Synthase Gene Expression Research Articles

Low prostaglandin-endoperoxide synthase-2 gene expression in colorectal carcinomas may predict poorer survival

Low prostaglandin-endoperoxide synthase-2 gene expression in colorectal carcinomas may predict poorer survival

In Vivo Glucose Transporter-2 Regulation of Dorsomedial Versus Ventrolateral VMN Astrocyte Metabolic Sensor and Glycogen Metabolic Enzyme Gene Expression in Female Rat.

Astrocyte glycogenolysis shapes ventromedial hypothalamic nucleus (VMN) regulation of glucostasis in vivo. Glucose transporter-2 (GLUT2), a plasma membrane glucose sensor, controls hypothalamic primary astrocyte culture glycogen metabolism in vitro. In vivo gene silencing tools and single-cell laser-catapult-microdissection/multiplex qPCR techniques were used here to examine whether GLUT2 governs dorsomedial (VMNdm) and/or ventrolateral (VMNvl) VMN astrocyte metabolic sensor and glycogen metabolic enzyme gene profiles. GLUT2 gene knockdown diminished astrocyte GLUT2 mRNA in both VMN divisions. Hypoglycemia caused GLUT2 siRNA-reversible up-regulation of this gene profile in the VMNdm, but down-regulated VMNvl astrocyte GLUT2 transcription. GLUT2 augmented baseline VMNdm and VMNvl astrocyte glucokinase (GCK) gene expression, but increased (VMNdm) or reduced (VMNvl) GCK transcription during hypoglycemia. GLUT2 imposed opposite control, namely stimulation versus inhibition of VMNdm or VMNvl astrocyte 5'-AMP-activated protein kinase-alpha 1 and -alpha 2 gene expression, respectively. GLUT2 stimulated astrocyte glycogen synthase (GS) gene expression in each VMN division. GLUT2 inhibited transcription of the AMP-sensitive glycogen phosphorylase (GP) isoform GP-brain type (GPbb) in each site, yet diminished (VMNdm) or augmented (VMNvl) astrocyte GP-muscle type (GPmm) mRNA. GLUT2 enhanced VMNdm and VMNvl glycogen accumulation during euglycemia, and curbed hypoglycemia-associated VMNdm glycogen depletion. Results show that VMN astrocytes exhibit opposite, division-specific GLUT2 transcriptional responsiveness to hypoglycemia. Data document divergent GLUT2 control of GCK, AMPK catalytic subunit, and GPmm gene profiles in VMNdm versus VMNvl astrocytes. Ongoing studies seek to determine how differential GLUT2 regulation of glucose and energy sensor function and glycogenolysis in each VMN location may affect local neuron responses to hypoglycemia.

The Toxoplasma gondii homolog of ATPase inhibitory factor 1 is critical for mitochondrial cristae maintenance and stress response.

The production of energy in the form of ATP by the mitochondrial ATP synthase must be tightly controlled. One well-conserved form of regulation is mediated via ATPase inhibitory factor 1 (IF1), which governs ATP synthase activity and gene expression patterns through a cytoprotective process known as mitohormesis. In apicomplexans, the processes regulating ATP synthase activity are not fully elucidated. Using the model apicomplexan Toxoplasma gondii, we found that knockout and overexpression of TgIF1, the structural homolog of IF1, significantly affected gene expression. Additionally, TgIF1 overexpression resulted in the formation of a stable TgIF1 oligomer and increased the presence of higher order ATP synthase oligomers. We also show that parasites lacking TgIF1 exhibit reduced mitochondrial cristae density, and that while TgIF1 levels do not affect growth in conventional culture conditions, they are crucial for parasite survival under hypoxia. Interestingly, TgIF1 overexpression enhances recovery from oxidative stress, suggesting a mitohormetic function. In summary, while TgIF1 does not appear to play a role in ATP synthase regulation under conventional growth conditions, our work uncovers its potential role in adapting to the stressors faced by T. gondii and other apicomplexans throughout their intricate life cycles.

P63 affects distinct metabolic pathways during keratinocyte senescence, evaluated by metabolomic profile and gene expression analysis

Unraveling the molecular nature of skin aging and keratinocyte senescence represents a challenging research project in epithelial biology. In this regard, depletion of p63, a p53 family transcription factor prominently expressed in human and mouse epidermis, accelerates both aging and the onset of senescence markers in vivo animal models as well as in ex vivo keratinocytes. Nonetheless, the biochemical link between p63 action and senescence phenotype remains largely unexplored. In the present study, through ultrahigh performance liquid chromatography–tandem mass spectroscopy (UPLC–MS/MS) and gas chromatography/mass spectrometry (GC/MS) metabolomic analysis, we uncover interesting pathways linking replicative senescence to metabolic alterations during p63 silencing in human keratinocytes. Integration of our metabolomic profiling data with targeted transcriptomic investigation empowered us to demonstrate that absence of p63 and senescence share similar modulation profiles of oxidative stress markers, pentose phosphate pathway metabolites and lyso-glycerophospholipids, the latter due to enhanced phospholipases gene expression profile often under p63 direct/indirect gene control. Additional biochemical features identified in deranged keratinocytes include a relevant increase in lipids production, glucose and pyruvate levels as confirmed by upregulation of gene expression of key lipid synthesis and glycolytic enzymes, which, together with improved vitamins uptake, characterize senescence phenotype. Silencing of p63 in keratinocytes instead, translates into a blunted flux of metabolites through both glycolysis and the Krebs cycle, likely due to a p63-dependent reduction of hexokinase 2 and citrate synthase gene expression. Our findings highlight the potential role of p63 in counteracting keratinocyte senescence also through fine regulation of metabolite levels and relevant biochemical pathways. We believe that our research might contribute significantly to the discovery of new implications of p63 in keratinocyte senescence and related diseases.

Confirmation of Glyphosate Resistance in Annual Bluegrass (Poa annua) via EPSPS Duplication in a Soybean and Rice Rotation

Abstract Annual bluegrass (Poa annua L.) populations in turfgrass have evolved resistance to several herbicides in the United States (US), but there has been no confirmed resistance from an agricultural field. Recently, glyphosate failed to control a P. annua population found in a field in a soybean [(Glycine max (L.) Merr.] and rice (Oryza sativa L.) rotation in Poinsett County, Arkansas. The present study focused on determining the sensitivity of a putatively-resistant accession (R1) to glyphosate compared with two susceptible accessions (S1 and S2). The experiments included a dose-response study, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene copy number and expression analysis, and assessment of mutations in EPSPS. Based on the dose-response analysis, R1 required 1,038 g ae ha-1 of glyphosate to cause 50% biomass reduction, whereas S1 and S2 only required 148.2 g and 145.5 g ae ha-1, respectively. The resistant index (RI) was approximately 7-fold relative to the susceptible accessions. Real-time polymerase chain reaction data revealed at least a 15-fold increase in the EPSPS copy number in R1, along with a higher gene expression. No mutations in EPSPS were found. Gene duplication was identified as the main mechanism conferring resistance in R1. The research presented here reports the first incidence of glyphosate resistance in P. annua from an agronomic field crop situation in the US.

Regulation of trehalose metabolism mediated by validamycin on chitin synthesis in Spodoptera frugiperda

AbstractTrehalase (TRE) is a key enzyme for degrading trehalose, which plays a vital role in the growth and development of insects. Although validamycin, a compound belonging to a class of efficient antibiotics and fungicides, can control pests by suppressing TRE activities, it remains unknown whether it acts on both trehalose and chitin metabolism in Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), a major pest of maize (Zea mays L., Poaceae). This study investigated the changes in trehalose metabolism after validamycin treatment in S. frugiperda and its effects on the downstream chitin synthesis pathway. Compared with the control, S. frugiperda exhibited varying degrees of mortality after treatment with four concentrations of validamycin, showing a dose‐dependent increase in mortality rate. The mortality rates 24 and 48 h after treatment with 0.07 mg μL−1 validamycin were 35.6% and 42.2%, respectively, indicating the effective lethal concentration. Treatment with 0.07 mg μL−1 validamycin led to developmental delay, abnormal molting, and death in S. frugiperda, but it exerted no lasting effects on the survival rate, pupal weight, and phenotype during its subsequent developmental stages. At 24 h after validamycin treatment, TRE1 and TRE2 activities and glucose content decreased significantly, whereas the trehalose content increased significantly. Treatment with validamycin significantly upregulated TRE1 and TRE2 expression after 24 and 48 h and downregulated the mRNA expression of chitin synthase A and B genes. However, after 72 h, chitin content was not significantly affected. Hence, validamycin can destroy the dynamic transformation balance of trehalose and glucose by inhibiting the activities of the two TREs, and further affect the expression of downstream chitin synthase genes. These findings provide a theoretical basis for using TRE inhibitors to control S. frugiperda.

Nocturnal burst emissions of germacrene D from the open disk florets of pyrethrum flowers induce moths to oviposit on a nonhost and improve pollination success.

Recent studies show that nocturnal pollinators may be more important to ecosystem function and food production than is currently appreciated. Here, we describe an agricultural field study of pyrethrum (Tanacetum cinerariifolium) flower pollination. Pyrethrum is genetically self-incompatible and thus is reliant on pollinators for seed set. Our pollinator exclusion experiment showed that nocturnal insects, particularly moths, significantly contribute to seed set and quality. We discovered that the most abundant floral volatile, the sesquiterpene (-)-germacrene D (GD), is key in attracting the noctuid moths Peridroma saucia and Helicoverpa armigera. Germacrene D synthase (GDS) gene expression regulates the specific GD production and accumulation in flowers, which, in contrast to related species, lose the habit of closing at night. We did observe that female moths also oviposited on pyrethrum leaves and flower peduncles, but found that only a small fraction of those eggs hatched. Larvae were severely stunted in development, most likely due to the presence of pyrethrin defense compounds. This example of exploitative mutualism, which blocks the reproductive success of the moth pollinator and depends on nocturnal interactions, is placed into an ecological context to explain why it may have developed.

Comprehensive phytochemical profiling and biological activities of Hodgsonia heteroclita subsp. indochinensis seed extracts

Hodgsonia heteroclita subsp. indochinensis, a member of the Cucurbitaceae family, is utilized in traditional medicinal remedies based on indigenous wisdom. This study aimed to comprehensively identify and analyze the bioactive phytoconstituents within H. heteroclita subsp. indochinensis seeds. Seeds were sequentially extracted with n-hexane, ethyl acetate, and methanol. Liquid chromatography-mass spectrometry analysis detected ferulic acid, salicylic acid, cucurbitacin E, stigmasterol glucoside, and β-sitosterol glucoside in all extracts. The total phenolic content in the HH(S)-EtOAc and HH(S)-MeOH was 14.22 ± 1.58 and 12.98 ± 1.03 mg gallic acid equivalent/g, respectively. Consequently, the HH(S)-EtOAc demonstrated antioxidant activity with an IC50 of 1.10 ± 0.28 mg/mL, while the HH(S)-MeOH displayed strong antioxidant potential with an IC50 of 0.04 ± 0.00 mg/mL according to an ABTS assay. Antibacterial evaluations of both the HH(S)-hexane and HH(S)-EtOAc revealed significant activity against Staphylococcus aureus (zone of inhibition (ZOI): 13.67 ± 2.31 and 11.67 ± 1.53 mm, respectively) but limited activity against Escherichia coli (ZOI: 7.33 ± 0.58 and 7.67 ± 0.58 mm, respectively). Additionally, the extracts exhibited low minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values, ranging from 62.50 to 250 mg/mL. The antiproliferative activity of seed extracts was assessed against two breast cancer cell lines (MCF-7 and MDA-MB-231), normal breast cells (MCF10A), and human embryonic kidney (HEK) 293T cells, through MTT and clonogenic assays. The results revealed IC50 values exceeding 400 μg/mL, indicating that the extracts are safe. Furthermore, all seed extracts (50 μg/mL) exhibited potent anti-inflammatory activity, evident by their substantial inhibition of nitric oxide production (p < 0.001) and inducible nitric oxide synthase (iNOS) gene expression (p < 0.05) in LPS-induced RAW264.7. These findings demonstrate the potential for H. heteroclita subsp. indochinensis seed extracts in the development of functional foods, nutraceuticals, and dietary supplements due to their diverse bioactive compounds and substantial biological activities, particularly their anti-inflammatory effects.

The Toxoplasma gondii homolog of ATPase inhibitory factor 1 is critical for mitochondrial cristae maintenance and stress response.

The production of energy in the form of ATP by the mitochondrial ATP synthase must be tightly controlled. One well-conserved form of regulation is mediated via ATPase inhibitory factor 1 (IF1), which governs ATP synthase activity and gene expression patterns through a cytoprotective process known as mitohormesis. In apicomplexans, the processes regulating ATP synthase activity are not fully elucidated. Using the model apicomplexan Toxoplasma gondii, we found that knockout and overexpression of TgIF1, the structural homolog of IF1, significantly affected gene expression. Additionally, TgIF1 overexpression resulted in the formation of a stable TgIF1 oligomer that increased the presence of higher order ATP synthase oligomers. We also show that parasites lacking TgIF1 exhibit reduced mitochondrial cristae density, and that while TgIF1 levels do not affect growth in conventional culture conditions, they are crucial for parasite survival under hypoxia. Interestingly, TgIF1 overexpression enhances recovery from oxidative stress, suggesting a mitohormetic function. In summary, while TgIF1 does not appear to play a role in metabolic regulation under conventional growth conditions, our work highlights its importance for adapting to stressors faced by T. gondii and other apicomplexans throughout their intricate life cycles.

Nitric oxide is involved in the regulation of guard mother cell division by inhibiting the synthesis of ACC.

A stoma forms by a series of asymmetric divisions of stomatal lineage precursor cell and the terminal division of a guard mother cell (GMC). GMC division is restricted to once through genetic regulation mechanisms. Here, we show that nitric oxide (NO) is involved in the regulation of the GMC division. NO donor treatment results in the formation of single guard cells (SGCs). SGCs are also produced in plants that accumulate high NO, whereas clustered guard cells (GCs) appear in plants with low NO accumulation. NO treatment promotes the formation of SGCs in the stomatal signalling mutants sdd1, epf1 epf2, tmm1, erl1 erl2 and er erl1 erl2, reduces the cell number per stomatal cluster in the fama-1 and flp1 myb88, but has no effect on stomatal of cdkb1;1 cyca2;234. Aminocyclopropane-1-carboxylic acid (ACC), a positive regulator of GMC division, reduces the NO-induced SGC formation. Further investigation found NO inhibits ACC synthesis by repressing the expression of several ACC SYNTHASE (ACS) genes, and in turn ACC represses NO accumulation by promoting the expression of HEMOGLOBIN 1 (HB1) encoding a NO scavenger. This work shows NO plays a role in the regulation of GMC division by modulating ACC accumulation in the Arabidopsis cotyledon.

Evidence of Urtica dioica Agglutinin's Antiproliferative and Anti-migratory Potentials on the Hyaluronic Acid-Overexpressing Prostate Cancer Cells.

Hyaluronic acid is composed of repeating sugar units, glucuronic acid and N-acetylglucosamine, which are often associated with increased tumor progression. Urtica dioica agglutinin is a potential component that exhibits a high affinity for binding to N-acetylglucosamine. This study aimed to investigate U. dioica Agglutinin's potential to inhibit the proliferation and migration of prostate cancer cells with high expression of hyaluronic acid through molecular docking and in vitro studies. The expression of hyaluronan synthase genes in prostate tissue and cell lines was checked by an in silico study, and the interaction between hyaluronic acid with both CD44 transmembrane glycoprotein and U. dioica agglutinin was analyzed through molecular docking. U. dioica Agglutinin's effect on cell viability (neutral red uptake assay), migration (scratch wound healing assays), and both CD44 and Nanog expression (quantitative real-time polymerase chain reaction) were assessed in vitro. The results showed that in prostate cancer cell lines, the PC3 cell line has the highest expression of hyaluronan synthase genes. U. dioica agglutinin exhibits an interaction of six specific residues on CD44 compared to hyaluronic acid's singular residue. While U. dioica agglutinin alone effectively reduced cell viability and wound closer (≥ 150 µg/mL), combining it with hyaluronic acid significantly shifted the effective concentration to a higher dose (≥ 350 µg/mL). These results, together with low Nanog and high CD44 gene expression, suggest that U. dioica agglutinin may impair the CD44-HA pathway in PC3 cells. This possibility is supported by U. dioica Agglutinin's ability to compete with hyaluronic acid for binding to CD44. Based on this, U. dioica agglutinin as a plant lectin shows promise in inhibiting cancer proliferation and migration by targeting its dependence on hyaluronic acid.

Study of the expression of cellulose synthase genes during plant growth of flax

Study of the expression of cellulose synthase genes during plant growth of flax

Regulation of nitrogen utilization and mycotoxin biosynthesis by the GATA transcription factor AaAreA in Alternaria alternata.

Alternaria alternata is a prevalent postharvest pathogen that generates diverse mycotoxins, notably alternariol (AOH) and alternariol monomethyl ether (AME), which are recurrent severe contaminants. Nitrogen sources modulate fungal growth, development, and secondary metabolism, including mycotoxin production. The GATA transcription factor AreA regulates nitrogen source utilization. However, little is known about its involvement in the regulation of nitrogen utilization in A. alternata. To examine the regulatory mechanism of AaAreA on AOH and AME biosynthesis in A. alternata, we analyzed the impact of diverse nitrogen sources on the fungal growth, conidiation and mycotoxin production. The use of a secondary nitrogen source (NaNO3) enhanced mycelial elongation and sporulation more than the use of a primary source (NH4Cl). NaNO3 favored greater mycotoxin accumulation than did NH4Cl. The regulatory roles of AaAreA were further clarified through gene knockout. The absence of AaAreA led to an overall reduction in growth in minimal media containing any nitrogen source except NH4Cl. AaAreA positively regulates mycotoxin biosynthesis when both NH4Cl and NaNO3 are used as nitrogen sources. Subcellular localization analysis revealed abundant nuclear transport when NaNO3 was the sole nitrogen source. The regulatory pathway of AaAreA was systematically revealed through comprehensive transcriptomic analyses. The deletion of AaAreA significantly impedes the transcription of mycotoxin biosynthetic genes, including aohR, pksI and omtI. The interaction between AaAreA and aohR, a pathway-specific transcription factor gene, demonstrated that AaAreA binds to the aohR promoter sequence (5'-GGCTATGGAAA-3'), activating its transcription. The expressed AohR regulates the expression of downstream synthase genes in the cluster, ultimately impacting mycotoxin production. This study provides valuable information to further understand how AreA regulates AOH and AME biosynthesis in A. alternata, thereby enabling the effective design of control measures for mycotoxin contamination.

2-Deoxy-D-Glucose Downregulates Fatty Acid Synthase Gene Expression Via an Endoplasmic Reticulum Stress-Dependent Pathway in HeLa Cells.

Fatty acid synthase (FASN) catalyzes the rate-limiting step of cellular lipogenesis. FASN expression is upregulated in various types of cancer cells, implying that FASN is a potential target for cancer therapy. 2-Deoxy-D-glucose (2-DG) specifically targets cancer cells by inhibiting glycolysis and glucose metabolism, resulting in multiple anticancer effects. However, whether the effects of 2-DG involve lipogenic metabolism remains to be elucidated. We investigated the effect of 2-DG administration on FASN expression in HeLa human cervical cancer cells. 2-DG treatment for 24 h decreased FASN mRNA and protein levels and suppressed the activity of an exogenous rat Fasn promoter. The use of a chemical activator or inhibitors or of a mammalian expression plasmid showed that neither AMPK nor the Sp1 transcription factor is responsible for the inhibitory effect of 2-DG on FASN expression. Administration of thapsigargin, an endoplasmic reticulum (ER) stress inducer, or 4-(2-aminoethyl) benzenesulfonyl fluoride (AEBSF), a site 1 protease inhibitor, mimicked the inhibitory effect of 2-DG on FASN expression. 2-DG did not further decrease FASN expression in the presence of thapsigargin or AEBSF. Site 1 protease mediates activation of ATF6, an ER stress mediator, as well as sterol regulatory element-binding protein 1 (SREBP1), a robust transcription factor for FASN. Administration of 2-DG or thapsigargin for 24 h suppressed activation of ATF6 and SREBP1, as did AEBSF. We speculated that these effects of 2-DG or thapsigargin are due to feedback inhibition via increased GRP78 expression following ER stress. Supporting this, exogenous overexpression of GRP78 in HeLa cells suppressed SREBP1 activation and Fasn promoter activity. These results suggest that 2-DG suppresses FASN expression via an ER stress-dependent pathway, providing new insight into the molecular basis of FASN regulation in cancer.

Con7 is a key transcription regulator for conidiogenesis in the plant pathogenic fungus Fusarium graminearum.

The ascomycete fungus Fusarium graminearum is the primary cause of head blight disease in wheat and barley, as well as ear and stalk rot in maize. Given the importance of conidia and ascospores in the disease cycle of F. graminearum, precise spatiotemporal regulation of these biological processes is crucial. In this study, we characterized the Magnaporthe oryzae Con7p ortholog and discovered that FgCon7 significantly influences various crucial aspects of fungal development and pathogenicity. Notably, overexpression of FgABAA partially restored developmental defects in the FgCON7 deletion mutant. ChIP-qPCR analysis confirmed a direct genetic link between FgABAA and FgCON7. Furthermore, our research revealed a clear correlation between FgCon7 and chitin accumulation and the expression of chitin synthase genes. These findings offer valuable insights into the genetic mechanisms regulating conidiation and the significance of mycelial differentiation in this plant pathogenic fungus.

Acetyl-L-carnitine Improves Depressive-like Behaviors Through Nitric Oxide Modulation in the Cuprizone Intoxication Mouse Model of Multiple Sclerosis

Background: Demyelination and inflammation are the most common pathobiological manifestations contributing to depression in multiple sclerosis (MS). Objectives: The current study aimed to evaluate the effects of acetyl-L-carnitine (ALC) in attenuating depressive-like symptoms in the cuprizone intoxication mouse model. Methods: C57BL/6 mice were categorized into three groups (n = 6 each) as follows: The control animals (CTL), the cuprizone-intoxicated mice (CPZ), and the group that received cuprizone and acetyl-L-carnitine (CPZ+ALC). Depressive-like behaviors were evaluated by the forced swim test (FST) and the tail suspension test (TST). The prefrontal cortex (PFC) and corpus callosum (CC) areas were assessed in terms of histopathology, biochemistry, and gene expression. Results: Following oral gavage of ALC, the immobility time, which represents the despairing time, significantly decreased compared to the CPZ group. Histopathological evaluation showed that remyelination in the CC increased significantly in animals receiving ALC compared to the CPZ mice. Acetyl-L-carnitine considerably decreased the nitric oxide (NO) level in the PFC of the brain in the demyelinated mice compared to the CPZ group. The qRT-PCR results revealed that ALC significantly increased neuronal nitric oxide synthase (nNOS) expression but decreased inducible nitric oxide synthase (iNOS) gene expression compared to the CPZ group. Conclusions: Acetyl-L-carnitine attenuated depressive-like behaviors in the cuprizone demyelination mouse model of MS. These neuroprotective effects of ALC may be exerted by facilitating the remyelination process and modulating the NO level in the PFC.

Enhanced polysaccharide production through quorum sensing system in Cordyceps militaris.

This study aimed to enhance extracellular polysaccharide (EPS) production in Cordyceps militaris by constructing a quorum sensing (QS) system to regulate the expression of biosynthetic enzyme genes, including phosphoglucomutase, hexokinase, phosphomannomutase, polysaccharide synthase, and UDP-glucose 4-epimerase genes. The study found higher EPS concentrations in seven recombinant strains compared to the wild-type C. militaris, indicating that the overexpression of key enzyme genes increased EPS production. Among them, the CM-pgm-2 strain exhibited the highest EPS production, reaching a concentration of 3.82 ± 0.26 g/L, which was 1.52 times higher than the amount produced by the wild C. militaris strain. Additionally, the regulatory effects of aromatic amino acids on the QS system of the CM-pgm-2 strain were investigated. Under the influence of 45 mg/L tryptophan, the EPS production in CM-pgm-2 reached 4.75 ± 0.20 g/L, representing a 1.90-fold increase compared to wild C. militaris strains. This study provided an effective method for the large-scale production of EPSs in C. militaris, and opened up new avenues for research into fungal QS mechanisms.

Diuretic effects of Hecogenin and Hecogenin acetate via aldosterone synthase inhibition

Hecogenin (HEC) is a steroidal saponin found in many plant species and serves as a precursor for steroidal drugs. The diuretic effects of HEC and its derivative, hecogenin acetate (HA), remain largely unexplored. The present study aimed to explore the potential diuretic effects of HEC and HA compared to furosemide (FUR) and spironolactone (SPIR). Additionally, the study aimed to explore the underlying mechanism particularly focusing on aldosterone synthase gene expression. Fifty-four Sprague-Dawley rats were allocated into nine groups (Group 1–9). Group 1 (control) received the vehicle, Groups 2 received FUR 10 mg/kg, Group 3, 4, and 5 were given HEC, while Groups 6, 7 and 8 received HA i.p at doses of 5, 10, and 25 mg/kg, respectively. Group 9 received SPIR i.p at the dose of 25 mg/kg. Urine volume, diuretic index and diuretic activity were monitored at 1, 2, 3, 4, 5, 6, and 24 h post-administration. Treatment was given daily for seven days. After that, rats were sacrificed and blood was collected for serum electrolytes determination. Adrenal glands were dissected out for gene expression studies. The results revealed that HEC and HA at the administered doses significantly and dose-dependently increased urine and electrolyte excretion. These results were primarily observed at 25 mg/kg of each compound. Gene expression studies demonstrated a dose-dependent reduction in aldosterone synthase gene expression, suggesting aldosterone synthesis inhibition as a potential mechanism for their diuretic activity. Notably, HA exhibited more pronounced diuretic effects surpassing those of HEC. This enhanced diuretic activity of HA can be attributed to its stronger impact on aldosterone synthase inhibition. These findings offer valuable insights into the diuretic effects of both HEC and HA along with their underlying molecular mechanisms.

Increasing the radiation-induced cytotoxicity by silver nanoparticles and docetaxel in prostate cancer cells.

Radiation therapy is utilized for treatment of localized prostate cancer. Nevertheless, cancerous cells frequently develop radiation resistance. While higher radiation doses have not always been effective, radiosensitizers have been extensively studied for their ability to enhance the cytotoxic effects of radiation.So, this study aims to evaluate the possible radiosensitization effects of docetaxel (DTX) and silver nanoparticles (SNP) in LNCaP cells. The cytotoxic effects of DTX, SNP and2Gy of X-Ray radiation treatments were assessed in human LNCaP cell line using the MTT test after 24 h. Moreover, the effects of DTX, SNP and radiation on Epidermal growth factor (EGF), Caspase 3, inducible nitric oxide synthase and E-cadherin gene expression were analyzed using the Real-time PCR method. The level of Hydrogen peroxide (H2O2), an oxidative stress marker, was also detected 24h after various single and combined treatments. The combinations of SNP (in low toxic concentration) and/or DTX (0.25× IC50 and 0.5 × IC50 concentrations for triple and double combinations respectively) with radiation induced significant cytotoxicity in LNCaP cells in comparison to monotherapies. These cytotoxic effects were associated with the downregulation of EGF mRNA. Additionally, H2O2 levels increased after Radiation + SNP + DTX triple combination and double combinations including Radiation + SNP and Radiation + DTX versus single treatments. The triple combination treatment also increased Caspase 3 and and E-cadherin mRNA levels in compared to single treatments in LNCaP cells. Our results indicate that the combination of SNP and DTX with radiation induces significant anti-cancer effects. Upregulation of Caspase 3 and E-cadherin gene expression, and decreased mRNA expression level of EGF may be exerted specifically by use of this combination versus single treatments.

Mitochondrial translation failure represses cholesterol gene expression via Pyk2-Gsk3β-Srebp2 axis.

Neurodegenerative diseases and other age-related disorders are closely associated with mitochondrial dysfunction. We previously showed that mice with neuron-specific deficiency of mitochondrial translation exhibit leukoencephalopathy because of demyelination. Reduced cholesterol metabolism has been associated with demyelinating diseases of the brain such as Alzheimer's disease. However, the molecular mechanisms involved and relevance to the pathogenesis remained unknown. In this study, we show that inhibition of mitochondrial translation significantly reduced expression of the cholesterol synthase genes and degraded their sterol-regulated transcription factor, sterol regulatory element-binding protein 2 (Srebp2). Furthermore, the phosphorylation of Pyk2 and Gsk3β was increased in the white matter of p32cKO mice. We observed that Pyk2 inhibitors reduced the phosphorylation of Gsk3β and that GSK3β inhibitors suppressed degradation of the transcription factor Srebp2. The Pyk2-Gsk3β axis is involved in the ubiquitination of Srebp2 and reduced expression of cholesterol gene. These results suggest that inhibition of mitochondrial translation may be a causative mechanism of neurodegenerative diseases of aging. Improving the mitochondrial translation or effectiveness of Gsk3β inhibitors is a potential therapeutic strategy for leukoencephalopathy.