenotypic screening concerning neuropsychiatric disorders. We have developed FORTIS, a tool based on pH sensitivity capable of detecting subtle changes in surface AMPARs at a neuronal population level. The expression of SEP-GluA1 or pHuji-GluA1 recombinant AMPAR subunits in mammalian neurons cultured in 96-well plates enables surface AMPARs to be monitored with a microplate reader. Thus, FORTIS can register rapid changes in surface AMPARs induced by drugs or genetic modifications without having to rely on conventional electrophysiology or imaging. By combining FORTIS with pharmacological manipulations, basal surface AMPARs, and plasticity-like changes can be monitored. We expect that employing FORTIS to screen for changes in surface AMPARs will accelerate both neuroscience research and drug discovery.This study was supported by the following agencies: National Institute for Biotechnology in the Negev; Israel Science Foundation (536/19); Spanish Ministry of Science (Europa Excelencia 15/02, SAF2016-78071-R)

Ceramide Metabolism and Parkinson’s Disease—Therapeutic Targets

Ceramide is a bioactive sphingolipid involved in numerous cellular processes. In addition to being the precursor of complex sphingolipids, ceramides can act as second messengers, especially when they are generated at the plasma membrane of cells. Its metabolic dysfunction may lead to or be a consequence of an underlying disease. Recent reports on transcriptomics and electrospray ionization mass spectrometry analysis have demonstrated the variation of specific levels of sphingolipids and enzymes involved in their metabolism in different neurodegenerative diseases. In the present review, we highlight the most relevant discoveries related to ceramide and neurodegeneration, with a special focus on Parkinson’s disease.This study was partially supported by grants from the Xunta de Galicia (Consellería de Economía e Industria: IN607A2018/3 & IN607D 2020/09), and Science Ministry of Spain (RTI2018-102165-B-I00 & RTC2019-007373-1). Furthermore, this study was also supported by grants from the INTERREG Atlantic Area (EAPA_791/2018_ NEUROATLANTIC project), INTERREG V A España Portugal (POCTEP) (0624_2IQBIONEURO_6_E) and the European Regional Development Fund (ERDF). Work in AGM lab is supported by grant IT-1106-16 from “Departamento de Educación, Universidades e Investigación” (Gobierno Vasco, Gasteiz-Virtoria, Spain). Moreover, M. Aramburu-Núñez (IFI18/00008) is recipient of iPFIS contract, and Sobrino (CPII17/00027) is recipient of a research contract from the Miguel Servet Program from the Instituto de Salud Carlos III. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript

Phosphatidic Acid Stimulates Myoblast Proliferation through Interaction with LPA1 and LPA2 Receptors

Phosphatidic acid (PA) is a bioactive phospholipid capable of regulating key biological functions, including neutrophil respiratory burst, chemotaxis, or cell growth and differentiation. However, the mechanisms whereby PA exerts these actions are not completely understood. In this work, we show that PA stimulates myoblast proliferation, as determined by measuring the incorporation of [3H]thymidine into DNA and by staining the cells with crystal violet. PA induced the rapid phosphorylation of Akt and ERK1/2, and pretreatment of the cells with specific small interferin RNA (siRNA) to silence the genes encoding these kinases, or with selective pharmacologic inhibitors, blocked PA-stimulated myoblast proliferation. The mitogenic effects of PA were abolished by the preincubation of the myoblasts with pertussis toxin, a Gi protein inhibitor, suggesting the implication of Gi protein-coupled receptors in this action. Although some of the effects of PA have been associated with its possible conversion to lysoPA (LPA), treatment of the myoblasts with PA for up to 60 min did not produce any significant amount of LPA in these cells. Of interest, pharmacological blockade of the LPA receptors 1 and 2, or specific siRNA to silence the genes encoding these receptors, abolished PA-stimulated myoblast proliferation. Moreover, PA was able to compete with LPA for binding to LPA receptors, suggesting that PA can act as a ligand of LPA receptors. It can be concluded that PA stimulates myoblast proliferation through interaction with LPA1 and LPA2 receptors and the subsequent activation of the PI3K/Akt and MEK/ERK1-2 pathways, independently of LPA formation.This research was funded by ‘Departamento de Educación del Gobierno Vasco (Gasteiz-Vitoria, Basque Country, Spain) grant number IT-1106-16 and ‘Ministerio de Ciencia, Innovación y Universidades (Madrid, Spain) grant number SAF2016-79695-R

Periodontitis is associated with subclinical cerebral and carotid atherosclerosis in hypertensive patients: A cross‑sectional study

Objective: To examine the relationship between periodontitis and subclinical intracranial atherosclerosis. The association of periodontitis with preclinical markers of atherosclerosis in other vascular territories was also explored. Material and methods: This was a cross-sectional study where 97 elderly subjects with a previous history of hypertension received an ultrasonographic evaluation to assess subclinical atherosclerosis in different vascular territories: (1) cerebral [pulsatility (PI) and resistance index (RI) of the middle cerebral artery], (2) carotid [intima-media thickness (IMT)], and (3) peripheral [ankle-brachial index (ABI)]. Additionally, participants underwent a full-mouth periodontal assessment together with blood sample collection to determine levels of inflammatory biomarkers (leukocytes, fibrinogen, and erythrocyte sedimentation rate), lipid fractions (total cholesterol and high- and low-density lipoprotein), and glucose. Results: Sixty-one individuals had periodontitis. Compared to subjects without periodontitis, those with periodontitis showed higher values of PI (1.24 ± 0.29 vs 1.01 ± 0.16), RI (0.70 ± 0.14 vs 0.60 ± 0.06), and IMT (0.94 ± 0.15 vs 0.79 ± 0.15) (all p < 0.001). No statistically significant differences were found neither for ABI or for other clinical and biochemical parameters. An independent association was found between periodontitis and increased intracranial atherosclerosis (ORadjusted = 10.16; 95% CI: 3.14-32.90, p < 0.001) and to a lesser extent with thicker carotid IMT (ORadjusted = 4.10; 95% CI: 1.61-10.48, p = 0.003). Conclusions: Periodontitis is associated with subclinical atherosclerosis in both intracranial and carotid arteries in elderly subjects with hypertension. Clinical relevance: The association of periodontitis with intracranial atherosclerosis implies that periodontitis patients might have greater chances to develop ischemic stroke in the futureOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study was partially supported by grants from the Xunta de Galicia (TS: IN607A2018/3 and TS: IN607D 2020/09), Spanish Ministry of Science (TS: RTI2018-102165-B-I00 and RTC2019-007373-1), Institute of Health Carlos III (PI22/00938), and RICOR-ICTUS Network (RD21/0006/003). Furthermore, this study was also supported by grants from the Interreg Atlantic Area (TS: EAPA_791/2018_ NeuroATLANTIC project), Interreg V-A España Portugal (POCTEP) (TS: 0624_2IQBIONEURO_6_E), and the European Regional Development Fund. YL is supported by a Sara Borrell fellowship (CD22/00051), and TS (CPII17/00027) and FC (CPII19/00020) are recipients of Miguel Servet contracts, all of them funded by the Institute of Health Carlos IIIS