cAMP Response Element Research Articles

MiR-32533 Reduces Cognitive Impairment and Amyloid-β Overload by Targeting CREB5-Mediated Signaling Pathways in Alzheimer's Disease.

MicroRNAs (miRNAs) are associated with amyloid-β (Aβ)dysmetabolism, a pivotal factor in the pathogenesis of Alzheimer's disease (AD). This study unveiled a novel miRNA, microRNA-32533 (miR-32533), featuring a distinctive base sequence identified through RNA sequencing of the APPswe/PSEN1dE9 (APP/PS1) mouse brain. Its role and underlying mechanisms were subsequently explored. Bioinformatics and confirmatory experiments revealed that miR-32533 had a novel 23-base sequence with minimal coding potential, functioning within the Drosha ribonuclease III (Drosha)/Dicer 1, ribonuclease III (Dicer)-dependent canonical pathway and identifiable via northern blot. miR-32533 was abundantly brain-distributed and downregulated in diverse AD-related models, including APP/PS1 andfive familial AD (5×FAD) mouse brains and AD patient plasma. Overexpression or inhibition of miR-32533 led to improvements or exacerbations in cognitive dysfunction, respectively, by modulating Aβproduction, apoptosis, oxidation, and neuroinflammation through targeting cAMP-responsive element binding protein 5(CREB5), which interacted with α disintegrin and metalloproteinase 10(ADAM10), beta-site amyloid precursor protein cleaving enzyme 1(BACE1), and presenilin 1 (PS1) promoters, thereby enhancing Aβ production through BACE1 and PS1 upregulation while suppressing non-amyloidogenic amyloid precursor protein (APP) processing via ADAM10 downregulation. Furthermore, modulation of the miR-32533/CREB5 axis ameliorated or worsened cognitive impairment by inhibiting or amplifying Aβ overproduction through the BACE1-involved amyloidogenic and ADAM10-involved non-amyloidogenic pathways. Overall, the findings suggest miR-32533 as a regulator of Aβ metabolism, oxidative stress, and neuroinflammation, establishing the miR-32533/CREB5 signaling pathways as potential therapeutic targets for combating Aβ accumulation and cognitive deficits in AD.

Repeated exposure to antibiotics exhibits anxiety-like behaviors with a reduction in neurogenesis in the ventral hippocampus of dentate gyrus.

Disruption of gut microbiota balance is known to contribute to the development of anxiety; however, it remains unclear whether dysbiosis-induced anxiety involves the glycogen synthase kinase-3β (GSK-3β)/cAMP response element binding protein (CREB)/brain-derived neurotrophic factor (BDNF) pathway and neurogenesis in the ventral hippocampal dentate gyrus (DG). In this study, Male ddY mice were administered an antibacterial cocktail to induce dysbiosis. The dysbiosis model displayed anxiety-like behaviors in the hole-board and elevated plus-maze tests, decreased the phosphorylation levels of GSK-3β (Ser9) and CREB, decreased the expression level of BDNF in the ventral hippocampus, and reduced neurogenesis in the ventral hippocampal DG. This suggests that dysbiosis-induced anxiety-like behaviors are associated with reduced neurogenesis in the ventral hippocampal DG via the GSK-3β/CREB/BDNF pathway.

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.

Effects of Age and Atomoxetine on Olfactory Perception and Learning and Underlying Plasticity Mechanisms in Rats.

The locus coeruleus (LC) plays a vital role in cognitive function through norepinephrine release. Impaired LC neuronal health and function is linked to cognitive decline during ageing and Alzheimer's disease. This study investigates age-related alterations in olfactory detection and discrimination learning, along with its reversal, in Long-Evans rats, and examines the effects of atomoxetine (ATM), a norepinephrine uptake inhibitor, on these processes. Adult (6-9 months) and aged (22-24 months) Long-Evans rats underwent odour detection threshold experiments with saline and two doses of ATM (0.3 and 1 mg/kg). Reward-based odour discrimination learning included simple, difficult and reversal learning tasks. LC neuron density, dopamine beta-hydroxylase and norepinephrine transporter expression in the piriform cortex (PC) and orbitofrontal cortex were measured. Reversal learning and olfactory threat extinction were used to measure behavioural flexibility. Immunohistochemistry and western blotting were used to analyse phosphorylated cAMP response element binding protein (pCREB) and cFos expression and exvivo electrophysiology assessed long-term depression (LTD) in the PC. Whereas adult and aged cohorts showed similar odour detection and discrimination learning, fewer aged rats acquired reversal learning successfully. ATM improved reward-based odour discrimination in adults but hindered learning reversal. A delayed CREB phosphorylation in the posterior PC associated with atomoxetine administration possibly underlies learning enhancement. ATM resulted in less freezing behaviour in a threat conditioning and extinction paradigm at moderate, but not at higher doses. ATM administration exvivo prevented PC LTD. These findings highlight the intricate effects of atomoxetine, influenced by target structures, and suggest potential interactions with other neurotransmitters. Our results contribute to understanding the impact of ageing and norepinephrine enhancers on cognitive processes.

Role of BDNF-TrkB signaling in the improvement of motor function and neuroplasticity after ischemic stroke in rats by transcranial direct current stimulation.

Transcranial direct current stimulation (tDCS) has an impact on improving cognitive and motor dysfunction induced by ischemia-reperfusion injury. However, to use this technology more rationally in clinical practice, a deepened understanding of the molecular mechanisms behind its therapeutic effects is needed. This study explored the role of the brain-derived neurotrophic factor(BDNF) and its associated receptor tropomyosin-receptor kinase B(TrkB) while deciphering the underlying mechanisms in transcranial direct current therapy to treat ischemic stroke. A middle cerebral artery occlusion-reperfusion(MCAO/R) model was established in rats to observe tDCS effects on brain damage. Behavioral tests, the modified neurologic severity score(mNSS), and the Hoffman reflex / the M wave(Hmax/Mmax) ratio helped assess motor function and neurologic deficits. HE and Nissl staining helped observe the morphological changes and count of nerve cells. We tested the expression of growth-associated protein-43(Gap-43) and microtubule-associated protein-2(Map-2), K+-Cl- co-transporter 2(KCC2), γ-aminobutyric acid(GABA), and key BDNF-TrkB downstream signaling, the phospholipase C gamma(PLCγ) / CaMK IV / cAMP response element binding protein(CREB), and extracellular signal-regulated protein kinase(ERK1/2) / ribosomal S6 kinase(RSK) using western blotting. Moreover, BDNF was analyzed in plasma using the enzyme-linked immunosorbent assay (ELISA) to investigate the tDCS effect on human BDNF expression levels. Finally, a BDNF receptor antagonist, ANA-12, was administered to explore the tDCS mechanism mediating BDNF-TrkB signaling. After tDCS treatment, the mNSS was improved, and the motor function was restored. Moreover, tDCS decreased cell swelling after MCAO/R and enhanced the number of neurons. tDCS treatment increased: (1) BDNF, Gap-43, Map-2 expression, (2) KCC2, GABA, and (3) PLCγ, CaMK IV, CREB and ERK1/2, RSK. Furthermore, ELISA results indicate that tDCS elevated human plasma BDNF protein expression. However, the therapeutic effect of tDCS was suppressed to a certain extent by adding ANA-12. Our findings indicate that tDCS may exert a neuroprotective effect by activating the downstream key molecules of BDNF-TrkB expression, for instance, PLCγ/ CaMK IV/ CREB and ERK/ RSK pathway. Moreover, tDCS can control neuronal excitability, promote axonal regeneration, and accelerate motor function recovery in ischemia reperfusion-injured rats.

LncRNA SNHG4 enhanced gastric cancer progression by modulating miR-409-3p/CREB1 axis.

Gastric cancer (GC) is a globally common cancer characterized by high incidence and mortality worldwide. Advances in the molecular understanding of GC provide promising targets for GC diagnosis and therapy. Long non-coding RNAs (lncRNAs) and their downstream regulators are regarded to be implicated in the progression of multiple types of malignancies. Studies have shown that the lncRNA small nucleolar RNA host gene 4 (SNHG4) serves as a tumor promoter in various malignancies, while its function in GC has yet to be characterized. Therefore, our study aimed to explore the role and underlying mechanism of SNHG4 in GC. We used qRT-PCR to analyze SNHG4 expression in GC tissues and cells. Kaplan-Meier analysis was used to assess the correlation between SNHG4 expression and the survival rate of GC patients. Cellular function experiments such as CCK-8, BrdU, colony formation, flow cytometry analysis, and transwell were performed to explore the effects of SNHG4 on GC cell proliferation, apoptosis, cell cycle, migration, and invasion. We also established xenograft mouse models to explore the effect of SNHG4 on GC tumor growth. Mechanically, dual luciferase reporter assay was used to verify the interaction between SNHG4 and miR-409-3p and between miR-409-3p and cAMP responsive element binding protein 1 (CREB1). The results indicated that SNHG4 was overexpressed in GC tissues and cell lines, and was linked with poor survival rate of GC patients. SNHG4 promoted GC cell proliferation, migration, and invasion while inhibiting cell apoptosis and cell cycle arrest in vitro. The in vivo experiment indicated that SNHG4 facilitated GC tumor growth. Furthermore, SNHG4 was demonstrated to bind to miR-409-3p. Moreover, CREB1 was directly targeted by miR-409-3p. Rescue assays demonstrated that miR-409-3p deficiency reversed the suppressive impact of SNHG4 knockdown on GC cell malignancy. Additionally, miR-409-3p was also revealed to inhibit GC cell proliferation, migration, and invasion by targeting CREB1. In conclusion, we verified that the SNHG4 promoted GC growth and metastasis by binding to miR-409-3p to upregulate CREB1, which may deepen the understanding of the underlying mechanism in GC development.

Electroacupuncture pretreatment ameliorates Golgi stress and the inflammation response against endotoxin-induced lung injury.

Sepsis is a life-threatening condition involving organ dysfunction characterized by a generalized inflammatory syndrome, and the associated mortality rate is high. Electroacupuncture (EA) exerts benefits in endotoxemia-induced lung injury, mainly through lung inflammation reduction and cellular homeostasis, although the anti-inflammatory mechanisms underlying these benefits remain to be completely understood. Mice were pretreated with EA or sham EA therapy 5days prior to the induction of endotoxemia through the administration of lipopolysaccharide (LPS) and cecal ligation and puncture (CLP). Histopathological changes, systemic inflammation and cell death in the lungs were assessed. Transmission electron microscopy was employed to visually identify the structure of the Golgi complex. We examined proteins involved in maintaining the structural integrity of the Golgi apparatus and proteins associated with Golgi stress. The potential molecular mechanisms were investigated through overexpression of CREB3. EA pretreatment effectively rescued the lung from pathological changes, lung edema, cell apoptosis, and survival rate in septic mice, along with the improvement of physiological parameters. Endotoxemia strongly induces fragmented Golgi stacks, leading to fragmentation and disintegration of its shape, inducing cell apoptosis, and causing the outbreak of a large amount of inflammation in the lungs. EA therapy can significantly inhibit the fragmented process of Golgi stress to rescue the morphological changes and exert anti-inflammatory effects. And this protective effect may be related to upregulation of cAMP responsive element binding protein 3 (CREB3) and ADP-Ribosylation Factor 4 (ARF4), one of the key pathways involved in Golgi stress response. However, Sham EA (SEA) treatment did not substantially improve the fragmentation, stacking, and separation of Golgi organization, and inflammatory damage induced by endotoxin remains. This study discovered that overexpression of CREB3 may diminish the protective efficacy of EA. Administering EA pretreatment at precisely selected acupoints notably improves the survival rate in mice challenged with endotoxemia and concurrently exerts a protective effect against inflammatory lung injury. This salutary impact is speculated to be mediated through the augmentation of the Golgi apparatus's stress response.

Reassessing the involvement of the CREB pathway in the circadian clock of Drosophila melanogaster

Circadian clocks are ubiquitous in almost all organisms on Earth and many key genes are highly conserved among species. In the mammalian suprachiasmatic nucleus, the cAMP response element binding protein (CREB) pathway is known to play a crucial role in conveying light-input to the transcription of clock genes. The fruit fly Drosophila melanogaster also expresses two Creb proteins, CrebA and CrebB, which have been associated with the circadian clock. For example, Drosophila Creb has been suggested to constitute a molecular link between neuronal excitability and clock gene transcription. In this study we subjected flies with clock cell specific CrebA or CrebB mutations to circadian behavioral and bioluminescence assays. Surprisingly, we found that neither loss of CrebA or CrebB did affect free-running locomotor behavior, rhythmic period oscillations in clock neurons, or light-dependent synchronization. In conclusion our findings question the conserved circadian role of the Creb pathway in Drosophila and encourage further studies to elucidate its potential function within insect circadian clocks.

Protein-coding mutation in Adcy3 increases adiposity and alters emotional behaviors sex-dependently in rats.

Adenylate cyclase 3 (Adcy3) has been linked to both obesity and major depressive disorder. We identified a protein-coding variant in the transmembrane (TM) helix of Adcy3 in rats; similar obesity variants have been identified in humans. This study investigates the role of a TM variant in adiposity and behavior. We mutated the TM domain of Adcy3 (Adcy3mut/mut) and created a heterozygous knockout (Adcy3+/-) in Wistar Kyoto (WKY) rats. Wild-type, Adcy3+/-, and Adcy3mut/mut rats were fed a high-fat diet for 12 weeks. We measured body weight, fat mass, glucose tolerance, food intake, metabolism, emotion-like behaviors, memory, and downstream proteins. Adcy3+/- and Adcy3mut/mut rats weighed more than wild-typerats due to increased fat mass. There were key sex differences: adiposity was driven by increased food intake in males but by decreased energy expenditure in females. Adcy3mut/mut males displayed increased passive coping and decreased memory, whereas Adcy3mut/mut females displayed increased anxiety-like behavior. Adcy3mut/mut males had decreased hypothalamic cAMP-response element binding protein (CREB) signaling, with decreased phospho-AMP-activated protein kinase (p-AMPK) signaling in both sexes. The ADCY3 TM domain plays a role in protein function via p-AMPK and CREB signaling. Adcy3 may contribute to the relationship between obesity and major depressive disorder, and sex influences the relationships between Adcy3, metabolism, and behavior.

Regulation of sleep amount by CRTC1 via transcription ofCrhin mice

The cAMP-response element binding protein (CREB) is required for regulation of daily sleep amount, whereas gain-of-function of CREB-regulated transcription coactivator 1 (CRTC1) causes severe insomnia in mice. However, the physiological functions of CRTCs and their downstream target genes in the regulation of sleep amount remain unclear. Here, we use adult brain chimeric (ABC)-expression/knockout platform for somatic genetics analysis of sleep in adult male mice. ABC-expression of constitutively active mutant CRTC1/2CAin the mouse brain neurons significantly reduces the amount of non-rapid eye movement sleep (NREMS) and/or REMS. Consistent with that SIK3 phosphorylates and inhibits CRTCs, ABC-expression of CRTC1/2/3CArescues the hypersomnia phenotype ofSleepy(Sik3Slp) mice. While ABC-Crtc2KOorCrtc3KOcauses no sleep phenotype, ABC-Crtc1KOor ABC-expression of dominant-negative CRTC (dnCRTC) results in modest reduction of NREMS amount accompanied with elevated NREMS delta power. Moreover, ABC-expression of CRTC1CAor dnCRTC in the excitatory neurons causes bidirectional changes of NREMS/REMS amount and/or NREMS delta power, whereas expression of CRTC1CAin the inhibitory neurons decreases REMS amount and increases NREMS delta power. The ability of CRTC1CAto regulate sleep requires its transactivation domain and CREB-binding domain and is dependent on CREB. Furthermore, we showed that inducible ABC-expression of corticotropin releasing hormone (Crh) and brain-derived neurotrophic factor (Bdnf)–two target genes of CRTCs–significantly reduces daily sleep amount. Notably, ABC-CrhKO, but notBdnfKO, rescues the insomnia phenotype of ABC-CRTC1CAmice. Taken together, these results indicate that CREB-CRTC1 complex regulates daily sleep amount by modulating the transcription ofCrhin the mouse brain neurons.Significance StatementCRTCs function as coactivators for CREB, a transcription factor required for the regulation of daily sleep amount in mice. Here, we found that CRTC1/2/3 function similarly to suppress NREMS and REMS in a CREB-dependent manner. Consistent with that CRTCs are substrates of SIK3 kinase, expression of constitutive active mutant CRTCsCArescue the hypersomnia phenotype ofSleepy(Sik3Slp) mice. Furthermore, we showed that CRTC1 reduces NREMS amount by upregulating the expression of neuropeptide CRH. These results elucidate the mechanism by which CRTCs regulates sleep amount and suggest a potential transcriptional mechanism in the stress-induced sleep/wake regulation.

2'-O-Galloylhyperin Prevents Tissue Remodeling in Thyroid Eye Disease: Prospects as a Thyrotropin Receptor Antagonist.

Thyroid eye disease (TED) is a challenging condition owing to relentless orbital tissue remodeling, with thyrotropin receptor (TSHR) in orbital fibroblasts (OFs) serving as a promising therapeutic target. This study seeks to discover potential TSHR inhibitors among US Food and Drug Administration (FDA)-approved drugs and evaluate their effects on TED-OFs. Adipose tissues were sourced from the patients with or without TED. Isolated OFs were cultivated in proliferation medium or stimulated for adipogenic/fibrotic differentiation in 2-dimensional/3-dimenstional models, treated with 2'-O-galloylhyperin (2'-O-GH) (0, 5, 20, and 50 μM). Using structure-based virtual screening (SBVS), potential TSHR antagonists were identified. Cellular proliferation was analyzed by 5-ethynyl-2'-deoxyuridine (EdU) incorporation, flow cytometry, and spheroid size. Adipogenesis was determined by Oil Red O staining, Western blot, and immunofluorescence (IF). Fibrosis was assessed using wound-healing assays, Western blot and IF. Cyclic adenosine monophosphate (cAMP), hyaluronan (HA), and cytokine were quantified by enzyme-linked immunosorbent assay. Herein, the FDA-approved drug 2'-O-GH dose-dependently decreased cAMP production and the subsequent cAMP-response element binding protein (CREB) phosphorylation stimulated by a TSHR-stimulating monoclonal autoantibody M22, which was reversed by a consistently activated mutation of TSHR (L629F). As expected, 2'-O-GH attenuated lipid accumulation in TED-OFs, along with downregulation of key adipogenic markers, and 2'-O-GH ameliorated HA production during adipogenesis. Notably, 2'-O-GH dampened wound closure and fibrotic differentiation of TED-OF stimulated by transforming growth factor beta 1. Correspondingly, proliferation of TED-OFs was halted by 2'-O-GH. 2'-O-GH is promising for prevention of tissue remodeling of TED by exerting inhibitory effects on proliferation, differentiation, and HA deposition by inhibiting TSHR activation, implying its potential therapeutic value for TED.

Insulin Resistance Mediates the Association Between Vitamin D and Non-Alcoholic Fatty Liver Disease.

Vitamin D (VD) deficiency and insulin resistance (IR) increase the risk of non-alcoholic fatty liver disease (NAFLD), but few studies have explored the potential mechanisms by which IR mediates the association between VD and the pathogenesis of NAFLD at the genetic level using publicly available databases. This is a cross-sectional study, and we utilized the National Health and Nutrition Examination Survey (NHANES) dataset, as well as data from GSE200765 obtained from the Gene Expression Omnibus (GEO) website. A total of 723 individuals who had completed liver ultrasound examination and the detection of VD levels were included in the final analysis. A gene expression dataset, GSE200765, was also downloaded from the GEO website, to explore the potential mechanism of VD and NAFLD. In the NHANES data, covariates significantly differed in four VD categories, and the controlled attenuation parameter (CAP), vibration-controlled transient elastography-liver stiffness measurement (VCTE-LSM), and IR were reduced with an increase in VD levels. Mediation analysis revealed that IR mediated the association between VD and both CAP and LSM, and the estimated mediation effects were 29.0% and 39.8%, respectively. Bioinformatics analysis showed that seven differentially expressed genes (DEGs) (solute carrier family 2 member 2 [SLC2A2], protein phosphatase 1 regulatory subunit 3E [PPP1R3E], CAMP responsive element binding protein 3-like 3 [CREB3L3], Interleukin-6 [IL-6], peroxisome proliferator-activated receptor gamma coactivator 1-alpha [PPARGC1A], nuclear factor kappa B inhibitor alpha [NFKBIA], and phosphoenolpyruvate carboxykinase 2 [PCK2]) were enriched in the IR pathway in comparison groups (VD group vs. lipid group), suggesting that VD improved NAFLD via changed IR. VD deficiency and IR were the risk factors for NAFLD, and increased VD levels improved the status of NAFLD. The underlying mechanism may be that elevated VD levels reduced IR, which improved the expression of DEGs involved in the IR pathway.

CREB: A Promising Therapeutic Target for Treating Psychiatric Disorders.

Psychiatric disorders are complex, multifactorial illnesses. It is challenging for us to understand the underlying mechanism of psychiatric disorders. In recent years, the morbidity of psychiatric disorders has increased yearly, causing huge economic losses to the society. Although some progress, such as psychotherapy drugs and electroconvulsive therapy, has been made in the treatment of psychiatric disorders, including depression, anxiety, bipolar disorder, obsessive-compulsive and autism spectrum disorders, antidepressants and psychotropic drugs have the characteristics of negative effects and high rate of relapse. Therefore, researchers continue to seek suitable interventions. cAMP response element binding protein (CREB) belongs to a protein family and is widely distributed in the majority of brain cells that function as a transcription factor. It has been demonstrated that CREB plays an important role in neurogenesis, synaptic plasticity, and neuronal growth. This review provides a 10-year update of the 2013 systematic review on the multidimensional roles of CREB-mediated transcriptional signaling in psychiatric disorders. We also summarize the classification of psychiatric disorders and elucidate the involvement of CREB and related downstream signalling pathways in psychiatric disorders. Importantly, we analyse the CREB-related signal pathways involving antidepressants and antipsychotics to relieve the pathological process of psychiatric disorders. This review emphasizes that CREB signalling may have a vast potential to treat psychiatric disorders like depression. Furthermore, it would be helpful for the development of potential medicine to make up for the imperfection of current antidepressants and antipsychotics.

The transcription factor CREB regulates epithelial-mesenchymal transition of lens epithelial cells by phosphorylation-dependent and phosphorylation-independent mechanisms.

Epithelial mesenchymal transition (EMT) of lens epithelial cells (LECs) is one of the most important pathogenic mechanisms in lens fibrotic disorders, and the regulatory mechanisms of EMT have not been fully understood. Here, we demonstrate that the cAMP-response element binding protein (CREB) can regulate lens EMT in a phosphorylation-dependent and phosphorylation-independent manners with dual mechanisms. First, CREB-S133 phosphorylation is implicated in TGFβ-induced EMT of mouse LECs and also in injury-induced mouse anterior subcapsular cataract model. The interaction between CREB and p300 is necessary for CREB regulation of TGFβ-induced EMT, since inhibition of CREB-p300 interaction and p300 knockdown led to attenuated expression of mesenchymal genes. Second, S133A-CREB, a mutant mimicking constant dephosphorylation at S133, exhibits notable occupancy in the enhancers of mesenchymal genes and confers robust transcription activity on EMT genes. Introduction of R314A mutation in S133A-CREB, which abolishes the interaction between S133A-CREB and its co-activator, cAMP-regulated transcriptional co-activators led to substantial suppression of mesenchymal gene expression in mouse LECs. Taken together, our results showed that CREB regulates lens EMT in dual mechanisms and that the S133A-CREB acts as a novel transcription factor. Mechanistically, CREB interacts with p300 in a S133 phosphorylation-dependent manner to positively regulate lens EMT genes. In contrast, S133A-CREB interacts with cAMP-regulated transcriptional co-activators to confer a robust activation of lens EMT genes.

Exposure to Radiofrequency Electromagnetic Fields Enhances Melanin Synthesis by Activating the P53 Signaling Pathway in Mel-Ab Melanocytes.

The skin is the largest body organ that can be physiologically affected by exposure to radiofrequency electromagnetic fields (RF-EMFs). We investigated the effect of RF-EMFs on melanogenesis; Mel-Ab melanocytes were exposed to 1760 MHz radiation with a specific absorption rate of 4.0 W/kg for 4 h/day over 4 days. Exposure to the RF-EMF led to skin pigmentation, with a significant increase in melanin production in Mel-Ab melanocytes. The phosphorylation level of cAMP response element binding protein (CREB) and the expression of microphthalmia-associated transcription factor (MITF), which regulate the expression of tyrosinase, were significantly increased in Mel-Ab after RF-EMF exposure. Interestingly, the expression of tyrosinase was significantly increased, but tyrosinase activity was unchanged in the RF-EMF-exposed Mel-Ab cells. Additionally, the expression of p53 and melanocortin 1 receptor (MC1R), which regulate MITF expression, was significantly increased. These results suggest that the RF-EMF induces melanogenesis by increasing phospho-CREB and MITF activity. Importantly, when Mel-Ab cells were incubated at 38 °C, the melanin production and the levels of tyrosinase significantly decreased, indicating that the increase in melanin synthesis by RF-EMF exposure is not due to a thermal effect. In conclusion, RF-EMF exposure induces melanogenesis in Mel-Ab cells through the increased expression of tyrosinase via the activation of MITF or the phosphorylation of CREB, which are initiated by the activation of p53 and MC1R.

The Effect of Caffeine Exposure on Sleep Patterns in Zebrafish Larvae and Its Underlying Mechanism.

The effect of caffeine on the behavior and sleep patterns of zebrafish larvae, as well as its underlying mechanisms, has been a topic of great interest. This study aimed to investigate the impact of caffeine on zebrafish larval sleep/wake behavior and the expression of key regulatory genes such as cAMP-response element binding protein (CREB) and adenosine (ADA) in the sleep pathway. To begin, the study determined the optimal dose and duration of caffeine exposure, with the optimal doses found to be 31.25 μM, 62.5 μM, and 120 μM. Similarly, the optimal exposure time was established as no more than 120 h, ensuring a mortality rate of less than 10%. The confirmation of these conditions was achieved through the assessment of angiogenesis and the inflammatory reaction. As a result, the treatment time point of 24 h post-fertilization (hpf) was selected to examine the effects of caffeine on zebrafish larval sleep rhythm (48 h, with a light cycle of 14:10). Furthermore, the study analyzed the expression of clock genes (bmal1a, per1b, per2, per3, cry2), adenosine receptor genes (adora1a, adora1b, adora2aa, adora2ab, adora2b), and key regulatory factors (CREB and ADA). The research confirmed that caffeine could induce sleep pattern disorders, significantly upregulate adenosine receptor genes (adora1a, adora1b, adora2a, adora2ab, adora2b) (p < 0.05), and markedly decrease the total sleep time and sleep efficiency of the larvae. Additionally, the activity of ADA significantly increased during the exposure (p < 0.001), and the tissue-specific expression of CREB was also significantly increased, as assessed by immunofluorescence. Caffeine may regulate circadian clock genes through the ADA/ADORA/CREB pathway. These findings not only enhance our understanding of the effects of caffeine on zebrafish larvae but also provide valuable insights into the potential impact of caffeine on human behavior and sleep.

Ketamine attenuates kidney damage and depression-like behaviors in mice with cisplatin-induced acute kidney injury

Acute kidney injury (AKI) is a serious condition characterized by decreased urine output, often accompanied by psychiatric symptoms like depression. However, there are limited pharmacological treatments available for AKI and its associated depressive symptoms. In this study, we investigated whether cisplatin-induced AKI in mice leads to depression-like behaviors and whether ketamine could alleviate both the kidney injury and these behaviors. Mice with cisplatin-induced AKI exhibited elevated levels of creatinine and urea, kidney damage, increased kidney injury molecule-1 protein, and pathological changes in the liver, colon, and spleen. They also showed depression-like behaviors and reduced expression of synaptic proteins in the prefrontal cortex. Remarkably, a single dose of ketamine significantly reduced these symptoms and pathological changes. Interestingly, the beneficial effects of ketamine on the kidneys, other organs, and depression-like behaviors, were reversed by the tropomyosin receptor kinase B (TrkB) inhibitor ANA-12. Western blot analysis revealed the involvement of the TrkB and ERK (extracellular signal-regulated kinase)-CREB (cAMP response element binding protein) signaling pathway. Additionally, metabolomics analysis indicated that blood metabolites, such as C16-ceramide, may contribute to the effects of ketamine in this model. These findings suggest that cisplatin-induced nephrotoxicity in AKI mice contributes to depression-like behaviors, and ketamine can alleviate both kidney damage and depression-like symptoms by modulating the TrkB and ERK-CREB signaling pathways, as well as altering blood metabolites. However, the role of the kidney-brain axis in these depression-like behaviors remains unclear. Furthermore, ketamine may have therapeutic potential for treating kidney diseases such as AKI, along with associated depressive symptoms.

Validation of selective catalytic BmCBP inhibitors that regulate the Bm30K-24 protein expression in silkworm, Bombyx mori.

The cAMP response element binding protein (CREB)-binding protein (CBP) is a histone acetyltransferase that plays an indispensable role in regulating the acetylation of histone and non-histone proteins. Recently, it has been discovered that chemical inhibitors A485 and C646 can bind to Bombyx mori's CBP (BmCBP) and inhibit its acetyltransferase activity. Notably, the binding ability of A485 with BmCBP showed a very low Kd value of 48 nM by surface plasmon resonance (SPR) test. Further identification showed that both A485 and C646 can decrease the acetylation level of known substrate H3K27 and only 1 μM of A485 can almost completely inhibit the acetylation of H3K27, suggesting that A485 is an effective inhibitor of BmCBP's acetyltransferase activity. Moreover, it was confirmed that A485 could downregulate the expression of acetylated Bm30K-24 protein at a post-translational level through acetylation modification by BmCBP. Additionally, it was found that A485 can downregulate the stability of Bm30K-24 and improve its ubiquitination level, suggesting that the acetylation modification by BmCBP could compete with ubiquitination modification at the same lysine site on Bm30K-24, thereby affecting its protein stability. Here, we predict that A485 may be a potent CBP acetyltransferase inhibitor which could be utilized to inhibit acetyltransferase activity in insects, including silkworms.

Limosilactobacillus Fermentun ZS09 Can Improve Antibiotic-Induced Motor Dysfunction in Mice by Regulating the Brain-Gut Functions.

When consumed in appropriate quantities, probiotics, which are live microorganisms, are good for health. In this study, a mouse model of antibiotic-induced dyskinesia was established using a sterile mixed antibiotic solution to investigate the preventive impact of Limosilactobacillus fermentum ZS09 (LFZS09) on this condition in mice. Following modeling, alterations in the serum and brain tissue of mice were assessed for motor measures such as running and swimming, malondialdehyde (MDA), superoxide dismutase, reduced glutathione, interleukin (IL-6, IL-10), and tumor necrosis factor (TNF)-α. The mouse cecum was used to evaluate the relative mRNA expression levels of the intestinal barrier genes, namely occludin-1, zona occludens-1 (ZO-1), and claudin-1. The relative mRNA expression levels of cAMP-response element binding protein (CREB), extracellular signal-regulated kinase (ERK), and brain-derived neurotrophic factor (BDNF) genes in the mouse brain tissue were also evaluated. Compared with the model group, LFZS09 considerably increased the swimming and running duration of mice, significantly decreased the levels of the inflammatory factors TNF-α and IL-6 and increased SOD expression in the mouse brain, and decreased MDA accumulation in the mouse brain and serum. Furthermore, LFZS09 upregulated occludin-1 gene expression in the cecal tissue to maintain the intestinal barrier, which in turn maintained the normal physiological function of the body. LFZS09 also enhanced the effect of BDNF and increased the expression of BDNF metabolic pathway-related genes, namely CREB, ERK1/2, and BDNF, in the mouse brain tissue. LFZS09 increased the number of Lactobacillus and Bifidobacterium in the gut of mice with motor dysregulation, and decreased the number of Enterococcus and Clostridium perfringens. The findings indicate that LFZS09 regulates antibiotic-induced motor impairment in mice, thereby offering a theoretical foundation for future studies and probiotic or parabiotics production aimed at augmenting motor function.

Polydeoxyribonucleotide ameliorates IL-1β-induced impairment of chondrogenic differentiation in human bone marrow-derived mesenchymal stem cells

Osteoarthritis (OA) is a degenerative disease of the joints, prevalent worldwide. Polydeoxyribonucleotide (PDRN) is used for treating knee OA. However, the role of PDRN in IL-1β-induced inflammatory responses in human bone marrow-derived mesenchymal stem cells (hBMSCs) remains unknown. Here, we investigated the role of PDRN in IL-1β-induced impairment of chondrogenic differentiation in hBMSCs. hBMSCs treated with PDRN showed a large micromass, enhanced safranin O and alcian blue staining intensity, and increased expression of chondrogenic genes in IL-1β-induced inflammatory responses, in addition to regulation of catabolic and anabolic genes. In addition, PDRN treatment suppressed the expression of inflammatory cytokines and mitigated IL-1β-induced apoptosis in hBMSCs. Mechanistically, PDRN treatment increased the formation of cyclic adenosine monophosphate (cAMP) and upregulated the phosphorylation of cAMP-dependent protein kinase A (PKA)/cAMP response element binding protein (CREB) through the adenosine A2A receptor in hBMSCs and thus blocked the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling pathway. Thus, IL-1β-induced expression of inflammatory cytokines in hBMSCs was directly reduced by adenosine A2A receptor activation. Based on our results, we suggest that PDRN may be a promising MSC-based therapeutic agent for OA.