Pirfenidone Reverts Global DNA Hypomethylation, Promoting DNMT1/UHRF/PCNA Coupling Complex in Experimental Hepatocarcinoma.

Hepatocellular carcinoma (HCC) development is associated with altered modifications in DNA methylation, changing transcriptional regulation. Emerging evidence indicates that DNA methyltransferase 1 (DNMT1) plays a key role in the carcinogenesis process. This study aimed to investigate how pirfenidone (PFD) modifies this pathway and the effect generated by the association between c-Myc expression and DNMT1 activation. Rats F344 were used for HCC development using 50 mg/kg of diethylnitrosamine (DEN) and 25 mg/kg of 2-Acetylaminofluorene (2-AAF). The HCC/PFD group received simultaneous doses of 300 mg/kg of PFD. All treatments lasted 12 weeks. On the other hand, HepG2 cells were used to evaluate the effects of PFD in restoring DNA methylation in the presence of the inhibitor 5-Aza. Histopathological, biochemical, immunohistochemical, and western blot analysis were carried out and our findings showed that PFD treatment reduced the amount and size of tumors along with decreased Glipican-3, ß-catenin, and c-Myc expression in nuclear fractions. Also, this treatment improved lipid metabolism by modulating PPARγ and SREBP1 signaling. Interestingly, PFD augmented DNMT1 and DNMT3a protein expression, which restores global methylation, both in our in vivo and in vitro models. In conclusion, our results suggest that PFD could slow down HCC development by controlling DNA methylation.

Pirfenidone Protects from UVB-Induced Photodamage in Hairless Mice.

BACKGROUND: Ultraviolet radiation (UV) is the main environmental factor that causes histological degenerative changes of the skin giving rise to a chronic process called photodamage. Non-melanoma skin cancer induced by UVB radiation is a result of a cascade of molecular events caused by DNA damage in epidermis cells, including persistent inflammation, oxidative stress, and suppression of T cell-mediated immunity. Retinoids such as tretinoin have been widely used in skin to treat photoaging and photodamage, though its secondary adverse effects have been recognized. Pirfenidone (PFD) has emerged as an antifibrogenic, anti-inflammatory and antioxidant agent, and in this work its efficacy was evaluated in a model of UVB-induced photodamage. METHODS: Epidermal, dermal, and inflammatory changes were measured by histomorphometric parameters. In addition, gene, and protein expression of key molecules in these processes were evaluated. RESULTS: Our results revealed an anti-photodamage effect of topical PFD with absence of inflammatory skin lesions determined by dermoscopy. In addition, PFD reduced elastosis, improved organization, arrangement, and deposition of dermal collagens, downregulated several pro-inflammatory markers such as NF-kB, IL-1, IL-6 and TNFα, and decreased keratinocyte damage. CONCLUSION: Topical pirfenidone represents a promising agent for the treatment of cell photodamage in humans. Clinical trials need to be carried out to explore this premise.

Oxidative and Fibrinolytic Mechanisms: Two Important Processes to Consider in Platelet Storage

Objective: Platelet-rich plasma (PRP) is used in multiple coagulation disorders. Its therapeutic effectiveness relies on technical procedures related to PRP procurement and preservation because free radicals induce platelet activation and aging. This work aims to elucidate the oxidative mechanisms involved in activation of platelets obtained from PRP during storage. Materials and Methods: One hundred ten PRP batches were obtained from healthy donors and kept under stirring at a temperature of 20-24 °C. Protein extraction was performed from platelet homogenates and plasma at different times of storage from day 1 to 20. The activities of antioxidant markers such as catalase (CAT), superoxide dismutase, and ceruloplasmin, as well as fibrinolytic protein activity metalloproteases 2 and 3, plasmin, and urokinase plasminogen activator, were analyzed by zymography assays. Oxidized proteins were also determined. Results: Significant activity of antioxidant enzymes and fibrinolytic molecules was observed on day 5 of storage in PRP homogenates, which increased over time and was concomitantly correlated with oxidized protein levels. Reverse enzymatic activity patterns were observed in plasma, except for CAT, which remained unchanged. Conclusion: Storage conditions of platelets from PRP for up to 5 days induced in vitro platelet activation by oxidative damage and proteolysis. This finding confirms the need for proper management of these blood products to preserve their viability and functionality.

Moringa oleifera Improves MAFLD by Inducing Epigenetic Modifications.

BACKGROUND AND AIMS: Metabolic Associated Fatty Liver Disease (MAFLD) encompasses a spectrum of diseases from simple steatosis to nonalcoholic steatohepatitis (NASH). Here, we investigated the hepatoprotective role of Moringa oleifera aqueous extract on hepatic miRNAs, genes and protein expression, as well as histological and biochemical parameters in an experimental model of NASH. METHODS: Male C57BL/6J mice were fed with a high fat diet (HFD, 60% lipids, 42 gr/L sugar in water) for 16 weeks. Moringa extract was administered via gavage during the final 8 weeks. Insulin Tolerance Test (ITT) and HOMA-IR were calculated. Serum levels of insulin, resistin, leptin and PAI-1 and hepatic expression of miR-21a-5p, miR-103-3p, miR-122-5p, miR-34a-5p and SIRT1, AMPKα and SREBP1c protein were evaluated. Alpha-SMA immunohistochemistry and hematoxylin-eosin, Masson's trichrome and sirius red staining were made. Hepatic transcriptome was analyzed using microarrays. RESULTS: Animals treated with Moringa extract improved ITT and decreased SREBP1c hepatic protein, while SIRT1 increased. Hepatic expression of miR-21a-5p, miR-103-3p and miR-122-5p, miR34a-5p was downregulated. Hepatic histologic analysis showed in Moringa group (HF + MO) a significant decrease in inflammatory nodules, macro steatosis, fibrosis, collagen and αSMA reactivity. Analysis of hepatic transcriptome showed down expression of mRNAs implicated in DNA response to damage, endoplasmic reticulum stress, lipid biosynthesis and insulin resistance. Moringa reduced insulin resistance, de novo lipogenesis, hepatic inflammation and ER stress. CONCLUSIONS: Moringa prevented progression of liver damage in a model of NASH and improved biochemical, histological and hepatic expression of genes and miRNAs implicated in MAFLD/NASH development.

The Role of NRF2 in Obesity-Associated Cardiovascular Risk Factors.

The raising prevalence of obesity is associated with an increased risk for cardiovascular diseases (CVDs), particularly coronary artery disease (CAD), and heart failure, including atrial fibrillation, ventricular arrhythmias and sudden death. Obesity contributes directly to incident cardiovascular risk factors, including hyperglycemia or diabetes, dyslipidemia, and hypertension, which are involved in atherosclerosis, including structural and functional cardiac alterations, which lead to cardiac dysfunction. CVDs are the main cause of morbidity and mortality worldwide. In obesity, visceral and epicardial adipose tissue generate inflammatory cytokines and reactive oxygen species (ROS), which induce oxidative stress and contribute to the pathogenesis of CVDs. Nuclear factor erythroid 2-related factor 2 (NRF2; encoded by Nfe2l2 gene) protects against oxidative stress and electrophilic stress. NRF2 participates in the regulation of cell inflammatory responses and lipid metabolism, including the expression of over 1000 genes in the cell under normal and stressed environments. NRF2 is downregulated in diabetes, hypertension, and inflammation. Nfe2l2 knockout mice develop structural and functional cardiac alterations, and NRF2 deficiency in macrophages increases atherosclerosis. Given the endothelial and cardiac protective effects of NRF2 in experimental models, its activation using pharmacological or natural products is a promising therapeutic approach for obesity and CVDs. This review provides a comprehensive summary of the current knowledge on the role of NRF2 in obesity-associated cardiovascular risk factors.

Topical Pirfenidone-Loaded Liposomes Ophthalmic Formulation Reduces Haze Development after Corneal Alkali Burn in Mice.

Corneal chemical burns (CCBs) frequently result in corneal fibrosis or haze, an opacity of the cornea that obstructs vision and induces corneal blindness. Diverse strategies have been employed to prevent or reduce CCB-related corneal haze. In this study, we evaluated the physicochemical characteristics and biologic effects of a topical pirfenidone (PFD)-loaded liposomal formulation (PL) on a corneal alkali burn mice model. We found that PL was appropriate for ocular application due to its physiologic tear pH, osmolarity and viscosity suitable for topical ophthalmic use. Regarding its therapeutic activity, PL-treated mice had significantly reduced haze size and density, corneal edema, corneal thickness, and corneal inflammatory infiltration, in contrast to PFD in aqueous solution (p < 0.01). Importantly, the antifibrotic activity of PL (reduction of corneal haze) was associated with modulation of transforming growth factor (TGF)-ß and Interleukin (IL)-1ß genes. PL suppressed TGF-ß expression and restored normal IL-1ß expression in corneal tissue more efficiently in contrast to PFD in aqueous solution. In conclusion, PFD showed essential anti-inflammatory and anti-fibrotic effects in the treatment of alkali burns. Noteworthy, a new formulation of PFD-loaded liposomes remarkably improved these effects, standing out as a promising treatment for corneal haze.

Hepatocarcinogenesis Prevention by Pirfenidone Is PPARγ Mediated and Involves Modification of Nuclear NF-kB p65/p50 Ratio.

Targeted therapies for regulating processes such as inflammation, apoptosis, and fibrogenesis might modulate human HCC development. Pirfenidone (PFD) has shown anti-fibrotic and anti-inflammatory functions in both clinical and experimental studies. The aim of this study was to evaluate PPARγ expression and localization in samples of primary human tumors and assess PFD-effect in early phases of hepatocarcinogenic process. Human HCC tissue samples were obtained by surgical resection. Experimental hepatocarcinogenesis was induced in male Fischer-344 rats. TGF-ß1 and α-SMA expression was evaluated as fibrosis markers. NF-kB cascade, TNFα, IL-6, and COX-2 expression and localization were evaluated as inflammation indicators. Caspase-3, p53, and PARP-1 were used as apoptosis markers, PCNA for proliferation. Finally, PPARα and PPARγ expression were evaluated to understand the effect of PFD on the activation of such pathways. PPARγ expression was predominantly localized in cytoplasm in human HCC tissue. PFD was effective to prevent histopathological damage and TGF-ß1 and α-SMA overexpression in the experimental model. Anti-inflammatory effects of PFD correlate with diminished IKK and decrease in both IkB-phosphorylation/NF-kB p65 expression and p65-translocation into the nucleus. Pro-apoptotic PFD-induced effects are related with p53 expression, Caspase-3 p17 activation, and PARP-1-cleavage. In conclusion, PFD acts as a tumor suppressor by preventing fibrosis, reducing inflammation, and promoting apoptosis in MRHM.

PPARs as Metabolic Sensors and Therapeutic Targets in Liver Diseases.

Carbohydrates and lipids are two components of the diet that provide the necessary energy to carry out various physiological processes to help maintain homeostasis in the body. However, when the metabolism of both biomolecules is altered, development of various liver diseases takes place; such as metabolic-associated fatty liver diseases (MAFLD), hepatitis B and C virus infections, alcoholic liver disease (ALD), and in more severe cases, hepatocelular carcinoma (HCC). On the other hand, PPARs are a family of ligand-dependent transcription factors with an important role in the regulation of metabolic processes to hepatic level as well as in other organs. After interaction with specific ligands, PPARs are translocated to the nucleus, undergoing structural changes to regulate gene transcription involved in lipid metabolism, adipogenesis, inflammation and metabolic homeostasis. This review aims to provide updated data about PPARs' critical role in liver metabolic regulation, and their involvement triggering the genesis of several liver diseases. Information is provided about their molecular characteristics, cell signal pathways, and the main pharmacological therapies that modulate their function, currently engaged in the clinic scenario, or in pharmacological development.

Molecular Mechanisms of Obesity-Linked Cardiac Dysfunction: An Up-Date on Current Knowledge.

Obesity is defined as excessive body fat accumulation, and worldwide obesity has nearly tripled since 1975. Excess of free fatty acids (FFAs) and triglycerides in obese individuals promote ectopic lipid accumulation in the liver, skeletal muscle tissue, and heart, among others, inducing insulin resistance, hypertension, metabolic syndrome, type 2 diabetes (T2D), atherosclerosis, and cardiovascular disease (CVD). These diseases are promoted by visceral white adipocyte tissue (WAT) dysfunction through an increase in pro-inflammatory adipokines, oxidative stress, activation of the renin-angiotensin-aldosterone system (RAAS), and adverse changes in the gut microbiome. In the heart, obesity and T2D induce changes in substrate utilization, tissue metabolism, oxidative stress, and inflammation, leading to myocardial fibrosis and ultimately cardiac dysfunction. Peroxisome proliferator-activated receptors (PPARs) are involved in the regulation of carbohydrate and lipid metabolism, also improve insulin sensitivity, triglyceride levels, inflammation, and oxidative stress. The purpose of this review is to provide an update on the molecular mechanisms involved in obesity-linked CVD pathophysiology, considering pro-inflammatory cytokines, adipokines, and hormones, as well as the role of oxidative stress, inflammation, and PPARs. In addition, cell lines and animal models, biomarkers, gut microbiota dysbiosis, epigenetic modifications, and current therapeutic treatments in CVD associated with obesity are outlined in this paper.

Prolonged-release pirfenidone prevents obesity-induced cardiac steatosis and fibrosis in a mouse NASH model.

PURPOSE: Obesity is associated with systemic insulin resistance and cardiac hypertrophy with fibrosis. Peroxisome proliferator-activated receptors (PPARs) regulate carbohydrate and lipid metabolism, improving insulin sensitivity, triglyceride levels, inflammation, and oxidative stress. We previously demonstrated that prolonged-release pirfenidone (PR-PFD) is an agonistic ligand for Pparα with anti-inflammatory and anti-fibrotic effects, and might be a promising drug for cardiac diseases-treatment. Here, we investigated the effects of PR-PFD in ventricular tissue of mice with nonalcoholic steatohepatitis (NASH) and obesity induced by high-fat/high-carbohydrate (HFHC) diet. METHODS: Five male C57BL/6 J mice were fed with normal diet (ND) and ten with HFHC diet for 16 weeks; at 8 weeks of feeding, five mice with HFHC diet were administered PR-PFD (350 mg/kg/day) mixed with HFHC diet. RESULT: Systemic insulin resistance, heart weight/body weight ratio, myocardial steatosis with inflammatory foci, hypertrophy, and fibrosis were prevented by PR-PFD. In addition, HFHC mice showed significantly increased desmin, Tgfß1, Timp1, collagen I (Col I), collagen III (Col III), TNF-α, and Nrf2 mRNA levels, including α-SMA, NF-kB, Nrf2, troponin I, Acox1, Cpt1A, and Lxrα protein levels compared with the ND ventricular tissues. Mechanistically, HFHC mice with PR-PFD treatment significantly decreased these genes overexpressed by HFHC diet. Furthermore, PR-PFD overexpressed the Pgc1a mRNA levels and Pparα, Pparγ, Acox1, and Cpt1A protein levels. CONCLUSIONS: The results suggest that PR-PFD could be a promising drug for the prevention and treatment of cardiac steatosis and fibrosis induced by obesity.

Fibrosis regression is induced by AdhMMP8 in a murine model of chronic kidney injury.

Adenoviral vector AdhMMP8 (human Metalloproteinase-8 cDNA) administration has been proven beneficial in various experimental models of liver injury improving liver function and decreasing fibrosis. In this study, we evaluated the potential therapeutic AdhMMP8 effect in a chronic kidney damage experimental model. Chronic injury was induced by orogastric adenine administration (100mg/kg/day) to Wistar rats for 4 weeks. AdhMMP8 (3x1011vp/kg) was administrated in renal vein during an induced-ligation-ischemic period to facilitate kidney transduction causing no-additional kidney injury as determined by histology and serum creatinine. Animals were sacrificed at 7- and 14-days post-Ad injection. Fibrosis, histopathological features, serum creatinine (sCr), BUN, and renal mRNA expression of αSMA, Col-1α, TGF-ß1, CTGF, BMP7, IL-1, TNFα, VEGF and PAX2 were analyzed. Interestingly, AdhMMP8 administration resulted in cognate human MMP8 protein detection in both kidneys, whereas hMMP8 mRNA was detected only in the left kidney. AdhMMP8 significantly reduced kidney tubule-interstitial fibrosis and glomerulosclerosis. Also, tubular atrophy and interstitial inflammation were clearly decreased rendering improved histopathology, and down regulation of profibrogenic genes expression. Functionally, sCr and BUN were positively modified. The results showed that AdhMMP8 decreased renal fibrosis, suggesting that MMP8 could be a possible therapeutic candidate for kidney fibrosis treatment.

Roles of Nrf2 in Liver Diseases: Molecular, Pharmacological, and Epigenetic Aspects.

Liver diseases represent a critical health problem with 2 million deaths worldwide per year, mainly due to cirrhosis and its complications. Oxidative stress plays an important role in the development of liver diseases. In order to maintain an adequate homeostasis, there must be a balance between free radicals and antioxidant mediators. Nuclear factor erythroid 2-related factor (Nrf2) and its negative regulator Kelch-like ECH-associated protein 1 (Keap1) comprise a defense mechanism against oxidative stress damage, and growing evidence considers this signaling pathway as a key pharmacological target for the treatment of liver diseases. In this review, we provide detailed and updated evidence regarding Nrf2 and its involvement in the development of the main liver diseases such as alcoholic liver damage, viral hepatitis, steatosis, steatohepatitis, cholestatic damage, and liver cancer. The molecular and cellular mechanisms of Nrf2 cellular signaling are elaborated, along with key and relevant antioxidant drugs, and mechanisms on how Keap1/Nrf2 modulation can positively affect the therapeutic response are described. Finally, exciting recent findings about epigenetic modifications and their link with regulation of Keap1/Nrf2 signaling are outlined.

Pirfenidone Is an Agonistic Ligand for PPARα and Improves NASH by Activation of SIRT1/LKB1/pAMPK.

Nonalcoholic steatohepatitis (NASH) is recognized by hepatic lipid accumulation, inflammation, and fibrosis. No studies have evaluated the prolonged-release pirfenidone (PR-PFD) properties on NASH features. The aim of this study is to evaluate how PR-PFD performs on metabolic functions, and provide insight on a mouse model of human NASH. Male C57BL/6J mice were fed with either normo diet or high-fat/carbohydrate diet for 16 weeks and a subgroup also fed with PR-PFD (300 mg/kg/day). An insulin tolerance test was performed at the end of treatment. Histological analysis, determination of serum hormones, adipocytokines measurement, and evaluation of proteins by western blot was performed. Molecular docking, in silico site-directed mutagenesis, and in vitro experiments using HepG2 cultured cells were performed to validate PR-PFD binding to peroxisome proliferator-activated receptor alpha (PPAR-α), activation of PPAR-α promoter, and sirtuin 1 (SIRT1) protein expression. Compared with the high-fat group, the PR-PFD-treated mice displayed less weight gain, cholesterol, very low density lipoprotein and triglycerides, and showed a significant reduction of hepatic macrosteatosis, inflammation, hepatocyte ballooning, fibrosis, epididymal fat, and total adiposity. PR-PFD restored levels of insulin, glucagon, adiponectin, and resistin along with improved insulin resistance. Noteworthy, SIRT1-liver kinase B1-phospho-5' adenosine monophosphate-activated protein kinase signaling and the PPAR-α/carnitine O-palmitoyltransferase 1/acyl-CoA oxidase 1 pathway were clearly induced in high fat + PR-PFD mice. In HepG2 cells incubated with palmitate, PR-PFD induced activation and nuclear translocation of both PPARα and SIRT1, which correlated with increased SIRT1 phosphorylated in serine 47, suggesting a positive feedback loop between the two proteins. These results were confirmed with both synthetic PPAR-α and SIRT1 activators and inhibitors. Finally, we found that PR-PFD is a true agonist/ligand for PPAR-α. Conclusions: PR-PFD provided an anti-steatogenic effect and protection for inflammation and fibrosis.

Hydrodynamics-based liver transfection achieves gene silencing of CB1 using short hairpin RNA plasmid in cirrhotic rats.

BACKGROUND: There is a correlation between the endocannabinoid system and hepatic fibrosis based on the activation of CB1 and CB2 receptors; where CB1 has profibrogenic effects. Gene therapy with a plasmid carrying a shRNA for CB1 delivered by hydrodynamic injection has the advantage of hepatic tropism, avoiding possible undesirable effects of CB1 pharmacological inhibition. OBJECTIVE: To evaluate hydrodynamics-based liver transfection in an experimental model of liver cirrhosis of a plasmid with the sequence of a shRNA for CB1 and its antifibrogenic effects. METHODS: Three shRNA (21pb) were designed for blocking CB1 mRNA at positions 877, 1232 and 1501 (pshCB1-A, B, C). Sequences were cloned in the pENTR™/U6. Safety was evaluated monitoring CB1 expression in brain tissue. The silencing effect was determined in rat HSC primary culture and CCl4 cirrhosis model. Hydrodynamic injection in cirrhotic liver was through iliac vein and with a dose of 3mg/kg plasmid. Serum levels of liver enzymes, mRNA levels of TGF-ß1, Col IA1 and α-SMA and the percentage of fibrotic tissue were analyzed. RESULTS: Hydrodynamic injection allows efficient CB1 silencing in cirrhotic livers and pshCB1-B (position 1232) demonstrated the main CB1-silencing. Using this plasmid, mRNA level of fibrogenic molecules and fibrotic tissue considerably decrease in cirrhotic animals. Brain expression of CB1 remained unaltered. CONCLUSION: Hydrodynamics allows a hepatotropic and secure transfection in cirrhotic animals. The sequence of the shCB1-B carried in a plasmid or any other vector has the potential to be used as therapeutic strategy for liver fibrosis.

Fragmentation of the Golgi Apparatus in Neuroblastoma Cells Is Associated with Tau-Induced Ring-Shaped Microtubule Bundles.

Abnormal fibrillary aggregation of tau protein is a pathological condition observed in Alzheimer's disease and other tauopathies; however, the presence and pathological significance of early non-fibrillary aggregates of tau remain under investigation. In cell and animal models expressing normal or modified tau, toxic effects altering the structure and function of several membranous organelles have also been reported in the absence of fibrillary structures; however, how these abnormalities are produced is an issue yet to be addressed. In order to obtain more insights into the mechanisms by which tau may disturb intracellular membranous elements, we transiently overexpressed human full-length tau and several truncated tau variants in cultured neuroblastoma cells. After 48 h of transfection, either full-length or truncated tau forms produced significant fragmentation of the Golgi apparatus (GA) with no changes in cell viability. Noteworthy is that in the majority of cells exhibiting dispersion of the GA, a ring-shaped array of cortical or perinuclear microtubule (Mt) bundles was also generated under the expression of either variant of tau. In contrast, Taxol treatment of non-transfected cells increased the amount of Mt bundles but not sufficiently to produce fragmentation of the GA. Tau-induced ring-shaped Mt bundles appeared to be well-organized and stable structures because they were resistant to Nocodazole post-treatment and displayed a high level of tubulin acetylation. These results further indicate that a mechanical force generated by tau-induced Mt-bundling may be responsible for Golgi fragmentation and that the repeated domain region of tau may be the main promoter of this effect.

Quercetin Reverses Rat Liver Preneoplastic Lesions Induced by Chemical Carcinogenesis.

Quercetin is a flavonoid widely studied as a chemopreventive agent in different types of cancer. Previously, we reported that quercetin has a chemopreventive effect on the liver-induced preneoplastic lesions in rats. Here, we evaluated if quercetin was able not only to prevent but also to reverse rat liver preneoplastic lesions. We used the modified resistant hepatocyte model (MRHM) to evaluate this possibility. Treatment with quercetin was used 15 days after the induction of preneoplastic lesions. We found that quercetin reverses the number of preneoplastic lesions and their areas. Our results showed that quercetin downregulates the expression of EGFR and modulates this signaling pathway in spite of the activated status of EGFR as detected by the upregulation of this receptor, with respect to that observed in control rats. Besides, quercetin affects the phosphorylation status of Src-1, STAT5, and Sp-1. The better status of the liver after the treatment with quercetin could also be confirmed by the recovery in the expression of IGF-1. In conclusion, we suggest that quercetin reversed preneoplastic lesions by EGFR modulation and the activation state of Src, STAT5, and Sp1, so as the basal IGF-1.