Solute Carrier Research Articles

N6-methyladenosine modification of SLC38A7 promotes cell migration, invasion, oxidative phosphorylation, and mitochondrial function in gastric cancer

Solute carrier (SLC) 38 family responsible for trans-membrane transport of neutral amino acids, plays a role in the proliferation, invasion, and metastasis of cancer cells, but its role in gastric cancer (GC) progression remains unclear. This study aimed to explore the biological effects of SLC38A7 and its regulatory mechanisms in GC. RNA expression data, tumor tissue specimens, and GC cell lines were used for bioinformatics and experimental analyses. Cell Counting Kit-8 assay, wound healing assay, and Transwell invasion assay were used to evaluate cell viability, migration, and invasion, respectively. Oxidative phosphorylation, mitochondrial membrane potential and expression of the critical proteins in the mitochondrial respiratory chain were assayed using extracellular flux analysis, flow cytometry, and Western blot, respectively. RNA immunoprecipitation assay was used to explore the mechanisms of N6-methyladenosine (m6A) methylation. SLC38A7 was upregulated in GC tissue and cell lines. SLC38A7 silencing suppressed cell viability, migration, invasion, oxidative phosphorylation, and mitochondrial function in cancer cells. SLC38A7 overexpression had the opposite biological effects. Interactions between SLC38A7 and methyltransferase like 3 (METTL3) or insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) were detected. SLC38A7 mRNA stability was maintained by METTL3/IGF2BP2 axis in an m6A-dependent manner. Our results suggest that SLC38A7, stabilized by METTL3 and IGF2BP2-mediated m6A methylation, enhances cell viability, migration, invasion, oxidative phosphorylation, and mitochondrial function in GC, highlighting its role as a potential therapeutic target for GC.

The Influence of OCT3 and MATE2 Genetic Polymorphisms in Poor Response to Metformin in Type 2 Diabetes Mellitus.

The response of patients with Type 2 diabetes mellitus (T2DM) to metformin may be a variation because of genetic differences in solute carrier (SLC) transporter proteins and other effect factors, which have an important effect on how metformin is processed in the body and its efficiency for glycaemic control. This study was conducted to investigate the impact of certain genetic variants of the organic cation transporter genes OCT3 (SLC22A3 rs12194182 and rs8187722) and MATE2 (SLC47A2 rs12943590) and their association with glycaemic parameters in patients with T2DM who respond poorly to metformin. This cross-sectional study involved 150 Iraqi cases with T2DM who were prescribed a daily dose of (1000 mg/day) metformin for a minimum of 3 months. Various parameters included are as follows: demographic data, glycaemic parameters and three SNPs: rs12943590 variant of SLC47A2, rs12194182 and rs8187722 variant of SLC22A3 using the standard PCR-sequencing technique. Thirty-nine patients (26.17%) were responders, whereas 111 patients (73.82%) could not respond to metformin treatment. Upon analysing the genotypes of the rs12943590 variants of SLC47A2, rs12194182 and rs8187722 SNPs of SLC22A3, the present findings revealed a nonsignificant association of genetic variations in all SNPs with metformin response. SLC47A2 (rs12943590) showed nonsignificant associations of the GG, AA and AG genotyping; SLC22A3 (rs12194182) showed nonsignificant associations of the TT, TC and CC genotyping; and SLC22A3 (rs8187722) showed nonsignificant associations of the AA, CC and AC genotyping between two groups. Variations in genes SLC22A3 and SLC47A2 did not have a significant role in the response of patients with T2DM to metformin (1000 mg/day).

Abstract P389: Immunogenic Peptides Responsible for Experimental Hypertension Contribute to Systemic Lupus Erythematosus

Introduction: Hypertension and systemic lupus erythematosus (SLE) lead to modification of self-peptides by isolevuglandin (isoLG) lipid oxidation products. These self-peptides are presented by class 1 major histocompatibility complexes and drive CD8 + T cell activation. We have identified self-peptides from the sodium/glucose cotransporter2 (SGLT2); cadherin 16; Kelch domain-containing protein 7A and solute carrier family 23 that are IsoLG-adducted and cause CD8 + T cell activation in both ang II and L-NAME/high salt models of hypertension. These prime hypertension in response to low dose ang II. Hypothesis: We hypothesized that the same immunogenic peptides responsible for experimental hypertension contribute to systemic lupus erythematosus. Methods: A fluorescent probe made of recombinant IgG and the murine class 1 MHC H2-D b was loaded with either unadducted SGLT2 peptide or an isoLG-adducted SGLT2 peptide. This probe was used in flow cytometry to detect CD8 + T cells specific for this peptide antigen in 12-week-old C57Bl/6 and female B6SLE1.2.3 mice. Results: The unadducted SGLT2 probe recognized < 1% of CD8 + T cells (Figure). In contrast, ang II-infusion caused a striking increase in IsoLG-SGLT2 specific CD8 + T cells in C57Bl/6 aortas (Figure panels A and D). In C57Bl/6 very few CD8 + T cells recognizing IsoLG-SGLT2 were observed in the spleen (Panel B and E). Importantly, from 5 to 20% of CD8 + T cells in spleens of female B6SLE1.2.3 mice recognized the IsoLG-SGLT2 peptide (Figure panels C and E). Image 1. Conclusions: These findings strongly suggest that IsoLG-adducted peptides responsible for ang II-induced hypertension contribute to SLE and suggest that these conditions share similar immunogenicity.

Inhibition of mitochondrial citrate shuttle alleviates metabolic syndromes induced by high-fat diet.

The mitochondrial citrate shuttle, which relies on the solute carrier family 25 member 1 (SLC25A1), plays a pivotal role in transporting citrate from the mitochondria to the cytoplasm. This shuttle supports glycolysis, lipid biosynthesis, and protein acetylation. Previous research has primarily focused on SLC25A1 in pathological models, particularly high-fat diet (HFD)-induced obesity. However, the impact of SLC25A1 inhibition on nutrient metabolism under HFD remains unclear. To address this gap, we used zebrafish (Danio rerio) and Nile tilapia (Oreochromis niloticus) to evaluate the effects of inhibiting Slc25a1. In zebrafish, we administered Slc25a1-specific inhibitors (CTPI-2) for 4 wk, whereas Nile tilapia received intraperitoneal injections of dsRNA to knock down slc25a1b for 7 days. Inhibition of the mitochondrial citrate shuttle effectively protected zebrafish from HFD-induced obesity, hepatic steatosis, and insulin resistance. Of note, glucose tolerance was unaffected. Inhibition of Slc25a1 altered hepatic protein acetylation patterns, with decreased cytoplasmic acetylation and increased mitochondrial acetylation. Under HFD conditions, Slc25a1 inhibition promoted fatty acid oxidation and reduced hepatic triglyceride (TAG) accumulation by deacetylating carnitine palmitoyltransferase 1a (Cpt1a). In addition, Slc25a1 inhibition triggered acetylation-induced inactivation of Pdhe1α, leading to a reduction in glucose oxidative catabolism. This was accompanied by enhanced glucose uptake and storage in zebrafish livers. Furthermore, Slc25a1 inhibition under HFD conditions activated the SIRT1/PGC1α pathway, promoting mitochondrial proliferation and enhancing oxidative phosphorylation for energy production. Our findings provide new insights into the role of nonhistone protein acetylation via the mitochondrial citrate shuttle in the development of hepatic lipid deposition and hyperglycemia caused by HFD.NEW & NOTEWORTHY The mitochondrial citrate shuttle is a crucial physiological process for maintaining metabolic homeostasis. In the present study, we found that inhibition of mitochondrial citrate shuttle (Slc25a1) could alleviate metabolic syndromes induced by high-fat diet (HFD) through remodeling hepatic protein acetylation modification. Briefly, Slc25a1 inhibition reduces hepatic triglyceride deposition by deacetylating Cpt1a and reduces glucose oxidative catabolism by acetylating Pdhe1α. Our study provides new insights into the treatment of diet-induced metabolic syndromes.

557. POTENTIAL THERAPEUTIC TARGETS OF TRPV2 AND SLC12A2 IN ESOPHAGEAL ADENOCARCINOMA CANCER STEM CELLS

Abstract Background Cancer stem cells (CSCs) are resistant to current anticancer drugs and radiation. The membrane transporters have recently been reported to play crucial roles for Esophageal adenocarcinoma (EA) CSCs. The aim of our study was to investigate ion channel expression profiles in esophageal adenocarcinoma CSCs (EACSCs) and to examine these potential as therapeutic targets. Methods Using the EA cell line OE33, cells with strong ALDH1A1 activity, a CSC marker, were isolated by flow cytometry. The characteristics of CSCs for the separated cells were verified by sphere formation assay, the expression of CSC markers on real-time reverse transcription-polymerase chain reaction and western blotting, and anti-cancer agent sensitivity assay. Gene expression profiles in EACSCs were examined by a microarray analysis. The transporters, high expression in CSC, were examined the anti-tumor effect of these inhibitors. Results Separated cells formed spheres in low-adhesion plates. The expressions of CSC markers were higher in CSCs than in non-CSCs. The CSCs also exhibited resistance to cisplatin and redifferentiation potential. The microarray analysis showed that the expression of transient receptor potential vanilloid 2 (TRPV2) and solute carrier family 12 member 2 (SLC12A2), which related to ion channels, were upregulated in CSCs. The cytotoxicities of tranilast and furosemide, which were TRPV2 and SLC12A2 inhibitors respectively, were added to cisplatin. Conclusions We revealed that TRPV2 and SLC12A2 are highly expressed in EACSCs and have potential as therapeutic targets for EA.

Biallelic variation in the choline and ethanolamine transporter FLVCR1 underlies a severe developmental disorder spectrum

PurposeFLVCR1 encodes a solute carrier protein implicated in heme, choline, and ethanolamine transport. Although Flvcr1−/− mice exhibit skeletal malformations and defective erythropoiesis reminiscent of Diamond-Blackfan anemia (DBA), biallelic FLVCR1 variants in humans have previously only been linked to childhood or adult-onset ataxia, sensory neuropathy, and retinitis pigmentosa. MethodsWe identified individuals with undiagnosed neurodevelopmental disorders and biallelic FLVCR1 variants through international data sharing and characterized the functional consequences of their FLVCR1 variants. ResultsWe ascertained 30 patients from 23 unrelated families with biallelic FLVCR1 variants and characterized a novel FLVCR1-related phenotype: severe developmental disorders with profound developmental delay, microcephaly (z-score −2.5 to −10.5), brain malformations, epilepsy, spasticity, and premature death. Brain malformations ranged from mild brain volume reduction to hydranencephaly. Severely affected patients share traits, including macrocytic anemia and skeletal malformations with Flvcr1−/− mice and DBA. FLVCR1 variants significantly reduce choline and ethanolamine transport and/or disrupt mRNA splicing. ConclusionThese data demonstrate a broad FLVCR1-related phenotypic spectrum ranging from severe multiorgan developmental disorders resembling DBA to adult-onset neurodegeneration. Our study expands our understanding of Mendelian choline and ethanolamine disorders and illustrates the importance of anticipating a wide phenotypic spectrum for known disease genes and incorporating model organism data into genome analysis to maximize genetic testing yield.

Identification of SLC25A46 interaction interfaces with mitochondrial membrane fusogens Opa1 and Mfn2

Mitochondrial fusion requires the sequential merger of four bilayers to two. The outer-membrane solute carrier protein SLC25A46 interacts with both the outer and inner-membrane dynamin family GTPases Mfn1/2 and Opa1. While SLC25A46 levels are known to affect mitochondrial morphology, how SLC25A46 interacts with Mfn1/2 and Opa1 to regulate membrane fusion is not understood. In this study, we use crosslinking mass-spectrometry and AlphaFold 2 modeling to identify interfaces mediating a SLC25A46 interactions with Opa1 and Mfn2. We reveal that the bundle signaling element of Opa1 interacts with SLC25A46, and present evidence of a Mfn2 interaction involving the SLC25A46 cytosolic face. We validate these newly identified interaction interfaces and show that they play a role in mitochondrial network maintenance.

Preliminary Analysis of Solute Carrier Family in Nucleotide Rescue Synthesis in Glioma

Glioma is a highly proliferative and aggressive tumor type that arises from glial cells in the central nervous system. The nucleotides required for the proliferation and replication of glioma cells are crucial to their pathogenesis and often cannot be synthesized entirely de novo by tumor cells. These nucleotides must be taken up from the extracellular milieu to achieve the purpose of proliferation, a process that is mediated by solute carriers in the SLC28, SLC29, and SLC43 families. The expression of these solute carriers is linked to the proliferation of glioma cells, indicating their key role in glioma metabolism. Understanding the mechanisms underlying nucleotide transport and metabolism in gliomas may lead to the development of novel therapeutics that target these metabolic pathways and improve the prognosis for patients with glioma. Solute carrier family SLC28-, SLC29-, and SLC43-mediated nucleotide transport is involved in the proliferation of glioma and plays an important role in the proliferation and invasion of glioma. Among them, SLC43A3 is a potential biomarker for glioma proliferation, and the data presented here provide evidence for solute carrier involvement in glioma metabolism and construct a prognostic model.

SLC13A3 is a major effector downstream of activated β-catenin in liver cancer pathogenesis

Activated Wnt/β-catenin pathway is a key genetic event in liver cancer development. Solute carrier (SLC) transporters are promising drug targets. Here, we identify SLC13A3 as a drug-targetable effector downstream of β-catenin in liver cancer. SLC13A3 expression is elevated in human liver cancer samples with gain of function (GOF) mutant CTNNB1, the gene encoding β-catenin. Activation of β-catenin up-regulates SLC13A3, leading to intracellular accumulation of endogenous SLC13A3 substrates. SLC13A3 is identified as a low-affinity transporter for glutathione (GSH). Silencing of SLC13A3 downregulates the leucine transporter SLC7A5 via c-MYC signaling, leading to leucine depletion and mTOR inactivation. Furthermore, silencing of SLC13A3 depletes GSH and induces autophagic ferroptosis in β-catenin-activated liver cancer cells. Importantly, both genetic inhibition of SLC13A3 and a small molecule SLC13A3 inhibitor suppress β-catenin-driven hepatocarcinogenesis in mice. Altogether, our study suggests that SLC13A3 could be a promising therapeutic target for treating human liver cancers with GOF CTNNB1 mutations.

Membrane transport of rare earth metal ions N, N’-bisdioctylphosphorylmethyl-1,4-diaminobutane by the active transport mechanism

The method of membrane extraction for rare earth elements (REE) using the carrier N, N’-bisdioctylphosphorylmethyl-1,4-diaminobutane (DPDA-8) ions, leveraging an active transport mechanism, has been optimized. The distribution of DPDA-8 within the membrane pores was confirmed using scanning electron microscopy (SEM). Both light and heavy REE extractions from a simulated solution using DPDA-8 and trioctylphosphine oxide (TOPO) in 1,2-dichlorobenzene were explored. The influence of feed solution pH, carrier and anion concentration, supported liquid membrane (SLM) type and stability, and cell temperature, among other parameters, were meticulously examined. The results indicate a decrease in permeability with a decrease in feed solution pH attributed to competitive acid transport through the membrane. Additionally, the formation of H-complexes between carriers and perchloric or phosphoric acids was investigated using Fourier Transform Infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques. Changes in the stretching bands of amino and phosphine oxide groups in DPDA-8 were monitored and characterized. XRD analysis of the crystal structures of salts DPDA-6·ClO4 and DPDA-12·H2PO4 revealed a two-dimensional layered supramolecular organization with varying anion positions relative to hydrophobic fragments. The DPDA-8 carrier demonstrated significantly higher permeability values compared to TOPO, with differences in permeability exceeding twofold for certain metals. FTIR spectroscopy identified the main coordination centers of DPDA-8 during the liquid–liquid extraction of specific REEs.

Non-syndromic congenital sideroblastic anaemia; phenotype, and genotype of 15 Indian patients.

Sideroblastic anaemias are a diverse group of congenital and acquired bone marrow failure disorders marked by the presence of ring sideroblasts, ineffective erythropoiesis, and systemic iron overload. Congenital Sideroblastic anaemia (CSA) is mainly caused by gene mutations associated with heme synthesis, iron-sulfur [Fe-S] cluster, and mitochondrial protein synthesis pathways. The most prevalent form of CSA is caused by mutations in the erythroid-specific -amino levulinate synthase (ALAS2) gene, which encodes the first enzyme in the heme synthesis pathway in red blood cells. The second most prevalent form of CSA is caused by a mutation in the Solute carrier family 25 member 38 (SLC25A38) gene, which codes for an erythroid-specific protein of the inner mitochondrial membrane. Additionally, 15-20 genes are altogether associated with CSA. In this study, we aim to identify the CSA patients, understand their genetics and establish genotype-phenotype correlation. We have identified fifteen cases of CSA using our targeted NGS (t-NGS) panel. The major clinical findings in our cohort were microcytic anaemia, ring sideroblasts, and dyserythropoiesis in the bone marrow. Currently, two patients are responsive to pyridoxine, while the rest are on blood transfusion support. We have identified ten variants in three different genes of CSA (ALAS2, SLC25A38 & HSPA9). Five patients harbour four hemizygous variants- p.Ala282Ser, p.Arg170Cys, p.Arg204Gln and exon 2 duplication in the ALAS2 gene. In seven patients, we have identified three homozygous mutations - p.Pro190Arg, p.Arg187Gln and p.Arg134Cys in the SLC25A38 gene. These mutations have been predominantly identified in the European population. Three patients revealed three heterozygous variants p. Thr463Ile, D326Tyr, and Arg284Trp in the HSPA9 gene. PyMoL was used to evaluate the functional effects of these variations and understand their effect on the structure of the protein. We believe that by combining a bone marrow examination with genetic sequencing, CSA patients can acquire a definitive diagnosis.

Knockout of the orphan membrane transporter Slc22a23 leads to a lean and hyperactive phenotype with a small hippocampal volume.

Epidemiological studies suggest that poor nutrition during pregnancy predisposes offspring to the development of lifestyle-related noncommunicable diseases and psychiatric disorders later in life. However, the molecular mechanisms underlying this predisposition are not well understood. In our previous study, using rats as model animals, we showed that behavioral impairments are induced by prenatal undernutrition. In this study, we identified solute carrier 22 family member 23 (Slc22a23) as a gene that is irreversibly upregulated in the rat brain by undernutrition during fetal development. Because the substrate of the SLC22A23 transporter has not yet been identified and the biological role of the Slc22a23 gene in vivo is not fully understood, we generated pan-Slc22a23 knockout rats and examined their phenotype in detail. The Slc22a23 knockout rats showed a lean phenotype, an increase in spontaneous locomotion, and improved endurance, indicating that they are not overweight and are even healthier in an ad libitum feeding environment. However, the knockout rats had reduced hippocampal volume, and the behavioral analysis suggested that they may have impaired cognitive function regarding novel objects.

Mitochondrial related variants associated with cardiovascular traits.

Cardiovascular disease (CVD) is responsible for over 30% of mortality worldwide. CVD arises from the complex influence of molecular, clinical, social, and environmental factors. Despite the growing number of autosomal genetic variants contributing to CVD, the cause of most CVDs is still unclear. Mitochondria are crucial in the pathophysiology, development and progression of CVDs; the impact of mitochondrial DNA (mtDNA) variants and mitochondrial haplogroups in the context of CVD has recently been highlighted. We investigated the role of genetic variants in both mtDNA and nuclear-encoded mitochondrial genes (NEMG) in CVD, including coronary artery disease (CAD), hypertension, and serum lipids in the UK Biobank, with sub-group analysis for diabetes. We investigated 371,542 variants in 2,527 NEMG, along with 192 variants in 32 mitochondrial genes in 381,994 participants of the UK Biobank, stratifying by presence of diabetes. Mitochondrial variants showed associations with CVD, hypertension, and serum lipids. Mitochondrial haplogroup J was associated with CAD and serum lipids, whereas mitochondrial haplogroups T and U were associated with CVD. Among NEMG, variants within Nitric Oxide Synthase 3 (NOS3) showed associations with CVD, CAD, hypertension, as well as diastolic and systolic blood pressure. We also identified Translocase Of Outer Mitochondrial Membrane 40 (TOMM40) variants associated with CAD; Solute carrier family 22 member 2 (SLC22A2) variants associated with CAD and CVD; and HLA-DQA1 variants associated with hypertension. Variants within these three genes were also associated with serum lipids. Our study demonstrates the relevance of mitochondrial related variants in the context of CVD. We have linked mitochondrial haplogroup U to CVD, confirmed association of mitochondrial haplogroups J and T with CVD and proposed new markers of hypertension and serum lipids in the context of diabetes. We have also evidenced connections between the etiological pathways underlying CVDs, blood pressure and serum lipids, placing NOS3, SLC22A2, TOMM40 and HLA-DQA1 genes as common nexuses.

DNA Methylation in Recurrent Glioblastomas: Increased TEM8 Expression Activates the Src/PI3K/AKT/GSK-3β/B-Catenin Pathway.

Glioblastomas (GBM) are infiltrative malignant brain tumors which mostly recur within a year's time following surgical resection and chemo-radiation therapy. Studies on glioblastoma cells following radio-chemotherapy, have been demonstrated to induce trans-differentiation, cellular plasticity, activation of DNA damage response and stemness. As glioblastomas are heterogenous tumors that develop treatment resistance and plasticity, we investigated if there exist genome-wide DNA methylation changes in recurrent tumors. Utilizing genome-wide DNA methylation arrays, we compared the DNA methylation profile of 11 primary (first occurrence) tumors with 13 recurrent (relapsed) GBM, to delineate the contribution of epigenetic changes associated with therapy exposure, therapy resistance, and relapse of disease. Our data revealed 1,224 hypermethylated- and 526 hypomethylated-probes in recurrent glioblastomas compared to primary disease. We found differential methylation of solute carrier and ion channel genes, interleukin receptor/ligand genes, tumor-suppressor genes and genes associated with metastasis. We functionally characterized one such hypomethylated-up-regulated gene, namely anthrax toxin receptor 1/tumor endothelial marker 8 (ANTXR1/TEM8), whose expression was validated to be significantly up-regulated in recurrent glioblastomas compared to primary tumors and confirmed by immunohistochemistry. Using overexpression and knockdown approaches, we showed that TEM8 induces proliferation, invasion, migration, and chemo-radioresistance in glioblastoma cells. Additionally, we demonstrated a novel mechanism of β-catenin stabilization and activation of the β-catenin transcriptional program due to TEM8 overexpression via a Src/PI3K/AKT/GSK3β/β-catenin pathway. We report genome-wide DNA methylation changes in recurrent GBM and suggest involvement of the TEM8 gene in GBM recurrence and progression.

Low expression of thiamine pyrophosphokinase-1 contributes to brain susceptibility to thiamine deficiency.

Thiamine deficiency is a well-known risk factor for the development of severe encephalopathy, such as Wernicke encephalopathy and Korsakoff syndrome, but the underlying mechanism is still mysterious. This study aims to investigate the expression levels of thiamine metabolism genes in different tissues and their impact on brain susceptibility to thiamine deficiency. The mRNA and protein levels of four genes known to be associated with thiamine metabolism: thiamine pyrophosphokinase-1 (Tpk), Solute carrier family 19 member 2 (Slc19a2), Slc19a3, and Slc25a19, in the brain, kidney, and liver of mice were examined. Thiamine diphosphate (TDP) levels were measured in these tissues. Mice were subjected to dietary thiamine deprivation plus pyrithiamine (PTD), a specific TPK inhibitor, or pyrithiamine alone to observe the reduction in TDP and associated pathological changes. TPK mRNA and protein expression levels were lowest in the brain compared to the kidney and liver. Correspondingly, TDP levels were also lowest in the brain. Mice treated with PTD or pyrithiamine alone showed an initial reduction in brain TDP levels, followed by reductions in the liver and kidney. PTD treatment caused significant neuron loss, neuroinflammation, and blood-brain barrier disruption, whereas dietary thiamine deprivation alone did not. TPK expression level is the best indicator of thiamine metabolism status. Low TPK expression in the brain appears likely to contribute to brain susceptibility to thiamine deficiency, underscoring a critical role of TPK in maintaining cerebral thiamine metabolism and preventing thiamine deficiency-related brain lesions.

The Neuroprotective and Anxiolytic Effects of Magnesium Sulfate on Retinal Dopaminergic Neurons in 6-OHDA-Induced Parkinsonian Rats: A Pilot Study.

This study investigates the protective effects of magnesium sulfate on dopamine neurons in the retinas of rats with 6-hydroxydopamine (6-OHDA)-induced Parkinson's disease (PD). Rapidly progressing cognitive decline often precedes or coincides with the motor symptoms associated with PD. PD patients also frequently exhibit visual function abnormalities. However, the specific mechanisms underlying visual dysfunction in PD patients are not yet fully understood. Therefore, this study aims to investigate whether magnesium homeostasis affects dopaminergic neurons in the retina of PD rats. Thirty-six rats were divided into four groups: (1) control, (2) control with magnesium sulfate (control/MgSO4), (3) Parkinson's disease (PD), and (4) Parkinson's disease with magnesium sulfate (PD/MgSO4). The apomorphine-induced (APO) rotation test assessed the success of the PD models. The open-field experiment measured the rats' anxiety levels. Tyrosine hydroxylase (TH) and glutamate levels, indicators of dopamine neuron survival, were detected using immunofluorescence staining. Protein levels of solute carrier family 41 A1 (SCL41A1), magnesium transporter 1 (MagT1), and cyclin M2 (CNNM2) in the retina were analyzed using Western blot. Results showed that, compared to the PD group, rats in the PD/MgSO4 group had improved psychological states and motor performance at two and four weeks post-surgery. The PD/MgSO4 group also exhibited significantly higher TH fluorescence intensity in the left retinas and lower glutamate fluorescence intensity than the PD group. Additional experiments indicated that the protein levels of SLC41A1, MagT1, and CNNM2 were generally higher in the retinas of the PD/MgSO4 group, along with an increase in retinal magnesium ion content. This suggests that magnesium sulfate may reduce glutamate levels and protect dopamine neurons in the retina. Thus, magnesium sulfate might have therapeutic potential for visual functional impairments in PD patients.

WNKs and Sodium Transporter Function in Solute Exchange with Implications for Blood Pressure Regulation as Elucidated through Drosophila.

Like other multicellular organisms, the fruit fly Drosophila melanogaster must maintain homeostasis of the internal milieu, including the maintenance of constant ion and water concentrations. In mammals, the WNK-SPAK/OSR1 (With No Lysine (K)- Ste20-proline/alanine rich kinase/oxidative stress response 1) kinase cascade is an important regulator of epithelial ion transport in the kidney. This pathway regulates SLC12 family cotransporters, including sodium-potassium-2-chloride (NKCC), sodium chloride (NCC) and potassium chloride (KCC) cotransporters. The WNK-SPAK/OSR1 kinase cascade also regulates epithelial ion transport via regulation of the Drosophila NKCC in the Malpighian tubule, the renal epithelium of the fly. Studies in Drosophila have contributed to the understanding of multiple regulators of WNK pathway signaling, including intracellular chloride and potassium, the scaffold protein Mo25, hypertonic stress, hydrostatic pressure, and macromolecular crowding. These will be discussed, together with implications for mammalian kidney function and blood pressure control.

Mechanism of proton transport in SLC25 family proteins

Mechanism of proton transport in SLC25 family proteins

Upregulated solute-carrier family genes in the hippocampus of schizophrenia can be rescued by antipsychotic medications

Background and hypothesisOur previous studies have found that functional changes in the hippocampal circuit from dentate gyrus (DG) to cornu ammonis 3 and 1 (CA3, CA1) are highly associated with schizophrenia (SZ). However, no studies have explored the genetic expression across the three and two human hippocampal subfields (DG-CA3-CA1 and CA3-CA1) between subjects with SZ and healthy controls (CT). Study designWe matched cohorts between CT (n = 13) and SZ (n = 13). Among SZ, 6 subjects were on antipsychotics (AP) while 7 were off AP. We combined RNA-seq data from all three and two hippocampal subfields and performed differentially expressed gene analyses across DG-CA3-CA1 and CA3-CA1 affected by either SZ or AP. Study resultsWe found that differentially expressed genes (DEGs) from effects of SZ and AP across DG-CA3-CA1 and CA3-CA1 were highly associated with gene ontology terms related to hormonal and immune signaling, cellular mitosis and apoptosis, ion and amino acid transports, and protein modification and degradation. Additionally, we found that multiple genes related to solute-carrier family and immune signaling were significantly upregulated across DG-CA3-CA1 and CA3-CA1 in patients with SZ relative to CT, and AP consistently and robustly repressed the expression of these upregulated genes in the DG-CA3-CA1 and CA3-CA1 from subjects with SZ. ConclusionsTogether, these data suggest that the upregulated solute-carrier family genes in the hippocampus might have important roles in the pathophysiology of SZ, and that AP may reduce the symptoms of psychosis in SZ via rescuing the solute-carrier gene expression.

Sea buckthorn extract mitigates chronic obstructive pulmonary disease by suppression of ferroptosis via scavenging ROS and blocking p53/MAPK pathways

Ethnopharmacological relevanceSea buckthorn (Hippophae rhamnoides), a traditional Tibetan medicinal herb, exhibits protective effects against cardiovascular and respiratory diseases. Although Sea buckthorn extract (SBE) has been confirmed to alleviate airway inflammation in mice, its therapeutic effect and underlying mechanism on chronic obstructive pulmonary disease (COPD) requires further clarification. Aim of the studyTo elucidate the alleviative effect and molecular mechanism of SBE on lipopolysaccharides (LPS)/porcine pancreatic elastase (PPE)-induced COPD by blocking ferroptosis. MethodsThe anti-ferroptotic effects of SBE were evaluated in human BEAS-2B bronchial epithelial cells using CCK8, RT-qPCR, western blotting, and transmission electron microscopy. Transwell was employed to detect chemotaxis of neutrophils. COPD model was induced by intranasally administration of LPS/PPE in mice and measured by alterations of histopathology, inflammation, and ferroptosis. RNA-sequencing, western blotting, antioxidant examination, flow cytometry, DARTS, CETSA, and molecular docking were then used to investigate its anti-ferroptotic mechanisms. ResultsIn vitro, SBE not only suppressed erastin- or RSL3-induced ferroptosis by suppressing lipid peroxides (LPOs) production and glutathione (GSH) depletion, but also suppressed ferroptosis-induced chemotactic migration of neutrophils via reducing mRNA expression of chemokines. In vivo, SBE ameliorated LPS/PPE-induced COPD phenotypes, and inhibited the generation of LPOs, cytokines, and chemokines. RNA-sequencing showed that p53 pathway and mitogen-activated protein kinases (MAPK) pathway were implicated in SBE-mediated anti-ferroptotic action. SBE repressed erastin- or LPS/PPE-induced overactivation of p53 and MAPK pathway, thereby decreasing expression of diamine acetyltransferase 1 (SAT1) and arachidonate 15-lipoxygenase (ALOX15), and increasing expression of glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11). Mechanistically, erastin-induced elevation of reactive oxygen species (ROS) was reduced by SBE through directly scavenging free radicals, thereby contributing to its inhibition of p53 and MAPK pathways. CETSA, DARTS, and molecular docking further showed that ROS-generating enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) may be the target of SBE. Overexpression of NOX4 partially impaired the anti-ferroptotic activity of SBE. ConclusionOur results demonstrated that SBE mitigated COPD by suppressing p53 and MAPK pro-ferroptosis pathways via directly scavenging ROS and blocking NOX4. These findings also supported the clinical application of Sea buckthorn in COPD therapy.