Novel AR/AR-V7 and Mnk1/2 Degrader, VNPP433-3ß: Molecular Mechanisms of Action and Efficacy in AR-Overexpressing Castration Resistant Prostate Cancer In Vitro and In Vivo Models.

Prostate cancer (PCa) relies in part on AR-signaling for disease development and progression. Earlier, we developed drug candidate galeterone, which advanced through phase 2-clinical trials in treating castration-resistant PCa (CRPC). Subsequently, we designed, synthesized, and evaluated next-generation galeterone-analogs including VNPP433-3ß which is potently efficacious against pre-clinical models of PCa. This study describes the mechanism of action of VNPP433-3ß that promotes degradation of full-length AR (fAR) and its splice variant AR-V7 besides depleting MNK1/2 in in vitro and in vivo CRPC models that stably overexpresses fAR. VNPP433-3ß directly engages AR within the cell and promotes proteasomal degradation of fAR and its splice variant AR-V7 by enhancing the interaction of AR with E3 ligases MDM2/CHIP but disrupting AR-HSP90 binding. Next, VNPP433-3ß decreases phosphorylation of 4EBP1 and abates binding of eIF4E and eIF4G to 5' cap of mRNA by depleting MNK1/2 with consequent depletion of phosphorylated eIF4E. Finally, RNA-seq demonstrates modulation of multiple pathways that synergistically contribute to PCa inhibition. Therefore, VNPP433-3ß exerts its antitumor effect by imposing 1) transcriptional regulation of AR and AR-responsive oncogenes 2) translational regulation by disrupting mRNA-5'cap-dependent translation initiation, 3) reducing AR half-life through enhanced proteasomal degradation in vitro and AR-overexpressing tumor xenografts in vivo.

Classical RAS proteins are not essential for paradoxical ERK activation induced by RAF inhibitors.

RAF inhibitors unexpectedly induce ERK signaling in normal and tumor cells with elevated RAS activity. Paradoxical activation is believed to be RAS dependent. In this study, we showed that LY3009120, a pan-RAF inhibitor, can unexpectedly cause paradoxical ERK activation in KRASG12C-dependent lung cancer cell lines, when KRAS is inhibited by ARS1620, a KRASG12C inhibitor. Using H/N/KRAS-less mouse embryonic fibroblasts, we discovered that classical RAS proteins are not essential for RAF inhibitor-induced paradoxical ERK signaling. In their absence, RAF inhibitors can induce ERK phosphorylation, ERK target gene transcription, and cell proliferation. We further showed that the MRAS/SHOC2 complex is required for this process. This study highlights the complexity of the allosteric RAF regulation by RAF inhibitors, and the importance of other RAS-related proteins in this process.

Anticancer properties of novel zinc oxide quantum dot nanoparticles against breast cancer stem-like cells.

Cancer stem cells (CSCs) play an essential role in cancer development, metastasis, relapse, and resistance to treatment. In this article, the effects of three synthesized ZnO nanofluids on proliferation, apoptosis, and stemness markers of breast cancer stem-like cells are reported. The antiproliferative and apoptotic properties of ZnO nanoparticles were evaluated on breast cancer stem-like cell-enriched mammospheres by MTS assay and flowcytometry, respectively. The expression of stemness markers, including WNT1, NOTCH1, ß-catenin, CXCR4, SOX2, and ALDH3A1 was assessed by real-time PCR. Western blotting was used to analyze the phosphorylation of Janus kinase 2 (JAK2) and Signal Transducer and Activator of Transcription 3 (STAT3). Markers of stemness were significantly decreased by ZnO nanofluids, especially sample (c) with code ZnO-148 with a different order of addition of polyethylene glycol solution at the end of formulation, which considerably decreased all the markers compared to the controls. All the studied ZnO nanofluids considerably reduced viability and induced apoptosis of spheroidal and parental cells, with ZnO-148 presenting the most effective activity. Using CD95L as a death ligand and ZB4 as an extrinsic apoptotic pathway blocker, it was revealed that none of the nanoparticles induced apoptosis through the extrinsic pathway. Results also showed a marked inhibition of the JAK/STAT pathway by ZnO nanoparticles; confirmed by downregulation of Mcl-1 and Bcl-XL expression. The present data demonstrated that ZnO nanofluids could combat breast CSCs via decreasing stemness markers, stimulating apoptosis, and suppressing JAK/STAT activity.

Delta-like canonical Notch ligand 3 as a potential therapeutic target in malignancies: A brief overview.

Delta-like canonical Notch ligand 3 (DLL3) is a member of the Delta/Serrate/Lag2 (DSL) Notch receptor ligand family and plays a crucial role in Notch signaling, which influences various cellular processes including differentiation, proliferation, survival, and apoptosis. DLL3 is expressed throughout the presomitic mesoderm and is localized to the rostral somatic compartments; mutations in DLL3 induce skeletal abnormalities such as spondylocostal dysostosis. Recently, DLL3 has attracted interest as a novel molecular target due to its high expression in neuroendocrine carcinoma of the lung. Moreover, a DLL3-targeting Ab-drug conjugate, rovalpituzumab tesirine (ROVA-T), has been developed as a new treatment with proven antitumor activity. However, the development of ROVA-T was suspended because of shorter overall survival compared to topotecan, the second-line standard treatment. Thus, several studies on the mechanism and function of DLL3 in several malignancies are underway to find a new strategy for targeting DLL3. In this review, we discuss the roles of DLL3 in various malignancies and the future perspectives of DLL3-related research, especially as a therapeutic target.

Multifaceted Mechanisms of Action of Metformin Which Have Been Unraveled One after Another in the Long History.

While there are various kinds of drugs for type 2 diabetes mellitus at present, in this review article, we focus on metformin which is an insulin sensitizer and is often used as a first-choice drug worldwide. Metformin mainly activates adenosine monophosphate-activated protein kinase (AMPK) in the liver which leads to suppression of fatty acid synthesis and gluconeogenesis. Metformin activates AMPK in skeletal muscle as well, which increases translocation of glucose transporter 4 to the cell membrane and thereby increases glucose uptake. Further, metformin suppresses glucagon signaling in the liver by suppressing adenylate cyclase which leads to suppression of gluconeogenesis. In addition, metformin reduces autophagy failure observed in pancreatic ß-cells under diabetic conditions. Furthermore, it is known that metformin alters the gut microbiome and facilitates the transport of glucose from the circulation into excrement. It is also known that metformin reduces food intake and lowers body weight by increasing circulating levels of the peptide hormone growth/differentiation factor 15 (GDF15). Furthermore, much attention has been drawn to the fact that the frequency of various cancers is lower in subjects taking metformin. Metformin suppresses the mechanistic target of rapamycin (mTOR) by activating AMPK in pre-neoplastic cells, which leads to suppression of cell growth and an increase in apoptosis in pre-neoplastic cells. It has been shown recently that metformin consumption potentially influences the mortality in patients with type 2 diabetes mellitus and coronavirus infectious disease (COVID-19). Taken together, metformin is an old drug, but multifaceted mechanisms of action of metformin have been unraveled one after another in its long history.

Evaluation of the Effect of Mannuronic Acid as a Novel NSAID With Immunosuppressive Properties on Expression of SOCS1, SOCS3, SHIP1, and TRAF6 Genes and Serum Levels of IL-6 and TNF-α in Patients With Multiple Sclerosis.

Multiple sclerosis (MS) is described as a chronic inflammatory, demyelinating disease of the central nervous system on an autoimmune basis, which is the most frequent reason for nontraumatic disability in youth. The efficacy and safety of ß-D-nannuronic acid (M2000) as a novel immunosuppressive drug (patented PCT/EP2017/067920) has been shown in an experimental model of MS and also in a phase 2 clinical trial. The effects of M2000 on SOCS1, SOCS3, TRAF6, and SHIP1 gene expression and also serum levels of IL-6 and TNF-α in secondary progressive multiple sclerosis patients have been assessed in this study. In this study, 14 secondary progressive multiple sclerosis patients and 14 healthy subjects (as the control group) were recruited from the phase 2 clinical trial (Clinical Trial identifier, IRCT2016111313739N6). Gene expression of SOCS1, SOCS3, TRAF6, and SHIP1 was measured at baseline and after 6 months of therapy with M2000 using a quantitative real-time polymerase chain reaction method. Furthermore, the serum levels of IL-6 and TNF-α were assessed by the enzyme-linked immunosorbent assay method. Our results showed that the gene expression of SOCS1, SOCS3, and SHIP1 was increased after 6 months of therapy with M2000 in MS patients. Moreover, the serum levels of IL-6 and TNF-α of patients declined compared with baseline, but this was not statistically significant. The results of this study demonstrated that M2000, with immunosuppressive properties, could upregulate SOCS1, SOCS3, and SHIP1 genes in patients with secondary progressive multiple sclerosis.

Ac-FLTD-CMK inhibits pyroptosis and exerts neuroprotective effect in a mice model of traumatic brain injury.

Pyroptosis has been reported to contribute to the traumatic brain injury (TBI) process. Ac-FLTD-CMK is a newly synthesized pyroptosis inhibitor. However, whether Ac-FLTD-CMK inhibits pyroptosis and plays a neuroprotective role after TBI is unknown. The present study aimed to determine the effects of Ac-FLTD-CMK on TBI in a mouse model. Male C57BL/6 mice were randomly divided into sham, TBI + vehicle, and TBI + Ac-FLTD-CMK groups. TBI was induced using a weight-drop apparatus. Intraventricular injection of Ac-FLTD-CMK was performed 30 min after TBI. Caspase-1, caspase-11, gasdermin-D (GSDMD), and caspase-3 expression in the peri-contusional cortex were assessed by western blotting. Interleukin-1ß (IL-1ß) and interleukin-18 (IL-18) expression in the peri-contusional cortex were measured using ELISA. Behavioral experiments, brain water content, Evans blue extravasation, lactate dehydrogenase (LDH) release, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling staining were also performed. The results showed that Ac-FLTD-CMK administration significantly downregulated caspase-1 p20, caspase-11 p20, GSDMD N-terminal, IL-1ß, and IL-18 expression; reduced LDH release; alleviated neuronal death; attenuated brain edema and blood-brain barrier damage; and improved neurobehavioral function. These findings indicate that Ac-FLTD-CMK treatment suppresses pyroptosis and protects mice against TBI.

PORIMIN: The key to (+)-Usnic acid-induced liver toxicity and oncotic cell death in normal human L02 liver cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Usnic acid (UA) is one of the well-known lichen metabolites that induces liver injury. It is mainly extracted from Usnea longissima and U. diffracta in China or from other lichens in other countries. U. longissima has been used as traditional Chinese medicine for treatment of cough, pain, indigestion, wound healing and infection. More than 20 incidences with hepatitis and liver failure have been reported by the US Food and Drug Administration since 2000. UA is an uncoupler of oxidative phosphorylation causing glutathione and ATP depletion. Previous histological studies observed extensive cell and organelle swellings accompanied with hydrotropic vacuolization of hepatocytes. AIM OF THE STUDY: This study was to investigate the mechanism of UA-induced liver toxicity in normal human L02 liver cells and ICR mice using various techniques, such as immunoblotting and siRNA transfection. MATERIALS AND METHODS: Assays were performed to evaluate the oxidative stress and levels of GSH, MDA and SOD. Double flouresencence staining was used for the detection of apoptotic cell death. The protein expressions, such as glutathione S transferase, glutathione reductase, glutathione peroxidase 4, catalase, c-Jun N-terminal protein kinase, caspases, gastamin-D and porimin were detected by Western blotting. Comparisons between transfected and non-transfected cells were applied for the elucidation of the role of porimin in UA-induced hepatotoxicity. Histopathological examination of mice liver tissue, serum total bilirubin and hepatic enzymes of alanine aminotransferase and aspatate aminotransferase were also studied. RESULTS: The protein expressions of glutathione reductase, glutathione S transferase and glutathione peroxidase-4 were increased significantly in normal human L02 liver cells. Catalase expression was diminished in dose-dependent manner. Moreover, (+)-UA did not induce the activation of caspase-3, caspase-1 or gasdermin-D. No evidence showed the occurrence of pyroptosis. However, the porimin expressions were increased significantly. In addition, (+)-UA caused no cytotoxicity in the porimin silencing L02 cells. CONCLUSIONS: In conclusion, (+)-UA induces oncotic L02 cell death via increasing protein porimin and the formation of irreversible membrane pores. This may be the potential research area for future investigation in different aspects especially bioactivity and toxicology.

Circular RNA TMEM87A promotes cell proliferation and metastasis of gastric cancer by elevating ULK1 via sponging miR-142-5p.

BACKGROUND: Circular RNAs (circRNAs) act as vital regulators of gene expression in a variety of cancers. However, the role of circRNAs in gastric cancer (GC) remains largely unexplored. Herein, we identified that circTMEM87A sponges miR-142-5p to promote GC progression through up-regulating ULK1 expression. METHODS: The expression of circTMEM87A in GC was determined by RNA sequencing and quantitative real-time PCR (qRT-PCR). The effects of knockdown or exogenous expression of circTMEM87A on GC cell phenotypes were evaluated both in vitro and in vivo. The interacting miRNA of circTMEM87A was predicted by bioinformatics and confirmed by RNA pull-down, dual-luciferase reporter assay and fluorescence in situ hybridization (FISH). The mechanism by which circTMEM87A/miR-142-5p/ULK1 axis promotes GC was determined by western blot, GFP/mRFP-LC3 puncta analysis, transmission electron microscope (TEM). RESULTS: CircTMEM87A was dramatically elevated in GC tissues and cell lines, and high circTMEM87A expression was closely correlated with poor prognosis of GC patients. Knockdown of circTMEM87A suppressed cell growth, migration, invasion and induced apoptosis in vitro, as well as inhibited GC tumorigenicity and lung metastasis potential in vivo. Meanwhile, circTMEM87A overexpression had the opposite effects. Furthermore, we demonstrated that circTMEM87A could act as a sponge of miR-142-5p to regulate ULK1 expression and GC progression. CONCLUSIONS: Our findings suggest that circTMEM87A functions as an oncogene through the miR-142-5p/ULK1 axis in GC. CircTMEM87A might be a prognostic biomarker as well as a promising therapeutic target for GC.

MNK Inhibition Sensitizes KRAS-Mutant Colorectal Cancer to mTORC1 Inhibition by Reducing eIF4E Phosphorylation and c-MYC Expression.

KRAS-mutant colorectal cancers are resistant to therapeutics, presenting a significant problem for ∼40% of cases. Rapalogs, which inhibit mTORC1 and thus protein synthesis, are significantly less potent in KRAS-mutant colorectal cancer. Using Kras-mutant mouse models and mouse- and patient-derived organoids, we demonstrate that KRAS with G12D mutation fundamentally rewires translation to increase both bulk and mRNA-specific translation initiation. This occurs via the MNK/eIF4E pathway culminating in sustained expression of c-MYC. By genetic and small-molecule targeting of this pathway, we acutely sensitize KRASG12D models to rapamycin via suppression of c-MYC. We show that 45% of colorectal cancers have high signaling through mTORC1 and the MNKs, with this signature correlating with a 3.5-year shorter cancer-specific survival in a subset of patients. This work provides a c-MYC-dependent cotargeting strategy with remarkable potency in multiple Kras-mutant mouse models and metastatic human organoids and identifies a patient population that may benefit from its clinical application. SIGNIFICANCE: KRAS mutation and elevated c-MYC are widespread in many tumors but remain predominantly untargetable. We find that mutant KRAS modulates translation, culminating in increased expression of c-MYC. We describe an effective strategy targeting mTORC1 and MNK in KRAS-mutant mouse and human models, pathways that are also commonly co-upregulated in colorectal cancer.This article is highlighted in the In This Issue feature, p. 995.

GABAB receptor intracellular signaling: novel pathways for depressive disorder treatment?

Affecting over 320 million people around the world, depression has become a formidable challenge for modern medicine. In addition, an increasing number of studies cast doubt on the monoamine theory of depressive disorder and, worryingly, antidepressant medications only significantly benefit patients with severe depression. Thus, it is not surprising that researchers have shown an increased interest in new theories attempting to explain the pathogenesis of this disease. One example is the excitatory/inhibitory transmission imbalance theory. These abnormalities involve glutamate and γ-aminobutyric acid (GABA) signaling. Studies on GABAB receptors and their antagonists are particularly promising for the treatment of depressive disorders. In this paper, intracellular pathways controlled by GABAB receptors and their links to depression are described, including the impact of ketamine on GABAergic synaptic transmission.

The KBTBD6/7-DRD2 axis regulates pituitary adenoma sensitivity to dopamine agonist treatment.

Pituitary adenoma (PA) is one of the most common intracranial tumors, and approximately 40% of all PAs are prolactinomas. Dopamine agonists (DAs), such as cabergoline (CAB), have been successfully used in the treatment of prolactinomas. The expression of dopamine type 2 receptor (DRD2) determines the therapeutic effect of DAs, but the molecular mechanisms of DRD2 regulation are not fully understood. In this study, we first demonstrated that DRD2 underwent proteasome-mediated degradation. We further employed the yeast two-hybrid system and identified kelch repeat and BTB (POZ) domain containing 7 (KBTBD7), a substrate adaptor for the CUL3-RING ubiquitin (Ub) ligase complex, as a DRD2-interacting protein. KBTBD6/7 directly interacted with, and ubiquitinated DRD2 at five ubiquitination sites (K221, K226, K241, K251, and K258). CAB, a high-affinity DRD2 agonist, induced DRD2 internalization, and cytoplasmic DRD2 was degraded via ubiquitination under the control of KBTBD6/7, the activity of which attenuated CAB-mediated inhibition of the AKT/mTOR pathway. KBTBD7 knockout (KO) mice were generated using the CRISPR-Cas9 technique, in which the static level of DRD2 protein was elevated in the pituitary gland, thalamus, and heart, compared to that of WT mice. Consistently, the expression of KBTBD6/7 was negatively correlated with that of DRD2 in human pituitary tumors. Moreover, KBTBD7 was highly expressed in dopamine-resistant prolactinomas, but at low levels in dopamine-sensitive prolactinomas. Knockdown of KBTBD6/7 sensitized MMQ cells and primary pituitary tumor cells to CAB treatment. Conversely, KBTBD7 overexpression increased CAB resistance of estrogen-induced in situ rat prolactinoma model. Together, our findings have uncovered the novel mechanism of DRD2 protein degradation and shown that the KBTBD6/7-DRD2 axis regulates PA sensitivity to DA treatment. KBTBD6/7 may thus become a promising therapeutic target for pituitary tumors.

Cannabinoid 1 Receptor Antagonists Play a Neuroprotective Role in Chronic Alcoholic Hippocampal Injury Related to Pyroptosis Pathway.

BACKGROUND: Alcohol use disorders affect millions of people worldwide, and there is growing evidence that excessive alcohol intake causes severe damage to the brain of both humans and animals. Numerous studies on chronic alcohol exposure in animal models have identified that many functional impairments are associated with the hippocampus, which is a structure exhibiting substantial vulnerability to alcohol exposure. However, the precise mechanisms that lead to structural and functional impairments of the hippocampus are poorly understood. Herein, we report a novel cell death type, namely pyroptosis, which accounts for alcohol neurotoxicity in mice. METHODS: For this study, we used an in vivo model to induce alcohol-related neurotoxicity in the hippocampus. Adult male C57BL/6 mice were treated with 95% alcohol vapor either alone or in combination with selective cannabinoid receptor antagonists or agonists, and VX765 (Belnacasan), which is a selective caspase-1 inhibitor. RESULTS: Alcohol-induced in vivo pyroptosis occurs because of an increase in the levels of pyroptotic proteins such as nucleotide-binding domain (NOD)-like receptor protein 3 (NLRP3), caspase-1, gasdermin D (GSDMD), and amplified inflammatory response. Our results indicated that VX765 suppressed the expression of caspase-1 and inhibited the maturation of the proinflammatory cytokines interleukin-1ß (IL-1ß) and IL-18. Additionally, chronic alcohol intake created an imbalance in the endocannabinoid system and regulated 2 cannabinoid receptors (CB1R and CB2R) in the hippocampus. Specific antagonists of CB1R (AM251 and AM281) significantly ameliorated alcohol-induced pyroptosis signaling and inactivated the inflammatory response. CONCLUSIONS: Alcohol induces hippocampal pyroptosis, which leads to neurotoxicity, thereby indicating that pyroptosis may be an essential pathway involved in chronic alcohol-induced hippocampal neurotoxicity. Furthermore, cannabinoid receptors are regulated during this process, which suggests promising therapeutic strategies against alcohol-induced neurotoxicity through pharmacologic inhibition of CB1R.

Increased expression of the transforming growth factor ß-inducible gene HIC-5 in systemic sclerosis skin and fibroblasts: a novel antifibrotic therapeutic target.

OBJECTIVE: SSc is a systemic fibrotic disease affecting skin, numerous internal organs and the microvasculature. The molecular pathogenesis of SSc tissue fibrosis has not been fully elucidated, although TGF-ß1 plays a crucial role. The Hic-5 protein encoded by the TGF-ß1-inducible HIC-5 gene participates in numerous TGF-ß-mediated pathways, however, the role of Hic-5 in SSc fibrosis has not been investigated. The aim of this study was to examine HIC-5 involvement in SSc tissue fibrosis. METHODS: Affected skin from three patients with diffuse SSc and dermal fibroblasts cultured from affected and non-affected SSc skin were examined for HIC-5 and COL1A1 gene expression. Real-time PCR, IF microscopy, western blotting and small interfering RNA-mediated HIC-5 were performed. RESULTS: HIC-5 and COL1A1 transcripts and Hic-5, type 1 collagen (COL1) and α-smooth muscle actin (α-SMA) protein levels were increased in clinically affected SSc skin compared with normal skin and in cultured dermal fibroblasts from affected SSc skin compared with non-affected skin fibroblasts from the same patients. HIC-5 knockdown caused a marked reduction of COL1 production in SSc dermal fibroblasts. CONCLUSION: HIC-5 expression is increased in affected SSc skin compared with skin from normal individuals. Affected SSc skin fibroblasts display increased HIC-5 and COL1A1 expression compared with non-affected skin fibroblasts from the same patients. Hic-5 protein was significantly increased in cultured SSc dermal fibroblasts. HIC-5 mRNA knockdown in SSc fibroblasts caused >50% reduction of COL1 production. Although these are preliminary results owing to the small number of skin samples studied, they indicate that Hic-5 plays a role in the profibrotic activation of SSc dermal fibroblasts and may represent a novel molecular target for antifibrotic therapy in SSc.

Effects of Mitochondrial-Derived Peptides (MDPs) on Mitochondrial and Cellular Health in AMD.

Substantive evidence demonstrates the contribution of mitochondrial dysfunction in the etiology and pathogenesis of Age-related Macular Degeneration (AMD). Recently, extensive characterization of Mitochondrial­Derived Peptides (MDPs) has revealed their cytoprotective role in several diseases, including AMD. Here we summarize the varied effects of MDPs on cellular and mitochondrial health, which establish the merit of MDPs as therapeutic targets for AMD. We argue that further research to delve into the mechanisms of action and delivery of MDPs may advance the field of AMD therapy.

Chronic Binge Alcohol Exposure During Pregnancy Alters mTOR System in Rat Fetal Hippocampus.

BACKGROUND: Gestational alcohol exposure can contribute to fetal alcohol spectrum disorders (FASD), an array of cognitive, behavioral, and physical developmental impairments. Mammalian target of rapamycin (mTOR) plays a key role in regulating protein synthesis in response to neuronal activity, thereby modulating synaptic plasticity and long-term memory formation in the brain. Based on our previous quantitative mass spectrometry proteomic studies, we hypothesized that gestational chronic binge alcohol exposure alters mTOR signaling and downstream pathways in the fetal hippocampus. METHODS: Pregnant Sprague-Dawley rats were assigned to either a pair-fed control (PF-Cont) or a binge alcohol (Alcohol) treatment group. Alcohol dams were acclimatized via a once-daily orogastric gavage of 4.5 g/kg alcohol (peak BAC, 216 mg/dl) from GD 5-10 and progressed to 6 g/kg alcohol (peak BAC, 289 mg/dl) from GD 11-21. Pair-fed dams similarly received isocaloric maltose dextrin. RESULTS: In the Alcohol group, following this exposure paradigm, fetal body weight and crown-rump length were decreased. The phosphorylation level of mTOR (P-mTOR) in the fetal hippocampus was decreased in the Alcohol group compared with controls. Alcohol exposure resulted in dysregulation of fetal hippocampal mTORC1 signaling, as evidenced by an increase in total 4E-BP1 expression. Phosphorylation levels of 4E-BP1 and p70 S6K were also increased following alcohol exposure. P-mTOR and P-4E-BP1 were exclusively detected in the dentate gyrus and oriens layer of the fetal hippocampus, respectively. DEPTOR and RICTOR expression levels in the fetal hippocampus were increased; however, RAPTOR was not altered by chronic binge alcohol exposure. CONCLUSION: We conclude that chronic binge alcohol exposure during pregnancy alters mTORC1 signaling pathway in the fetal hippocampus. We conjecture that this dysregulation of mTOR protein expression, its activity, and downstream proteins may play a critical role in FASD neurobiological phenotypes.

Dapagliflozin attenuates renal gluconeogenic enzyme expression in obese rats.

The kidneys release glucose into the systemic circulation through glucose reabsorption and renal gluconeogenesis. Currently, the significance of renal glucose release in pathological conditions has become a subject of interest. We examined the effect of sodium-dependent glucose cotransporter 2 inhibitor (SGLT2i) on renal gluconeogenic enzyme expression in obese rats. Male Wistar rats (180-200 g) were fed either a normal diet (ND, n = 6) or a high-fat diet. At 16 weeks, after confirming the degree of glucose intolerance, high-fat diet-fed rats were randomly subdivided into three groups (n = 6/group): untreated group (HF), treated with dapagliflozin 1 mg/kg/day (HFSG) and treated with metformin 30 mg/kg/day (HFM). The treatment was continued for 4 weeks. We observed that dapagliflozin or metformin mitigated the enhanced expression of renal gluconeogenic enzymes, PEPCK, G6Pase and FBPase, as well as improved glucose tolerance and renal function in obese rats. Dapagliflozin downregulated the elevated expression of gluconeogenic transcription factors p-GSK3ß, p-CREB and coactivator PGC1α in the renal cortical tissue. Metformin reduced the expression levels of renal cortical FOXO1 and CREB. Furthermore, reduced renal insulin signaling was improved and renal oxidative stress was attenuated by either dapagliflozin or metformin treatment in obese rats. We concluded that glucose tolerance was improved by dapagliflozin in obese prediabetic rats by suppressing renal glucose release from not only glucose reabsorption but also renal gluconeogenesis through improving renal cortical insulin signaling and oxidative stress. The efficacy of dapagliflozin in improving renal insulin signaling, oxidative stress and renal function was greater than that of metformin.

Sodium butyrate-activated TRAF6-TXNIP pathway affects A549 cells proliferation and migration.

TNF receptor-associated factor 6 (TRAF6) promotes the development of human lung cancer through bridging RAS and NF-kB pathways; on the other hand, thioredoxin-interacting protein (TXNIP) suppresses the growth of tumors. However, the crosstalk between TRAF6 and TXNIP in non-small cell lung cancer (NSCLC) is currently unclear. Here, we found that TXNIP expression induced by sodium butyrate (NaBu) was TRAF6-dependent. Moreover, TXNIP interacted with TRAF6 via its PPxY motif. Polyubiquitylation analysis with wild-type or mutant (Cysteine70 to Alanine) of TRAF6 further showed TRAF6 ubiquitylated TXNIP. NaBu reinforced the interaction of TRAF6/TXNIP as well as TXNIP' polyubiquitylation. Moreover, treated with NaBu, the A549 cells with TRAF6/TXNIP double knockdown showed an enhanced protein expression of E-cadherin comparing to cells with single gene or negative knockdown. The experimental results of transwell and nude mice xenograft showed that knocking down both TRAF6 and TXNIP in A549 cells affected its migration and proliferation compared to that of single knockdown or negative control cells. On the other hand, TXNIP localization was different depending on the cell types and fused-tag (eg, FLAG or GFP). Our results revealed TRAF6 regulated the expression and polyubiquitylation of TXNIP in a NaBu-dependent manner, alleviating tumorigenesis of TRAF6.

Ketogenesis-generated ß-hydroxybutyrate is an epigenetic regulator of CD8+ T-cell memory development.

Glycogen has long been considered to have a function in energy metabolism. However, our recent study indicated that glycogen metabolism, directed by cytosolic phosphoenolpyruvate carboxykinase Pck1, controls the formation and maintenance of CD8+ memory T (Tmem) cells by regulating redox homeostasis1. This unusual metabolic program raises the question of how Pck1 is upregulated in CD8+ Tmem cells. Here, we show that mitochondrial acetyl coenzyme A is diverted to the ketogenesis pathway, which indirectly regulates Pck1 expression. Mechanistically, ketogenesis-derived ß-hydroxybutyrate is present in CD8+ Tmem cells; ß-hydroxybutyrate epigenetically modifies Lys 9 of histone H3 (H3K9) of Foxo1 and Ppargc1a (which encodes PGC-1α) with ß-hydroxybutyrylation, upregulating the expression of these genes. As a result, FoxO1 and PGC-1α cooperatively upregulate Pck1 expression, therefore directing the carbon flow along the gluconeogenic pathway to glycogen and the pentose phosphate pathway. These results reveal that ketogenesis acts as an unusual metabolic pathway in CD8+ Tmem cells, linking epigenetic modification required for memory development.