Solute Carrier Research Articles

NSUN2 Knockdown Promotes the Ferroptosis of Colorectal Cancer Cells Via m5C Modification of SLC7A11 mRNA.

The high occurrence and death rates of colorectal cancer (CRC) make it a major health concern. Recent studies have identified NOP2/Sun RNA methyltransferase family member 2 (NSUN2), an RNA methyltransferase, as a key regulator in various tumor types. However, how exactly NSUN2-mediated m5C alteration affects CRC is still a mystery. This study seeks to understand how NSUN2 contributes to the growth and death of colorectal cancer cells. New tissue samples were taken in order to investigate NSUN2 expression in CRC. In vitro tests were performed to evaluate NSUN2's function. We used m5C-methylated-RNA immunoprecipitation and RNA stability experiments to find out how NSUN2 works on Solute carrier family 7 member 11 (SLC7A11, also called xCT). Downregulation of NSUN2 limits CRC cell growth and induces ferroptosis, as we show that NSUN2 was substantially expressed in CRC. In terms of the molecular mechanism, NSUN2 controls the translation and stability of SLC7A11 mRNA by regulating its m5C methylation. Functional tests show that SLC7A11 compensates for the NSUN2 knockdown-induced decrease in cell proliferation. Additionally, SLC7A11 overexpression restores ferroptosis to CRC cells after NSUN2 knockdown. These findings emphasize NSUN2's crucial role in modulating colorectal cancer cell growth and survival via SLC7A11, pointing to promising new therapeutic targets.

Network pharmacology and experimental verification to investigate the mechanism of isoliquiritigenin for the treatment of Alzheimer’s disease

Isoliquiritigenin (ISL), a flavone isolated from licorice, has been demonstrated to exhibit anti-inflammatory and antioxidant properties in the treatment of Alzheimer’s disease (AD). However, the molecular details of the contribution of ISL to AD remain largely elusive. The present study aimed to investigate the molecular mechanisms of ISL against AD. In this study, AD targets and ISL targets were collected via different databases. The overlapped targets between AD and ISL were generated with Venny. Then we performed Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway enrichment analyses on these common targets. The protein-protein interaction (PPI) network was constructed and clusters were obtained using the Molecular Complex Detection (MCODE) and the Cytohubba plugins. Further, molecular docking study was performed for these core targets. Subsequently, the receiver operating characteristic (ROC) curve analysis and the assessment of hub gene expression levels between AD and healthy individuals were used to estimate a possible link between target genes in AD. Finally, experiments were conducted to verify the therapeutic mechanism of ISL in lipopolysaccharide (LPS)-induced BV2 microglial cells. GO and KEGG pathway analysis found that ISL was significantly enriched in regulation of mitogen-activated protein kinase (MAPK) signaling pathway. The PPI network manifested 7 key targets including albumin (ALB), epidermal growth factor receptor (EGFR), solute carrier family 2 member 1 (SLC2A1), insulin-like growth factor 1 (IGF1), mitogen-activated protein kinase 1 (MAPK1), peroxisome proliferator activated receptor alpha (PPARA) and peroxisome proliferator activated receptor gamma (PPAR-γ, PPARG). Molecular docking showed that ISL had high binding affinity with these key targets. The experimental results revealed that ISL decreased extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and increased the expression of PPAR-γ, and suppressed the production of proinflammatory mediators. Our work revealed that ISL might be an effective treatment strategy in the treatment of AD by its anti-inflammatory effect towards microglia through the ERK/PPAR-γ pathway.

Beyond SGLT2: proximal tubule transporters as potential drug targets for chronic kidney disease.

The proximal tubule is responsible for reabsorbing about 60% of filtered solutes and water and is critical for the secretion of metabolic waste products, drugs and toxins. A large number of highly specialized ion channels and transport proteins belonging to the SLC and ABC transporter families are involved. Their activity is directly or indirectly linked to ATP consumption and requires large quantities of energy and oxygen supply. Moreover, the activity of these transporters is often coupled to the movement of Na+ ions thus influencing also salt and water balance, as well as transport and regulatory processes in downstream segments. Because of their relevance for systemic ion balance, for renal metabolism or for affecting regulatory processes, proximal tubule transporters are attractive targets for existing drug and for novel strategies to reduce kidney disease progression or to alleviate the consequences of decreased kidney function. In this review, the relevance of some major proximal tubule transport systems as drug targets in individuals with chronic kidney disease (CKD) is discussed. Inhibitors of the sodium-glucose cotransporter 2, SGLT2, are now part of standard therapy in patients with CKD and/or heart failure. Also, indirect inhibition of Na+/H+-exchangers by carbonic anhydrase inhibitors and uricosuric drugs have been used for decades. Inhibition of phosphate and amino acid transporters have recently been proposed as novel principles to remove excess phosphate or to protect the proximal tubule metabolically, respectively. In addition, organic cation and anion transporters involved in drug and toxin excretion may serve as targets of new drugs. The advantages and challenges associated with (novel) drugs targeting proximal tubule transport are discussed.

O-GlcNAcylation attenuates ischemia-reperfusion-induced pulmonary epithelial cell ferroptosis via the Nrf2/G6PDH pathway

BackgroundLung ischemia–reperfusion (I/R) injury is a common clinical pathology associated with high mortality. The pathophysiology of lung I/R injury involves ferroptosis and elevated protein O-GlcNAcylation levels, while the effect of O-GlcNAcylation on lung I/R injury remains unclear. This research aimed to explore the effect of O-GlcNAcylation on reducing ferroptosis in pulmonary epithelial cells caused by I/R.ResultsFirst, we identified O-GlcNAc transferase 1 (Ogt1) as a differentially expressed gene in lung epithelial cells of acute lung injury/acute respiratory distress syndrome (ALI/ARDS) patients, using single-cell sequencing, and Gene Ontology analysis (GO analysis) revealed the enrichment of the ferroptosis process. We found a time-dependent dynamic alteration in lung O-GlcNAcylation during I/R injury. Proteomics analysis identified the differentially expressed proteins enriched in ferroptosis and multiple redox-related pathways based on KEGG annotation. Thus, we generated Ogt1-conditional knockout mice and found that Ogt1 deficiency aggravated ferroptosis, as evidenced by lipid reactive oxygen species (lipid ROS), malondialdehyde (MDA), Fe2+, as well as alterations in critical protein expression glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11). Consistently, we found that elevated O-GlcNAcylation inhibited ferroptosis sensitivity in hypoxia/reoxygenation (H/R) injury-induced TC-1 cells via O-GlcNAcylated NF-E2-related factor-2 (Nrf2). Furthermore, both the chromatin immunoprecipitation (ChIP) assay and the dual-luciferase reporter assay indicated that Nrf2 could bind with translation start site (TSS) of glucose-6-phosphate dehydrogenase (G6PDH) and promote its transcriptional activity. As an important rate-limiting enzyme in the pentose phosphate pathway (PPP), elevated G6PDH provided a mass of nicotinamide adenine dinucleotide phosphate (NADPH) to improve the redox state of glutathione (GSH) and eventually led to ferroptosis resistance. Rescue experiments proved that Nrf2 knockdown or Nrf2-T334A (O-GlcNAcylation site) mutation abolished the protective effect of ferroptosis resistance.ConclusionsIn summary, we revealed that O-GlcNAcylation could protect against I/R lung injury by reducing ferroptosis sensitivity via the Nrf2/G6PDH pathway. Our work will provide a new basis for clinical therapeutic strategies for pulmonary ischemia–reperfusion-induced acute lung injury.

Research progress of cysteine transporter SLC7A11 in endocrine and metabolic diseases.

SLC7A11, often called xCT, belongs to the SLC family of transporters, which mediates the cellular influx of cystine and the efflux of glutamate. These transport processes are crucial for synthesizing GSH, enhancing the cell's ability to mitigate oxidative stress (OS). Emerging studies highlight the pivotal role of OS in triggering and exacerbating various metabolic and endocrine disorders, underlining the critical importance of regulating SLC7A11 expression levels. This study reviews the diverse roles of SLC7A11 in endocrine and metabolic diseases, examining its relationship with the metabolism of three key nutrients: proteins and amino acids, carbohydrates, and lipids. Additionally, the involvement of SLC7A11 in the onset and development of various common endocrine and metabolic disorders is analyzed. Additionally, it provides an overview of the current clinical and experimental use of SLC7A11 inhibitors and agonists. This review aims to offer insightful perspectives into the involvement of SLC7A11 in endocrine and metabolic pathologies and to foster the development of innovative therapeutic strategies that target SLC7A11.

Solute carrier family 2 members (SLC2A) as potential targets for the treatment of head and neck squamous cell carcinoma patients

ObjectiveSolute carrier family 2 (SLC2A) members have drawn interest in cancer research due to their crucial function in glucose metabolism. To understand their role in Head and Neck Squamous Cell Carcinoma (HNSCC), we have comprehensively analyzed the gene expression of SLC2A family members in HNSCC patients. MethodRNAseq data of 520 HNSCC patients and 46 normals was downloaded from The Cancer Genome Atlas (TCGA) and analyzed using various statistical methods in R. ResultComparison of gene expression between normal and tumor samples showed significantly higher expression of SLC2A1, 4, 6, and 9 in tumor samples compared to normal. Further analysis revealed that both HPV(−)ve and HPV(+)ve samples showed significantly higher expression of SLC2A1 as compared to normal, though the difference was more pronounced in the case of HPV(−)ve. In contrast, SLC2A9 showed a highly significant difference between HPV(−)ve and normal but not between HPV(+)ve and normal. Furthermore, SLC2A genes showed significant variation among the basal (BA), classical (CL), and mesenchymal (MS) expression groups of HNSCC patients. SLC2A1 and 9 were significantly overexpressed in the BA group as compared to the other two groups, suggesting that these two genes can be utilized for the targeted therapy of HPV(−)ve HNSCC patients of the BA group. ConclusionOur results suggest that the biology of SLC2A family members is complex and, they may be playing different roles in different genomic backgrounds. More studies on SLC2A family members are needed to utilize them for targeted therapy or as diagnostic biomarkers.

Bombyx mori PAT4 gene inhibits BmNPV infection and replication through autophagy.

Proton-assisted amino acid transporter 4 (PAT4) is a member of the solute carrier (SLC) 36 family, which mediates the transmembrane transport of amino acids and their derivatives. However, the function of PAT4 in Bombyx mori is not clear. In this study, BmPAT4 was cloned and identified using PCR technology. Its open reading frame (ORF) includes 1,395bp, encoding 464 amino acid (Aa). Moreover, the sequence of BmPAT4 has the highest similarity with wild Bombyx.mandarina, Spodoptera frugiperda and Spodoptera litura, and it has ten transmembrane domains. BmPAT4 was localized in the cell membrane and expressed in all tissues of the silkworm. After Bombyx mori nuclear polyhedrosis virus (BmNPV) infection, the expression of BmPAT4 in midgut, hemolymph and fat body was significantly up-regulated. In addition, overexpression of BmPAT4 in BmN cells could significantly inhibit the proliferation of BmNPV, and the expression of several genes in autophagy pathway decreased significantly. On the contrary, down-regulation of BmPAT4 expression by RNA interference can promote BmNPV replication and proliferation, and the expression of key genes in autophagy pathway is significantly increased. This is the first time to report that BmPAT4 has an antiviral effect in silkworm. Moreover, the silkworm activates BmTORC1 via BmPAT4, which inhibits autophagy in silkworm cells, resulting in a lack of energy and raw materials for BmNPV infection and replication in cells.

On the potential of Zn@B38 superatom as a drug delivery vehicle for several anticancer drugs: A DFT study

The interaction between a boron-based Zn@B38 superatom and five drugs, including cisplatin (DDP), 5-fluorouracil (FU), mercaptopurine (MP), hydroxyurea (HU) and nitrogen mustard (CM) have been investigated. The adsorption of these anticancer drugs onto Zn@B38 reduces the energy gap of this superatom. Except for DDP, these drugs exhibit strong covalent interaction with the vertex of Zn@B38 because the lone pair of N/O atom of FU, MP, HU, and CM can fill into the empty atomic orbital of the electron-deficient boron atom of Zn@B38 to form polar covalent bonds, resulting in the charge transfer from drugs to Zn@B38. Hence, the adsorption energies of drug@[Zn@B38] (drug = FU, MP, HU, and CM) are −37.67 ∼ −57.21 kcal/mol, but can be significantly decreased to −8.63 ∼ 5.48 kcal/mol upon protonation, suggesting that these drugs can be efficiently adsorbed by the Zn@B38 carrier in neutral aqueous solution but are easily released in the acidic tumor microenvironment.

SLC25A1 promotes lymph node metastasis of esophageal squamous cell carcinoma by regulating lipid metabolism.

Solute carrier family 25 member 1 (SLC25A1) affects lipid metabolism and energy regulation in multiple types of tumor cell, affecting their proliferation and survival. To the best of our knowledge, however, the impact of SLC25A1 on the proliferation and survival of esophageal squamous cell carcinoma (ESCC) cells has yet to be explored. Here, SLC25A1 expression was detected in ESCC tissues and cell lines. SLC25A1 was silenced or blocked by lentivirus transfection or 2‑[(4‑chloro‑3‑nitrophenyl)sulfonylamino]benzoic acid in ESCC cells. To evaluate the impact of SLC25A1 on in vivo and in vitro proliferation, invasion and migration of ESCC cells, Cell Counting‑Kit, wound healing, colony formation, Transwell, EdU, flow cytometry, tumor xenograft in nude mice, lipid metabolism and energy metabolism detection assays were performed. Reverse transcription‑quantitative PCR and western blot analysis were performed to determine expression of downstream molecules and pathway proteins following the silencing and blockade of SLC25A1. SLC25A1 was significantly overexpressed in ESCC tissue and cell lines. The targeted silencing of SLC25A1 or inhibition of its protein led to a significant decrease in proliferative, invasive and migratory capabilities of ESCC cells, accompanied by increased apoptosis. Additionally, silencing of the SLC25A1 gene significantly inhibited xenograft tumor growth in vivo. The present results indicate that knockdown or blockade of SLC25A1 can significantly impede the malignant biological behavior of ESCC.

Tumor-derived miR-203a-3p potentiates muscle wasting by inducing muscle ferroptosis in pancreatic cancer.

Pancreatic cancer (PC) cachexia, characterized by profound muscle wasting and systemic inflammation, remains a formidable clinical challenge due to its multifactorial nature and complex molecular underpinnings. This study delves into the intricate interplay between microRNA (miRNA) dysregulation and ferroptosis, a form of iron-dependent cell death, in PC cachexia. Specifically, we identified tumor-derived miR-203a-3p as a pivotal miRNA that promotes muscle atrophy by upregulating muscle ferroptosis. Our findings revealed that miR-203a-3p targets zinc finger E-box binding homeobox 1 (ZEB1), subsequently enhancing the expression of the iron transporter solute carrier family 11 member 2 (SLC11A2), thereby facilitating ferroptosis-associated skeletal muscle cell death. Through in vivo experiments using a PC cachexic mouse model, we demonstrated that inhibiting ferroptosis effectively attenuated muscle wasting, highlighting its critical role in the pathogenesis of PC cachexia. These results provide a molecular framework elucidating how miRNA regulation and ferroptosis converge to drive muscle atrophy, offering novel therapeutic avenues for mitigating cachexia in PC patients. By targeting these pathways, we aim to improve muscle preservation and overall survival in this devastating disease.

Long non-coding RNA ZFAS1 promotes ferroptosis by regulating the miR-185-5p/SLC25A28 axis in clear cell renal cell carcinoma.

Ferroptosis is a novel, iron-dependent regulated cell death mode. The biochemical features of ferroptosis include iron accumulation, lipid peroxidation, inhibition of glutathione peroxidase 4 (GPX4) and antioxidant glutathione (GSH) decrease through inhibition of the system xc- transporter. Zinc finger NFX1 type-containing 1 (ZNFX1) antisense RNA 1 (ZFAS1) is a long non-coding RNA that has been identified as an oncogene in various types of cancers. However, its regulatory role and molecular mechanisms in clear cell renal cell carcinoma (ccRCC) ferroptosis remain unclear. In this study, the ferroptosis inducers (FINS) (erastin and RSL3) were found to increase ZFAS1 expression through the facilitation of SP1 binding to the ZFAS1 promoter. ZFAS1 increased mRNA and protein levels of solute carrier family 25 member 28 (SLC25A28) via functioning as a miR-185-5p sponge. Overexpressed SLC25A28 increased the production of ROS and caused a decrease in NADPH and GSH in cells treated with FINS. In addition, overexpression of ZFAS1 enhanced ferroptosis both in vitro and in vivo. Altogether, this study demonstrates that ZFAS1 is a crucial element of ferroptosis in ccRCC, as it is responsible for the regulation of miR-185-5p and SLC25A28. Introducing ferroptosis could be a beneficial approach to treat ccRCC patients with high ZFAS1 levels.

Evaluating lactate metabolism for prognostic assessment and therapy response prediction in gastric cancer with emphasis on the oncogenic role of SLC5A12.

Gastric cancer remains a common malignancy with poor prognosis. While lactate metabolism is recognized as a significant factor in tumor progression, its potential as a predictive tool for treatment response remains unexplored. This study introduces a novel Lactate-Related Gene Signature (LRGS) designed to predict both survival outcomes and therapy responses in gastric cancer patients. We comprehensively analyzed 335 lactate-related genes from 11 metabolic pathways using MSigDB, identifying 278 differentially expressed genes between gastric cancer and normal tissues. Employing the LASSO Cox regression model, we developed an innovative LRGS formula based on the expression of 16 key lactate-related genes. The impact of Solute Carrier Family 5 Member 12 (SLC5A12), a gene of particular interest, on gastric cancer cell functions was evaluated using in vitro assays and an in vivo zebrafish model. Our newly established LRGS demonstrated robust capability in stratifying gastric cancer patients by survival risk. Notably, the LRGS-low subtype showed significantly improved overall and disease-free survival rates compared to the LRGS-high subtype. A key finding was LRGS's ability to predict patient responses to both adjuvant chemotherapy and immunotherapy. Random forest analysis identified SLC5A12 as the most significant gene differentiating gastric cancer from normal tissues. Functional experiments confirmed SLC5A12's role in promoting gastric cancer cell proliferation, invasion, and migration both in vitro and in vivo. The LRGS is a dependable and efficient prognostic tool for assessing the survival outcomes in individuals with gastric cancer, as well as a predictor of patient response to adjuvant chemotherapy and immunotherapy.

WWOX-mediated p53/SAT1 and NRF2/FPN1 axis contribute to toosendanin-induced ferroptosis in hepatocellular carcinoma.

Although ferroptosis as an emerging way exhibits tremendous promising in the therapy of hepatocellular carcinoma (HCC), the novel therapeutic agents targeting ferroptosis are still scarce. In our previous study, we found that the natural products toosendanin (TSN) possessed significant anti-proliferative efficacy by regulating WW domain-containing oxidoreductase (WWOX) in HCC. However, there is very limited understanding about TSN-induced ferroptosis, and the role of WWOX in ferroptosis has not been studied. In present study, we investigated the effect and underlying molecular mechanisms of TSN in WWOX-mediated ferroptosis in HCC. We found that TSN induced ferroptosis in HCC cells and its effect was dependent on WWOX. RNA-seq and RT-qPCR assay identified that TSN significantly increased spermidine/spermine N1-acetyltransferase 1 (SAT1) expression while decreased solute carrier family 40 member 1 (SLC40A1) expression, which play vital roles in ferrous ion transport. Further dual-luciferase reporter assay and Co-IP assay revealed that TSN-induced WWOX activation controlled the transcriptional activity of p53 and NF-E2-related factor 2 (NRF2) by regulating their interaction. Meanwhile, IF assay and WB assay confirmed that TSN increased the nuclear distribution of p-WWOX and p-p53 dimers, but impeded the nuclear translocation of NRF2 by inducing its ubiquitination degradation, ultimately regulating the transcription of their downstream target genes. In addition, the results from cell viability assay and the tumor xenograft model verified that co-treatment of TSN, ML385 (NRF2 inhibitor), and MIRA-1 (p53 activator) could effectively inhibit HCC cells growth in the presence of Fer-1 (ferroptosis inhibitor) in vitro and in vivo. Overall, our study contributes to the necessary understanding of the molecular mechanisms of WWOX-mediated ferroptosis regulation, and identifies TSN as a potential therapeutic agent targeting ferroptosis for HCC.

Comprehensive analysis of mitochondrial solute carrier family 25 (SLC25) identifies member 19 (SLC25A19) as a regulatory factor in hepatocellular carcinoma.

The mitochondrial solute carrier family 25 (SLC25) is known to play a pivotal role in oncogenesis, yet its specific involvement in hepatocellular carcinoma (HCC) remains poorly elucidated. In this study, we performed a clustering analysis of HCC patients in the Cancer Genome Atlas database based on the expression levels of SLC25 members, and conducted clinical feature analysis for each patient within the clusters. Subsequently, we developed a prognostic model using a Lasso regression approach with SLC25A19, SLC25A49, and SLC25A51 as features, and generated a risk score for each HCC patient. We then identified SLC25A19 as a potential prognostic marker for HCC through single-cell analysis, and validated this finding using in vitro and in vivo experiments. Our results revealed significant differences in the expression of most SLC25 family members in HCC patients, enabling the stratification of patients into three clusters, with those in cluster 1 exhibiting the most favorable prognosis and showing a correlation with enhanced immune infiltration. The risk scores derived from the features SLC25A19, SLC25A49, and SLC25A51 effectively predicted the prognosis of HCC patients, with area under the curve (AUC) values exceeding 0.7 in the test group. Single-cell analysis further demonstrated h eightened expression of SLC25A19 in the immune microenvironment of HCC, and in vitro experiments indicated that SLC25A19 may regulate the proliferation, migration, invasion, cycle, and apoptosis of liver cancer cells through the Wnt pathway. In the HepG2 animal model, overexpression of SLC25A19 significantly promotes tumor growth, while knockdown inhibits tumor growth. Analysis of patient tumor tissues shows that SLC25A19 is highly expressed in liver cancer tissues and is associated with CD8+ T cell infiltration. In conclusion, our comprehensive analysis of the role of SLC25 in HCC unveiled SLC25A19 as a potential regulatory factor in HCC.

SLC25A1 and ACLY maintain cytosolic acetyl-CoA and regulate ferroptosis susceptibility via FSP1 acetylation.

Ferroptosis, an iron-dependent form of programmed cell death characterized by excessive lipid hydroperoxides accumulation, emerges as a promising target in cancer therapy. Among the solute carrier (SLC) superfamily, the cystine/glutamate transporter system antiporter components SLC3A2 and SLC7A11 are known to regulate ferroptosis by facilitating cystine import for ferroptosis inhibition. However, the contribution of additional SLC superfamily members to ferroptosis remains poorly understood. Here, we use a targeted CRISPR-Cas9 screen of the SLC superfamily to identify SLC25A1 as a critical ferroptosis regulator in human cancer cells. SLC25A1 drives citrate export from the mitochondria to the cytosol, where it fuels acetyl-CoA synthesis by ATP citrate lyase (ACLY). This acetyl-CoA supply sustains FSP1 acetylation and prevents its degradation by the proteasome via K29-linked ubiquitin chains. K168 is the primary site of FSP1 acetylation and deacetylation by KAT2B and HDAC3, respectively. Pharmacological inhibition of SLC25A1 and ACLY significantly enhances cancer cell susceptibility to ferroptosis both in vitro and in vivo. Targeting the SLC25A1-ACLY axis is therefore a potential therapeutic strategy for ferroptosis-targeted cancer intervention.

Fasting-mimicking diet-enriched Bifidobacterium pseudolongum suppresses colorectal cancer by inducing memory CD8+ T cells

BackgroundFasting-mimicking diet (FMD) boosts the antitumour immune response in patients with colorectal cancer (CRC). The gut microbiota is a key host immunity regulator, affecting physiological homeostasis and disease pathogenesis.ObjectiveWe aimed...

Old World alphaviruses use distinct mechanisms to infect brain microvascular endothelial cells for neuroinvasion.

Several alphaviruses bypass the blood-brain barrier (BBB), causing debilitating or fatal encephalitis. Sindbis virus (SINV) has been extensively studied in vivo to understand alphavirus neuropathogenesis; yet the molecular details of neuroinvasion at the BBB remain poorly understood. We investigated alphavirus-BBB interactions by pairing a physiologically relevant, human pluripotent stem cell derived model of brain microvascular endothelial cells (BMECs) with SINV strains of opposite neuroinvasiveness. Our system demonstrates that SINV neuroinvasion correlates with robust infection of the BBB. Specifically, SINV genetic determinants of neuroinvasion enhance viral entry into BMECs. We also identify solute carrier family 2 member 3 (SLC2A3, also named GLUT3) as a potential BMEC-specific entry factor exploited for neuroinvasion. Strikingly, efficient BBB infection is a conserved phenotype that correlates with the neuroinvasive capacity of several Old World alphaviruses, including chikungunya virus. Here, we reveal BBB infection as a shared pathway for alphavirus neuroinvasion that can be targeted for preventing alphavirus-induced encephalitis.

Mutant KRAS and CK2 Cooperatively Stimulate SLC16A3 Activity to Drive Intrahepatic Cholangiocarcinoma Progression.

Intrahepatic cholangiocarcinoma (iCCA) is a lethal malignancy affecting the liver and biliary system. Enhanced understanding of the pathogenic mechanisms underlying iCCA tumorigenesis and the discovery of appropriate therapeutic targets are imperative to improve patient outcomes. Here, we investigated the functions and regulations of solute carrier family 16 member 3 (SLC16A3), which has been reported to be a biomarker of poor prognosis in iCCA. High SLC16A3 expression was enriched in KRAS-mutated iCCA tumors, and mutant KRAS elevated SLC16A3 expression via the PI3K/AKT/mTORC1/HIF1α pathway. SLC16A3 not only enhanced glycolysis but also induced epigenetic reprogramming to regulate iCCA progression. Phosphorylation of SLC16A3 at S436 (p-S436) was vital for its oncogenic function and was linked to iCCA progression. Casein kinase 2 (CK2) directly phosphorylated SLC16A3 at S436, and CK2 inhibition with CX-4945 (silmitasertib) reduced the growth of KRAS-mutated iCCA tumor xenografts and patient-derived organoids. Together, this study provides valuable insights into the diverse functions of SLC16A3 in iCCA and comprehensively elucidates the upstream regulatory mechanisms, providing potential therapeutic strategies for iCCA patients with KRAS mutations.

An essential role for TASL in mouse autoimmune pathogenesis and Toll-like receptor signaling

TASL is an immune adaptor that binds to the solute carrier SLC15A4 and facilitates activation of the transcription factor IRF5 during Toll-like receptor (TLR) signaling. Similar to IRF5 and SLC15A4, single nucleotide polymorphisms (SNPs) within TASL have been implicated in increased susceptibility to systemic lupus erythematosus (SLE) in patients. However, the biological function of TASL in vivo and how SLE-associated SNPs increase disease risk is unknown. Here we report that mice deficient in Tasl lack responses to TLR7/9 stimulation and are protected from autoimmune symptoms induced by Aldara or pristane. Loss of Tasl reduces IRF5 phosphorylation and cytokine production in multiple immune cell types but has no effect on other aspects of TLR signaling. Conversely, an SLE-associated TASL risk variant increases TASL protein expression via codon usage, resulting in augmented cytokine production in human cells. Altogether, our study validates the essential function of TASL in TLR signaling and autoimmune pathogenesis.

Potential therapeutic effect of dimethyl fumarate on Treg/Th17 cell imbalance in biliary atresia.

The imbalance between Tregs and proinflammatory Th17 cells in children with biliary atresia (BA) causes immune damage to cholangiocytes. Dimethyl fumarate (DMF), an immunomodulatory drug, regulates the Treg/Th17 balance in diseases like multiple sclerosis (MS). This study explores DMF's effect on Treg/Th17 balance in BA and its potential mechanism. The differential gene expression profiles in liver of BA and choledochal cyst (CC) patients were analyzed by single-cell RNA sequencing (scRNA-seq). Treg and Th17 cell frequencies in BA hilar lymph nodes (LNs) were determined by flow cytometry. CD3+ T cells were isolated from BA hilar LNs and treated with DMF in vitro to observe their differentiation. The effects of DMF were evaluated on BA mouse model, and enzyme-linked immunosorbent assay to measure biochemical markers and cytokine profiles. The Treg/Th17 ratio in the liver was determined by flow cytometry. Nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream antioxidant genes solute carrier family 7 member 1 (Slc7a11), heme oxygenase - 1 (Hmox1) was validated by q-PCR and Western blot. ScRNA-seq showed CD4+ T cells in BA liver were enriched in antioxidant pathways. The Treg/Th17 ratio in BA hilar LNs was significantly reduced compared to CC. In vitro, DMF promoted Treg differentiation and inhibited Th17 differentiation. In vivo, the Treg/Th17 ratio increased in the liver of the DMF 40 mg/kg group. In the 40 mg/kg DMF group, interleukin-17 A (IL-17 A) expression decreased as seen in pathological staining. DMF increased Nrf2, Hmox1, Slc7a11 mRNA and protein levels in DMF 40 mg/kg group. There is a Treg/Th17 imbalance in BA patients' hilar LNs, which DMF can restore in vitro. DMF improves the survival rate of BA mice and corrects the Treg/Th17 imbalance, possibly via the Nrf2/antioxidant response elements (ARE) pathway.