A missense variant in SLC12A3 gene enhances aberrant splicing causing Gitelman syndrome.

Gitelman syndrome (GS) is the most prevalent genetic tubulopathy characterized by several electrolyte abnormalities, including hypokalemia, hypomagnesemia, hypocalciuria, metabolic alkalosis, and hyperreninemic hyperaldosteronism. These features are caused by a bi-allelic mutation in the SLC12A3 gene. In this report, we present a case of GS in an asymptomatic woman who incidentally exhibited hypokalemia during an antenatal check-up. Her biochemical profile was consistent with GS. Genetic analysis revealed two heterozygous variants in trans, namely, NM_001126108.2:c.625C>T; p.(Arg209Trp) and c.965C>T; p.(Ala322Val). The c.625C>T; p.(Arg209Trp) variant has previously been experimentally confirmed as a loss-of-function (LOF) variant. However, the functional impact of the c.965C>T variant, located at the 5 prime end of exon 8, has not been fully elucidated. Through the utilization of both complementary DNA (cDNA) and minigene analysis, we confirmed that the c.965C>T variant can generate two distinct cDNA transcripts. The first transcript carries a missense mutation, p.(Ala322Val) in the full SLC12A3 transcript, while the second transcript consists of an in-frame deletion of both exons 7 and 8 in the SLC12A3 transcript, in which may result in the loss of transmembrane regions 5 - 6 involved in chloride transport. Our findings provide insights into the intricate mechanisms of splicing, highlighting how a variant in one exon can remotely influence the transcription of an upstream exon, as observed with the variant in exon 8 impacting the transcription of exon 7.

Congenital hereditary endothelial dystrophy with progressive sensorineural deafness: a case report of Harboyan syndrome

ABSTRACT We present the case of a 37-year-old woman who underwent bilateral penetrating keratoplasty for congenital hereditary endothelial dystrophy at the age of 10 years. Over the subsequent 27 years, the patient's vision slowly deteriorated. Our examination revealed decompensation of the right corneal graft. We addressed this with regraft surgery. We then learned that the patient had been suffering from progressive hearing loss since adolescence. Tonal audiometry revealed hearing per ceptive deafness of 25 dB, which was more prominent in the left ear. Because the patterns of progressive sensorineural hearing loss and congenital hereditary endothelial dystrophy have both been linked to the same gene, slc4a11, we tested our patient for mutations in this gene. The test was positive for a heterozygous slc4a11 gene fifth exon mutation on chromosome 20p13-p12, which causes a frameshift. A combined clinical and genetic evaluation confirmed a diagnosis of Harboyan syndrome. After the genetic diagnosis of the disease, she was evaluated for the need for a hearing aid due to her hearing loss. The patient was also informed about genetic counseling.

Hepatocyte-specific SLC27A4 deletion ameliorates nonalcoholic fatty liver disease in mice via suppression of phosphatidylcholine-mediated PXR activation.

BACKGROUND: The protein Solute carrier family 27 member 4 (SLC27A4) is crucial for fatty acid synthesis and ß-oxidation, but its role in hepatic steatosis and nonalcoholic fatty liver disease (NAFLD) progression is not fully understood. METHODS: Mice with AAV-mediated overexpression of Slc27a4 in liver and hepatocytes-specific deletion of Slc27a4 were fed a standard chow diet, a high-fat diet (HFD), or a methionine and choline-deficient diet (MCD). Serum and liver tissues were collected and analyzed by biochemical assay, histology, lipidomic analysis, RNA-seq analysis, qPCR, western blot and immunofluorescence. RESULTS: This study found elevated expression of SLC27A4 in individuals with NAFLD and OAPA-treated MPHs cells, leading to increased lipid accumulation and diet-induced liver steatosis, inflammation, and fibrosis. Conversely, hepatocyte-specific deletion of Slc27a4 improved the development of both NAFLD and NASH. SLC27A4 overexpression resulted in increased hepatic pregnane X receptor (PXR) expression and accumulation of phosphatidylcholine (PC), which activates PXR signaling and inducing SLC27A4 expression. PXR overexpression hinders the protective impact of Slc27a4 deletion on lipid accumulation and inflammation, whereas its deficiency in mice reduces the effect of Slc27a4 overexpression on NAFLD development. CONCLUSION: These results indicate that SLC27A4 plays a critical role of lipid accumulation and inflammation, and is implicated in the development of NAFLD progression, rendering it potentially actionable target for NAFLD treatment.

In silico analysis shows slc1a4 as a potential target of hsa-mir-133a for regulating glutamine metabolism in gastric cancer.

Cutting-edge research has spotlighted glutamine metabolism as a promising therapeutic target in managing gastric cancer. This investigation highlights the upregulated glutamine transporters by leveraging clinical data from the TCGA Database and the expression analysis of the transcriptome profile of stomach adenocarcinoma (STAD) patients. Notably, it identifies SLC1A4 as a potential glutamine transporter in STAD. The screening of human miRNAs conducted using the TargetScan database, and the subsequent docking analysis present multiple miRNAs with the potential of being explored as therapeutic agents. By integrating transcriptome profiling, miRNA screening, and molecular docking, this study reveals, for the first time, the potential of hsa-mir-133a-1 in targeting slc1a4, along with its known target mTOR, in stomach cancer. The myriad interactions that can be regulated by this silencing mechanism are anticipated to ultimately reduce glutamine uptake in STAD. This study provides compelling evidence of glutamine transport via SLC1A4 in stomach cancer and delves into how it might impact mTOR and some of its pivotal downstream molecules. Considering these findings, novel therapeutic strategies can be devised to further enhance existing methods for combating gastric cancer.

ZNF217 Mediates Transcriptional Activation of GRHL3 to Regulate SLC22A31 and Promote Malignant Progression in Thyroid Cancer.

The incidence of thyroid cancer (THCA) has increased worldwide during the past 40 years. However, an understanding of the mechanisms and major transcription factors involved in THCA is insufficient to identify therapeutic targets against THCA. To reveal such mechanisms, we conducted bioinformatics analyses to assess the differential expression in human THCA sample and normal tissue sample, leading us to focus on the function of the ZNF217/GRHL3/ SLC22A31 axis in mediating biological activity in THCA. The genes of interest were interfered with lentiviral vectors, and transfection efficiency was verified using RT-qPCR. ZNF217, GRHL3, and SLC22A31 were abundantly expressed in THCA tissues or cells. Knockdown of GRHL3, ZNF217, or SLC22A31 all significantly curtailed the malignant biological behavior of THCA cells. ZNF217 promoted GRHL3 expression through transcriptional activation, thereby increasing the transcription of SLC22A31. Ectopic expression of GRHL3 or SLC22A31 abated the suppressing impact of ZNF217 or GRHL3 knockdown on the biological activity of THCA cells. Collectively, our results demonstrated that ZNF217 acted as an activator of GRHL3, thereby promoting the expression of SLC22A31 and the malignant activity of THCA cells.

Hearing loss with two pathogenic SLC26A4 variants and positive thyroid autoantibody: A case report.

SLC26A4 causes Pendred syndrome (PS) and nonsyndromic hearing loss. PS is distinguished based on perchlorate discharge test abnormality, goiter, and hypothyroidism in some patients. The pathophysiology of thyroid dysfunction in PS differs from that of autoimmune thyroid disease, in that it is considered to be caused by an iodide organification defect. It is believed that both diseases may incidentally coexist, and that SLC26A4 may play an important role in the etiology of autoimmune thyroid disease. Herein, we describe a case of a girl with hearing loss who had two pathogenic SLC26A4 variants and tested positive for thyroid peroxidase (TPO) antibody. She was diagnosed with hearing loss and vestibular aqueduct enlargement at the age of 4 yr. Deafness gene screening revealed two pathogenic SLC26A4 variants. As SLC26A4 variants can cause PS, the patient underwent thorough thyroid examination. Her thyroid gland was within the physiological range of mild enlargement. Although thyroid function test results were normal, the patient tested positive for TPO antibody. The patient was diagnosed with "suspected PS" and "suspected Hashimoto's thyroiditis," both of which increase the risk of developing hypothyroidism. Evaluating the comorbidity of Hashimoto's thyroiditis with the SLC26A4 variant in terms of complications is critical.

Atlantoaxial Instability due to Os Odontoideum in a Child with Christianson Syndrome.

Introduction: Christianson syndrome is a rare neurodevelopmental disorder associated with mutations in the SLC9A6 gene located on the chromosome X. It is characterized by intellectual disability, developmental delay, speech and language impairments, dysmorphic features, seizures, ataxia, and neurobehavioral problems. Case Presentation: A 5-year-old boy was presented with respiratory failure and then progressive muscle weakness in all four extremities. He manifested acquired microcephaly, intellectual disability, global developmental delay, distinct dysmorphic facial features, seizures, spastic tetraparesis, truncal hypotonia, speech impairment, failure to thrive, malnutrition, recurrent lung infections, self-mutilation, primary hyperparathyroidism, medullary nephrocalcinosis, and atlantoaxial instability due to os odontoideum. Brain magnetic resonance imaging revealed atlantoaxial instability due to os odontoideum, a narrow foramen magnum, myelopathy due to spinal cord compression, and cerebral and cerebellar atrophy. Discussion: This report highlights a significant contribution by introducing a child with Christianson syndrome describing atlantoaxial instability due to os odontoideum, a previously undocumented phenomenon. This report suggests a potential link between Christianson syndrome and atlantoaxial instability. In children with Christianson syndrome experiencing increased muscle weakness in all extremities during follow-up, consideration of underlying myelopathy due to os odontoideum is advised.

Disulfidptosis: a novel cell death modality induced by actin cytoskeleton collapse and a promising target for cancer therapeutics.

Disulfidptosis is a novel discovered form of programmed cell death (PCD) that diverges from apoptosis, necroptosis, ferroptosis, and cuproptosis, stemming from disulfide stress-induced cytoskeletal collapse. In cancer cells exhibiting heightened expression of the solute carrier family 7 member 11 (SLC7A11), excessive cystine importation and reduction will deplete nicotinamide adenine dinucleotide phosphate (NADPH) under glucose deprivation, followed by an increase in intracellular disulfide stress and aberrant disulfide bond formation within actin networks, ultimately culminating in cytoskeletal collapse and disulfidptosis. Disulfidptosis involves crucial physiological processes in eukaryotic cells, such as cystine and glucose uptake, NADPH metabolism, and actin dynamics. The Rac1-WRC pathway-mediated actin polymerization is also implicated in this cell death due to its contribution to disulfide bond formation. However, the precise mechanisms underlying disulfidptosis and its role in tumors are not well understood. This is probably due to the multifaceted functionalities of SLC7A11 within cells and the complexities of the downstream pathways driving disulfidptosis. This review describes the critical roles of SLC7A11 in cells and summarizes recent research advancements in the potential pathways of disulfidptosis. Moreover, the less-studied aspects of this newly discovered cell death process are highlighted to stimulate further investigations in this field.

Lysine 473 Regulates the Progression of SLC7A11, the Cystine/Glutamate Exchanger, through the Secretory Pathway.

System xc-, the cystine/glutamate exchanger, is a membrane transporter that plays a critical role in the antioxidant response of cells. Recent work has shown that System xc- localizes to the plasma membrane during oxidative stress, allowing for increased activity to support the production of glutathione. In this study, we used site-directed mutagenesis to examine the role of C-terminal lysine residues (K422, K472, and K473) of xCT (SLC7A11) in regulating System xc-. We observed that K473R exhibits loss of transporter activity and membrane localization and is 7.5 kD lower in molecular weight, suggesting that K473 regulates System xc- trafficking and is modified under basal conditions. After ruling out ubiquitination and neddylation, we demonstrated that unlike WT xCT, K473R lacks N- and O-glycosylation and is sequestered in the endoplasmic reticulum. Next, we demonstrated that K473Q, a constitutively acetylated lysine mimic, also exhibits loss of transporter activity, decreased membrane expression, and a 4 kD decrease in molecular weight; however, it is N- and O-glycosylated and localized to the endoplasmic reticulum and Golgi. These results suggest that acetylation and deacetylation of K473 in the endoplasmic reticulum and Golgi, respectively, serve to regulate the progression of the transporter through the biosynthetic pathway.

A Village in the Southeastern Region of Iran Harboring the c.716T>A (p.Val239Asp) Mutation in SLC26A4.

After GJB2, SLC26A4 is the second most common contributor to autosomal recessive nonsyndromic hearing loss (ARNSHL) worldwide. In this study, we used Exome Sequencing (ES) to present a village with 31 individuals affected by hereditary hearing loss (HHL) in southeastern Iran near the border of Pakistan. The village harbored the known pathogenic missense SLC26A4 (NM_000441.2):c.716T>A (p.Val239Asp) mutation, which has a founder effect attributed to Pakistan, Iran's southeastern neighbor. Our findings, in addition to unraveling the molecular cause of non-syndromic hearing loss in these patients and further confirming the common ancestry and migration story between the people of this region and Pakistan, provide further insight into the genetic background of this region and highlight the importance of understanding the mutation spectrum of GJB2 and SLC26A4 in different regions to choose cost-effective strategies for molecular genetic testing.

HPV16 integration regulates ferroptosis resistance via the c-Myc/miR-142-5p/HOXA5/SLC7A11 axis during cervical carcinogenesis.

BACKGROUND: Ferroptosis, a newly identified form of regulated cell death triggered by small molecules or specific conditions, plays a significant role in virus-associated carcinogenesis. However, whether tumours arising after high-risk HPV integration are associated with ferroptosis is unexplored and remains enigmatic. METHODS: High-risk HPV16 integration was analysed by high-throughput viral integration detection (HIVID). Ferroptosis was induced by erastin, and the levels of ferroptosis were assessed through the measurement of lipid-reactive oxygen species (ROS), malondialdehyde (MDA), intracellular Fe2+ level and transmission electron microscopy (TEM). Additionally, clinical cervical specimens and an in vivo xenograft model were utilized for the study. RESULTS: Expression of HPV16 integration hot spot c-Myc negatively correlates with ferroptosis during the progression of cervical squamous cell carcinoma (CSCC). Further investigation revealed that the upregulated oncogene miR-142-5p in HPV16-integrated CSCC cells served as a critical downstream effector of c-Myc in its target network. Inhibiting miR-142-5p significantly decreased the ferroptosis-suppressing effect mediated by c-Myc. Through a combination of computational and experimental approaches, HOXA5 was identified as a key downstream target gene of miR-142-5p. Overexpression of miR-142-5p suppressed HOXA5 expression, leading to decreased accumulation of intracellular Fe2+ and lipid peroxides (ROS and MDA). HOXA5 increased the sensitivity of CSCC cells to erastin-induced ferroptosis via transcriptional downregulation of SLC7A11, a negative regulator of ferroptosis. Importantly, c-Myc knockdown increased the anti-tumour activity of erastin by promoting ferroptosis both in vitro and in vivo. CONCLUSIONS: Collectively, these data indicate that HPV16 integration hot spot c-Myc plays a novel and indispensable role in ferroptosis resistance by regulating the miR-142-5p/HOXA5/SLC7A11 signalling axis and suggest a potential therapeutic approach for HPV16 integration-related CSCC.

Regulatory Effects of SLC7A2-CPB2 on Lymphangiogenesis: A New Approach to Suppress Lymphatic Metastasis in HNSCC.

BACKGROUND: Lymph node metastasis (LNM) is a critical factor affecting the outcomes of head and neck squamous cell carcinoma (HNSCC) and the main reason for treatment failure. This study was designed to examine the effects of the key genes involved in the LNM of HNSCC. METHODS: Tissue samples (HNSCC) were examined by transcriptome sequencing, and the core genes associated with LNM were detected via bioinformatics analysis. The functions of these core genes were then validated using the TCGA biological database and their effects on the propagation, invasion, and metastasis of HNSCC cells were evaluated through cell culture experiments. Moreover, the effect of core gene expression on the LNM capability of HNSCC was confirmed via a footpad xenograft mice model. RESULTS: In the findings, a key gene involved in the LNM of HNSCC was identified as SLC7A2. It was correlated with adverse clinical prognosis and expressed with low expression in HNSCC tissues. As shown in cell culture experiments, FaDu and SCC15 cell growth, invasion, and migration were inhibited when SLC7A2 was overexpressed. Further, cell apoptosis was stimulated, and lymphangiogenesis was suppressed through the downregulation of CPB2 expression. Animal studies demonstrated that the growth and LNM of HNSCC cells were inhibited by SLC7A2 overexpression. CONCLUSION: It is concluded that SLC7A2 is involved in HNSCC lymphatic metastasis by controlling CPB2 function. The results are anticipated to offer new directions for the effective treatment of HNSCC.

Hypothesis-based investigation of known AD risk variants reveals the genetic underpinnings of neuropathological lesions observed in Alzheimer's-type dementia.

Alzheimer's disease (AD) is the leading cause of dementia worldwide. Besides neurofibrillary tangles and amyloid beta (Aß) plaques, a wide range of co-morbid neuropathological features can be observed in AD brains. Since AD has a very strong genetic background and displays a wide phenotypic heterogeneity, this study aims at investigating the genetic underpinnings of co-morbid and hallmark neuropathological lesions. This was realized by obtaining the genotypes for 75 AD risk variants from low-coverage whole-genome sequencing data for 325 individuals from the Leuven Brain Collection. Association testing with deeply characterized neuropathological lesions revealed a strong and likely direct effect of rs117618017, a SNP in exon 1 of APH1B, with tau-related pathology. Second, a relation between APOE and granulovacuolar degeneration, a proxy for necroptosis, was also discovered in addition to replication of the well-known association of APOE with AD hallmark neuropathological lesions. Additionally, several nominal associations with AD risk genes were detected for pTDP pathology, α-synuclein lesions and pTau-related pathology. These findings were confirmed in a meta-analysis with three independent cohorts. For example, we replicated a prior association between TPCN1 (rs6489896) and LATE-NC risk. Furthermore, we identified new putative LATE-NC-linked SNPs, including rs7068231, located upstream of ANK3. We found association between BIN1 (rs6733839) and α-synuclein pathology, and replicated a prior association between USP6NL (rs7912495) and Lewy body pathology. Additionally, we also found that UMAD1 (rs6943429) was nominally associated with Lewy body pathology. Overall, these results contribute to a broader general understanding of how AD risk variants discovered in large-scale clinical genome-wide association studies are involved in the pathological mechanisms of AD and indicate the importance of downstream elimination of phenotypic heterogeneity introduced in these studies.

Structural insights into human zinc transporter ZnT1 mediated Zn2+ efflux.

Zinc transporter 1 (ZnT1), the principal carrier of cytosolic zinc to the extracellular milieu, is important for cellular zinc homeostasis and resistance to zinc toxicity. Despite recent advancements in the structural characterization of various zinc transporters, the mechanism by which ZnTs-mediated Zn2+ translocation is coupled with H+ or Ca2+ remains unclear. To visualize the transport dynamics, we determined the cryo-electron microscopy (cryo-EM) structures of human ZnT1 at different functional states. ZnT1 dimerizes via extensive interactions between the cytosolic (CTD), the transmembrane (TMD), and the unique cysteine-rich extracellular (ECD) domains. At pH 7.5, both protomers adopt an outward-facing (OF) conformation, with Zn2+ ions coordinated at the TMD binding site by distinct compositions. At pH 6.0, ZnT1 complexed with Zn2+ exhibits various conformations [OF/OF, OF/IF (inward-facing), and IF/IF]. These conformational snapshots, together with biochemical investigation and molecular dynamic simulations, shed light on the mechanism underlying the proton-dependence of ZnT1 transport.

The role and possible mechanism of the ferroptosis-related SLC7A11/GSH/GPX4 pathway in myocardial ischemia-reperfusion injury.

BACKGROUND: Myocardial ischemia-reperfusion injury (MI/RI) is an unavoidable risk event for acute myocardial infarction, with ferroptosis showing close involvement. We investigated the mechanism of MI/RI inducing myocardial injury by inhibiting the ferroptosis-related SLC7A11/glutathione (GSH)/glutathione peroxidase 4 (GPX4) pathway and activating mitophagy. METHODS: A rat MI/RI model was established, with myocardial infarction area and injury assessed by TTC and H&E staining. Rat cardiomyocytes H9C2 were cultured in vitro, followed by hypoxia/reoxygenation (H/R) modeling and the ferroptosis inhibitor lipoxstatin-1 (Lip-1) treatment, or 3-Methyladenine or rapamycin treatment and overexpression plasmid (oe-SLC7A11) transfection during modeling. Cell viability and death were evaluated by CCK-8 and LDH assays. Mitochondrial morphology was observed by transmission electron microscopy. Mitochondrial membrane potential was detected by fluorescence dye JC-1. Levels of inflammatory factors, reactive oxygen species (ROS), Fe2+, malondialdehyde, lipid peroxidation, GPX4 enzyme activity, glutathione reductase, GSH and glutathione disulfide, and SLC7A11, GPX4, LC3II/I and p62 proteins were determined by ELISA kit, related indicator detection kits and Western blot. RESULTS: The ferroptosis-related SLC7A11/GSH/GPX4 pathway was repressed in MI/RI rat myocardial tissues, inducing myocardial injury. H/R affected GSH synthesis and inhibited GPX4 enzyme activity by down-regulating SLC7A11, thus promoting ferroptosis in cardiomyocytes, which was averted by Lip-1. SLC7A11 overexpression improved H/R-induced cardiomyocyte ferroptosis via the GSH/GPX4 pathway. H/R activated mitophagy in cardiomyocytes. Mitophagy inhibition reversed H/R-induced cellular ferroptosis. Mitophagy activation partially averted SLC7A11 overexpression-improved H/R-induced cardiomyocyte ferroptosis. H/R suppressed the ferroptosis-related SLC7A11/GSH/GPX4 pathway by inducing mitophagy, leading to cardiomyocyte injury. CONCLUSIONS: Increased ROS under H/R conditions triggered cardiomyocyte injury by inducing mitophagy to suppress the ferroptosis-related SLC7A11/GSH/GPX4 signaling pathway activation.

HDAC10 inhibits non-small-cell lung cancer cell ferroptosis through the microRNA-223-5p-SLC7A11 axis.

Objective: Non-small-cell lung cancer (NSCLC) is a leading attributor to cancer deaths. High HDAC10 and low microRNA (miR)-223-5p levels have been observed in NSCLC. But their roles remain elusive. This study illustrated their roles in NSCLC cell ferroptosis and the mechanism. Methods: HDAC10, miR-223-5p, and solute carrier family 7 member 11 (SLC7A11) levels in cells were determined by RT-qPCR. Iron ion content, reactive oxygen species (ROS), and glutathione (GSH) levels were tested using reagent kits, and levels of SLC7A11 and Acyl-CoA synthesis long chain family (ACSL4) were examined using Western blot. Chromatin immunoprecision was performed to analyze the enrichment of HDAC10 and acetylated lysine 9 of histone H3 (H3K9ac) on the miR-223-5p promoter. The targeted binding of miR-223-5p and SLC7A11 was analyzed by dual-luciferase assay. Joint experiments were designed to identify the role of miR-223-5p/SLC7A11 axis in HDAC10-regulated ferroptosis in NSCLC cells. Results: HDAC10 was highly expressed in NSCLC cells. Silencing HDAC10 significantly reduced GSH and SLC7A11 levels, upregulated iron ion content, ROS levels, and ACSL4 expression, promoting cell ferroptosis. Mechanically, HDAC10 inhibited miR-223-5p expression through H3K9ac deacetylation of the miR-223-5p promoter, thereby targeting SLC7A11. The joint experimental results showed that overexpression of SLC7A11 or downregulation of miR-223-5p alleviated the promoting effect of silencing HDAC10 on ferroptosis in NSCLC cells. Conclusion: HDAC10 inhibits miR-223-5p expression through H3K9ac deacetylation of the miR-223-5p promoter, thereby promoting SLC7A11 expression and inhibiting ferroptosis in NSCLC cells.

Association of SLC19A1 Gene Polymorphisms and Its Regulatory miRNAs with Methotrexate Toxicity in Children with Acute Lymphoblastic Leukemia.

Methotrexate (MTX) is an anti-folate chemotherapeutic agent that is considered to be a gold standard in Acute Lymphoblastic Leukemia (ALL) therapy. Nevertheless, toxicities induced mainly due to high doses of MTX are still a challenge for clinical practice. MTX pharmacogenetics implicate various genes as predictors of MTX toxicity, especially those that participate in MTX intake like solute carrier family 19 member 1 (SLC19A1). The aim of the present study was to evaluate the association between SLC19A1 polymorphisms and its regulatory miRNAs with MTX toxicity in children with ALL. A total of 86 children with ALL were included in this study and were all genotyped for rs2838958, rs1051266 and rs1131596 SLC19A1 polymorphisms as well as the rs56292801 polymorphism of miR-5189. Patients were followed up (48, 72 and 96 h) after treatment with MTX in order to evaluate the presence of MTX-associated adverse events. Our results indicate that there is a statistically significant correlation between the rs1131596 SLC19A1 polymorphism and the development of MTX-induced hepatotoxicity (p = 0.03), but there is no significant association between any of the studied polymorphisms and mucositis or other side effects, such as nausea, emesis, diarrhea, neutropenia, skin rash and infections. In addition, when genotype TT of rs1131596 and genotype AA of rs56292801 are both present in a patient then there is a higher risk of developing severe hepatotoxicity (p = 0.0104).

Presentation and outcome in carriers of pathogenic variants in SLC34A1 and SLC34A3 encoding sodium-phosphate transporter NPT 2a and 2c.

Pathogenic variants in SLC34A1 and SLC34A3 encoding sodium-phosphate transporter 2a and 2c are rare causes of phosphate wasting. Since data on presentation and outcomes are scarce, we collected clinical, biochemical and genetic data via an online questionnaire and the support of European professional organizations. One hundred thirteen patients (86% children) from 90 families and 17 countries with pathogenic or likely pathogenic variants in SLC34A1 or SLC34A3 and a median follow-up of three years were analyzed. Biallelic SLC34A1 variant carriers showed polyuria, failure to thrive, vomiting, constipation, hypercalcemia and nephrocalcinosis in infancy, while biallelic SLC34A3 carriers presented in childhood or even adulthood with rickets/osteomalacia and/or osteopenia/osteoporosis, hypophosphatemia and, less frequently, nephrocalcinosis, while the prevalences of kidney stones were comparable. Adult biallelic SLC34A3 carriers had a six-fold increase chronic kidney disease (CKD) prevalence compared to the general population. All biallelic variant carriers shared a common biochemical pattern including elevated 1,25(OH)2D and alkaline phosphatase levels, suppressed parathyroid hormone (PTH), and hypercalciuria. Heterozygous carriers showed similar but less pronounced phenotypes. In biallelic SLC34A1 carriers, an attenuation of clinical features was observed after infancy, independent of treatment. Phosphate treatment was given in 55% of patients, median duration two years, and resulted in significant reduction, although not normalization, of alkaline phosphatase and of hypercalciuria but an increase in PTH levels, while 1,25(OH)2D levels remained elevated. Thus, our study indicates that biallelic SLC34A1 and SLC34A3 carriers show distinct, albeit overlapping phenotypes, with the latter having an increased risk of CKD in adulthood. Phosphate treatment may promote kidney phosphate loss and enhance 1,25(OH)2D synthesis via increased PTH production.

E2F2 Reprograms Macrophage Function By Modulating Material and Energy Metabolism in the Progression of Metabolic Dysfunction-Associated Steatohepatitis.

Macrophages are essential for the development of steatosis, hepatic inflammation, and fibrosis in metabolic dysfunction-associated steatohepatitis(MASH). However, the roles of macrophage E2F2 in the progression of MASH have not been elucidated. This study reveals that the expression of macrophage E2F2 is dramatically downregulated in MASH livers from mice and humans, and that this expression is adversely correlated with the severity of the disease. Myeloid-specific E2F2 depletion aggravates intrahepatic inflammation, hepatic stellate cell activation, and hepatocyte lipid accumulation during MASH progression. Mechanistically, E2F2 can inhibit the SLC7A5 transcription directly. E2F2 deficiency upregulates the expression of SLC7A5 to mediate amino acids flux, resulting in enhanced glycolysis, impaired mitochondrial function, and increased macrophages proinflammatory response in a Leu-mTORC1-dependent manner. Moreover, bioinformatics analysis and CUT &Tag assay identify the direct binding of Nrf2 to E2F2 promoter to promote its transcription and nuclear translocation. Genetic or pharmacological activation of Nrf2 effectively activates E2F2 to attenuate the MASH progression. Finally, patients treated with CDK4/6 inhibitors demonstrate reduced E2F2 activity but increased SLC7A5 activity in PBMCs. These findings indicated macrophage E2F2 suppresses MASH progression by reprogramming amino acid metabolism via SLC7A5- Leu-mTORC1 signaling pathway. Activating E2F2 holds promise as a therapeutic strategy for MASH.

Exome Sequence Data of Eight SLC Transporters Reveal That SLC22A1 and SLC22A3 Variants Alter Metformin Pharmacokinetics and Glycemic Control.

Background: Type 2 diabetes (T2D) is one of the leading causes of mortality and is a public health challenge worldwide. Metformin is the first-choice treatment for T2D; its pharmacokinetics (PK) is facilitated by members of the solute carrier (SLC) superfamily of transporters, it is not metabolized, and it is excreted by the kidney. Although interindividual variability in metformin pharmacokinetics is documented in the Mexican population, its pharmacogenomics is still underexplored. We aimed to identify variants in metformin SLC transporter genes associated with metformin PK and response in Mexican patients. Methods: Using exome data from 2217 Mexican adults, we identified 86 biallelic SNVs in the eight known genes encoding SLC transporters, with a minor allele frequency ≥ 1%, which were analyzed in an inadequate glycemic control (IGC) association study in T2D metformin treated patients. Metformin PK was evaluated in a pediatric cohort and the effect of associated SNVs was correlated. Results: Functional annotation classified two SNVs as pathogenic. The association study revealed two blocks associated with IGC. These haplotypes comprise rs622591, rs4646272, rs4646273, and rs4646276 in SLC22A1; and rs1810126 and rs668871 in SLC22A3. PK profiles revealed that homozygotes of the SLC22A1 haplotype reached lower plasma metformin concentrations 2 h post administration than the other groups. Conclusions: Our findings highlight the potential of pharmacogenomics studies to enhance precision medicine, which may involve dosage adjustments or the exploration of alternative therapeutic options. These hold significant implications for public health, particularly in populations with a high susceptibility to develop metabolic diseases, such as Latin Americans.