Pharmacological Activation of SIRT3 Modulates the Response of Cancer Cells to Acidic pH.

Cancer cells modulate their metabolism, creating an acidic microenvironment that, in turn, can favor tumor progression and chemotherapy resistance. Tumor cells adopt strategies to survive a drop in extracellular pH (pHe). In the present manuscript, we investigated the contribution of mitochondrial sirtuin 3 (SIRT3) to the adaptation and survival of cancer cells to a low pHe. SIRT3-overexpressing and silenced breast cancer cells MDA-MB-231 and human embryonic kidney HEK293 cells were grown in buffered and unbuffered media at pH 7.4 and 6.8 for different times. mRNA expression of SIRT3 and CAVB, was measured by RT-PCR. Protein expression of SIRT3, CAVB and autophagy proteins was estimated by western blot. SIRT3-CAVB interaction was determined by immunoprecipitation and proximity ligation assays (PLA). Induction of autophagy was studied by western blot and TEM. SIRT3 overexpression increases the survival of both cell lines. Moreover, we demonstrated that SIRT3 controls intracellular pH (pHi) through the regulation of mitochondrial carbonic anhydrase VB (CAVB). Interestingly, we obtained similar results by using MC2791, a new SIRT3 activator. Our results point to the possibility of modulating SIRT3 to decrease the response and resistance of tumor cells to the acidic microenvironment and ameliorate the effectiveness of anticancer therapy.

Ultrastructural Changes of Neuroendocrine Pheochromocytoma Cell Line PC-12 Exposed In Vitro to Rotenone.

Rotenone is a pesticide used in research for its ability to induce changes similar, in vivo and in vitro, to those observed in Parkinson's disease (PD). This includes a selective death of dopaminergic neurons in the substantia nigra. Nonetheless, the precise mechanism through which rotenone modifies structure and function of neurons remains unclear. The PC12 cells closely resemble dopamine terminal neurons. This makes it a preferred model for studying the morphology of central dopamine neurons and predicting neurotoxicity. In this paper, we investigated the effects of 0.5 µM rotenone for 24-48 h on PC12 cell viability and ultrastructure (TEM), trying to identify primary and more evident alterations that can be related to neuronal damages similar to that seen in animal PD models. Cell viability decreased after 24 h rotenone treatment, with a further decrease after 48 h. Ultrastructural changes included vacuolar degeneration, mitochondrial mild swelling, decrease in the number of neuropeptide granules, and the loss of cell-to-cell adhesion. These findings are in agreement with previous research suggesting that rotenone, by inhibiting energy production and increasing ROS generation, is responsible for significant alterations of the ultrastructure and cell death of PC12 cells. Our data confirm the link between rotenone exposure, neuronal damage, and changes in dopamine metabolism, suggesting its role in the pathogenesis of PD.

Long-Term Clinical-Pathologic Results of Enzyme Replacement Therapy in Prehypertrophic Fabry Disease Cardiomyopathy.

BACKGROUND: The limited ability of enzyme replacement therapy (ERT) in removing globotriaosylceramide from cardiomyocytes is recognized for advanced Fabry disease cardiomyopathy (FDCM). Prehypertrophic FDCM is believed to be cured or stabilized by ERT. However, no pathologic confirmation is available. We report here on the long-term clinical-pathologic impact of ERT on prehypertrophic FDCM. METHODS AND RESULTS: Fifteen patients with Fabry disease with left ventricular maximal wall thickness ≤10.5 mm at cardiac magnetic resonance required endomyocardial biopsy because of angina and ventricular arrhythmias. Endomyocardial biopsy showed coronary small-vessel disease in the angina cohort, and vacuoles in smooth muscle cells and cardiomyocytes ≈20% of the cell surface containing myelin bodies at electron microscopy. Patients received α-agalsidase in 8 cases, and ß-agalsidase in 7 cases. Both groups experienced symptom improvement except 1 patients treated with α-agalsidase and 1 treated with ß-agalsidase. After ERT administration ranging from 4 to 20 years, all patients had control cardiac magnetic resonance and left ventricular endomyocardial biopsy because of persistence of symptoms or patient inquiry on disease resolution. In 13 asymptomatic patients with FDCM, left ventricular maximal wall thickness and left ventricular mass, cardiomyocyte diameter, vacuole surface/cell surface ratio, and vessels remained unchanged or minimally increased (left ventricular mass increased by <2%) even after 20 years of observation, and storage material was still present at electron microscopy. In 2 symptomatic patients, FDCM progressed, with larger and more engulfed by globotriaosylceramide myocytes being associated with myocardial virus-negative lymphocytic inflammation. CONCLUSIONS: ERT stabilizes storage deposits and myocyte dimensions in 87% of patients with prehypertrophic FDCM. Globotriaosylceramide is never completely removed even after long-term treatment. Immune-mediated myocardial inflammation can overlap, limiting ERT activity.

A numerical analysis of ventilation motion after chest surgery with a RESPIRholter device.

This case report presents a numerical evaluation of respiration in terms of biomechanical parameters of chest motion. This experimental evaluation is performed with RESPIRholter, a wearable device specifically developed to monitor the movement in the ribcage through the motion of the sixth rib whose characteristic motion is considered as representative of the motion of the thorax. Here we present test results acquired with a RESPIRholter device in a 6-h acquisition. These results characterize respiration biomechanics for diagnostic purposes in a chest surgery patient, highlighting the diagnostic utility of RESPIRholter in the identification of post-operation respiratory problem.

Infertility in Fabry's Disease: role of hypoxia and inflammation in determining testicular damage.

Introduction: Fabry's disease (FD) is a genetic X-linked systemic and progressive rare disease characterized by the accumulation of globotriaosylceramide (GB3) into the lysosomes of many tissues. FD is due to loss-of-function mutations of α-galactosidase, a key-enzyme for lysosomal catabolism of glycosphingolipids, which accumulate as glycolipid bodies (GB). In homozygous males the progressive deposition of GB3 into the cells leads to clinical symptoms in CNS, skin, kidney, etc. In testis GB accumulation causes infertility and alterations of spermatogenesis. However, the precise damaging mechanism is still unknown. Our hypothesis is that GB accumulation reduces blood vessel lumen and increases the distance of vessels from both stromal cells and seminiferous parenchyma; this, in turn, impairs oxygen and nutrients diffusion leading to subcellular degradation of seminiferous epithelium and sterility. Methods: To test this hypothesis, we have studied a 42-year-old patient presenting a severe FD and infertility, with reduced number of spermatozoa, but preserved sexual activity. Testicular biopsies were analyzed by optical (OM) and transmission electron microscopy (TEM). Activation and cellular localization of HIF-1α and NFκB was analyzed by immunofluorescence (IF) and RT-PCR on homogeneous tissue fractions after laser capture microdissection (LCMD). Results: OM and TEM showed that GB were abundant in vessel wall cells and in interstitial cells. By contrast, GB were absent in seminiferous epithelium, Sertoli's and Leydig's cells. However, seminiferous tubular epithelium and Sertoli's cells showed reduced diameter, thickening of basement membrane and tunica propria, and swollen or degenerated spermatogonia. IF showed an accumulation of HIF-1α in stromal cells but not in seminiferous tubules. On the contrary, NFκB fluorescence was evident in tubules, but very low in interstitial cells. Finally, RT-PCR analysis on LCMD fractions showed the expression of pro-inflammatory genes connected to the HIF-1α/NFκB inflammatory-like pathway. Conclusion: Our study demonstrates that infertility in FD may be caused by reduced oxygen and nutrients due to GB accumulation in blood vessels cells. Reduced oxygen and nutrients alter HIF-1α/NFκB expression and localization while activating HIF-1α/NFκB driven-inflammation-like response damaging seminiferous tubular epithelium and Sertoli's cells.

Doxorubicin-Induced Cardiac Senescence Is Alleviated Following Treatment with Combined Polyphenols and Micronutrients through Enhancement in Mitophagy.

Oxidative stress and impaired mitophagy are the hallmarks of cardiomyocyte senescence. Specifically, a decrease in mitophagic flux leads to the accumulation of damaged mitochondria and the development of senescence through increased ROS and other mediators. In this study, we describe the preventive role of A5+, a mix of polyphenols and other micronutrients, in doxorubicin (DOXO)-induced senescence of H9C2 cells. Specifically, H9C2 cells exposed to DOXO showed an increase in the protein expression proteins of senescence-associated genes, p21 and p16, and a decrease in the telomere binding factors TRF1 and TRF2, indicative of senescence induction. Nevertheless, A5+ pre-treatment attenuated the senescent-like cell phenotype, as evidenced by inhibition of all senescent markers and a decrease in SA-ß-gal staining in DOXO-treated H9C2 cells. Importantly, A5+ restored the LC3 II/LC3 I ratio, Parkin and BNIP3 expression, therefore rescuing mitophagy, and decreased ROS production. Further, A5+ pre-treatment determined a ripolarization of the mitochondrial membrane and improved basal respiration. A5+-mediated protective effects might be related to its ability to activate mitochondrial SIRT3 in synergy with other micronutrients, but in contrast with SIRT4 activation. Accordingly, SIRT4 knockdown in H9C2 cells further increased MnSOD activity, enhanced mitophagy, and reduced ROS generation following A5+ pre-treatment and DOXO exposure compared to WT cells. Indeed, we demonstrated that A5+ protects H9C2 cells from DOXO-induced senescence, establishing a new specific role for A5+ in controlling mitochondrial quality control by restoring SIRT3 activity and mitophagy, which provided a molecular basis for the development of therapeutic strategies against cardiomyocyte senescence.

Hypertrophic obstructive cardiomyopathy caused by Fabry disease: implications for surgical myectomy.

Hypertrophic obstructive cardiomyopathy can be the phenotype of storage disorders as Fabry disease cardiomyopathy. In this instance, its recognition through GLA gene analysis and preventive administration of enzyme replacement therapy may reduce heart failure risk of surgical septal myectomy (SSM). A 59-year-old man was referred for SSM as dyspnoea and low threshold muscle fatigue associated to severe left ventricular outflow obstruction (gradient of 100 mmHg) due to both interventricular septal hypertrophy and mitral leaflet systolic anterior motion were not controlled by metoprolol 100 mg bid. Electrocardiogram showed sinus rhythm and a complete left bundle branch block. Cardiac magnetic resonance imaging showed a preserved left ventricular (LV) contractility (ejection fraction 70%) but failed to reveal reduced T1 mapping and fibrosis of postero-lateral LV wall suggesting Fabry disease cardiomyopathy. Cardiac catheterization and coronary angiography documented increased LV end-diastolic pressure but normal coronary arteries. SSM was followed by acute renal and heart failure with left ventricular ejection fraction declining to 35%. Histology of SSM showed regularly arranged severely enlarged cardiomyocytes containing extensive vacuoles that were intensely positive to immunofluorescence with anti-Gb3 antibodies and appeared at electron microscopy to consist of myelin bodies suggesting the diagnosis of FD. This entity was confirmed by low blood levels of alpha-galactosidase A (0.8 nmol/mL/h; NV > 1), high values of Lyso-Gb3 (5.85 nmol/L; NV < 2.3), and the presence of the pathogenic mutation c.644A>G in the exon 5 of GLA gene. This study emphasizes the importance of a genetic screening for FD before SSM be considered for hypertrophic obstructive cardiomyopathy.

SIRT5 Activation and Inorganic Phosphate Binding Reduce Cancer Cell Vitality by Modulating Autophagy/Mitophagy and ROS.

Cancer cells show increased glutamine consumption. The glutaminase (GLS) enzyme controls a limiting step in glutamine catabolism. Breast tumors, especially the triple-negative subtype, have a high expression of GLS. Our recent study demonstrated that GLS activity and ammonia production are inhibited by sirtuin 5 (SIRT5). We developed MC3138, a selective SIRT5 activator. Treatment with MC3138 mimicked the deacetylation effect mediated by SIRT5 overexpression. Moreover, GLS activity was regulated by inorganic phosphate (Pi). Considering the interconnected roles of GLS, SIRT5 and Pi in cancer growth, our hypothesis is that activation of SIRT5 and reduction in Pi could represent a valid antitumoral strategy. Treating cells with MC3138 and lanthanum acetate, a Pi chelator, decreased cell viability and clonogenicity. We also observed a modulation of MAP1LC3B and ULK1 with MC3138 and lanthanum acetate. Interestingly, inhibition of the mitophagy marker BNIP3 was observed only in the presence of MC3138. Autophagy and mitophagy modulation were accompanied by an increase in cytosolic and mitochondrial reactive oxygen species (ROS). In conclusion, our results show how SIRT5 activation and/or Pi binding can represent a valid strategy to inhibit cell proliferation by reducing glutamine metabolism and mitophagy, leading to a deleterious accumulation of ROS.

Circulating Anti-GB3 Antibody as a Biomarker of Myocardial Inflammation in Patients with Fabry Disease Cardiomyopathy.

BACKGROUND: Fabry disease cardiomyopathy (FDCM) has manifested some resistance to enzyme replacement therapy (ERT), particularly in its advanced phase. Recently, myocardial inflammation of autoimmune origin has been demonstrated in FDCM. AIMS: The objective of this study was the assessment of circulating anti-globotriaosylceramide (GB3) antibodies as potential biomarkers of myocardial inflammation in FDCM, defined by the additional presence of ≥CD3+ 7 T lymphocytes/low-power field associated with focal necrosis of adjacent myocytes. Its sensitivity was based on the evidence of overlapping myocarditis at left ventricular endomyocardial biopsy. METHODS AND RESULTS: From January 1996 to December 2021, 85 patients received a histological diagnosis of FDCM in our department and 48 (56.5%) of them had an overlapping myocardial inflammation with negative PCR for common cardiotropic viruses, positive antiheart, and antimyosin abs. The presence of anti-GB3 antibodies was evaluated with an in-house ELISA assay (BioGeM scarl Medical Investigational Research, MIR-Ariano Irpino, Italy), along with antiheart and antimyosin abs, in the FDCM patients and compared with control healthy individuals. The correlation between levels of circulating anti-GB3 autoantibody myocardial inflammation and FDCM severity was assessed. Anti-Gb3 antibodies were above the positivity cut-off in 87.5% of FDCM subjects with myocarditis (42 out of 48), while 81.1% of FDCM patients without myocarditis were identified as negative for Gb3 antibodies. Positive anti-Gb3 abs correlated with positive antiheart and antimyosin abs. CONCLUSIONS: The present study suggests a potential positive role of anti-GB3 antibodies as a marker of overlapping cardiac inflammation in patients with FDCM.

Infiltration of Conduction Tissue Is a Major Cause of Electrical Instability in Cardiac Amyloidosis.

BACKGROUND: The pathology of conduction tissue (CT) and relative arrhythmias in living subjects with cardiac amyloid have never been reported. AIMS: To report CT pathology and its arrhythmic correlations in human cardiac amyloidosis. METHODS AND RESULTS: In 17 out of 45 cardiac amyloid patients, a left ventricular endomyocardial biopsy included conduction tissue sections. It was identified by Aschoff-Monckeberg histologic criteria and positive immunostaining for HCN4. The degree of conduction tissue infiltration was defined as mild when ≤30%, moderate when 30-70% and severe when >70% cell area was replaced. Conduction tissue infiltration was correlated with ventricular arrhythmias, maximal wall thickness and type of amyloid protein. Mild involvement was observed in five cases, moderate in three and severe in nine. Involvement was associated with a parallel infiltration of conduction tissue artery. Conduction infiltration correlated with the severity of arrhythmias (Spearman rho = 0.8, p < 0.001). In particular, major ventricular tachyarrhythmias requiring pharmacologic treatment or ICD implantation occurred in seven patients with severe, one patient with moderate and none with mild conduction tissue infiltration. Pacemaker implantation was required in three patients, with complete conduction section replacement. No significant correlation was observed between the degree of conduction infiltration and age, cardiac wall thickness or type of amyloid protein. CONCLUSIONS: Amyloid-associated cardiac arrhythmias correlate with the extent of conduction tissue infiltration. Its involvement is independent from type and severity of amyloidosis, suggesting a variable affinity of amyloid protein to conduction tissue.

An extensive review on phenolic compounds and their potential estrogenic properties on skin physiology.

Polyphenolic compounds constitute a diverse group of natural components commonly occurring in various plant species, known for their potential to exert both beneficial and detrimental effects. Additionally, these polyphenols have also been implicated as endocrine-disrupting (ED) chemicals, raising concerns about their widespread use in the cosmetics industry. In this comprehensive review, we focus on the body of literature pertaining to the estrogenic properties of ED chemicals, with a particular emphasis on the interaction of isoflavones with estrogen receptors. Within this review, we aim to elucidate the multifaceted roles and effects of polyphenols on the skin, exploring their potential benefits as well as their capacity to act as ED agents. By delving into this intricate subject matter, we intend to provoke thoughtful consideration, effectively opening a Pandora's box of questions for the reader to ponder. Ultimately, we invite the reader to contemplate whether polyphenols should be regarded as friends or foes in the realm of skincare and endocrine disruption.

First Evidence of Anti-Steatotic Action of Macrotympanain A1, an Amphibian Skin Peptide from Odorrana macrotympana.

Many different amphibian skin peptides have been characterized and proven to exert various biological actions, such as wound-healing, immunomodulatory, anti-oxidant, anti-inflammatory and anti-diabetic effects. In this work, the possible anti-steatotic effect of macrotympanain A1 (MA1) (FLPGLECVW), a skin peptide isolated from the Chinese odorous frog Odorrana macrotympana, was investigated. We used a well-established in vitro model of hepatic steatosis, consisting of lipid-loaded rat hepatoma FaO cells. In this model, a 24 h treatment with 10 µg/mL MA1 exerted a significant anti-steatotic action, being able to reduce intracellular triglyceride content. Accordingly, the number and diameter of cytosolic lipid droplets (LDs) were reduced by peptide treatment. The expression of key genes of hepatic lipid metabolism, such as PPARs and PLINs, was measured by real-time qPCR. MA1 counteracted the fatty acid-induced upregulation of PPARγ expression and increased PLIN3 expression, suggesting a role in promoting lipophagy. The present data demonstrate for the first time a direct anti-steatotic effect of a peptide from amphibian skin secretion and pave the way to further studies on the use of amphibian peptides for beneficial actions against metabolic diseases.

Removal of cardiac AL amyloid with positive remodelling of cardiomyocytes and of restrictive cardiomyopathy.

Herein, we describe histological mobilization of light chain cardiac amyloid documented by sequential left ventricular endomyocardial biopsies. These findings were associated with positive remodelling of cardiomyocytes and of restrictive cardiomyopathy resulting from 14 courses of chemotherapy over 17 years of time. Histological and ultrastructural findings of light chain cardiac amyloid removal led to increase in cardiomyocyte dimension and electrocardiogram voltages, reduction of biventricular wall thickness with improvement of left ventricular diastolic function, and NYHA class shifting from III to I.

Downregulation of Mannose-6-Phosphate Receptors in Fabry Disease Cardiomyopathy: A Potential Target for Enzyme Therapy Enhancement.

Background: The efficacy of enzyme replacement therapy (ERT) in mobilizing globotryaosylceramide (GB-3) from Fabry cardiomyocytes is limited. The mechanism involved is still obscure. Methods: Assessment of M6Pr, M6Pr-mRNA, and Ubiquitin has been obtained by Western blot analysis and real-time PCR of frozen endomyocardial biopsy samples, from 17 pts with FD, various degree of left ventricular hypertrophy, and maximal wall thickening (MWT) from 11.5 and 20 mm. The diagnosis and severity of FDCM followed definitions of GLA mutation, α-galactosidase A enzyme activity, cardiac magnetic resonance, and left ventricular endomyocardial biopsy with the quantification of myocyte hypertrophy and the extent of Gb-3 accumulation. All patients have received alpha or beta agalsidase for ≥3 years without a reduction in LV mass nor an increase in T1 mapping at CMR. Controls were surgical biopsies from 15 patients undergoing mitral valve replacement. Results: Protein analysis showed mean M6Pr in FDCM to be 5.4-fold lower than in a normal heart (4289 ± 6595 vs. 23,581 ± 4074, p = 0.0996) (p < 0.001): specifically, 9-fold lower in males, p = 0.009, (p < 0.001) and 3-fold lower in females, p = 0.5799, (p < 0.001) showing, at histology, a mosaic of normal and diseased cells. M6Pr-mRNA expression was normal, while ubiquitin showed an increase of 4.6 fold vs. controls (13,284 ± 1723 vs. 2870 ± 690, p = 0.001) suggesting that ubiquitin-dependent post-translational degradation is likely responsible for the reduction of M6Pr in FDCM. Conclusion: M6Pr expression is remarkably reduced in FDCM as a likely result of post-translational degradation. This may explain the reduced efficacy of ERT and be a therapeutic target for the enhancement of ERT activity.

Innovative In Vitro Strategy for Assessing Aluminum Bioavailability in Oral Care Cosmetics.

Aluminum is an element found in nature and in cosmetic products. It can interfere with the metabolism of other cations, thus inducing gastrointestinal disorder. In cosmetics, aluminum is used in antiperspirants, lipsticks, and toothpastes. The aim of this work is to investigate aluminum bioavailability after accidental oral ingestion derived from the use of a toothpaste containing a greater amount of aluminum hydroxide than advised by the Scientific Committee on Consumer Safety (SCCS). To simulate in vitro toothpaste accidental ingestion, the INFOGEST model was employed, and the amount of aluminum was measured through the ICP-AES analysis. Tissue barrier integrity was analyzed by measuring transepithelial electric resistance, and the tissue architecture was checked through light microscopy. The margin of safety was also calculated. Overall, our results indicate that the acute exposure to aluminum accidentally ingested from toothpastes is safe for the final user, even in amounts higher than SCCS indications.

Nicotine in Combination with SARS-CoV-2 Affects Cells Viability, Inflammatory Response and Ultrastructural Integrity.

The aims of our study are to: (i) investigate the ability of nicotine to modulate the expression level of inflammatory cytokines in A549 cells infected with SARS-CoV-2; (ii) elucidate the ultrastructural features caused by the combination nicotine+SARS-CoV-2; and (iii) demonstrate the mechanism of action. In this study, A549 cells pretreated with nicotine were either exposed to LPS or poly(I:C), or infected with SARS-CoV-2. Treated and untreated cells were analyzed for cytokine production, cytotoxicity, and ultrastructural modifications. Vero E6 cells were used as a positive reference. Cells pretreated with nicotine showed a decrease of IL6 and TNFα in A549 cells induced by LPS or poly(I:C). In contrast, cells exposed to SARS-CoV-2 showed a high increase of IL6, IL8, IL10 and TNFα, high cytopathic effects that were dose- and time-dependent, and profound ultrastructural modifications. These modifications were characterized by membrane ruptures and fragmentation, the swelling of cytosol and mitochondria, the release of cytoplasmic content in extracellular spaces (including osmiophilic granules), the fragmentation of endoplasmic reticulum, and chromatin disorganization. Nicotine increased SARS-CoV-2 cytopathic effects, elevating the levels of inflammatory cytokines, and inducing severe cellular damage, with features resembling pyroptosis and necroptosis. The protective role of nicotine in COVID-19 is definitively ruled out.

Immunosuppressive therapy in virus-negative inflammatory cardiomyopathy: 20-year follow-up of the TIMIC trial.

AIMS: Long-term results of the Tailored IMmunosuppression in virus-negative Inflammatory Cardiomyopathy (TIMIC) trial protocol have been evaluated. METHODS AND RESULTS: Eighty-five patients with endomyocardial biopsy-proven virus-negative chronic inflammatory cardiomyopathy were enrolled in the randomized, double-blind, placebo-controlled TIMIC trial and received prednisone and azathioprine (n = 43) vs. placebo (n = 42) for 6 months. Immunosuppressive treatment promoted an improvement in cardiac function in 88% of the cases compared with none of the patients in the placebo group, which were switched to a 6-month immunosuppressive therapy at the end of the 6-month study period. Long-term (up to 20 years) clinical outcomes of the whole cohort of 85 patients originally enrolled in the TIMIC trial (Group A) were compared with those of a 1:2 propensity score-matched control cohort of patients untreated with the TIMIC protocol (Group B) and followed for a comparable period of time. The primary outcome was a composite of cardiovascular death and heart transplantation. At long-term follow-up, the risk of cardiovascular death [hazard ratio (HR) 6.77; 95% confidence interval (CI) 2.36-19.45] and heart transplantation (HR 7.92; 95% CI 1.80-34.88) was significantly higher in Group B patients. Group A showed a persistent improvement in the left ventricular ejection fraction compared with Group B (HR 7.24; 95% CI 3.05-17.18). A higher number of Group B patients underwent implantable cardioverter defibrillator implantation. The incidence of recurrent myocarditis was similar between groups, and patients with evidence of a recurrent cardiac inflammatory process promptly responded to a TIMIC protocol application. CONCLUSION: Virus-negative inflammatory cardiomyopathy benefits from immunosuppressive therapy even after long-term follow-up. Recurrence appears to respond to a new TIMIC protocol application.

Sirtuins and Hypoxia in EMT Control.

Epithelial-mesenchymal transition (EMT), a physiological process during embryogenesis, can become pathological in the presence of different driving forces. Reduced oxygen tension or hypoxia is one of these forces, triggering a large number of molecular pathways with aberrant EMT induction, resulting in cancer and fibrosis onset. Both hypoxia-induced factors, HIF-1α and HIF-2α, act as master transcription factors implicated in EMT. On the other hand, hypoxia-dependent HIF-independent EMT has also been described. Recently, a new class of seven proteins with deacylase activity, called sirtuins, have been implicated in the control of both hypoxia responses, HIF-1α and HIF-2α activation, as well as EMT induction. Intriguingly, different sirtuins have different effects on hypoxia and EMT, acting as either activators or inhibitors, depending on the tissue and cell type. Interestingly, sirtuins and HIF can be activated or inhibited with natural or synthetic molecules. Moreover, recent studies have shown that these natural or synthetic molecules can be better conveyed using nanoparticles, representing a valid strategy for EMT modulation. The following review, by detailing the aspects listed above, summarizes the interplay between hypoxia, sirtuins, and EMT, as well as the possible strategies to modulate them by using a nanoparticle-based approach.