Monocarboxylic Acid Transporter Research Articles

A universal self-delivery lactate metabolism regulating polyprodrug enhances tumor photodynamic therapy

Lactate plays vital roles in promoting immunosuppressive tumor microenvironment, tumor angiogenesis and drug resistance, therefore, lactate modulation is a promising strategy to conquer the restrictions of many therapeutic modalities. A universal drug self-delivery nano-platform with easy synthesis and superior biosafety for lactate regulation is still needed. Herein, α-cyano-4-hydroxycinnamic acids (α-CHC), as monocarboxylic acid transporter 1 (MCT1) inhibitors, are polycondensed into poly (α-cyano-4-hydroxycinnamic acid) (PCHC) for the first time to function as both the lactate metabolism regulation prodrug and a drug carrier of, in this case, photosensitizer Protoporphyrin IX (PpIX). Once triggering by the intracellular esterase, the co-assembled PCHC@PpIX nanoparticles (shorted as PCPp NPs) are degraded accordingly and the generated α-CHC monomer inhibits MCT1 to cut down the lactate influx and further reduces endogenous oxygen (O2) loss in tumor cells. By utilizing the elevated O2 level, the released PpIX produces more cytotoxic reactive oxygen species (ROS) and only a single dosage (total PpIX: 0.10 mg per mice) with extremely low light exposure (3.5 J cm-2) is needed for tumor elimination. This work provides a charming lactate metabolic modulating polyprodrug based self-delivery nano-platform for universal hydrophobic drug delivery to improve anticancer efficacy especially for those oxygen dependent therapeutic strategies.

Aerobic exercise-induced HIF-1α upregulation in heart failure: exploring potential impacts on MCT1 and MPC1 regulation

BackgroundThe terminal stage of ischemic heart disease develops into heart failure (HF), which is characterized by hypoxia and metabolic disturbances in cardiomyocytes. The hypoxic failing heart triggers hypoxia-inducible factor-1α (HIF-1α) actions in the cells sensitized to hypoxia and induces metabolic adaptation by accumulating HIF-1α. Furthermore, soluble monocarboxylic acid transporter protein 1 (MCT1) and mitochondrial pyruvate carrier 1 (MPC1), as key nodes of metabolic adaptation, affect metabolic homeostasis in the failing rat heart. Aerobic exercise training has been reported to retard the progression of HF due to enhancing HIF-1α levels as well as MCT1 expressions, whereas the effects of exercise on MCT1 and MPC1 in HF (hypoxia) remain elusive. This research aimed to investigate the action of exercise associated with MCT1 and MPC1 on HF under hypoxia.MethodsThe experimental rat models are composed of four study groups: sham stented (SHAM), HF sedentary (HF), HF short-term exercise trained (HF-E1), HF long-term exercise trained (HF-E2). HF was initiated via left anterior descending coronary artery ligation, the effects of exercise on the progression of HF were analyzed by ventricular ultrasound (ejection fraction, fractional shortening) and histological staining. The regulatory effects of HIF-1α on cell growth, MCT1 and MPC1 protein expression in hypoxic H9c2 cells were evaluated by HIF-1α activatort/inhibitor treatment and plasmid transfection.ResultsOur results indicate the presence of severe pathological remodelling (as evidenced by deep myocardial fibrosis, increased infarct size and abnormal hypertrophy of the myocardium, etc.) and reduced cardiac function in the failing hearts of rats in the HF group compared to the SHAM group. Treadmill exercise training ameliorated myocardial infarction (MI)-induced cardiac pathological remodelling and enhanced cardiac function in HF exercise group rats, and significantly increased the expression of HIF-1α (p < 0.05), MCT1 (p < 0.01) and MPC1 (p < 0.05) proteins compared to HF group rats. Moreover, pharmacological inhibition of HIF-1α in hypoxic H9c2 cells dramatically downregulated MCT1 and MPC1 protein expression. This phenomenon is consistent with knockdown of HIF-1α at the gene level.ConclusionThe findings propose that long-term aerobic exercise training, as a non- pharmacological treatment, is efficient enough to debilitate the disease process, improve the pathological phenotype, and reinstate cardiac function in HF rats. This benefit is most likely due to activation of myocardial HIF-1α and upregulation of MCT1 and MPC1.

H2S-Powered Nanomotors for Active Therapy of Tumors by Inducing Ferroptosis and Lactate-Pyruvate Axis Disorders.

Disruption of the symbiosis of extra/intratumoral metabolism is a good strategy for treating tumors that shuttle resources from the tumor microenvironment. Here, we report a precision treatment strategy for enhancing pyruvic acid and intratumoral acidosis to destroy tumoral metabolic symbiosis to eliminate tumors; this approach is based on PEGylated gold and lactate oxidase-modified aminated dendritic mesoporous silica with lonidamine and ferrous sulfide loading (PEG-Au@DMSNs/FeS/LND@LOX). In the tumor microenvironment, LOX oxidizes lactic acid to produce pyruvate, which represses tumor cell proliferation by inhibiting histone gene expression and induces ferroptosis by partial histone monoubiquitination. In acidic tumor conditions, the nanoparticles release H2S gas and Fe2+ ions, which can inhibit catalase activity to promote the Fenton reaction of Fe2+, resulting in massive ·OH production and ferroptosis via Fe3+. More interestingly, the combination of H2S and LND (a monocarboxylic acid transporter inhibitor) can cause intracellular acidosis by lactate, and protons overaccumulate in cells. Multiple intracellular acidosis is caused by lactate-pyruvate axis disorders. Moreover, H2S provides motive power to intensify the shuttling of nanoparticles in the tumor region. The findings confirm that this nanomedicine system can enable precise antitumor effects by disrupting extra/intratumoral metabolic symbiosis and inducing ferroptosis and represents a promising active drug delivery system candidate for tumor treatment.

Adaptive Metabolic Responses Facilitate Blood-Brain Barrier Repair in Ischemic Stroke via BHB-Mediated Epigenetic Modification of ZO-1 Expression.

Adaptive metabolic responses and innate metabolites hold promising therapeutic potential for stroke, while targeted interventions require a thorough understanding of underlying mechanisms. Adiposity is a noted modifiable metabolic risk factor for stroke, and recent research suggests that it benefits neurological rehabilitation. During the early phase of experimental stroke, the lipidomic results showed that fat depots underwent pronounced lipolysis and released fatty acids (FAs) that feed into consequent hepatic FA oxidation and ketogenesis. Systemic supplementation with the predominant ketone beta-hydroxybutyrate (BHB) is found to exert discernible effects on preserving blood-brain barrier (BBB) integrity and facilitating neuroinflammation resolution. Meanwhile, blocking FAO-ketogenesis processes by administration of CPT1α antagonist or shRNA targeting HMGCS2 exacerbated endothelial damage and aggravated stroke severity, whereas BHB supplementation blunted these injuries. Mechanistically, it is unveiled that BHB infusion is taken up by monocarboxylic acid transporter 1 (MCT1) specifically expressed in cerebral endothelium and upregulated the expression of tight junction protein ZO-1 by enhancing local β-hydroxybutyrylation of H3K9 at the promoter of TJP1 gene. Conclusively, an adaptive metabolic mechanism is elucidated by which acute lipolysis stimulates FAO-ketogenesis processes to restore BBB integrity after stroke. Ketogenesis functions as an early metabolic responder to restrain stroke progression, providing novel prospectives for clinical translation.

Enhanced oral and pulmonary delivery of biomacromolecules via amplified transporter targeting

Ligand-modified nanocarriers can promote oral or inhalative administration of macromolecular drugs across the intestinal or pulmonary mucosa. However, enhancing the unidirectional transport of the nanocarriers through “apical uptake→intracellular transport→basolateral exocytosis” route remains a hot topic and challenge in current research. Forskolin is a naturally occurring diterpenoid compound extracted from the roots of C. forskohlii. In our studies, we found that forskolin could increase the transcellular transport of butyrate-modified nanoparticles by 1.67-fold and 1.20-fold in Caco-2 intestinal epithelial cell models and Calu-3 lung epithelial cell models, respectively. Further mechanistic studies revealed that forskolin, on the one hand, promoted the cellular uptake of butyrate-modified nanoparticles by upregulating the expression of monocarboxylic acid transporter-1 (MCT-1) on the apical membrane. On the other hand, forskolin facilitated the binding of MCT-1 to caveolae, thereby mediating butyrate-modified nanoparticles hijacking caveolae to promote the basolateral exocytosis of butyrate-modified nanoparticles. Studies in normal mice model showed that forskolin could promote the transmucosal absorption of butyrate-modified nanoparticles by >2-fold, regardless of oral or inhalative administration. Using semaglutide as the model drug, both oral and inhalation delivery approaches demonstrated significant hypoglycemic effects in type 2 diabetes mice model, in which inhalative administration was more effective than oral administration. This study optimized the strategies aimed at enhancing the transmucosal absorption of ligand-modified nanocarriers in the intestinal or pulmonary mucosa.

Metabolic pathways of glucose and fructose: II Spatiotemporal expression of genes involved in synthesis and transport of lactate in ovine conceptuses†.

Lactate, an abundant molecule in fetal fluids and blood of mammalian species, is often overlooked as a metabolic waste product generated during pregnancy. Most of the glucose and fructose consumed by ovine conceptuses is converted to lactate, but proteins involved in lactate metabolism and transport have not been investigated. This study characterized total lactate produced by ovine conceptuses throughout gestation, as well as expression of mRNAs and proteins involved in lactate metabolism. Lactate increased in abundance in the uterine lumen during the preimplantation period and was more abundant than pyruvate. The abundance of lactate in allantoic and amniotic fluids increased with advancing days of gestation and most abundant on Day 125 of pregnancy (P < 0.05). Lactate dehydrogenase subunits A (converts pyruvate to lactate) and B (converts lactate to pyruvate) were expressed by conceptuses throughout gestation. Lactate is transported via monocarboxylic acid transporters SLC16A1 and SLC16A3, both of which were expressed by the conceptus throughout gestation. Additionally, the interplacentomal chorioallantois from Day 126 expressed SLC16A1 and SLC16A3 and transported lactate across the tissue. Hydrocarboxylic acid receptor 1 (HCAR1), a receptor for lactate, was localized to the uterine luminal and superficial glandular epithelia of pregnant ewes throughout gestation and conceptus trophectoderm during the peri-implantation period of gestation. These results provide novel insights into the spatiotemporal profiles of enzymes, transporters, and receptor for lactate by ovine conceptuses throughout pregnancy.

Abstract 7502: MCT1 and ΜCT4 on circulating tumor cells isolated from non small cell lung cancer patients

Abstract Background: Lung cancer is the leading cause of cancer-related deaths. Non-small-cell lung cancer (NSCLC) is the most common subtype of lung cancer and is characterized by poor prognosis and survival rate. This is associated with the fact that most patients are diagnosed at advanced stages of the disease and the possibility of recurrence after treatment remains high. Monocarboxylate transporters 1 and 4 (MCT1 and MCT4) play a crucial role in cellular metabolism, as they are responsible for the transport of lactate and other monocarboxylic acids across the plasma membrane. Their function can further regulate cell survival and proliferation, especially under hypoxic conditions. To elucidate the relationship between CTCs and the metabolic aspect of cancer, we aimed to investigate the expression of MCT1 and MCT4 in CTCs derived from NSCLC patients and its potential association with patients’ outcome. Methods: Fifty-three NSCLC patients at baseline were enrolled in the current study. CTCs were isolated using the ISET system and triple immunofluorescence experiments were performed, using CK, MCT1, MCT4, and CD45 antibodies. The expression of MCT1 and MCT4 in CTCs was assessed by confocal laser scanning microscopy and statistical analysis was performed using SPSS software. Results: CTCs were detected in 29 out of 53 (55%) NSCLC patients. CK expression was characterized as high or low, with the predominant phenotypes among CK-positive patients being the CKhigh/MCT1+/CD45-and CKlow/MCT4-/CD45- (63% and 66%, respectively). Whereas the phenotype CKhigh/MCT4+/CD45- was detected in 52% of the patients. The phenotypes with the lowest frequency were the CKlow/MCT4+/CD45- (7%), CKlow/MCT1+/CD45- (15%), and the CKhigh/MCT1-/CD45- (15%). Most of the isolated CTCs had the CKhigh/MCT1+/CD45- and CKlow/MCT4-/CD45- phenotypes with a mean percentage of 48% and 51% respectively, while only a small number of CTCs per patient were CKlow/MCT1+/CD45- or CKlow/MCT4+/CD45- (8%and 5%, respectively). The phenotype CKlow/MCT1-/CD45- was associated with poorer overall survival (OS) [p = 0.005, (15 vs 33 months respectively)], HR=0.351), while the presence of more than 3 CKhigh/MCT4+/CD45- CTCs was related to poorer progression-free survival (PFS) [p = 0.042 (4 vs 17 months respectively)]. Conclusions: MCT1 and MCT4 were expressed in a high proportion of NSCLC patients at baseline and may constitute interesting biomarkers relevant to cancer progression. However, further analysis in a larger cohort of patients is required to clarify their potential significance in clinical practice. Citation Format: Karolina Mangani, Evangelia Pantazaka, Evi Lianidou, Vassilis Gerogoulias, Athanasios Kotsakis, Athina Markou, Galaktia Kallergi. MCT1 and ΜCT4 on circulating tumor cells isolated from non small cell lung cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7502.

Abstract 4221: Characterization and comparison of hypoxia inducing factors on tumor growth and metastasis in 2D and 3D tumor models

Abstract The monocarboxylic acid transporter 4 (Mct-4), a downstream biomarker of hypoxia inducing factor (HIF)-1α, is involved in the cellular response to hypoxia, as indicated by the hypoxic response element in its promoter region. Using a tumorsphere assay as an in vitro 3-dimensional (3D) model generated using 384-well ultra-low attachment (ULA) plates for cell proliferation analysis using a plate-based image cytometer, we identify a hypoxic response in the tumorsphere model that is distinct from that of cells grown under 2-dimensional (2D) normoxic conditions and demonstrate a key role for Mct-4 in enabling 3D growth. The tumorsphere model yields evidence of an essential role for Mct-4 in multiple cell lines which were genetically modified to underexpress and overexpress Mct-4, evidence not apparent in a standard 2D model of growth in the same cell lines. In addition, we identify the effects of overexpressing Mct-4 in cancer cell migration using a transwell chamber assay. We also show that the response to hypoxia may be circumvented by transfection with a CMV promoter driven Mct-4, which confers constitutive 3D growth, wherein tumorsphere growth inhibition by small molecule HIF-1α inhibitors is mitigated. Finally, we demonstrate quantifiable gene/protein expression differences between 2D and 3D cancer models based on the normoxic and hypoxic conditions. Therefore, the tumorsphere 3D model generated using 384-well ULA plates in combination with high-throughput image cytometer is demonstrated to provide a convenient, robust, and reproducible tool and method for the elucidation of mechanisms of action underlying tumor growth and migration in the hypoxic tumor microenvironment. Citation Format: James McDonald, Leo Li-Ying Chan, Sarah Kessel, Bo Lin, Paul Weingarten. Characterization and comparison of hypoxia inducing factors on tumor growth and metastasis in 2D and 3D tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4221.

IPSC-Derived Endothelial Cells Reveal LDLR Dysfunction and Dysregulated Gene Expression Profiles in Familial Hypercholesterolemia.

Defects in the low-density lipoprotein receptor (LDLR) are associated with familial hypercholesterolemia (FH), manifested by atherosclerosis and cardiovascular disease. LDLR deficiency in hepatocytes leads to elevated blood cholesterol levels, which damage vascular cells, especially endothelial cells, through oxidative stress and inflammation. However, the distinctions between endothelial cells from individuals with normal and defective LDLR are not yet fully understood. In this study, we obtained and examined endothelial derivatives of induced pluripotent stem cells (iPSCs) generated previously from conditionally healthy donors and compound heterozygous FH patients carrying pathogenic LDLR alleles. In normal iPSC-derived endothelial cells (iPSC-ECs), we detected the LDLR protein predominantly in its mature form, whereas iPSC-ECs from FH patients have reduced levels of mature LDLR and show abolished low-density lipoprotein uptake. RNA-seq of mutant LDLR iPSC-ECs revealed a unique transcriptome profile with downregulated genes related to monocarboxylic acid transport, exocytosis, and cell adhesion, whereas upregulated signaling pathways were involved in cell secretion and leukocyte activation. Overall, these findings suggest that LDLR defects increase the susceptibility of endothelial cells to inflammation and oxidative stress. In combination with elevated extrinsic cholesterol levels, this may result in accelerated endothelial dysfunction, contributing to early progression of atherosclerosis and other cardiovascular pathologies associated with FH.

Bacterial butyrate mediates the anti-atherosclerotic effect of silybin

Silybin (SIL) is a versatile bioactive compound used for improving liver damage and lipid disorders and is also thought to be beneficial for atherosclerosis (AS). The goal of this study was to investigate the efficacy of SIL in the treatment of AS in ApoE−/−mice fed a high-fat diet and explore the mechanism underlying treatment outcomes. We found that SIL significantly alleviated AS-related parameters, including the extent of aortic plaque formation, hyperlipidemia, and adhesion molecule secretion in the vascular endothelium. 16 S rRNA gene sequencing analysis, together with the application of antibiotics, showed that intestinal butyrate-producing bacteria mediated the ameliorative effect of SIL on AS. Further analysis revealed that SIL facilitated butyrate production by increasing the level of butyryl-CoA: acetate CoA-transferase (BUT). The increased expression of monocarboxylic acid transporter-1 (MCT1) induced by butyrate and MCT4 induced by SIL in the apical and basolateral membranes of colonocytes, respectively, resulted in enhanced absorption of intestinal butyrate into the circulation, leading to the alleviation of arterial endothelium dysfunction. Moreover, the SIL-mediated increase in intestinal butyrate levels restored gut integrity by upregulating the expression of tight junction proteins and promoting gut immunity, thus inhibiting the AS-induced inflammatory response. This is the first study to show that SIL can alleviate AS by modulating the production of bacterial butyrate and its subsequent absorption.

ROS responsive nanoparticles mediated inhibition of monocarboxylic acid transporters to enhance chemoimmunotherapy by overcoming low immune response in osteosarcoma

Maintaining intracellular pH homeostasis and regulating the acidity of the tumor microenvironment (TME) are critical for the proliferation and progression of highly glycolytic-dependent cancer cells. This is primarily achieved through the activity of monocarboxylate transporters 1 (MCT1) and monocarboxylate transporters 4 (MCT4), which promotes metabolic symbiosis among tumor cells and enables immune evasion. Consequently, targeting monocarboxylic acid transporters (MCTs) offers an effective strategy for cancer treatment. However, the widespread expression of MCTs and the potential toxicity of MCT inhibitors on normal cells have hindered their clinical utility. Herein, we designed reactive oxygen species (ROS)-sensitive nanoparticles loaded with the MCT1/4 inhibitor syrosingopine (Syro) and cisplatin (IV) prodrugs for the treatment of osteosarcoma. The nanoparticles could efficiently accumulate in the tumor cells and achieve abundant production of ROS, therefore enhancing therapeutic efficacy with the delivery of cisplatin and Syro. The excessive ROS levels induced severe endoplasmic reticulum (ER) stress, triggered immunogenic cell death (ICD), and activated adaptive immunity. This study demonstrates a safe and effective nano-delivery system that enhances tumor chemoimmunotherapy by reshaping lactate distribution in TME, thereby providing an effective new treatment strategy for osteosarcoma.

Liver-Derived Ketogenesis via Overexpressing HMGCS2 Promotes the Recovery of Spinal Cord Injury.

The liver is the major ketogenic organ of the body, and ketones are reported to possess favorable neuroprotective effects. This study aims to elucidate whether ketone bodies generated from the liver play a critical role in bridging the liver and spinal cord. Mice model with a contusive spinal cord injury (SCI) surgery is established, and SCI induces significant histological changes in mice liver. mRNA-seq of liver tissue shows the temporal changes of ketone bodies-related genes, β-hydroxybutyrate dehydrogenase (BDH1) and solute carrier family 16 (monocarboxylic acid transporters), member 6 (SLC16A6). Then, an activated ketogenesis model is created with adult C57BL/6 mice receiving the tail intravenous injection of GPAAV8-TBG-Mouse-Hmgcs2-CMV- mCherry -WPRE (HMGCS2liver ) and mice receiving equal AAV8-Null being the control group (Vectorliver ). Then, the mice undergo either a contusive SCI or sham surgery. The results show that overexpression of HMG-CoA synthase (Hmgcs2) in mice liver dramatically alleviates SCI-mediated pathological changes and promotes ketogenesis in the liver. Amazingly, liver-derived ketogenesis evidently alleviates neuron apoptosis and inflammatory microglia activation and improves the recovery of motor function of SCI mice. In conclusion, a liver-spinal cord axis can be bridged via ketone bodies, and enhancing the production of the ketone body within the liver has neuroprotective effects on traumatic SCI.

Characterization and comparison of hypoxia inducing factors on tumor growth and metastasis between two- and three-dimensional cancer models

The monocarboxylic acid transporter 4 (Mct-4), a downstream biomarker of hypoxia inducing factor (HIF)-1α, is involved in the cellular response to hypoxia, as indicated by the hypoxic response element in its promoter region. Using a tumorsphere assay as an in vitro 3-dimensional (3D) model generated using 384-well ultra-low attachment (ULA) plates for cell proliferation analysis using a plate-based image cytometer, we identify a hypoxic response in the tumorsphere model that is distinct from that of cells grown under 2-dimensional (2D) normoxic conditions and demonstrate a key role for Mct-4 in enabling 3D growth. The tumorsphere model yields evidence of an essential role for Mct-4 in multiple cell lines, which were genetically modified to underexpress and overexpress Mct-4, evidence not apparent in a standard 2D model of growth in the same cell lines. In addition, we identify the effects of overexpressing Mct-4 in cancer cell migration using a transwell chamber assay. We also show that the response to hypoxia may be circumvented by transfection with a CMV promoter driven Mct-4, which confers constitutive 3D growth, wherein tumorsphere growth inhibition by small molecule HIF-1α inhibitors is mitigated. Finally, we demonstrate quantifiable gene/protein expression differences between 2D and 3D cancer models based on the normoxic and hypoxic conditions. Therefore, the tumorsphere 3D model generated using 384-well ULA plates in combination with high-throughput image cytometer is demonstrated to provide a convenient, robust, and reproducible tool and method for the elucidation of mechanisms of action underlying tumor growth and migration in the hypoxic tumor microenvironment.

Fibroblast growth factor 21 protects the liver from apoptosis in a type 1 diabetes mouse model via regulating L-lactate homeostasis

Aims/HypothesisFibroblast growth factor 21 (FGF21) is a hepatokine with pleiotropic effects on glucose and lipid metabolic homeostasis. Here, we aimed to elucidate the mechanisms underlying the protective effects of FGF21 on L-lactate homeostasis and liver lesions in a type 1 diabetes mellitus (T1DM) mice model. MethodsSix-week-old male C57BL/6 mice were divided into control, T1DM, and FGF21 groups. We also examined hepatic apoptotic signaling and functional indices in wild-type and hydroxycarboxylic acid receptor 1 (HCA1) knockout mice with T1DM or long-term L-lactate exposure. After preincubation of high glucose- or L-lactate treated hepatic AML12 cells, L-lactate uptake, apoptosis, and monocarboxylic acid transporter 2 (MCT2) expression were investigated. ResultsIn a mouse model of T1DM, hepatic FGF21 expression was downregulated by approximately 1.5-fold at 13 weeks after the hyperglycemic insult. In vivo administration of exogenous FGF21 (2 mg/kg) to diabetic or L-lactate-infused mice significantly prevented hepatic oxidative stress and apoptosis by activating extracellular signal-regulated kinase (ERK)1/2, p38 mitogen-activated protein kinase (MAPK) and AMP-activated protein kinase (AMPK) pathways. HCA1-KO mice were less susceptible to diabetes- and L-lactate-induced hepatic apoptosis and dysfunction. In addition, inhibition of PI3K-mTOR activity revealed that FGF21 prevented L-lactate-induced Cori cycle alterations and hepatic apoptosis by upregulating MCT2 protein translation. Conclusions/InterpretationThese results demonstrate that L-lactate homeostasis may be a therapeutic target for T1DM-related hepatic dysfunction. The protective effects of FGF21 on hepatic damage were associated with its ability to ameliorate MCT2-dependent Cori cycle alterations and prevent HCA1-mediated inhibition of ERK1/2, p38 MAPK, and AMPK signaling.

Evodiamine impairs HIF1A histone lactylation to inhibit Sema3A-mediated angiogenesis and PD-L1 by inducing ferroptosis in prostate cancer

Prostate cancer (PCa) is among the most commonly diagnosed solid cancers in male adults. However, most anti-angiogenic therapies and immunotherapies fail to achieve durable remission in advanced PCa. Integrative analysis indicated that Sema3A was negatively correlated with the pathological malignancy and was involved in angiogenesis, cell adhesion, and immune infiltrates in PCa. Sema3A significantly inhibited vascular endothelial growth factor (VEGFA)-induced colony formation, cell proliferation, and PD-L1 expression in PCa cells. Network pharmacological analysis demonstrated that evodiamine, a natural alkaloid compound derived from Evodiae fructus fruits, might regulate Sema3A, lipid metabolism, and monocarboxylic acid transport signaling of PCa. Evodiamine evidently inhibited PCa cell viability in a time-dose-dependent manner. Furthermore, evodiamine impaired angiogenesis by increasing Sema3A expression, and induced ferroptosis by reducing glutathione peroxidase 4 (GPX4) expression, which could be reversed by the ferroptosis blocker ferrostatin-1. Lactate treatment increased hypoxia-inducible factor (HIF)-1α and PD-L1 expressions while restricting Sema3A expression in PCa cells, which could be reversed by silencing monocarboxylate transporter 4 (MCT4) expression. Moreover, evodiamine markedly blocked lactate-induced angiogenesis by restricting histone lactylation and expression of HIF1A in PCa cells, further enhancing Sema3A transcription while inhibiting that of PD-L1. In vivo, evodiamine remarkably inhibited PCa xenograft growth in nude mice, repressing expressions of HIF1α, H3K18la, GPX4, PD-L1, and proliferation, while hindering angiogenesis by increasing Sema3A expression. Therefore, Sema3A represents an essential antineoplastic biomarker, while evodiamine may act as a metabolic-epigenetic modulator, as well as a promising agent in either PCa anti-angiogenic therapy or immunotherapy.

Transepithelial transport characteristics of Hydroxysafflor yellow A across cellular monolayers and the effects of the influx and efflux transporters

Hydroxysafflor yellow A (HSYA), the major biologically active constituent distributed in the florets of Carthamus tinctorius L. (safflower), is concerned with potential health-promoting functions against cardiovascular diseases. However, little information on clarifying the intestinal absorption characteristics of HSYA has been reported, which has limited its widespread application in the medical and healthcare fields. The intention of this research was to systematically characterize the transepithelial transport of HSYA using in vitro cell monolayer models (Caco-2, mucus-producing Caco-2/HT29-MTX-E12, MDCKⅡ and P-gp overexpressed MDCKⅡ-MDR1 cell monolayers). The apparent permeability coefficient (Papp) from the apical to the basolateral side of HSYA is approximately (4.30 ± 0.22) × 10⁻⁸ cm/s, suggesting that HSYA is poorly absorbed across the intestinal epithelium. The transport and uptake of HSYA depends on time, concentration, pH and temperature, and the Papp values increase with ethylene diamine tetraacetic acid pretreatment, indicating that the transport mechanisms of HSYA include passive diffusion (transcellular and paracellular pathways) and carrier-mediated transport. Meanwhile, transporter inhibitors were added in transport and uptake experiments, the results showed that carrier-mediated efflux and influx transport of HSYA is relevant to P-glycoprotein and H⁺ correlative transporters (e.g., peptide transporter 1, monocarboxylic acid transporter). In addition, the mucus layer acts as a barrier to HSYA absorption, as evidenced by a decrease in Papp (22–47%) and cellular uptake (18%) in the coculture model compared to the Caco-2 cell model. Detailed knowledge on the transepithelial transport of HSYA would provide insights to improve the pharmacological activities of HSYA and expand its application in food and healthcare fields.

In a zebrafish biomedical model of human Allan-Herndon-Dudley syndrome impaired MTH signaling leads to decreased neural cell diversity.

Maternally derived thyroid hormone (T3) is a fundamental factor for vertebrate neurodevelopment. In humans, mutations on the thyroid hormones (TH) exclusive transporter monocarboxylic acid transporter 8 (MCT8) lead to the Allan-Herndon-Dudley syndrome (AHDS). Patients with AHDS present severe underdevelopment of the central nervous system, with profound cognitive and locomotor consequences. Functional impairment of zebrafish T3 exclusive membrane transporter Mct8 phenocopies many symptoms observed in patients with AHDS, thus providing an outstanding animal model to study this human condition. In addition, it was previously shown in the zebrafish mct8 KD model that maternal T3 (MTH) acts as an integrator of different key developmental pathways during zebrafish development. Using a zebrafish Mct8 knockdown model, with consequent inhibition of maternal thyroid hormones (MTH) uptake to the target cells, we analyzed genes modulated by MTH by qPCR in a temporal series from the start of segmentation through hatching. Survival (TUNEL) and proliferation (PH3) of neural progenitor cells (dla, her2) were determined, and the cellular distribution of neural MTH-target genes in the spinal cord during development was characterized. In addition, in-vivo live imaging was performed to access NOTCH overexpression action on cell division in this AHDS model. We determined the developmental time window when MTH is required for appropriate CNS development in the zebrafish; MTH is not involved in neuroectoderm specification but is fundamental in the early stages of neurogenesis by promoting the maintenance of specific neural progenitor populations. MTH signaling is required for developing different neural cell types and maintaining spinal cord cytoarchitecture, and modulation of NOTCH signaling in a non-autonomous cell manner is involved in this process. The findings show that MTH allows the enrichment of neural progenitor pools, regulating the cell diversity output observed by the end of embryogenesis and that Mct8 impairment restricts CNS development. This work contributes to the understanding of the cellular mechanisms underlying human AHDS.

Differential Effects of Chronic Ethanol Use on Mouse Neuronal and Astroglial Metabolic Activity.

Chronic alcohol use disorder, a major risk factor for the development of neuropsychiatric disorders including addiction to other substances, is associated with several neuropathology including perturbed neuronal and glial activities in the brain. It affects carbon metabolism in specific brain regions, and perturbs neuro-metabolite homeostasis in neuronal and glial cells. Alcohol induced changes in the brain neurochemical profile accompany the negative emotional state associated with dysregulated reward and sensitized stress response to withdrawal. However, the underlying alterations in neuro-astroglial activities and neurochemical dysregulations in brain regions after chronic alcohol use are poorly understood. This study evaluates the impact of chronic ethanol use on the regional neuro-astroglial metabolic activityusing 1H-[13C]-NMR spectroscopy in conjunction with infusion of [1,6-13C2]glucose and sodium [2-13C]acetate, respectively, after 48h of abstinence. Besides establishing detailed 13C labeling of neuro-metabolites in a brain region-specific manner, our results show chronic ethanol induced-cognitive deficits along with a reduction in total glucose oxidation rates in the hippocampus and striatum. Furthermore, using [2-13C]acetate infusion, we showed an alcohol-induced increase in astroglial metabolic activity in the hippocampus and prefrontal cortex. Interestingly, increased astroglia activity in the hippocampus and prefrontal cortex was associated with a differential expression of monocarboxylic acid transporters that are regulating acetate uptake and metabolism in the brain.

The effects of esketamine on the intestinal microenvironment and intestinal microbiota in mice.

This study aimed to investigate the impact of esketamine on the intestinal flora and microenvironment in mice using mRNA transcriptome sequencing and 16S rRNA sequencing. Ten female mice were randomly assigned to two groups. One group received daily intramuscular injections of sterile water, while the other group received esketamine. After 24days, the mice were sacrificed, and their intestinal tissues and contents were collected for 16S rRNA sequencing and mRNA transcriptome sequencing. The intergroup differences in the mouse intestinal flora were analyzed. Differentially expressed genes were utilized to construct ceRNA networks and transcription factor regulatory networks to assess the effects of esketamine on the intestinal flora and intestinal tissue genes. Esketamine significantly altered the abundance of intestinal microbiota, including Adlercreutzia equolifaciens and Akkermansia muciniphila. Differential expression analysis revealed 301 significantly upregulated genes and 106 significantly downregulated genes. The ceRNA regulatory network consisted of 6 lncRNAs, 44 miRNAs, and 113 mRNAs, while the regulatory factor network included 13 transcription factors and 53 target genes. Gene Ontology enrichment analysis indicated that the differentially expressed genes were primarily associated with immunity, including B-cell activation and humoral immune response mediation. The biological processes in the ceRNA regulatory network primarily involved transport, such as organic anion transport and monocarboxylic acid transport. The functional annotation of target genes in the TF network was mainly related to epithelial cells, including epithelial cell proliferation and regulation. Esketamine induces changes in gut microbiota and the intestinal microenvironment, impacting the immune environment and transport modes.

Decreased β-hydroxybutyrate and ketogenic amino acid levels in depressed human adults.

β-hydroxybutyrate (BHB) is a major ketone body synthesized mainly in the liver mitochondria and is associated with stress and severity of depression in humans. It is known to alleviate depressive-like behaviors in mouse models of depression. In this study, plasma BHB, ketogenic and glucogenic amino acids selected from the Tohoku Medical Megabank Project Community-Based Cohort Study were analysed and measured using nuclear magnetic resonance spectroscopy. The Center for Epidemiologic Studies Depression Scale (CES-D) was utilized to select adult participants with depressive symptoms (CES-D ≥ 16; n = 5722) and control participants (CES-D < 16; n = 18,150). We observed significantly reduced plasma BHB, leucine, and tryptophan levels in participants with depressive symptoms. Using social defeat stress (SDS) mice models, we found that BHB levels in mice sera increased after acute SDS, but showed no change after chronic SDS, which differed from human plasma results. Furthermore, acute SDS increased mitochondrial BHB levels in the prefrontal cortex at 6 h. In contrast, chronic SDS significantly increased the amount of food intake but reduced hepatic mitochondrial BHB levels in mice. Moreover, gene transcriptions of voltage-dependent anion-selective channel 1 (Vdac1) and monocarboxylic acid transporter 1 (Mct1), major molecules relevant to mitochondrial biogenesis and BHB transporter, significantly decreased in the liver and PFC after chronic SDS exposure. These results provide evidence that hepatic and prefrontal mitochondrial biogenesis plays an important role in BHB synthesis under chronic stress and in humans with depressive symptoms.