Hepatic p63 regulates glucose metabolism by repressing SIRT1.

OBJECTIVE: p63 is a transcription factor within the p53 protein family that has key roles in development, differentiation and prevention of senescence, but its metabolic actions remain largely unknown. Herein, we investigated the physiological role of p63 in glucose metabolism. DESIGN: We used cell lines and mouse models to genetically manipulate p63 in hepatocytes. We also measured p63 in the liver of patients with obesity with or without type 2 diabetes (T2D). RESULTS: We show that hepatic p63 expression is reduced on fasting. Mice lacking the specific isoform TAp63 in the liver (p63LKO) display higher postprandial and pyruvate-induced glucose excursions. These mice have elevated SIRT1 levels, while SIRT1 knockdown in p63LKO mice normalises glycaemia. Overexpression of TAp63 in wild-type mice reduces postprandial, pyruvate-induced blood glucose and SIRT1 levels. Studies carried out in hepatocyte cell lines show that TAp63 regulates SIRT1 promoter by repressing its transcriptional activation. TAp63 also mediates the inhibitory effect of insulin on hepatic glucose production, as silencing TAp63 impairs insulin sensitivity. Finally, protein levels of TAp63 are reduced in obese persons with T2D and are negatively correlated with fasting glucose and homeostasis model assessment index. CONCLUSIONS: These results demonstrate that p63 physiologically regulates glucose homeostasis.

Long-term outcomes of nummular headache: A series of 168 patients and 1198 patient-years of follow-up.

BACKGROUND: Since the first description of nummular headache (NH), more than 500 cases have been described, delineating its clinical phenotype and response to treatment. However, data on the natural history of NH and outcomes during long-term follow-up are not currently available. The present study aimed to describe the long-term outcomes and follow-up of a large series of patients with NH. METHODS: A descriptive observational ambisective study with a series of cases was conducted. The study population included adult patients with primary NH and a minimum of 12 months of follow-up. Demographic variables, previous medical history, clinical phenotype, diagnosis and treatment of NH, temporal pattern, and long-term evolution were analysed. RESULTS: In total, 168 patients were enrolled and followed for a median [interquartile range (IQR)] of 80.5 (55-118.5) months. The temporal pattern after NH onset was chronic in 67.9% and, at diagnosis, the median (IQR) number of pain days per month was 20 [10-30] days with 138 (82.1%) patients with ≥8 days of pain per month. Preventive treatment was needed by 112 (66.7%) patients. The most frequently used drugs were gabapentin (69/112; 61.6%), onabotulinumtoxinA (38/112; 33.9%), amitriptyline (31/112; 27.7%) and lamotrigine (21/112; 18.7%). Response to preventive treatment was at least partial in 91/112 (81.3%) patients. At the end of follow-up, 81 (48.2%) patients had inactive NH. Of patients with active NH, the median (IQR) number of headache days per month was 3 (1-12) days and patients had ≥8 days of pain in 35 (20.8%) cases. CONCLUSIONS: Long-term outcomes of NH were positive in most patients. After a median of 6.7 years of follow-up, 48% of cases were inactive. Two-thirds of patients required preventive treatment, and 80% of them were treatment-responsive. In NH cases that remained symptomatic, the headache frequency was lower, and the proportion of patients with chronic NH decreased from 68% to 11%.

GCKIII (Germinal Center Kinase III) Kinases STK24 and STK25 (Serine/Threonine Kinase 24 and 25) Inhibit Cavernoma Development.

BACKGROUND: Cavernous cerebral malformations can arise because of mutations in the CCM1, CCM2, or CCM3 genes, and lack of Cdc42 has also been reported to induce these malformations in mice. However, the role of the CCM3 (cerebral cavernous malformation 3)-associated kinases in cavernoma development is not known, and we, therefore, have investigated their role in the process. METHODS: We used a combination of an in vivo approach, using mice genetically modified to be deficient in the CCM3-associated kinases STK24 and STK25 (serine/threonine kinases 24 and 25), and the in vitro model of human endothelial cells in which expression of STK24 and STK25 was inhibited by RNA interference. RESULTS: Mice deficient for both Stk24 and Stk25, but not for either of them individually, developed aggressive vascular lesions with the characteristics of cavernomas at an early age. Stk25 deficiency also gave rise to vascular anomalies in the context of Stk24 heterozygosity. Human endothelial cells deficient for both kinases phenocopied several of the consequences of CCM3 loss, and single STK25 deficiency also induced KLF2 expression, Golgi dispersion, altered distribution of ß-catenin, and appearance of stress fibers. CONCLUSIONS: The CCM3-associated kinases STK24 and STK25 play a major role in the inhibition of cavernoma development.

Inhibition of carnitine palmitoyltransferase 1A in hepatic stellate cells protects against fibrosis.

BACKGROUND & AIMS: The pathogenesis of liver fibrosis requires activation of hepatic stellate cells (HSCs); once activated, HSCs lose intracellular fatty acids but the role of fatty acid oxidation and carnitine palmitoyltransferase 1A (CPT1A) in this process remains largely unexplored. METHODS: CPT1A was found in HSCs of patients with fibrosis. Pharmacological and genetic manipulation of CPT1A were performed in human HSC cell lines and primary HCSs. Finally, we induced fibrosis in mice lacking CPT1A specifically in HSCs. RESULTS: Herein, we show that CPT1A expression is elevated in HSCs of patients with non-alcoholic steatohepatitis, showing a positive correlation with the fibrosis score. This was corroborated in rodents with fibrosis, as well as in primary human HSCs and LX-2 cells activated by transforming growth factor ß1 (TGFß1) and fetal bovine serum (FBS). Furthermore, both pharmacological and genetic silencing of CPT1A prevent TGFß1- and FBS-induced HSC activation by reducing mitochondrial activity. The overexpression of CPT1A, induced by saturated fatty acids and reactive oxygen species, triggers mitochondrial activity and the expression of fibrogenic markers. Finally, mice lacking CPT1A specifically in HSCs are protected against fibrosis induced by a choline-deficient high-fat diet, a methionine- and choline-deficient diet, or treatment with carbon tetrachloride. CONCLUSIONS: These results indicate that CPT1A plays a critical role in the activation of HSCs and is implicated in the development of liver fibrosis, making it a potentially actionable target for fibrosis treatment. LAY SUMMARY: We show that the enzyme carnitine palmitoyltransferase 1A (CPT1A) is elevated in hepatic stellate cells (HSCs) in patients with fibrosis and mouse models of fibrosis, and that CPT1A induces the activation of these cells. Inhibition of CPT1A ameliorates fibrosis by preventing the activation of HSCs.

The L-α-Lysophosphatidylinositol/G Protein-Coupled Receptor 55 System Induces the Development of Nonalcoholic Steatosis and Steatohepatitis.

BACKGROUND AND AIMS: G protein-coupled receptor (GPR) 55 is a putative cannabinoid receptor, and l-α-lysophosphatidylinositol (LPI) is its only known endogenous ligand. Although GPR55 has been linked to energy homeostasis in different organs, its specific role in lipid metabolism in the liver and its contribution to the pathophysiology of nonalcoholic fatty liver disease (NAFLD) remains unknown. APPROACH AND RESULTS: We measured (1) GPR55 expression in the liver of patients with NAFLD compared with individuals without obesity and without liver disease, as well as animal models with steatosis and nonalcoholic steatohepatitis (NASH), and (2) the effects of LPI and genetic disruption of GPR55 in mice, human hepatocytes, and human hepatic stellate cells. Notably, we found that circulating LPI and liver expression of GPR55 were up-regulated in patients with NASH. LPI induced adenosine monophosphate-activated protein kinase activation of acetyl-coenzyme A carboxylase (ACC) and increased lipid content in human hepatocytes and in the liver of treated mice by inducing de novo lipogenesis and decreasing ß-oxidation. The inhibition of GPR55 and ACCα blocked the effects of LPI, and the in vivo knockdown of GPR55 was sufficient to improve liver damage in mice fed a high-fat diet and in mice fed a methionine-choline-deficient diet. Finally, LPI promoted the initiation of hepatic stellate cell activation by stimulating GPR55 and activation of ACC. CONCLUSIONS: The LPI/GPR55 system plays a role in the development of NAFLD and NASH by activating ACC.

Acute intraocular toxicity caused by perfluorocarbon liquids: safety control systems of medical devices.

BACKGROUND: Acute retinal toxicity has been demonstrated to be associated with the intraoperative use of perfluorocarbon liquids (PFCLs), especially perfluorooctane (PFO). Recently, several cases of PFO-associated blindness have been reported in Spain, Holland, France, Italy, the Middle East, and South America. METHODS: As a result, a new ISO guideline (ISO 16672:2020) was drafted, discussed, approved, and released in 2019. This recent ISO16672:2020 guideline recommends performing direct cytotoxicity tests as an option along with chemical analysis to measure PFCL quality (purity and safety). RESULTS: In this review paper, it has been emphasized why an appropriate biological test, specifically direct exposure of PFCL to live cells, for measuring cytotoxicity must be performed with each PFCL batch along with chemical analysis. CONCLUSIONS: The paper intends to compile all available information to discuss possible approaches for avoiding adverse clinical cases in future.

[Infectious Disease Prevention Group: Update on vaccines, 2022]. / Prevención de las enfermedades infecciosas. Actualización en vacunas PAPPS 2022.

The update of the preventive activities for this year 2022 in the field of infectious diseases is of special relevance due to the importance that prevention has gained and more specifically, vaccination as a tool to control the pandemic caused by the SARS-CoV-2 virus declared on March 11, 2020. The pandemic has focused much of the prevention efforts on its containment, but the importance of maintaining high vaccination coverage of the rest of the recommended vaccines to maintain good control of vaccine-preventable diseases and avoid complications in particularly vulnerable patients should not be forgotten. In this year's review we present a practical document with the aim of providing tools to primary care professionals who work with adults, to make the indication of each vaccine whether it is systematically recommended or if it is because the patient belongs to some risk group due to their condition or underlying pathology. In this way, throughout the document, we will comment on the most innovative aspects of systematic vaccination (flu, pneumococcus, meningococcal vaccines and vaccines against the human papillomavirus [HPV]), the new vaccines (pandemic vaccines against COVID-19, vaccines against herpes zoster of subunits, vaccines against monkeypox) and the recommended vaccines according to risk condition (pregnancy and lactation, travelers, patients with immunosuppression or underlying pathology).

Secondary Nummular Headache: A New Case Series and Review of the Literature.

BACKGROUND: Nummular headache (NH) is defined in the International Classification of Headache Disorders (ICHD) by the presence of localized pain circumscribed to a small round area of the scalp, not better accounted by any other diagnosis. As in many other primary headache disorders, secondary cases might occur. To date, 13 secondary cases have been published. We aim to present a long series of secondary NH and review the literature of symptomatic NH. PATIENTS AND METHODS: Retrospective analysis of an observational prospective cohort in a headache unit located in a tertiary hospital. We included patients that fulfilled ICHD criteria and were attributed to a secondary cause. We describe the clinical characteristics, the underlying causes, and the response to treatment. RESULTS: We included 274 NH patients; eight of them (2.9%) were considered secondary. In one patient the underlying cause was subcutaneous, as for six cases the lesion was located in the bone (two hemangiomas, one osteoma, three different types of cysts), and in one was intracranial but closely related with internal diploe (cavernoma). Among our patients with secondary NH, a preventive therapy was not always needed and, when required, gabapentin or onabotulinumtoxinA were used with positive response. CONCLUSIONS: Secondary NH phenotype overlaps primary NH. Therefore, we recommend routine imaging study in every NH patient. Concerning treatment, it was not necessary to remove the underlying lesion to control the pain and many cases responded to the same prophylactics as primary NH cases.

Phenotypic characterization of acute headache attributed to SARS-CoV-2: An ICHD-3 validation study on 106 hospitalized patients.

INTRODUCTION: Headache is a common symptom of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In this study, we aimed to characterize the phenotype of headache attributed to SARS-CoV-2 infection and to test the International Classification of Headache Disorders (ICHD-3) phenotypic criteria for migraine and tension-type headache. METHODS: The study design was a cross-sectional study nested in a cohort. We screened all consecutive patients that were hospitalized and had a positive SARS-CoV-2 test. We included patients that described headache if the headache was not better explained by another ICHD-3 diagnosis. Patients were interviewed by two neurologists. RESULTS: We screened 580 patients and included 130 (mean age 56 years, 64% female). Headache was the first symptom of the infection in 26% of patients and appeared within 24 hours in 62% of patients. The headache was bilateral in 85%, frontal in 83%, and with pressing quality in 75% of patients. Mean intensity was 7.1, being severe in 64%. Hypersensitivity to stimuli occurred in 57% of patients. ICHD-3 criteria for headache attributed to systemic viral infection were fulfilled by 94% of patients; phenotypic criteria for migraine were fulfilled by 25% of patients, and tension-type headache criteria by 54% of patients. CONCLUSION: Headache attributed to SARS-CoV-2 infection in hospitalized patients has severe intensity, frontal predominance and oppressive quality. It occurs early in the course of the disease. Most patients fulfilled ICHD-3 criteria for headache attributed to systemic viral infection; however, the phenotype might resemble migraine in a quarter of cases and tension-type headache in half of the patients.

Chemical compounds causing severe acute toxicity in heavy liquids used for intraocular surgery.

Perfluorocarbon liquids (PFCLs) have been considered safe for intraocular manipulation of the retina, but since 2013 many cases of acute eye toxicity cousing blindness have been reported in various countries when using various commercial PFCLs. All these PFCLs were CE marked (Conformité Européenne), which meant they had been subjected to evaluation complying with the International Organization for Standardization (ISO) guidelines. These dramatic events raised questions about the safety of PFCLs and the validity of some cytotoxicity tests performed under ISO guidelines. Samples from toxic batches were analyzed by gas chromatography-mass spectrometry combined with Raman and infrared spectrometry. Perfluorooctanoic acid, dodecafluoro-1-heptanol, ethylbenzene and tributyltin bromide were identified and evaluated by a direct contact cytotoxicity test using ARPE-19 cell line, patented by our group (EP 3467118 A1). Perfluorooctanoic acid at a concentration of >0.06 mM and tributyltin bromide at a concentration of ≥0.016 mM were shown to be toxic, whereas the concentration found in the toxic samples reached 0.48 mM, and 0.111 mM, respectively. These finding emphasized the idea that determination of partially fluorinated compounds are not enough to guarantee the safety of these medical devices.

The Human Digestive Tract Is Capable of Degrading Gluten from Birth.

The human gastrointestinal system has the capacity to metabolize dietary gluten. The capacity to degrade gliadin-derived peptide is present in humans from birth and increases during the first stages of life (up to 6-12 months of age). Fecal samples from 151 new-born and adult non-celiac disease (NCD) volunteers were collected, and glutenase and glianidase activities were evaluated. The capacity of total fecal proteins to metabolize 33-mer, 19-mer, and 13-mer gliadin peptides was also evaluated by high-performance liquid chromatography (HPLC). Feces from new-borns (meconium) showed glutenase and gliadinase activities, and peptidase activity against all three gliadin peptides. Maximal gluten degradative activity was observed in fecal samples from the youngest volunteers (0-12 months old). After the age of nine months, the gluten digestive capacity of gastrointestinal tract decreases and, from ±8 years old, individuals lose the ability to completely degrade toxic peptides. The gastrointestinal proteases involved in gluten digestion: elastase 2A, elastase 3B, and carboxipeptidase A1 are present from earlier stages of life. The human digestive tract contains the proteins capable of metabolizing gluten from birth, even before starting gluten intake. Humans are born with the ability to digest gluten and to completely degrade the potentially toxic gliadin-derived peptides (33-, 19-, and 13-mer).

[Infectious Disease Prevention Group. Update on vaccines, 2020]. / Prevención de las enfermedades infecciosas. Actualización en vacunas, 2020.

Vaccine development is one of the fastest growing sectors in medicine now and in the future, as we are living with the emergency health care for the SARS-CoV-2 coronavirus. The semFYC PAPPS program biannually publishes the recommendations of the group and, in this edition, special emphasis is placed on the common vaccination proposed by the Ministry of Health, where, at last, it no longer discriminates between paediatrics and adults, and proposes a calendar throughout life. The main novelties in the field of vaccinology today are focused on the consolidation of the nonavalent vaccine against the human papilloma virus and in the change of the dose of monovalent meningitis vaccine C for the tetravalent one, ACWY, at age 12. The pandemic we are experiencing has led to the postponement of most preventive activities. On the return to «normality¼, the vaccination calendar must be examined, and completed if necessary.

The MST3/STK24 kinase mediates impaired fasting blood glucose after a high-fat diet.

AIMS/HYPOTHESIS: The identification of mediators in the pathogenesis of type 2 diabetes mellitus is essential for the full understanding of this disease. Protein kinases are especially important because of their potential as pharmacological targets. The goal of this study was to investigate whether mammalian sterile-20 3 (MST3/STK24), a stress-regulated kinase, is involved in metabolic alterations in obesity. METHODS: Glucose regulation of Mst3 (also known as Stk24)-knockout mice was analysed both in 129;C57 mixed background mice and in C57/BL6J mice fed normally or with a high-fat diet (HFD). This work was complemented with an analysis of the insulin signalling pathway in cultured human liver cells made deficient in MST3 using RNA interference. RESULTS: MST3 is phosphorylated in the livers of mice subject to an obesity-promoting HFD, and its deficiency lowers the hyperglycaemia, hyperinsulinaemia and insulin resistance that the animals develop with this diet, an effect that is seen even without complete inactivation of the kinase. Lack of MST3 results in activation of the insulin signalling pathway downstream of IRS1, in both cultured liver cells and the liver of animals after HFD. This effect increases the inhibition of forkhead box (FOX)O1, with subsequent downregulation of the expression of gluconeogenic enzymes. CONCLUSIONS/INTERPRETATION: MST3 inhibits the insulin signalling pathway and is important in the development of insulin resistance and impaired blood glucose levels after an HFD.

Low-alcohol Beers: Flavor Compounds, Defects, and Improvement Strategies.

Beer consumers are accustomed to a product that offers a pleasant and well-defined taste. However, in alcohol-free and alcohol-reduced beers these characteristics are totally different from those in regular beer. Therefore, it is important to evaluate and determine the different flavor compounds that affect organoleptic characteristics to obtain a product that does not contain off-flavors, or taste of grass or wort. The taste defects in alcohol-free beer are mainly attributed to loss of aromatic esters, insufficient aldehydes, reduction or loss of different alcohols, and an indeterminate change in any of its compounds during the dealcoholization process. The dealcoholization processes that are commonly used to reduce the alcohol content in beer are shown, as well as the negative consequences of these processes to beer flavor. Possible strategies to circumvent such negative consequences are suggested.

Clostridium difficile isolates with high linezolid MICs harbor the multiresistance gene cfr.

We studied the molecular mechanisms of linezolid resistance in 9 isolates of toxigenic Clostridium difficile with high linezolid MICs. The activity of linezolid was determined against 891 clinical isolates of toxigenic C. difficile. The MIC50 and MIC90 of linezolid were 0.75 µg/ml and 1.5 µg/ml, respectively. Nine strains (1%) showed high linezolid MICs (6 µg/ml to 16 µg/ml) and also were resistant to clindamycin, erythromycin, and chloramphenicol. These strains were selected for molecular studies: sequencing of domain V of the 23 rRNA gene, detection of the cfr methyltransferase gene, and sequencing of the ribosomal protein genes rplC and rplD. Molecular relatedness between strains was assessed using PCR ribotyping and MLVA (multilocus variable-number tandem-repeat analysis) typing. The strains belonged to ribotypes 001 (2/9), 017 (6/9), and 078 (1/9). MLVA showed that strains of ribotype 001 and 017 belonged to the same clonal complex in each ribotype. We did not detect mutations in the 23S rRNA gene. The cfr gene was detected in 7 of 9 strains. Sequencing of cfr amplicons revealed a similarity of 100% to a fragment of transposon Tn6218 of C. difficile, which was annotated as a putative chloramphenicol/florfenicol resistance protein. We were unable to detect mechanisms of resistance to linezolid in the 2 strains belonging to ribotype 001. While the relevance of our results lies in the detection of the cfr gene as a possible mechanism of resistance to linezolid in C. difficile, our findings should be assessed by further investigations to characterize these possible cfr genes and their contribution to linezolid resistance.

New trends in beer flavour compound analysis.

As the beer market is steadily expanding, it is important for the brewing industry to offer consumers a product with the best organoleptic characteristics, flavour being one of the key characteristics of beer. New trends in instrumental methods of beer flavour analysis are described. In addition to successfully applied methods in beer analysis such as chromatography, spectroscopy, nuclear magnetic resonance, mass spectrometry or electronic nose and tongue techniques, among others, sample extraction and preparation such as derivatization or microextraction methods are also reviewed.

First case of autochthonous Clostridium difficile PCR ribotype 027 detected in Spain.

INTRODUCTION: Clostridium difficile ribotype 027 (Cd027) has caused outbreaks in the United States, Canada, and Europe since 2001. In Spain, the importance of Cd027 is still unknown. In 2007, we began active surveillance of Cd027 to determine its incidence in our hospital. METHODS: From January 2007 to April 2012, isolates of C. difficile by multiplex PCR were studied to detect toxin genes. Binary toxin-positive isolates were characterized using PCR-ribotyping. Cd027 were further characterized by toxino-typing, sequencing of tcdC gene, and MLVA (multilocus-variable-number-tandem-repeat-analysis). RESULTS: Only 8 strains were Cd027 from 3666 isolates of C. difficile analyzed during the study period. These strains were isolated from 4 patients: a Spanish patient previously hospitalized in the UK, a pregnant laboratory technician, a British tourist, and a Spanish patient without epidemiological antecedents for acquiring Cd027. MLVA typing of Cd027 isolates revealed 4 different patterns. The first patient had 2 episodes of diarrhea caused by different Cd027. The strains from the first episode of patient 1 and the strain from patient 2 were grouped in the same clonal cluster (these cases were previously published as laboratory transmission), while strains from patients 3 and 4 were genetically unrelated to each other, and to the strains from patients 1 and 2. CONCLUSION: We report the first finding of an autochthonous case of non-severe Cd027 infection. Our results indicate that Cd027 diarrhea is uncommon in our area, and it appears mainly as imported cases. MLVA typing enables us to distinguish different genotypes among our Cd027 isolates.

Visualization and Identification of Silicone Oil Emulsification Using Dynamic Infrared Confocal Scanning Laser Ophthalmoscopy.

Introduction: Silicone oil (SO) is a crucial agent used as an intraocular tamponade in the treatment of complex vitreoretinal diseases. Despite its effectiveness, SO is prone to emulsification, which can lead to significant and sometimes irreversible complications in both the anterior and posterior segments of the eye. The detection and monitoring of SO emulsification are therefore of paramount importance. Traditional imaging modalities have limitations in visualizing SO, leading to the exploration of more advanced imaging techniques. This study introduces the application of dynamic infrared confocal scanning laser ophthalmoscopy (IRcSLO) for this purpose and evaluates its effectiveness. Case Presentation: We report on 2 patients who underwent pars plana vitrectomy with subsequent SO injection for the management of retinal detachment. Postsurgery, both patients were imaged using the Heidelberg Retina Tomography Spectralis IRcSLO. The focus was on the visualization of the SO status, including the presence and distribution of emulsified SO droplets. The IRcSLO imaging technique demonstrated its capability to effectively visualize emulsified SO droplets. Interestingly, this was also true for cases where the SO had been removed. The emulsified droplets were observed as micron-sized, spherical entities with a nonuniform distribution throughout the vitreous cavity. Conclusion: Dynamic IRcSLO has proven to be an effective imaging modality for visualizing the emulsification of SO, offering a novel perspective into the characterization of SO droplets. It facilitates the analysis of droplet count, motility, and precise localization within the vitreous cavity. The findings from the case presentations underscore the variability of SO emulsification patterns and the sensitivity of IRcSLO in detecting even minuscule emulsified droplets. This imaging technique has significant potential for future research, particularly in understanding the timing of emulsification, the factors contributing to it, and the development of possible preventive strategies. Additionally, it allows for a more in-depth analysis of the behavior of emulsified SO droplets across different SO viscosities, which could be instrumental in optimizing patient outcomes.

Adaptor protein cerebral cavernous malformation 3 (CCM3) mediates phosphorylation of the cytoskeletal proteins ezrin/radixin/moesin by mammalian Ste20-4 to protect cells from oxidative stress.

While studying the functions of CCM3/PDCD10, a gene encoding an adaptor protein whose mutation results in vascular malformations, we have found that it is involved in a novel response to oxidative stress that results in phosphorylation and activation of the ezrin/radixin/moesin (ERM) family of proteins. This phosphorylation protects cells from accidental cell death induced by oxidative stress. We also present evidence that ERM phosphorylation is performed by the GCKIII kinase Mst4, which is activated and relocated to the cell periphery after oxidative stress. The cellular levels of Mst4 and its activation after oxidative stress depend on the presence of CCM3, as absence of the latter impairs the phosphorylation of ERM proteins and enhances death of cells exposed to reactive oxygen species. These findings shed new light on the response of cells to oxidative stress and identify an important pathophysiological situation in which ERM proteins and their phosphorylation play a significant role.