Response Element-binding Protein Research Articles

RON receptor tyrosine kinase regulates glycolysis through MAPK/CREB signaling to affect ferroptosis and chemotherapy sensitivity of thyroid cancer cells.

Anaplastic thyroid cancer (ATC) is one of the deadliest and most aggressive human malignancies for which there is currently no effective treatment. Tyrosine kinase receptor RON is highly expressed in various cancer types, including colon, pancreatic and thyroid cancer. However, its underlying role in ATC is not fully understood. The present study investigated the therapeutic potential and molecular mechanism of RON in ATC. RON expression in thyroid cancer cells was detected by western blotting. Glycolysis was assessed by measuring the extracellular acidification rate, glucose uptake, lactate concentration, and expression levels of glucose transporter 1, hexokinase 2 and pyruvate kinase M1/2. In addition, ferroptosis was assessed by detecting the levels of total iron, lipid peroxide and reactive oxygen species, and the expression levels of ferroptosis‑related proteins. Furthermore, mitochondrial function were assessed by JC‑1 staining and detection kits, respectively. The results demonstrated that RON was highly expressed in thyroid cancer cell lines. Furthermore, RON interference inhibited glycolysis, promoted ferroptosis, elevated cell sensitivity to chemotherapy and affected mitochondrial function in thyroid cancer cells. Further experiments demonstrated that RON interference affected the ferroptosis levels in thyroid cancer cells by inhibiting the glycolysis process. Mechanistically, the present results indicated that RON may affect ferroptosis, glycolysis and chemotherapy sensitivity by regulating MAPK/cAMP‑response element binding protein (CREB) signaling in thyroid cancer cells. In conclusion, the present study demonstrated that RON affected ferroptosis, glycolysis and chemotherapy sensitivity in thyroid cancer cells by regulating MAPK/CREB signaling, demonstrating its potential as a therapeutic target in thyroid cancer cells.

ZBED3 exacerbates hyperglycemia by promoting hepatic gluconeogenesis through CREB signaling

BackgroundElevated hepatic glucose production (HGP) is a prominent manifestation of impaired hepatic glucose metabolism in individuals with diabetes. Increased hepatic gluconeogenesis plays a pivotal role in the dysregulation of hepatic glucose metabolism and contributes significantly to fasting hyperglycemia in diabetes. Previous studies have identified zinc-finger BED domain-containing 3 (ZBED3) as a risk gene for type 2 diabetes (T2DM), and its single nucleotide polymorphism (SNPs) is closely associated with the fasting blood glucose level, suggesting a potential correlation between ZBED3 and the onset of diabetes. This study primarily explores the effect of ZBED3 on hepatic gluconeogenesis and analyzes the relevant signaling pathways that regulate hepatic gluconeogenesis. MethodsThe expression level of ZBED3 was assessed in the liver of insulin-resistant (IR)-related disease. RNA-seq and bioinformatics analyses were employed to examine the ZBED3-related pathway that modulated HGP. To investigate the role of ZBED3 in hepatic gluconeogenesis, the expression of ZBED3 was manipulated by upregulation or silencing using adeno-associated virus (AAV) in mouse primary hepatocytes (MPHs) and HHL-5 cells. In vivo, hepatocyte-specific ZBED3 knockout mice were generated. Moreover, AAV8 was employed to achieve hepatocyte-specific overexpression and knockdown of ZBED3 in C57BL/6 and db/db mice. Immunoprecipitation and mass spectrometry (IP-MS) analyses were employed to identify proteins that interacted with ZBED3. Co-immunoprecipitation (co-IP), glutathione S-transferase (GST) - pulldown, and dual-luciferase reporter assays were conducted to further elucidate the underlying mechanism of ZBED3 in regulating hepatic gluconeogenesis. ResultsThe expression of ZBED3 in the liver of IR-related disease models was found to be increased. Under the stimulation of glucagon, ZBED3 promoted the expression of hepatic gluconeogenesis-related genes PGC1A, PCK1, G6PC, thereby increasing HGP. Consistently, the rate of hepatic gluconeogenesis was found to be elevated in mice with hepatocyte-specific overexpression of ZBED3 and decreased in those with ZBED3 knockout. Additionally, the knockdown of ZBED3 in the liver of db/db mice resulted in a reduction in hepatic gluconeogenesis. Moreover, the study revealed that ZBED3 facilitated the nuclear translocation of protein arginine methyltransferases 5 (PRMT5) to influence the regulation of PRMT5-mediated symmetrical dimethylation of arginine (s-DMA) of cyclic adenosine monophosphate (cAMP) response element binding protein (CREB), which in turn affects the phosphorylation of CREB and ultimately promotes HGP. ConclusionsThis study indicates that ZBED3 promotes hepatic gluconeogenesis and serves as a critical regulator of the progression of diabetes.

Non-alcoholic fatty liver disease: Genetic susceptibility

The prevalence of Non-alcoholic Fatty Liver Disease (NAFLD) is increasing, particularly in individuals who consume minimal to no alcohol. Currently, NAFLD affects at least 32% of the global population. Although not all but approximately 5-10% cases of NAFLD progress to non-alcoholic steatohepatitis (NASH), a condition arising from lipotoxicity. Patients with NASH may further develop liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). However, it is important to note that progression from NAFLD to NASH and HCC is not inevitable for all patients. The pathogenesis of HCC in the context of NAFLD and NASH remains poorly understood, however, fat accumulation, often due to obesity or metabolic syndrome, leads to lipotoxicity. In individuals with type 2 diabetes (T2D), elevated insulin levels promote lipolysis in adipose tissue and activate lipid-synthesizing enzymes such as fatty acid synthase (FAS) and stearoyl-CoA desaturase 1 (SCD1), which contribute to lipid accumulation in the liver. Additionally, high glucose levels in T2D can alter gene regulation by activating carbohydrate response-element binding protein (ChREBP) and insulin can increase the activity of sterol regulatory element binding protein (SREBP-1c). These lipogenic transcription factors are known to directly or indirectly activate patatin-like phospholipase domain-containing protein 3 (PNPLA3). Recent research has found elevated levels of angiotensinogen (AGT) and des-angiotensin in both experimental animals and patients with NAFLD. Emerging evidence highlights the significance of genetic factors in the risk of developing NAFLD. Here we explore the association between specific genes and hepatosteatosis, detailing the roles of T2D and obesity in the progression from NAFLD to NASH, and involvement of hepatic stellate cells in liver fibrosis. Additionally, we examine the impact of genes such as PNPLA3, MBOAT7, TM6SF2, GKRP, CCN3, and AGT as well as role of single nucleotide polymorphisms in gene regulation and their contribution to the risk of NAFLD.

Activation of Follicle-Stimulating Hormone Receptor in Adrenal Zona Fasciculata Cells Promotes Cortisol Secretion: Implications for the Development of Menopause-Associated Diseases.

Changes in postmenopausal hormone levels are associated with a variety of disorders. This study elucidated the mechanism by which follicle-stimulating hormone (FSH) increases cortisol production involved in development of menopause-related diseases. The expression of FSH receptors (FSHRs) in murine adrenal zona fasciculata (AZF) cells and ATC7 cells was verified by immunofluorescence, western blotting and RT-PCR. The function of FSHR in promoting cortisol production was analyzed by cell culture and molecular biological methods. FSHR signaling pathways in ATC7 cells were analyzed by ELISA, qRT-PCR, and western blotting. Further, a mouse model was established by ovariectomy. Ovariectomized mice were treated with GnRHa. Ovariectomized mice initially received physiological doses of estrogen and were then injected with recombinant FSH. Then serum FSH, luteinizing hormone (LH), estradiol, and cortisol, and bone mineral density (BMD), blood pressure (BP) and heart rate (HR) were determined. FSHRs were expressed in murine AZF cells and ATC7 cells. FSH accelerated cortisol production through activated protein kinase A (PKA), cyclic adenosine monophosphate (cAMP)-response element binding protein (CREB), protein kinase B (PKB/AKT) and 5' AMP-activated protein kinase (MAPK) signaling pathways by Gsα-coupled FSHRs in ATC7 cells. Serum FSH levels (P<0.001) were elevated in ovariectomized mice with concurrent increases in cortisol (P<0.01), areal BMD (aBMD) (P<0.05), volumetric BMD (vBMD) (P<0.05), systolic BP (SBP) (P<0.05), diastolic BP (DBP) (P<0.05), and HR (P<0.05). However, the administration of GnRHa suppressed the increase in FSH levels and the elevation of cortisol, aBMD, vBMD, SBP, DBP, and HR induced by ovariectomy, even in the presence of normal serum estradiol levels. The study findings indicate that elevated FSH levels stimulate cortisol secretion, through a mechanism related to FSHRs expression in AZF cells.

Berberine Alleviates Sevoflurane Anesthesia-Induced Cognitive Dysfunction in Neonatal Mice via Regulating CREB1.

Sevoflurane has been shown to stimulate neurotoxicity and lead to cognitive impairment. Berberine is known for its role in regulating nervous system diseases, including cognitive dysfunction. This study aimed to investigate the effects of berberine on cognitive dysfunction induced by sevoflurane anesthesia and its potential mechanisms. In the in vivo study, neonatal mice were subjected to sevoflurane anesthesia to induce cognitive dysfunction. The cognitive function of the neonatal mice was evaluated using the Morris water maze test, open field test, and tail suspension test. Enzyme-linked immunosorbent assay (ELISA) was utilized to assess the levels of inflammatory factors. Immunohistochemistry (IHC) was conducted to detect ionized calcium-binding adaptor molecule 1 (IBA-1)-positive cells and cleaved caspase-3-positive cells in the hippocampus of the neonatal mice. Western blotting was used to measure the levels of cyclic adenosine monophosphate (cAMP) response element-binding protein 1 (CREB1) in hippocampal tissues and neurons. Hippocampal neurons were isolated from the hippocampus of neonatal mice. These neurons were treated with berberine or subjected to cell transfection. The cell counting kit-8 (CCK-8) assay and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay were conducted to measure cell viability and apoptosis of hippocampal neurons in vitro. Berberine significantly attenuated sevoflurane-induced cognitive impairment and inflammation in neonatal mice (p < 0.05 or p < 0.01). Additionally, berberine reduced sevoflurane-triggered neuronal apoptosis in the hippocampus of neonatal mice (p < 0.01). Sevoflurane markedly decreased CREB1 expression in the hippocampus of neonatal mice (p < 0.01), which was elevated by berberine treatment (p < 0.01). Mechanistically, sevoflurane significantly suppressed cell viability and promoted cell apoptosis of hippocampal neurons (p < 0.0001 or p < 0.01), which were mitigated by berberine (p < 0.05, p < 0.01, or p < 0.001). Furthermore, berberine significantly elevated CREB1 expression in sevoflurane-treated hippocampal neurons (p < 0.01). The beneficial effects of berberine on cell viability and apoptosis in sevoflurane-treated hippocampal neurons were blocked by CREB1 depletion (p < 0.001). Our results demonstrated that CREB1 was significantly decreased in the hippocampus of sevoflurane-treated neonatal mice in vivo and in sevoflurane-treated hippocampal neurons in vitro. This decrease was mitigated by berberine treatment. Moreover, berberine improved sevoflurane anesthesia-induced cognitive impairment in neonatal mice by attenuating neuronal inflammation and apoptosis in vivo. The inhibitory effects of berberine on sevoflurane-induced cell apoptosis were reversed by CREB1 downregulation. These findings indicate that berberine protects against sevoflurane anesthesia-induced cognitive impairment by reducing apoptosis of hippocampal neurons, partially through increasing CREB1 expression.

The Anti-Melanogenic Effects of Ganodermanontriol from the Medicinal Mushroom Ganoderma lucidum through the Regulation of the CREB and MAPK Signaling Pathways in B16F10 Cells.

Ganoderma lucidum, a member of the Basidiomycetes family, is attracting attention for its medicinal potential due to its biological activity and the presence of numerous bioactive compounds. Although it is known that extracts of this mushroom inhibit melanin production, there are few reports on a single substance associated with this effect. In this study, we identified ganodermanontriol (GT), a novel compound from G. lucidum, that effectively inhibited melanin biosynthesis in B16F10 cells. GT inhibits melanin production by suppressing the expression of cellular tyrosinase proteins and microphthalmia-related transcription factor (MITF). Furthermore, GT affects the phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) and mitogen-activated protein kinase (MAPK) signaling molecules, which are involved in melanogenesis in B16F10 cells. Finally, the biosynthesis of GT and other substances by G. lucidum was evaluated using HPLC analysis. Thus, this study revealed the mechanism by which GT in G. lucidum inhibits melanin production in B16F10 cells, and these findings will contribute to promoting the potential use of this mushroom in the future.

COX-2 optimizes cardiac mitochondrial biogenesis and exerts a cardioprotective effect during sepsis

BackgroundSeptic cardiomyopathy is a component of multiple organ dysfunction in sepsis. Mitochondrial dysfunction plays an important role in septic cardiomyopathy. Studies have shown that cyclooxygenase-2 (COX-2) had a protective effect on the heart, and prostaglandin E2 (PGE2), the downstream product of COX-2, was increasingly recognized to have a protective effect on mitochondrial function. ObjectiveThis study aims to demonstrate that COX-2/PGE2 can protect against septic cardiomyopathy by regulating mitochondrial function. MethodsCecal ligation and puncture (CLP) was used to establish a mouse model of sepsis and RAW264.7 macrophages and H9C2 cells were used to simulate sepsis in vitro. The NS-398 and celecoxib were used to inhibit the activity of COX-2. ZLN005 and SR18292 were used to activate or inhibit the PGC-1α activity. The mitochondrial biogenesis was examined through the Mitotracker Red probe, mtDNA copy number, and ATP content detection. ResultsThe experimental data suggested that COX-2 inhibition attenuated PGC-1α expression thus decreasing mitochondrial biogenesis, whereas increased PGE2 could promote mitochondrial biogenesis by activating PGC-1α. The results also showed that the effect of COX-2/PGE2 on PGC-1α was mediated by the activation of cyclic adenosine monophosphate (cAMP) response element binding protein (CREB). Finally, the effect of COX-2/PGE2 on the heart was also verified in the septic mice. ConclusionCollectively, these results suggested that COX-2/PGE2 pathway played a cardioprotective role in septic cardiomyopathy through improving mitochondrial biogenesis, which has changed the previous understanding that COX-2/PGE2 only acted as an inflammatory factor.

Exploring the analgesic potential of isorhamnetin: insights from formalin-induced pain and diabetic neuropathy models.

Isorhamnetin, a naturally occurring flavonoid compound, holds paramount importance as a primary constituent within several medicinal plants, exhibiting profound pharmacological significance. The aim of this study is to investigate the pain-relieving attributes of isorhamnetin in murine models through both formalin-induced pain and diabetic neuropathy scenarios. To achieve our objective, isorhamnetin was orally administered to mice at varying dosage levels (10 to 100 mg/kg). Pain-related behaviors were assessed using the formalin test during its secondary phase. Additionally, the potential pain-alleviating effect of isorhamnetin was evaluated in a diabetic neuropathy model induced by streptozotocin. Additionally, we carried out advanced interventions using naloxone, which is a well-known antagonist of opioid receptors, yohimbine, which blocks α2-adrenergic receptors, and methysergide, which inhibits serotonergic receptors, during the formalin test. The oral intake of isorhamnetin showed a decrease in behaviors associated with pain that was proportional to the dose observed during the second phase of the formalin test when induced by formalin. In the diabetic neuropathy model, isorhamnetin administration effectively reversed the reduced pain threshold observed. Notably, naloxone, the opioid receptor antagonist, effectively counteracted the pain-relieving effect produced by isorhamnetin in the formalin test, whereas yohimbine and methysergide did not yield similar outcomes. Isorhamnetin also led to a reduction in elevated spinal cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) levels triggered by formalin, with this effect reversed by pre-treatment with naloxone. The compound also suppressed heightened spinal phosphorylated CREB (p-CREB) levels caused by diabetic neuropathy. This research determined that isorhamnetin has notable abilities to relieve pain in models of formalin-induced pain and diabetic neuropathy. The pain-relieving mechanism of isorhamnetin in the formalin-induced pain model seems to be connected to the activation of spinal opioid receptors and the adjustment of CREB protein amounts. This insight improves our knowledge of how isorhamnetin could be used therapeutically to treat pain conditions stemming from formalin-induced pain and diabetic neuropathy.

Eicosapentaenoic Acid Rescues Cav1.2-L-Type Ca2+ Channel Decline Caused by Saturated Fatty Acids via Both Free Fatty Acid Receptor 4-Dependent and -Independent Pathways in Cardiomyocytes.

Dietary intake of omega-3 polyunsaturated fatty acids (eicosapentaenoic acid, EPA) exerts antiarrhythmic effects, although the mechanisms are poorly understood. Here, we investigated the possible beneficial actions of EPA on saturated fatty acid-induced changes in the L-type Ca2+ channel in cardiomyocytes. Cardiomyocytes were cultured with an oleic acid/palmitic acid mixture (OAPA) in the presence or absence of EPA. Beating rate reduction in cardiomyocytes caused by OAPA were reversed by EPA. EPA also retrieved a reduction in Cav1.2 L-type Ca2+ current, mRNA, and protein caused by OAPA. Immunocytochemical analysis revealed a distinct downregulation of the Cav1.2 channel caused by OAPA with a concomitant decrease in the phosphorylated component of a transcription factor adenosine-3',5'-cyclic monophosphate (cAMP) response element binding protein (CREB) in the nucleus, which were rescued by EPA. A free fatty acid receptor 4 (FFAR4) agonist TUG-891 reversed expression of Cav1.2 and CREB mRNA caused by OAPA, whereas an FFAR4 antagonist AH-7614 abolished the effects of EPA. Excessive reactive oxygen species (ROS) accumulation caused by OAPA decreased Cav1.2 and CREB mRNA expressions, which was reversed by an ROS scavenger. Our data suggest that EPA rescues cellular Cav1.2-Ca2+ channel decline caused by OAPA lipotoxicity and oxidative stresses via both free fatty acid receptor 4-dependent and -independent pathways.

Methylsulfonylmethane promotes melanogenesis via activation of JNK in Mel-Ab cells.

Methylsulfonylmethane (MSM), which contains organic sulphur, has been used for a long time as a medicinal ingredient because of its benefits to human health. MSM is reported to be protective against certain skin disorders, but it is unknown whether it affects melanin synthesis. Therefore, in our current research, we examined the possibility of MSM controlling the production of melanin in Mel-Ab melanocytes. In Mel-Ab cells, melanin contents and tyrosinase activities were assessed and quantified. The expression of microphthalmia-associated transcription factor (MITF) and tyrosinase was evaluated using western blot analysis, while MSM-induced signalling pathways were investigated. The MSM treatment significantly resulted in a dose-dependent increase in melanin production. Furthermore, MSM elevated melanin-related proteins, including MITF and tyrosinase. However, the rate-limiting enzyme of melanin production, tyrosinase, was not directly influenced by it. Therefore, we investigated potential melanogenesis-related signalling pathways that may have been triggered by MSM. Our findings showed that MSM did not influence the signalling pathways associated with glycogen synthase kinase 3β, cAMP response-element binding protein, extracellular signal-regulated kinase, or p38 mitogen-activated protein kinase. However, MSM phosphorylated c-Jun N-terminal kinases/stress-activated protein kinase (JNK/SAPK), which is known to induce melanogenesis. SP600125, a specific JNK inhibitor, inhibited MSM-induced melanogenesis. Taken together, our study indicates that MSM induces melanin synthesis and may serve as a therapeutic option for hypopigmentary skin disorders such as vitiligo.

Role of polymeric immunoglobulin receptor in glucose metabolism

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Fundación La Caixa 2022 HR22-0253. Comunidad de Madrid P2022/BMD-7333 INMUNOVAR-CM Background Type 2 diabetes and obesity are leading causes of death and disability worldwide, being both risk factors for cardiovascular disease. Intestinal immune system is being shown to have a key role in insulin resistance (IR). Polymeric immunoglobulin receptor (PIGR) is a transmembrane protein which facilitates the transcytosis of the soluble polymeric isoforms of immunoglobulin A (IgA) and is widely expressed in mucosal epithelial cells. IgA levels are reduced in obesity and the loss of IgA in mice worsens insulin resistance and increases inflammation in adipose tissue. However, the specific role of PIGR in IR has not been fully elucidated. Aim To analyze the role of PIGR in systemic glucose metabolism. Methods To determine the impact of global silencing of Pigr on whole-body glucose metabolism, we metabolically characterized the Pigr-/- female mouse 60% fat diet (HFD). We performed glucose and insulin tolerance tests. In vivo and ex vivo adiposity was measured by dual x-ray absorptiometry (DXA) and adipose tissue depots weight, fasting glucose and insulin plasma levels were determined at endpoint. Circulating IgA levels were measured by ELISA and IgA deposition in liver and adipose tissue of control and Pigr-/- mice was determined by western blot and immunohistochemistry. Results As previously described, we show that IgA serum levels were highly increased in Pigr -/- mice. Besides, we demonstrate that IgA deposition in liver and adipose tissue was increased in these mice. We demonstrate that global deletion of Pigr results in whole-body glucose intolerance and IR mice fed HFD. Fasting glucose levels (169.24±24.49 mg/dl in Pigr -/- mice vs 142±27mg/dl in control mice) and fasting insulin levels (1.27±0.42 ng/ml in Pigr -/- mice vs 0.92±0.37 ng/ml in control mice) were significantly increased in Pigr -/- mice fed HFD for 17 weeks. No differences were found in lipid profile levels (triglycerides, HDL-c, VLDL+LDL-c and NEFA). Interestingly, Pigr-/- mice show significant increased adiposity (46±4.11 % adiposity vs 50.6±4.9 in control) measured by DXA, which results in a significant increase in body weight (BW), compared to control (BW gain over 20 weeks on HFD: 21.85± 3.06 gr in Pigr -/- mice vs 17.93±2.1 gr). mRNA expression of the β isoform of carbohydrate responsive-element binding protein (ChREBPβ) is significantly reduced (0.5 folds vs control group) in Pigr -/- adipose tissue, which might link the whole-body metabolic phenotype to ChREBP-dependent glucose sensing by adipose tissue. Conclusion Global Pigr deletion results in whole-body glucose intolerance and IR in female mice fed HFD. Our results suggest cell-intrinsic mechanisms of Pigr deletion as well as extracellular components (increased IgA serum levels and deposition in tissues) as potential triggers of systemic glucose metabolism disruption. Management of PIGR levels might be key for glucose-metabolism-related pathologies.

Network pharmacology combined with molecular docking and molecular dynamic simulation to reveal the potential mechanism of lentinan ameliorating hyperlipidemia

Hyperlipidemia is closely related to multiple diseases and is characterized by abnormal serum lipid profiles. The biological function of lentinan in mice and rats was studied, but the mechanism of its lipid-lowering effect was not completely clear. In this study, network pharmacological analysis, molecular docking, and molecular dynamics simulation were used to explore the potential mechanism of its lipid-lowering effect and high-fat diet (HFD) mice was used to confirm the predicted mechanism. Our results indicated that lentinan could ameliorate hyperlipidemia by regulating peroxisome proliferator-activated receptors (PPARs), sterol response element-binding protein-1 (SREBP1), and nuclear factor kappa-B (NF-κB) in the hepatic tissues of mices. Further animal experiment showed that lentinan could regulate the mRNA expressions of lipid metabolism-related genes, such as PPARα, PPARδ, PPARγ, cluster of differentiation 36 (CD36) and SREBP-1c. Moreover, lentinan supplementation could reduce the expressions of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and inducible nitric oxide sythase (iNOS). In cell model, lentinan also could inhibit oleic acid-induced lipid droplet formation and the expressions of lipid metabolism-related genes and reduced inflammatory factor expressions in HepG2 cells, which further approved the results of animal experiment. Taken together, our results suggest that lentinan can ameliorate hyperlipidemia via regulating lipid metabolism-related gene expressions and reduce obesity-induced inflammatory response.

GOAT rs10096097 and CREB1 rs6740584 single nucleotide polymorphisms are associated with type 2 diabetes mellitus in Egyptians.

Diabetes mellitus (DM) is a chronic disorder that affects nearly half a billion people around the world and causes millions of deaths annually. Treatment of diabetes or related complications represents an economic burden not only for developing countries but also for the developed ones. Hence, new efficient therapeutic and preventive strategies and screening tools are necessary. The current work aimed to assess the potential association of single nucleotide polymorphisms (SNPs) in ghrelin O-acyltransferase (GOAT) rs10096097, cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) rs6740584, and v-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MafA) rs62521874 genes with type 2 DM susceptibility in Egyptians. A total of 96 patients with type 2 DM along with 72 healthy individuals participated in this study. Genotyping was executed via real-time polymerase chain reaction (PCR), and the serum protein levels of GOAT, CREB, and MafA were measured by enzyme-linked immunosorbent assay (ELISA). Genotyping revealed a significant association of GOAT rs10096097 and CREB1 rs6740584 SNPs with type 2 diabetes risk, with significantly higher GOAT rs10096097 G allele and CREB1 rs6740584 T allele frequencies in diabetic patients than in controls. However, insignificant association was identified between the MafA rs62521874 SNP and diabetes in the examined sample of the Egyptian residents. Serum GOAT, CREB1, and MafA protein levels did not vary significantly between diabetic and control individuals. Yet, significant variation in serum GOAT and CREB1 levels was detected between CREB1 rs6740584 genotypes within the diabetic group, with CT and TT genotype carriers showing higher levels than AA genotype patients. GOAT rs10096097 and CREB1 rs6740584, but not MafA rs62521874, SNPs are associated with type 2 diabetes risk in the studied Egyptians.

The protective effects of Irbesartan in cognitive impairment in hypertension.

Vascular cognitive impairment (VCI) is claimed as the second most common type of dementia after Alzheimer's disease (AD), in which hypertension is a critical inducer. Currently, hypertension-induced cognitive impairment lacks clinical treatments. Irbesartan is a long-acting angiotensin receptor antagonist with promising antihypertensive properties. Our research will focus on the potential function of Irbesartan on hypertension-induced cognitive impairment. Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats were orally dosed with normal saline or 20 mg/kg/day Irbesartan for 14 consecutive days, with 4 groups divided shown as below: WKY, Irbesartan, SHR, SHR+ Irbesartan. Firstly, the markedly increased systolic blood pressure observed in SHR rats was signally repressed by Irbesartan on Day 7 and 14 post-dosing. Moreover, notably decreased time of exploring the novel object in the object recognition task (ORT) test, elevated escape latency, and reduced time in the target quadrant in the Morris water maze (MWM) test were observed in SHR rats, which were prominently reversed by Irbesartan. Furthermore, the declined superoxide dismutase (SOD) activity, elevated malondialdehyde (MDA) level, increased cyclin-dependent kinase-5 (CDK5) activity, and enhanced protein level of p35/p25, p-Tau (pSer214)/Tau46, and brain-derived neurotrophic factor (BDNF) were memorably rescued by Irbesartan. Lastly, the activity of cAMP/cAMP response element binding protein (CREB) signaling in the hippocampus of SHR rats was markedly repressed, accompanied by an upregulation of phosphodiesterase 4B (PDE4B), which was observably rescued by Irbesartan. Collectively, Irbesartan protected against the hypertension-induced cognitive impairment in SHR rats by regulating the cAMP/CREB signaling.

Identification of CREB5 as a prognostic and immunotherapeutic biomarker in glioma through multi-omics pan-cancer analysis

BackgroundThe functional relevance of cyclic adenosine monophosphate (cAMP)-response element-binding protein 5 (CREB5) in cancers remains elusive, despite its significance as a member of the CREB family. The current research aims to explore the role of CREB5 in multiple cancers. MethodsPan-cancer analysis was performed to explore the expression patterns, prognostic value, mutational landscape as well as single-cell omic, immunologic, and drug sensitivity profiles of CREB5. Furthermore, we incorporated five distinct machine learning algorithms and determined that the least absolute shrinkage and selection operator-COX (LASSO-COX) algorithm, which exhibited the highest C index, was the optimal selection. Subsequently, we constructed a prognostic model centered around CREB5-associated genes. To elucidate the biological function of CREB5 in glioma cells, several assays including cell counting kit-8 (CCK-8), wound healing, transwell, flow cytometric were performed. ResultsCREB5 was overexpressed in pan-cancer and was linked to unfavorable prognosis, particularly in glioma. Furthermore, genetic alterations were determined in various types of cancer, and modifications in the CREB5 gene were linked to the prognosis. The single-cell omics and enrichment analyses showed that CREB5 was predominantly expressed in malignant glioma cells and was critically involved in the regulation of various oncogenic processes. Elevated levels of CREB5 were strongly linked with the infiltration of cancer-associated fibroblasts and the Th1 subset of CD4+ T cells. The validated CREB5-associated prognostic model reliably predicted the prognosis and drug response of glioma patients. The in vitro experiments showed that CREB5 promoted glioma cell proliferation, invasion, migration, and gap phase 2/mitotic (G2/M) phase arrest and recruited M2 macrophages into glioma cells. ConclusionCREB5 has the potential to act as an oncogene and a biological marker in multiple cancers, particularly glioma.

Transcriptional regulation of genetic variants in the SLC40A1 promoter.

Solute carrier 40A1 (SLC40A1) encodes ferroportin, which is the only known transmembrane protein that exports elemental iron from mammalian cells and is essential for iron homeostasis. Mutations in SLC40A1 are associated with iron-overload disorders. In addition to ferroportin diseases, SLC40A1 expression is downregulated in various cancer types. Despite the clinical significance of the SLC40A1 transporter, only a few studies have investigated genetic variants in SLC40A1. The present study was performed to identify genetic variations in the SLC40A1 promoter and functionally characterize each variant using in vitro assays. We investigated four haplotypes and five variants in the SLC40A1 promoter. We observed that haplotype 3 (H3) had significantly lower promoter activity than H1, whereas the activity of H4 was significantly higher than that of H1. Luciferase activity of H2 was comparable to that of H1. In addition, four variants of SLC40A1, c.-1355G>C, c.-662C>T, c.-98G>C, and c.-8C>G, showed significantly increased luciferase activity compared to the wild type (WT), whereas c.-750G>A showed significantly decreased luciferase activity compared to the WT. Three transcription factors, cAMP response element-binding protein-1 (CREB-1), chicken ovalbumin upstream promoter transcription factor 1, and hepatic leukemia factor (HLF), were predicted to bind to the promoter regions of SLC40A1 near c.-662C>T, c.-98G>C, and c.-8C>G, respectively. Among these, CREB-1 and HLF bound more strongly to the variant sequences than to the WT and functioned as activators of SLC40A1 transcription. Collectively, our findings indicate that the two SLC40A1 promoter haplotypes affect SLC40A1 transcription, which is regulated by CREB-1 and HLF.

PROKR1–CREB–NR4A2 axis for oxidative muscle fiber specification and improvement of metabolic function

Metabolic disorders are characterized by an imbalance in muscle fiber composition, and a potential therapeutic approach involves increasing the proportion of oxidative muscle fibers. Prokineticin receptor 1 (PROKR1) is a G protein-coupled receptor that plays a role in various metabolic functions, but its specific involvement in oxidative fiber specification is not fully understood. Here, we investigated the functions of PROKR1 in muscle development to address metabolic disorders and muscular diseases. A meta-analysis revealed that the activation of PROKR1 upregulated exercise-responsive genes, particularly nuclear receptor subfamily 4 group A member 2 (NR4A2). Further investigations using ChIP-PCR, luciferase assays, and pharmacological interventions demonstrated that PROKR1 signaling enhanced NR4A2 expression by Gs-mediated phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) in both mouse and human myotubes. Genetic and pharmacological interventions showed that the PROKR1-NR4A2 axis promotes the specification of oxidative muscle fibers in both myocytes by promoting mitochondrial biogenesis and metabolic function. Prokr1-deficient mice displayed unfavorable metabolic phenotypes, such as lower lean mass, enlarged muscle fibers, impaired glucose, and insulin tolerance. These mice also exhibited reduced energy expenditure and exercise performance. The deletion of Prokr1 resulted in decreased oxidative muscle fiber composition and reduced activity in the Prokr1-CREB-Nr4a2 pathway, which were restored by AAV-mediated Prokr1 rescue. In summary, our findings highlight the activation of the PROKR1-CREB-NR4A2 axis as a mechanism for increasing the oxidative muscle fiber composition, which positively impacts overall metabolic function. This study lays an important scientific foundation for the development of effective muscular-metabolic therapeutics with unique mechanisms of action.

Expression of CREBBP and EP300 Associated With Tumor Volume in Patients With Grade-3 Glioma: A Retrospective Analysis.

Reliable predictive data are crucial for making accurate treatment decisions in glioma patients, but it can be challenging to obtain due to limited information in many cases. Numerous research studies have indicated the involvement of cyclic adenosine monophosphate (cAMP)-response element binding protein (CREBBP) and E1A binding protein p300 (EP300) in tumorigenesis and tumor progression across various types. The messenger RNA (mRNA) expression levels of CREBBP and EP300 were retrospectively analyzed in 17 grade-3 glioma patients. The SYBR Green real-time polymerase chain reaction (RT-PCR) technique was employed for mRNA expression analysis, with the glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH) used as a reference gene for data normalization. In addition, the relationship between CREBBP, EP300 expression and patients' clinical information, imaging features, histologic features, immune factors, and overall survival was assessed through univariate analyses. The analysis of the data unveiled a statistically significant upregulation of CREBBP and EP300 mRNA expression levels in large gliomas as compared with their smaller counterparts (P < .05). Histological examination using hematoxylin and eosin (H&E) staining exhibited marked cellular heterogeneity, with heightened cell density observed specifically within tumors displaying elevated CREBBP expression levels. In contrast, there was a substantial downregulation of complement 3 and complement 4 within larger tumor volumes when compared with smaller ones (P < .05). However, these findings do not serve as clinically relevant prognostic indicators for glioma. It is suggested that higher expression levels of CREBBP and EP300 are positively associated with increased tumor volume. Inhibition of CREBBP and EP300 enhances local immunogenicity, leading to the recruitment of immune cells and release of cytokines for effective tumor eradication, ultimately resulting in the inhibition of tumor growth.

Phoenixin-20 ameliorates Sevoflurane inhalation-induced post-operative cognitive dysfunction in rats via activation of the PKA/CREB signaling.

Post-operative cognitive dysfunction (POCD) is a common complication after surgery due to the usage of anesthetics, such as Sevoflurane, which severely impacts the life quality of patients. Currently, the pathogenesis of Sevoflurane-induced POCD has not been fully elucidated but is reportedly involved with oxidative stress (OS) injury and aggravated inflammation. Phoenixin-20 (PNX-20) is a PNX peptide consisting of 20 amino acids with promising inhibitory effects on OS and inflammation. Herein, we proposed to explore the potential protective function of PNX-20 on Sevoflurane inhalation-induced POCD in rats. Sprague-Dawley (SD) rats were treated with 100 ng/g PNX-20 for 7 days with or without pre-inhalation with 2.2% Sevoflurane. Markedly increased escape latency and decreased time in the target quadrant in the Morris water maze (MWM) test, and aggravated pathological changes and apoptosis in the hippocampus tissue were observed in Sevoflurane-treated rats, which were markedly attenuated by PNX-20. Furthermore, the aggravated inflammation and OS in the hippocampus observed in Sevoflurane-treated rats were notably abolished by PNX-20. Moreover, the brain-derived neurotrophic factor (BDNF), protein kinase A (PKA), and phospho-cAMP response element binding protein/cAMP response element binding protein (p-CREB/CREB) levels were markedly decreased in Sevoflurane-treated rats, which were memorably increased by PNX-20. Our results indicated that PNX-20 ameliorated Sevoflurane inhalation-induced POCD in rats via the activation of PKA/CREB signaling, which might supply a new treatment approach for POCD.

Anti-Melanogenic Effects of Lilium lancifolium Root Extract via Downregulation of PKA/CREB and MAPK/CREB Signaling Pathways in B16F10 Cells

Hyperpigmentation disorders causing emotional distress require the topical use of depigmenting agents of natural origin. In this study, the anti-melanogenic effects of the Lilium lancifolium root extract (LRE) were investigated in B16F10 cells. Consequently, a non-cytotoxic concentration of the extract reduced intracellular melanin content and tyrosinase activity in a dose-dependent manner, correlating with the diminished expression of core melanogenic enzymes within cells. LRE treatment also inhibited cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB)/microphthalmia-associated transcription factor signaling, which regulates the expression of tyrosinase-related genes. Upon examining these findings from a molecular mechanism perspective, LRE treatment suppressed the phosphorylation of protein kinase A (PKA), p38, and extracellular signal-related kinase (ERK), which are upstream regulators of CREB. In addition, L-phenylalanine and regaloside A, specifically identified within the LRE using liquid chromatography-mass spectrometry, exhibited inhibitory effects on melanin production. Collectively, these results imply that LRE potentially suppresses cAMP-mediated melanogenesis by downregulating PKA/CREB and mitogen-activated protein kinase (MAPK)/CREB signaling pathways. Therefore, it can be employed as a novel therapeutic ingredient of natural origin to ameliorate hyperpigmentation disorders.