Epigenetic modulation of vascular calcification: looking for comprehending the role of sirt1 and histone acetylation in VSMC phenotypic transition.

In light of the complex origins of ectopic vascular calcification and its significant health implications, this study offers a comprehensive exploration of the molecular dynamics governing vascular smooth muscle cells (VSMCs). Focusing on epigenetic modulation, we investigate the transition from a contractile to a calcifying phenotype in VSMCs, with an emphasis on understanding the role of SIRT1. For this purpose, a single batch of human aortic SMCs, used at a specified passage number to maintain consistency, was subjected to calcium and phosphate overload for up to 72 hours. Our findings, validated through RT q-PCR, Western blot, immunofluorescence, and DNA methylation analyses, reveal a complex interplay between acetyltransferases and deacetylases during this phenotypic transition. We highlight HAT1A's critical role in histone acetylation regulation and the involvement of HDACs, as evidenced by subcellular localization studies. Moreover, we demonstrate the modulation of SIRT1 expression, a class III deacetylase, during VSMC calcification, underscoring the influence of DNA methylation in this process. Importantly, the study addresses previously unexplored aspects of the dynamic protein expression patterns observed, providing insight into the counterintuitive expressions of key proteins such as Runx2 and osterix. This research underscores the significant impact of epigenetic mechanisms, particularly the modulation of SIRT1, in the transition from a contractile to a calcifying phenotype in VSMCs, offering potential avenues for further exploration in the context of vascular calcification.

The role of extracellular vesicles in cancer.

Extracellular vesicles (EVs), which include small EVs such as exosomes, play a critical role in intercellular communication and are produced by both cancer and non-cancer cells. Several studies have shown that cancer cells exploit various strategies to regulate the biogenesis, composition, and functions of EVs primarily to promote cancer progression. Given that exosomes originate from major sorting hubs at the limiting membrane of endosomes, they are central to a signaling network that connects external stimuli with intrinsic tumor cell features. Exosomes contain diverse repertoires of molecular cargos, such as proteins, lipids, and nucleic acids, which determine their heterogeneity and functional properties in cancer progression. Therefore, targeting exosome biogenesis will enhance our understanding of tumorigenesis and also promote the discovery of novel approaches for cancer therapy. In this chapter we summarize the machinery of exosome biogenesis and the local, distant, and systemic effects of exosomes released by cancer cells. Furthermore, we explore how these exosomes regulate the anti-tumor immune response and epigenetic mechanisms to sustain cancer progression and their implications in cancer prevention and treatment.

c-Src kinase contributes on endothelial cells mechanotransduction in a heat shock protein 70-dependent turnover manner.

Shear stress changes are associated with a repertory of signaling cascade modulating vascular phenotype. As shear stress-related tensional forces might be associated with pathophysiological susceptibility, a more comprehensive molecular map needs to be addressed. Thus, we subjected human umbilical vein endothelial cells (HUVECs) to a circuit of different tensional forces in vitro considering the following three groups: (a) physiological blood flow shear stress condition (named Normo), (b) a hypertensive blood flow shear stress (named Hyper), and (c) these hyper-stressed cells were returned to Normo condition (named Return). The samples were properly collected to allow different methodologies analysis. Our data showed a pivotal involvement of c-Src on driving the mechanotransduction cascade by modulating signaling related with adhesion, survival (PI3K/Akt) and proliferative phenotype. Moreover, c-Src seems to develop important role during extracellular matrix remodeling. Additionally, proteomic analysis showed strong involvement of heat shock protein 70 (HSP70) in the hypertensive-stressed cells; it being significantly decreased in return phenotype. This result prompted us to investigate 20S proteasome as an intracellular proteolytic alternative route to promote the turnover of those proteins. Surprisingly, our data reveled significant overexpression of sets of proteasome subunit α-type (PSMA) and ß-type (PSMB) genes. In conjunction, our data showed c-Src as a pivotal protein to drive mechanotransduction in endothelial cells in a HSP70-dependent turnover scenario. Because shear patterns is associated with pathophysiological changes, such as atherosclerosis and hypertension, these results paved new road to understand the molecular mechanism on driving mechanotransduction in endothelial cells and, if drugable, these targets must be considered within pharmacological treatment optimization.

De novo tetrahydrobiopterin biosynthesis is impaired in the inflammed striatum of parkin(-/-) mice.

Parkinson's disease (PD), the second-most prevalent neurodegenerative disease, is primarily characterized by neurodegeneration in the substantia nigra pars compacta, resulting in motor impairment. Loss-of-function mutations in parkin are the major cause of the early onset familial form of the disease. Although rodents deficient in parkin (parkin(-/-) ) have some dopaminergic system dysfunction associated with central oxidative stress and energy metabolism deficiencies, these animals only display nigrostriatal pathway degeneration under inflammatory conditions. This study investigated the impact of the inflammatory stimulus induced by lypopolisaccharide (LPS) on tetrahydrobiopterin (BH4) synthesizing enzymes (de novo and salvage pathways), since this cofactor is essential for dopamine synthesis. The mitochondrial content and architecture was investigated in the striatum of LPS-exposed parkin(-/-) mice. As expected, the LPS (0.33 mg/kg; i.p.) challenge compromised spontaneous locomotion and social interaction with juvenile parkin(-/-) and WT mice. Moreover, the genotype impacted the kinetics of the investigation of the juvenile. The inflammatory scenario did not induce apparent changes in mitochondrial ultrastructure; however, it increased the quantity of mitochondria, which were of smaller size, and provoked the perinuclear distribution of the organelle. Furthermore, the BH4 de novo biosynthetic pathway failed to be up-regulated in the LPS challenge, a well-known stimulus for its activation. The LPS treatment increased sepiapterin reductase (SPR) expression, suggesting compensation by the salvage pathway. This might indicate that dopamine synthesis is compromised in parkin(-/-) mice under inflammatory conditions. Finally, this scenario impaired the striatal expression of the transcription factor BDNF, possibly favoring cell death.

Improvement of lipase obtaining system by orange waste-based solid-state fermentation: production, characterization and application.

Lipases are an economic important group of biocatalysts that can be produced by some fungal under solid-state fermentation. Orange wastes are source of lipases and potential substrates for lipases production. This work assessed 19 fugal strains cultivated in Citrus sinensis cv. Hamlin orange wastes (peel, frit and core) for production of lipases in order to generate compounds with antioxidant, antimicrobial and cytotoxic properties. Fifteen of those fungi grew and produced lipases, mainly the Aspergillus brasiliensis [National Institute of Quality Control (INCQS) 40036]/frit system, which showed 99.58 U/g total lipase. The substrate with the highest production of lipase was frit with 26.67 and 78.91 U/g of total lipases produced on average by the 15 microorganisms. Aspergillus niger 01/frit (33.53 U/g) and Aspergillus niger (INCQS 40015)/frit (34.76 U/g) systems showed the highest specificity values in all the herein tested synthetic substrates with 4, 12 and 16 carbons. Analysis of the fatty acid profile of hydrolysis products obtained in the most prominent systems applied to corn and sunflower oils showed: palmitic acid, linoleic acid, oleic acid, and stearic acid. These acids showed antioxidant capacity of up to 58% DPPH (2,2-diphenyl-1-pierylhydrazyl) radical reduction and antibacterial activity against Escherichia coli, Listeria monocytogenes, Pseudomonas aureginosa, Salmonella Enteritidis and Staphylococcus aureus, as well as cytotoxicity to SCC9 cells (squamous cancer cells).

Running for REST: Physical activity attenuates neuroinflammation in the hippocampus of aged mice.

Exercise improves mental health and synaptic function in the aged brain. However, the molecular mechanisms involved in exercise-induced healthy brain aging are not well understood. Evidence supports the role of neurogenesis and neurotrophins in exercise-induced neuroplasticity. The gene silencing transcription factor neuronal RE1-silencing transcription factor (REST)/neuron-restrictive silencer factor (NRSF) and an anti-inflammatory role of exercise are also candidate mechanisms. We evaluate the effect of 8weeks of physical activity on running wheels (RW) on motor and depressive-like behavior and hippocampal gene expression of brain-derived neurotrophic factor (BDNF), REST, and interleukins IL-1ß and IL-10 of adult and aged C57BL/6 mice. The aged animals exhibited impaired motor function and a depressive-like behavior: decreased mobility in the RW and open field and severe immobility in the tail suspension test. The gene expression of REST, IL-1ß, and IL-10 was increased in the hippocampus of aged mice. Physical activity was anxiolytic and antidepressant and improved motor behavior in aged animals. Physical activity also boosted BDNF and REST expression and decreased IL-1ß and IL-10 expression in the hippocampus of aged animals. These results support the beneficial role of REST in the aged brain, which can be further enhanced by regular physical activity.

Preconception exposure to malathion and glucose homeostasis in rats: Effects on dams during pregnancy and post-term periods, and on their progeny.

Understanding the individual and global impact of pesticides on human physiology and the different stages of life is still a challenge in environmental health. We analyzed here whether administration of the organophosphate insecticide malathion before pregnancy could affect glucose homeostasis during pregnancy and, in addition, generate possible later consequences in mothers and offspring. For this, adult Wistar rats were allocated into two groups and were treated daily (intragastric) with malathion (14 or 140 mg/kg, body mass (bm)) for 21-25 days. Corn oil was used as vehicle in the Control group. Subgroups were defined based on the absence (nulliparous) or presence (pregnant) of a copulatory plug. Pregnant rats were followed by an additional period of 2 months after the term (post-term), without continuing malathion treatment. Fetuses and adult offspring of males and females were also evaluated. We ran an additional experimental design with rats exposed to malathion before pregnancy at a dose of 0.1 mg/kg bm. Malathion exposure resulted in glucose intolerance in the mothers during pregnancy and post-term period, regardless of the exposure dose. This was accompanied by increased visceral adipose tissue mass, dyslipidemia, unchanged pancreatic ß-cell mass, and varying insulin responses to glucose in vivo. The number of total newborns and birthweight was not affected by malathion exposure. Adult offspring from both sexes also became glucose-intolerant, regardless of the pesticide dose their dams were exposed to. This alteration could be associated with changes at the epigenomic level, as reduced hepatic mRNA content of DNA methylases and demethylases was found. We demonstrated that periconceptional exposure to malathion with doses aiming to mimic from work environment to indirect contamination predisposes progenitors and offspring rats to glucose intolerance. Thus, we conclude that subchronic exposure to malathion is a risk factor for gestational diabetes and prediabetes later in life.

Prenatal restraint stress downregulates the hypothalamic kisspeptidergic system transcripts genes, reduces the estrogen plasma levels, delayed the onset of puberty, and reduced the sexual behavior intensity in female rats.

AIMS: This study investigated the possible relationships between the expression of the Kiss1 and Gpr54 gene expressions and the pituitary-gonadal hormones with the female onset of puberty and sexual behavior. The Kiss1 and Gpr54 gene expressions were examined because they are critical to controlling the hypothalamic activation of GnRH neurons and, in turn, the pituitary-gonadal hormones related to the early onset of puberty and sexual behavior. Further, it was evaluated that the pituitary and gonadal hormones involved in the vaginal opening and the expression of sexual behavior. METHODS: Pregnant rats exposed to PRS from gestation days 17 to 20 were evaluated for maternal and open-field behaviors. The maternal behavior was analyzed because it may alter brain sexual organization affecting the pups development. It was observed in female pups the physical and development and, in adult age, the open-field behavior, the anxiety-like behavior, the estrous cycle, the sexual behavior, the serum FSH, LH, estrogen, progesterone, and testosterone levels, and the gene expression of kisspeptin protein (Kiss1) and Gpr54 in the hypothalamus. RESULTS: the maternal and open-field behaviors were unaffected. In the F1 generation, PRS reduced weight at weaning, delayed the day of the vaginal opening and reduced the intensity of lordosis, the estrogen levels, and the Kiss1 and Gpr54 gene expression. These effects were attributed to hypothalamic kisspeptidergic system downregulation of transcripts genes and the reduced estrogen levels affected by the PRS.

The dopaminergic D1 receptor modulates the hyperactivity of Bapa mutant mice.

The mutant bate-palmas ("claps"; symbol - bapa) mice induced by the mutagenic chemical ENU present motor incoordination and postural alterations. A previous study showed that bapa mice present increased motor/exploratory behaviors during the prepubertal period due to increased striatal tyrosine hydroxylase expression, suggesting striatal dopaminergic system hyperactivity. This study aimed to evaluate the involvement of striatal dopaminergic receptors in the hyperactivity of bapa mice. Male bapa mice and their wild strain (WT) were used. Spontaneous motor behavior was observed in the open-field test, and stereotypy was evaluated after apomorphine administration. The effects of DR1 and DR2 dopaminergic antagonists (SCH-23,390; sulpiride) and the striatal DR1 and D2 receptor gene expression were evaluated. Relative to WT, bapa mice showed: 1) increased general activity for four days; 2) increased rearing and sniffing behavior and decreased immobility after apomorphine; 3) blockage of rearing behavior after the DR2 antagonist but no effect after DR1 antagonist; 4) blockage of sniffing behavior after the DR1 antagonist in bapa and WT mice but no effect after the DR2 antagonist; 5) increased immobility after the DR1 antagonist but no effect after the DR2 antagonist; 6) increased expression of striatal DR1 receptor gene and reduced the DR2 expression gene after apomorphine administration. Bapa mice showed increased activity in open field behavior. The increased rearing behavior induced by apomorphine of bapa mice resulted from the increased gene expression of the DR1 receptor.

Physical-Exercise-Induced Antioxidant Effects on the Brain and Skeletal Muscle.

Erythroid-related nuclear factor 2 (NRF2) and the antioxidant-responsive-elements (ARE) signaling pathway are the master regulators of cell antioxidant defenses, playing a key role in maintaining cellular homeostasis, a scenario in which proper mitochondrial function is essential. Increasing evidence indicates that the regular practice of physical exercise increases cellular antioxidant defenses by activating NRF2 signaling. This manuscript reviewed classic and ongoing research on the beneficial effects of exercise on the antioxidant system in both the brain and skeletal muscle.

Epigenetic modifications induced by exercise: Drug-free intervention to improve cognitive deficits associated with obesity.

Obesity and metabolic disorders are increasing worldwide and are associated with brain atrophy and dysfunction, which are risk factors for late-onset dementia and Alzheimer's disease. Epidemiological studies demonstrated that changes in lifestyle, including the frequent practice of physical exercise are able to prevent and treat not only obesity/metabolic disorders, but also to improve cognitive function and dementia. Several biochemical pathways and epigenetic mechanisms have been proposed to understand the beneficial effects of physical exercise on cognition. This manuscript revised central ongoing research on epigenetic mechanisms induced by exercise and the beneficial effects on obesity-associated cognitive decline, highlighting potential mechanistic mediators.

Antiproliferative xylan from corn cobs induces apoptosis in tumor cells.

Xylan is one of the most abundant hemicellulose constituents in the plant kingdom. We extracted xylan from corn cobs (XCC) using ultrasound. The structure of XCC was determined by NMR analysis, which revealed a composition of xylose:glucose:arabinose:galactose:mannose:glucuronic acid in a molar percentage ratio of 48:21:16:10:2.5:2.5. XCC induced the proliferation of murine macrophage cells (RAW 264.7) and inhibited the proliferation of human lung adenocarcinoma epithelial cells (A549) by 20% and human cervical adenocarcinoma cells (HeLa) by 60%. Several cell death-associated morphological changes were observed after the exposure of HeLa cells to XCC for 24 h. In addition, by using fluorescent probes, we observed a larger number of irregular and pyknotic nuclei with condensed chromatin bodies (nuclear condensation). FACS analysis showed an increase in the number of annexin V-positive and propidium iodide (PI)-positive cells (37.0%) in the presence of XCC compared with that of the negative control cells (5.0%). XCC also increased the ratio of Bax:Bcl-2 (3.5:1) and the levels of cytochrome c, caspase 3, and apoptosis-inducing factor (AIF) in treated cells. Therefore, the results demonstrated the antiproliferative potential of XCC, which induced apoptosis in HeLa cells.

Chronic Metabolic Derangement-Induced Cognitive Deficits and Neurotoxicity Are Associated with REST Inactivation.

Chronic metabolic alterations may represent a risk factor for the development of cognitive impairment, dementia, or neurodegenerative diseases. Hyperglycemia and obesity are known to imprint epigenetic markers that compromise the proper expression of cell survival genes. Here, we showed that chronic hyperglycemia (60 days) induced by a single intraperitoneal injection of streptozotocin compromised cognition by reducing hippocampal ERK signaling and by inducing neurotoxicity in rats. The mechanisms appear to be linked to reduced active DNA demethylation and diminished expression of the neuroprotective transcription factor REST. The impact of the relationship between adiposity and DNA hypermethylation on REST expression was also demonstrated in peripheral blood mononuclear cells in obese children with reduced levels of blood ascorbate. The reversible nature of epigenetic modifications and the cognitive impairment reported in obese children, adolescents, and adults suggest that the correction of the anthropometry and the peripheral metabolic alterations would protect brain homeostasis and reduce the risk of developing neurodegenerative diseases.

Mg-Al and Zn-Al Layered Double Hydroxides Promote Dynamic Expression of Marker Genes in Osteogenic Differentiation by Modulating Mitogen-Activated Protein Kinases.

The effect of LDH samples comprised of chloride anions intercalated between positive layers of magnesium/aluminum (Mg-Al LDH) or zinc/aluminum (Zn-Al LDH) chemical composition on pre-osteoblast performance is investigated. Non-cytotoxic concentrations of both LDHs modulated pre-osteoblast adhesion by triggering cytoskeleton rearrangement dependent on recruiting of Cofilin, which is modulated by the inhibition of the Protein Phosphatase 2A (PP2A), culminating in osteoblast differentiation with a significant increase of osteogenic marker genes. The alkaline phosphatase (ALP) and bone sialoprotein (BSP) are significantly up-modulated by both LDHs; however, Mg-Al LDH nanomaterial promoted even more significance than both experimental controls, while the phosphorylations of mitogen-activated protein kinase (MAPKs)- extracellular signal-regulated kinases (ERK) and c-Jun N-terminal kinase (JNK) significantly increased. MAPK signaling is necessary to activate Runt-related transcription factor 2 (RUNX2) gene. Concomitantly, it is also investigated whether challenged osteoblasts are able to modulate osteoclastogenesis by investigating both osteoprotegerin (OPG) and Receptor activator of nuclear factor kappa-ligand (RANKL) in this model; a dynamic reprogramming of both these genes is found, suggesting LDHs in modulating osteoclastogenesis. These results suggest that LDHs interfere in bone remodeling, and they can be considered as nanomaterials in graft-based bone healing or drug-delivery materials for bone disorders.

A possible anti-proliferative and anti-metastatic effect of irradiated riboflavin in solid tumours.

Riboflavin is a potent photosensitizer as well as part of the vitamin B complex. Recently we demonstrated that the products generated by irradiation of riboflavin have potential as anti-leukaemic therapy. The possible action, however, of the riboflavin photoproducts in solid cancers has not been addressed. Hence, we investigated the effects of irradiated riboflavin on androgen-independent human prostate cancer cells (PC3), a known model for solid tumour cells with an exceptional resistance to therapy. Our results show that riboflavin photoproducts are cytotoxic to these cells in a FasL-Fas-dependent manner. Furthermore, irradiated riboflavin inhibited matrix-degrading proteases, caused downregulation of VEGF and upregulation of TIMP1 suggesting anti-metastatic potential. Together, these results show that the anti-neoplastic action of riboflavin photoproducts is not limited to haematological malignancies, warranting clinical studies in solid tumours.

Genetic polymorphisms in the MMP-1 and MMP-3 gene may contribute to chronic periodontitis in a Brazilian population.

OBJECTIVES: Matrix metalloproteinase-1 and -3 (MMP-1, MMP-3) represent proteinases that degrade macromolecules of the extracellular matrix. These enzymes play a fundamental role during destruction of periodontal tissues. Genetic polymorphisms were characterized in the promoter region of the MMP-1 and MMP-3 genes. The aim of this study was to investigate the relationship between these genetic variations with chronic periodontitis in a Brazilian population. MATERIAL AND METHODS: Non-smoking subjects (n = 114) exhibiting sites > or = 5 mm clinical attachment loss were recruited for study. Control subjects (n = 109) should not exhibit clinical signals of periodontitis. MMP-1 (-1607 1G/2G, -519 A/G) and MMP-3 (-1612 5A/6A) gene promoter polymorphisms were genotyped using PCR-RFLP methods. RESULTS: Analysis of polymorphisms showed no differences in distribution of the -1607 1G/2G and -519 A/G variants in the MMP-1 gene between the healthy and periodontitis group (p > 0.05). However, the distribution of genotype frequencies of the -1612 5A/6A polymorphism in the MMP-3 gene showed that the 5A/5A genotype was significantly more frequent in the periodontitis group (p = 0.008). The same was not observed in the 5A/6A genotype once only one 5A allele is carried. We also observed a trend to increase the frequency of the MMP-1/MMP-3 haplotype (2G/5A) in the periodontitis group (p = 0.08). CONCLUSION: On the basis of the results, no significant association is found for the MMP-1 polymorphisms with susceptibility of periodontitis, while the MMP-3 gene polymorphism may contribute to periodontal tissue destruction during periodontitis in Brazilian subjects.