Pifithrin-µ Induces Stress Granule Formation, Regulates Cell Survival, and Rewires Cellular Signaling.

(1) Background: Stress granules (SGs) are cytoplasmic protein-RNA condensates that assemble in response to various insults. SG production is driven by signaling pathways that are relevant to human disease. Compounds that modulate SG characteristics are therefore of clinical interest. Pifithrin-µ is a candidate anti-tumor agent that inhibits members of the hsp70 chaperone family. While hsp70s are required for granulostasis, the impact of pifithrin-µ on SG formation is unknown. (2) Methods: Using HeLa cells as model system, cell-based assays evaluated the effects of pifithrin-µ on cell viability. Quantitative Western blotting assessed cell signaling events and SG proteins. Confocal microscopy combined with quantitative image analyses examined multiple SG parameters. (3) Results: Pifithrin-µ induced bona fide SGs in the absence of exogenous stress. These SGs were dynamic; their properties were determined by the duration of pifithrin-µ treatment. The phosphorylation of eIF2α was mandatory to generate SGs upon pifithrin-µ exposure. Moreover, the formation of pifithrin-µ SGs was accompanied by profound changes in cell signaling. Pifithrin-µ reduced the activation of 5'-AMP-activated protein kinase, whereas the pro-survival protein kinase Akt was activated. Long-term pifithrin-µ treatment caused a marked loss of cell viability. (4) Conclusions: Our study identified stress-related changes in cellular homeostasis that are elicited by pifithrin-µ. These insights are important knowledge for the appropriate therapeutic use of pifithrin-µ and related compounds.

p53 inhibitor or antioxidants reduce the severity of ethmoid plate deformities in zebrafish Type 3 Treacher Collins syndrome model.

Treacher Collins syndrome-3 (TCS-3) is a rare congenital craniofacial disorder attributed to variants in the RNA pol I subunit C (POLR1C). The pathogenesis of TCS-3 linked to polr1c involves the activation of apoptosis-dependent p53 pathways within neural crest cells (NCCs). This occurs due to disruptions in ribosome biogenesis, and the restoration of polr1c expression in early embryogenesis effectively rescues the observed craniofacial phenotype in polr1c-deficient zebrafish. Clinical variability in TCS patients suggests interactions between genes and factors like oxidative stress. Elevated production of reactive oxygen species (ROS) in epithelial cells may worsen phenotypic outcomes in TCS individuals. Our study confirmed excessive ROS production in facial regions, inducing apoptosis and altering p53 pathways. Deregulated cell-cycle and epithelial-to-mesenchymal transition (EMT) genes were also detected in the TCS-3 model. Utilizing p53 inhibitor (Pifithrin-α; PFT-α) or antioxidants (Glutathione; GSH and N-Acetyl-L-cysteine; NAC) effectively corrected migrated NCC distribution in the pharyngeal arch (PA), suppressed oxidative stress, prevented cell death, and modulated EMT inducers. Crucially, inhibiting p53 activation or applying antioxidants within a specific time window, notably within 30 h post-fertilization (hpf), successfully reversed phenotypic effects induced by polr1c MO.

Can flaxseed, chia or puncture vine affect mare ovarian cell functions and prevent the toxic effect of the environmental contaminant toluene?

The aim of this in vitro study was to examine the potential effect of functional food plant extracts, namely, extracts of flaxseed (Linum usitatissimum L.), chia (Salvia hispanica) and puncture vine (Tribulus terrestris L.), on basic mare ovarian cell functions and their response to the environmental contaminant toluene. Mare granulosa cells were incubated with and without toluene (0, 0.02, 0.2 or 2.0 µg/mL) in the presence or absence of flaxseed, chia and puncture vine extracts (10 µg/mL). Markers of cell proliferation (accumulation of proliferating cell nuclear antigen, PCNA) and apoptosis (accumulation of bax), viability (Trypan blue extrusion) and the release of progesterone (P), oxytocin (OT) and prostaglandin F 2 alpha (PGF) were measured. Toluene reduced all other measured parameters except OT release. All the tested plants were able to reduce cell viability and the release of P and PGF, but they did not influence other indexes. Moreover, flaxseed mitigated toluene action on ovarian cell proliferation, apoptosis, OT and PGF, whilst puncture vine prevented and inverted toluene action on P and PGF ourput. Chia extract did not modify toluene action on any parameter. On the other hand, toluene was able to promote the inhibitory action of flaxseed on cell viability and P release and to prevent the inhibitory action of all the plant extracts on PGF release. The present study (1) is the first demonstration, that flaxseed, chia and puncture vine can directly suppress mare ovarian cell functions, (2) shows that toluene can suppress basic ovarian cell functions and modify the reproductive effect of food plants and (3) demonstrates the ability of flaxseed and puncture vine, but not of chia, to prevent some toxic effect of toluene on mare ovarian cell functions.

Toxicity Assessment of an Anti-Cancer Drug of p-Toluene Sulfonamide in Zebrafish Larvae Based on Cardiovascular and Locomotion Activities.

p-Toluene sulfonamide (p-TSA), a small molecular drug with antineoplastic activity is widely gaining interest from researchers because of its pharmacological activities. In this study, we explored the potential cardio and neural toxicity of p-TSA in sublethal concentrations by using zebrafish as an in vivo animal model. Based on the acute toxicity assay, the 96hr LC50 was estimated as 204.3 ppm, suggesting the overall toxicity of p-TSA is relatively low in zebrafish larvae. For the cardiotoxicity test, we found that p-TSA caused only a minor alteration in treated larvae after no overall significant alterations were observed in cardiac rhythm and cardiac physiology parameters, as supported by the results from expression level measurements of several cardiac development marker genes. On the other hand, we found that acute p-TSA exposure significantly increased the larval locomotion activity during the photomotor test while prolonged exposure (4 days) reduced the locomotor startle reflex activities in zebrafish. In addition, a higher respiratory rate and blood flow velocity was also observed in the acutely treated fish groups compared to the untreated group. Finally, by molecular docking, we found that p-TSA has a moderate binding affinity to skeletal muscle myosin II subfragment 1 (S1), ATPase activity, actin- and Ca2+-stimulated myosin S1 ATPase, and v-type proton ATPase. These binding interactions between p-TSA and proteins offer insights into the potential molecular mechanism of action of p-TSA on observed altered responses toward photo and vibration stimuli and minor altered vascular performance in the zebrafish larvae.

Urea transporter B downregulates polyamines levels in melanoma B16 cells via p53 activation.

Urea transporter B (UT-B, encoded by the SLC14A1 gene) is a membrane channel protein involved in urea transmembrane transport. Compared with normal tissues, UT-B expression is significantly decreased in most tumours, especially melanoma. However, the UT-B role in tumorigenesis and development is still unclear. Herein, we investigated the effects of UT-B overexpression on polyamine metabolism and the urea cycle in murine melanoma B16 cells, to explore the roles of mitochondrial dysfunction and p53 activation in cell growth and polyamines metabolism. UT-B overexpression in B16 cells decreased cell growth, increased apoptosis, and significantly altered metabolic pathways related to the urea cycle, which were characterized by reduced production of urea and polyamines and increased production of nitric oxide. Subsequently, we observed that activation of the p53 pathway may be the main cause of the above phenomena. The p53 inhibitor pifithrin-α partially restored the production of polyamines, but the mitochondrial morphology and function were still impaired. Further treatment of UT-B-overexpressing B16 cells with reactive oxygen species scavenging agent N-acetyl-l-cysteine and coenzyme Q10 restored cell viability and mitochondrial function and increased polyamine production. In conclusion, UT-B overexpression caused mitochondrial dysfunction and increased oxidative stress in B16 cells, and then activated p53 expression, which may be one of the mechanisms leading to the decrease in intracellular polyamines.

Autophagic Activation and Decrease of Plasma Membrane Cholesterol Contribute to Anticancer Activities in Non-Small Cell Lung Cancer.

Non-small cell lung cancer (NSCLC), an aggressive subtype of pulmonary carcinomas with high mortality, accounts for 85% of all lung cancers. Drug resistance and high recurrence rates impede the chemotherapeutic effect, making it urgent to develop new anti-NSCLC agents. Recently, we have demonstrated that para-toluenesulfonamide is a potential anti-tumor agent in human castration-resistant prostate cancer (CRPC) through inhibition of Akt/mTOR/p70S6 kinase pathway and lipid raft disruption. In the current study, we further addressed the critical role of cholesterol-enriched membrane microdomain and autophagic activation to para-toluenesulfonamide action in killing NSCLC. Similar in CRPC, para-toluenesulfonamide inhibited the Akt/mTOR/p70S6K pathway in NSCLC cell lines NCI-H460 and A549, leading to G1 arrest of the cell cycle and apoptosis. Para-toluenesulfonamide significantly decreased the cholesterol levels of plasma membrane. External cholesterol supplement rescued para-toluenesulfonamide-mediated effects. Para-toluenesulfonamide induced a profound increase of LC3-II protein expression and a significant decrease of p62 expression. Double staining of lysosomes and cellular cholesterol showed para-toluenesulfonamide-induced lysosomal transportation of cholesterol, which was validated using flow cytometric analysis of lysosome staining. Moreover, autophagy inhibitors could blunt para-toluenesulfonamide-induced effect, indicating autophagy induction. In conclusion, the data suggest that para-toluenesulfonamide is an effective anticancer agent against NSCLC through G1 checkpoint arrest and apoptotic cell death. The disturbance of membrane cholesterol levels and autophagic activation may play a crucial role to para-toluenesulfonamide action.

Identification of neural oscillations and epileptiform changes in human brain organoids.

Brain organoids represent a powerful tool for studying human neurological diseases, particularly those that affect brain growth and structure. However, many diseases manifest with clear evidence of physiological and network abnormality in the absence of anatomical changes, raising the question of whether organoids possess sufficient neural network complexity to model these conditions. Here, we explore the network-level functions of brain organoids using calcium sensor imaging and extracellular recording approaches that together reveal the existence of complex network dynamics reminiscent of intact brain preparations. We demonstrate highly abnormal and epileptiform-like activity in organoids derived from induced pluripotent stem cells from individuals with Rett syndrome, accompanied by transcriptomic differences revealed by single-cell analyses. We also rescue key physiological activities with an unconventional neuroregulatory drug, pifithrin-α. Together, these findings provide an essential foundation for the utilization of brain organoids to study intact and disordered human brain network formation and illustrate their utility in therapeutic discovery.

Application of P53 mRNA in signal transduction mechanisms of skeletal muscle cells.

By analyzing the effects of P53 inhibitors and ladder climbing exercise on P53 mRNA transcription in skeletal muscle of mice, the application of P53 mRNA in signal transduction mechanism of skeletal muscle cells was studied. Several clean ICR mice were fed for experiment. The experimental mice were divided into groups to analyze the effect of P53 inhibitor on P53 mRNA transcription in gastrocnemius muscle of mice. The mice were randomly divided into The application of P53 mRNA in signal transduction mechanism of skeletal muscle cells was studied, and the corresponding endurance exercise program and ladder climbing training program were designed. According to the research, exercise is to some extent a stimulating factor affecting P53 inhibitor. Endurance training and injection of P53 inhibitor affect P53 mRNA content. Exercise has a benign effect on ICR mice injected with P53 inhibitor. The expression of P53 mRNA in skeletal muscle was significantly affected by climbing training in youth, and decreased by climbing training in old age. However, there was no difference between long-term climbing training and short-term climbing training in the expression of P53 mRNA in skeletal muscle.

Role of JNK and p53 in Implementation of Functions of Various Types of Regeneration-Competent Cells of the Nervous Tissue.

We studied the participation of JNK and p53 in the realization of the growth potential of different types of progenitors of the subventricular zone of mouse brain and secretion of neurotrophins by glial cells. The stimulating role of these signaling molecules in mitotic activity and specialization of multipotent neural stem cells was shown. It was found that JNK and p53 do not participate in the regulation of committed neuronal progenitor cells (clonogenic PSA-NCAM+ cells). A dependence of neurotrophic growth factors in individual populations of neuroglia on activity of these protein kinase and transcription factor was revealed. The role of JNK and p53 in astrocytes consists in stimulation of their secretion, and in microglial cells, on the contrary, in its inhibition. The secretory neurotrophic function of oligodendrogliocytes is not associated with JNK and p53 activity.

Facile synthesis, antimicrobial and antiviral evaluation of novel substituted phenyl 1,3-thiazolidin-4-one sulfonyl derivatives.

A series of novel substituted phenyl 1, 3-thiazolidin-4-one sulfonyl derivatives 5 (a-t) were synthesized and screened for their in-vitro anti-microbial and anti-viral activity. The result of the anti-microbial assay demonstrated compounds 5d, 5f, 5g, 5h, 5i, 5j showed prominent inhibitory activity against all the tested Gram-positive and Gram-negative bacterial strains, while compounds 5g, 5j, 5o, 5p, 5q showed significant activity against the entire set of fungal strains as compared to standard drug Ampicillin and Clotrimazole, respectively. The antimicrobial study revealed that compounds having electron-withdrawing groups showed significant antimicrobial potency. The most active antibacterial compound 5j showed potent inhibition of S. aureus DNA Gyrase enzyme as a possible mechanism of action for antimicrobial activity. Moreover, the antiviral testing of selected compounds showed considerable activity against Herpes simplex virus-1(KOS), Herpes simplex virus-2 (G), Herpes simplex virus-1(TK- KOS ACVr), Vaccinia virus, Human Coronavirus (229E), Reovirus-1, Sindbis virus, Coxsackie virus B4, Yellow Fever virus and Influenza A, B virus. Compounds 5h exhibited low anti-viral activity against HIV-1(strain IIIB) and HIV-2 (strain ROD). The study clearly outlined that synthesized compounds endowed with good antimicrobial property together with considerable antiviral activity.

ER stress-induced modulation of neural activity and seizure susceptibility is impaired in a fragile X syndrome mouse model.

Imbalanced neuronal excitability homeostasis is commonly observed in patients with fragile X syndrome (FXS) and the animal model of FXS, the Fmr1 KO. While alterations of neuronal intrinsic excitability and synaptic activity at the steady state in FXS have been suggested to contribute to such a deficit and ultimately the increased susceptibility to seizures in FXS, it remains largely unclear whether and how the homeostatic response of neuronal excitability following extrinsic challenges is disrupted in FXS. Our previous work has shown that the acute response following induction of endoplasmic reticulum (ER) stress can reduce neural activity and seizure susceptibility. Because many signaling pathways associated with ER stress response are mediated by Fmr1, we asked whether acute ER stress-induced reduction of neural activity and seizure susceptibility are altered in FXS. Our results first revealed that acute ER stress can trigger a protein synthesis-dependent prevention of neural network synchronization in vitro and a reduction of susceptibility to kainic acid-induced seizures in vivo in wild-type but not in Fmr1 KO mice. Mechanistically, we found that acute ER stress-induced activation of murine double minute-2 (Mdm2), ubiquitination of p53, and the subsequent transient protein synthesis are all impaired in Fmr1 KO neurons. Employing a p53 inhibitor, Pifithrin-α, to mimic p53 inactivation, we were able to blunt the increase in neural network synchronization and reduce the seizure susceptibility in Fmr1 KO mice following ER stress induction. In summary, our data revealed a novel cellular defect in Fmr1 KO mice and suggest that an impaired response to common extrinsic challenges may contribute to imbalanced neuronal excitability homeostasis in FXS.

The last two decades on preclinical and clinical research on inhalant effects.

This paper reviews the scientific evidence generated in the last two decades on the effects and mechanisms of action of most commonly misused inhalants. In the first section, we define what inhalants are, how they are used, and their prevalence worldwide. The second section presents specific characteristics that define the main groups of inhalants: (a) organic solvents; (b) aerosols, gases, and volatile anesthetics; and (c) alkyl nitrites. We include a table with the molecular formula, structure, synonyms, uses, physicochemical properties and exposure limits of representative compounds within each group. The third and fourth sections review the direct acute and chronic effects of common inhalants on health and behavior with a summary of mechanisms of action, respectively. In the fifth section, we address inhalant intoxication signs and available treatment. The sixth section examines the health effects, intoxication, and treatment of nitrites. The seventh section reviews current intervention strategies. Finally, we propose a research agenda to promote the study of (a) solvents other than toluene; (b) inhalant mixtures; (c) effects in combination with other drugs of abuse; (d) age and (e) sex differences in inhalant effects; (f) the long-lasting behavioral effects of animals exposed in utero to inhalants; (g) abstinence signs and neurochemical changes after interrupting inhalant exposure; (h) brain networks involved in inhalant effects; and finally (i) strategies to promote recovery of inhalant users.

Fructooligosaccharides production by immobilized Pichia pastoris cells expressing Schedonorus arundinaceus sucrose:sucrose 1-fructosyltransferase.

Fructooligosaccharides (FOSs)-fructose-based oligosaccharides-are typical prebiotics with health-promoting effects in humans and animals. The trisaccharide 1-kestotriose is the most attractive inulin-type FOS. We previously reported a recombinant sucrose:sucrose 1-fructosyltransferase (1-SST, EC 2.4.1.99) from Schedonorus arundinaceus (Sa) that efficiently converts sucrose into 1-kestotriose. In this study, Pichia pastoris PGFT6x-308 constitutively expressing nine copies of the Sa1-SST gene displayed fructosyltransferase activity in undisrupted biomass (49.8 U/ml) and culture supernatant (120.7 U/ml) in fed-batch fermentation (72 hr) with sugarcane molasses. Toluene permeabilization increased 2.3-fold the Sa1-SSTrec activity of whole cells entrapped in calcium-alginate beads. The reaction with refined or raw sugar (600 g/l) yielded 1-kestotriose and 1,1-kestotetraose in a ratio of 8:2 with their sum representing above 55% (wt/wt) of total carbohydrates. The FOSs yield decreased to 45% (wt/wt) when sugarcane syrup and molasses were used as cheaper sucrose sources. The beads retained 80% residual Sa1-SSTrec activity after a 30-day batchwise operation with refined cane sugar at 30°C and pH 5.5. The immobilized biocatalyst is attractive for the continuous production of short-chain FOSs, most particularly 1-kestotriose.

P53 inhibitor pifithrin-α inhibits ropivacaine-induced neuronal apoptosis via the mitochondrial apoptosis pathway.

The neurotoxicity of local anesthetics (LAs) has attracted more and more attention, However, they lack preventive and therapeutic measures. Many studies have shown that apoptosis plays an important role in the process of LA-induced neurotoxicity. As an important signaling molecule to activate apoptosis, p53 has been proved to be involved in the neurotoxicity induced by LAs, but the mechanism is unclear. In this study, we explored the effect of pifithrin-α (PFT-α), a p53 inhibitor, on apoptosis by ropivacaine (Rop) in vivo and in vitro. Cell viability and apoptosis detected by CCK-8 and a JC-1 apoptosis detection kit, the changes of spinal cord structure observed after hematoxylin and eosin staining, apoptosis of the spinal cord measured by terminal deoxynucleotidyl transferase dUTP nick end labeling staining, behavioral assessment of the nerve Injury evaluated by the detection of sciatic nerve conduction velocity (SNCV) andmechanical withdrawal threshold (MWT), the expression of p53 and many apoptosis-related genes included Bax, Bcl-2, and caspase-3 detected by quantitative real-time polymerase chain reaction, Western blot analysis, immunofluorescence, and immunohistochemistry. Results showed that PC12 cell viability decreased because of Rop, but the pretreatment of PFT-α could protect it. And PFT-α reduced the injuries in the spinal cord by Rop included vacuoles or edema. The results of immunofluorescence and immunohistochemistry testing showed that PFT-α inhibited the p53 protein upregulated by Rop. Apoptosis rate and many proapoptotic genes include p53, Bax, caspase-3 messenger RNA, and proteins were increased by Rop, but PFT-α could decrease it. In conclusion, PFT-α inhibited cell apoptosis and spinal cord injuries induced by Rop.

RhII -Catalyzed De-symmetrization of Ethane-1,2-dithiol and Propane-1,3-dithiol Yields Metallo-ß-lactamase Inhibitors.

Diversity-oriented synthesis (DOS) is a rich source for novel lead structures in Medicinal Chemistry. In this study, we present a DOS-compatible method for synthesis of compounds bearing a free thiol moiety. The procedure relies on Rh(II)-catalyzed coupling of dithiols to diazo building blocks. The synthetized library was probed against metallo-ß-lactamases (MBLs) NDM-1 and VIM-1. Biochemical and biological evaluation led to identification of novel potent MBL inhibitors with antibiotic adjuvant activity.

Regulation of amyloid-ß levels by matrix metalloproteinase-2/9 (MMP2/9) in the media of lung cancer cells.

In this study, we set out to identify regulators of intact amyloid-ß40/42 (Aß) levels in A549 (p53 wild-type) and H1299 (p53-null) lung cancer cell media. Higher Aß levels were detected in the media of A549 than H1299 cells without or with treatment with 4-methylumbelliferone (4-MU) and/or the anti-CD44 antibody (5F12). Using inhibitors, we found that PI3K, AKT, and NFκB are likely involved in regulating Aß levels in the media. However, increased Aß levels that more closely resembled those found upon 4-MU co-treatment resulted from MMP2/9 inhibition, suggesting that MMP2/9 maybe the main contributors to regulation of Aß levels in the media. Differences in Aß levels might be accounted for, in part, by p53 since blocking p53 function in A549 cells resulted in decreased Aß levels, increased MMP2/9 levels, increased PI3K/AKT activities and the phospho/total NFκB ratio. Using siRNA targeted against MMP2 or MMP9, we found increased Aß levels in the media, however, MMP2 knockdown led to Aß levels closely mimicking those detected by co-treatment with 4-MU. Cell viability or apoptosis upon treatment with either MMP2 or MMP9 siRNA along with Aß immunodepletion, showed that MMP2 is the predominant regulator of the cytotoxic effects induced by Aß in lung cancer cells.

Phenotypic and Functional Characteristics of a Novel Influenza Virus Hemagglutinin-Specific Memory NK Cell.

Immune memory represents the most efficient defense against invasion and transmission of infectious pathogens. In contrast to memory T and B cells, the roles of innate immunity in recall responses remain inconclusive. In this study, we identified a novel mouse spleen NK cell subset expressing NKp46 and NKG2A induced by intranasal influenza virus infection. These memory NK cells specifically recognize N-linked glycosylation sites on influenza hemagglutinin (HA) protein. Different from memory-like NK cells reported previously, these NKp46+ NKG2A+ memory NK cells exhibited HA-specific silence of cytotoxicity but increase of gamma interferon (IFN-γ) response against influenza virus-infected cells, which could be reversed by pifithrin-µ, a p53-heat shock protein 70 (HSP70) signaling inhibitor. During recall responses, splenic NKp46+ NKG2A+ NK cells were recruited to infected lung and modulated viral clearance of virus and CD8+ T cell distribution, resulting in improved clinical outcomes. This long-lived NK memory bridges innate and adaptive immune memory response and promotes the homeostasis of local environment during recall response.IMPORTANCE In this study, we demonstrate a novel hemagglutinin (HA)-specific NKp46+ NKG2A+ NK cell subset induced by influenza A virus infection. These memory NK cells show virus-specific decreased cytotoxicity and increased gamma interferon (IFN-γ) on reencountering the same influenza virus antigen. In addition, they modulate host recall responses and CD8 T cell distribution, thus bridging the innate immune and adaptive immune responses during influenza virus infection.

Deficiency of telomere-associated repressor activator protein 1 precipitates cardiac aging in mice via p53/PPARα signaling.

Background: Telomere shortening and dysfunction may cause metabolic disorders, tissue damage and age-dependent pathologies. However, little is known about the association of telomere-associated protein Rap1 with mitochondrial energy metabolism and cardiac aging. Methods: Echocardiography was performed to detect cardiac structure and function in Rap1+/+ and Rap1-/- mice at different ages (3 months, 12 months and 20 months). Telomere length, DNA damage, cardiac senescence and cardiomyocyte size were analyzed using the real-time PCR, Western blotting, senescence associated ß-galactosidase assay and wheat germ agglutinin staining, respectively. Western blotting was also used to determine the level of cardiac fatty acid metabolism related key enzymes in mouse and human myocardium. Chromatin immunoprecipitation assay was used to verify the direct link between p53 and PPARα. The p53 inhibitor, Pifithrin-α and PPARα activator WY14643 were utilized to identify the effects of Rap1/p53/PPARα signaling pathway. Results: Telomere was shortened concomitant with extensive DNA damage in aged Rap1-/- mouse hearts, evidenced by reduced T/S ratios and increased nuclear γH2AX. Meanwhile, the aging-associated phenotypes were pronounced as reflected by altered mitochondrial ultrastructure, enhanced senescence, cardiac hypertrophy and dysfunction. Mechanistically, acetylated p53 and nuclear p53 was enhanced in the Rap1-/- mouse hearts, concomitant with reduced PPARα. Importantly, p53 directly binds to the promoter of PPARα in mouse hearts and suppresses the transcription of PPARα. In addition, aged Rap1-/- mice exhibited reduced cardiac fatty acid metabolism. Pifithrin-α alleviated cardiac aging and enhanced fatty acid metabolism in the aged Rap1-/- mice. Activating PPARα with WY14643 in primarily cultured Rap1-/- cardiomyocytes restored maximal oxygen consumption rates. Reduced Rap1 expression and impaired p53/PPARα signaling also presented in aged human myocardium. Conclusion: In summary, Rap1 may link telomere biology to fatty acid metabolism and aging-related cardiac pathologies via modulating the p53/PPARα signaling pathway, which could represent a therapeutic target in preventing/attenuating cardiac aging.

Ethoxyquin and Butylated Hydroxy Toluene Distrub the Hematological Parameters and Induce Structural and Functional Alterations in Liver of Rats.

The current experiment aimed to assess the effect of the synthetic antioxidants ethoxyquin (EQ) and/or butylated hydroxytoluene (BHT) on the liver function tests, hematological parameters, and liver histoarchitecture in rats. A total of 50 male Sprague-Dawley rats were divided into five groups of 10 animals per group. The first group served as the control and did not receive any treatments, and the second group served as the vehicle control and was orally administrated 1 ml of corn oil day after day for consecutive 45 and 90 days. The third group (EQ) was orally administered 1 ml of EQ dissolved in corn oil day after day for consecutive 45 and 90 days in a dose of 1/5 LD50, and the fourth group (BHT) was orally received 1 ml of BHT dissolved in corn oil day after day for consecutive 45 and 90 days in a dose of 1/5 LD50. The fifth group (combination group) was orally administered both EQ and BHT at the same doses and durations described above. The present results showed that the final body weight was significantly decreased in the EQ- or BHT-treated group particularly at 90 days of exposure to both compounds. Furthermore, the liver weight was significantly elevated in EQ, BHT, and co-exposed groups at 45 and 90 days of exposure, compared to the control group. Moreover, EQ, BHT, and their co-exposure caused a significant elevation in the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) enzymes, as well as total bilirubin at 45 and 90 days of exposure. On the other hand, there was no significant change in the total albumin. Hemoglobin value, red blood cells, white blood cells, platelets, and differential leucocyte count at 45 and 90 days of exposure were significantly decreased. Histopathological significant findings in the liver were observed as vascular congestions, vacuolations, hydropic degenerations, lipidosis, and swelling, particularly in the co-exposed group for 90 days. These findings confirmed the hepatotoxic potential of EQ and BHT; therefore, it is recommended to control and limit the utilization of such chemicals.

Plant polyphenols can directly affect ovarian cell functions and modify toluene effects.

The influence of toluene alone and in combination with plant polyphenols apigenin, daidzein or rutin on viability, proliferation (proliferating cell nuclear antigen accumulation), apoptosis (Bax accumulation) and release of progesterone (P), testosterone (T) and estradiol (E) in cultured porcine ovarian granulosa cells was evaluated. Toluene reduced ovarian cell viability, proliferation and E release; it promoted P release, demonstrating no effect on apoptosis or T output. Apigenin alone failed to affect cell viability, proliferation, apoptosis and P and T release, but stimulated E release, promoting the inhibitory action of toluene on proliferation, preventing and even reversing the stimulatory effect of toluene on apoptosis and P. Daidzein alone reduced cell viability and promoted T release, preventing and reversing the stimulatory effect of toluene on cell proliferation. Rutin administration reduced cell viability and E output, promoting the inhibitory action of toluene on cell viability and stimulatory effect on P release, and preventing the inhibitory action of toluene on E release. Toluene reduced apigenin- and rutin-induced E release, promoting action of daidzein on cell viability. These observations suggest the action of toluene and plant polyphenols on ovarian cell functions and the functional interrelationships between these molecules in the ovary.