Activity Of Cells Research Articles

Biomimetic “nano-spears” for CAFs-targeting: splintered three “shields” with enhanced cisplatin anti-TNBC efficiency

The treatment dilemma of triple-negative breast cancer (TNBC) revolves around drug resistance and metastasis. Cancer-associated fibroblasts (CAFs) contribute to cisplatin (Cis) resistance and further metastasis in TNBC, making TNBC a difficult-to-treat disease. The dense stromal barrier which restricts drug delivery, invasive phenotype of tumor cells, and immunosuppressive tumor microenvironment (TME) induced by CAFs serve as three “shields” for TNBC against Cis therapy. Here, we designed a silybin-loaded biomimetic nanoparticle coated with anisamide-modified red blood cell membrane (ARm@SNP) as a “nanospear” for CAFs-targeting, which could shatter the “shields” and significantly exhibit inhibitory effect on 4T1 cells in combination with Cis both in vitro and in vivo. The ARm@SNP/Cis elicited 4T1 tumor growth arrest and destroyed three “shields” as follows: disintegrating the stromal barrier by inhibiting blood vessels growth and the expression of fibronectin; decreasing 4T1 cell invasion and metastasis by affecting the TGF-β/Twist/EMT pathway which impeded EMT activation; reversing the immunosuppressive microenvironment by increasing the activity and infiltration of immunocompetent cells. Based on CAFs-targeting, ARm@SNP reversed the resistance of Cis, remodeled the TME and inhibited invasion and metastasis while significantly improving the therapeutic effect of Cis on 4T1 tumor-bearing mice, providing a promising approach for treating intractable TNBC.

Dopamine‑iron homeostasis interaction rescues mitochondrial fitness in Parkinson's disease

Imbalances of iron and dopamine metabolism along with mitochondrial dysfunction have been linked to the pathogenesis of Parkinson's disease (PD). We have previously suggested a direct link between iron homeostasis and dopamine metabolism, as dopamine can increase cellular uptake of iron into macrophages thereby promoting oxidative stress responses. In this study, we investigated the interplay between iron, dopamine, and mitochondrial activity in neuroblastoma SH-SY5Y cells and human induced pluripotent stem cell (hiPSC)-derived dopaminergic neurons differentiated from a healthy control and a PD patient with a mutation in the α-synuclein (SNCA) gene. In SH-SY5Y cells, dopamine treatment resulted in increased expression of the transmembrane iron transporters transferrin receptor 1 (TFR1), ferroportin (FPN), and mitoferrin2 (MFRN2) and intracellular iron accumulation, suggesting that dopamine may promote iron uptake. Furthermore, dopamine supplementation led to reduced mitochondrial fitness including decreased mitochondrial respiration, increased cytochrome c control efficiency, reduced mtDNA copy number and citrate synthase activity, increased oxidative stress and impaired aconitase activity. In dopaminergic neurons derived from a healthy control individual, dopamine showed comparable effects as observed in SH-SY5Y cells. The hiPSC-derived PD neurons harboring an endogenous SNCA mutation demonstrated altered mitochondrial iron homeostasis, reduced mitochondrial capacity along with increased oxidative stress and alterations of tricarboxylic acid cycle linked metabolic pathways compared with control neurons. Importantly, dopamine treatment of PD neurons promoted a rescue effect by increasing mitochondrial respiration, activating antioxidant stress response, and normalizing altered metabolite levels linked to mitochondrial function. These observations provide evidence that dopamine affects iron homeostasis, intracellular stress responses and mitochondrial function in healthy cells, while dopamine supplementation can restore the disturbed regulatory network in PD cells.

Sesquiterpene coumarins with anti-vitiligo and cytotoxic activities from Ferula samarkandica

Two undescribed sesquiterpene coumarins (1–2) and eight known analogues (3–10) were isolated from the roots of Ferula samarkandica Korovin, growing in Uzbekistan. Their structures were established by comprehensive spectroscopic analysis including NMR, HRESIMS, UV and IR data. The absolute configurations were determined based on ECD calculations and confirmed by single-crystal X-ray diffraction analysis. Six compounds carrying 7′-carbonyl, 3′-carbonyl and 3′-acetoxy (4, 5, 6, 7, 9, 10) demonstrated anti-vitiligo potentials, in addition to five (4, 7, 8, 9, 10) with cytotoxic effects. Evaluation of anti-vitiligo activity in B16 cells revealed that compounds 4–7 and 9 exhibited promotion effects on melanin synthesis in B16 cells more potent than the positive control 8-methoxypsoralen (8-MOP), while 5, 7, 9 and 10 could also stimulate the tyrosinase activity superior to 8-MOP. Besides, compounds 4 and 7–10 also presented certain cytotoxic activities against HeLa, HT-29 and A549 cell lines, wherein 8 displayed a significant cytotoxicity against HT-29 cells with an IC50 value of 8.33 ± 0.34 μM.

Isolation of flavonoids from Tagetes patula(French Marigold) flowers: Cytotoxic and oxidant activity in human cervical carcinoma cells

Isolation of flavonoids from Tagetes patula(French Marigold) flowers: Cytotoxic and oxidant activity in human cervical carcinoma cells

Verification of the analytical performance of the serum magnesium assay on Abbott Architect ci8200

Magnesium is recognized as the fourth most important cation in the body and the second most abundant intracellular cation, following potassium. Its physiological significance lies in its capacity to form complexes with crucial intracellular anionic ligands, notably ATP, and its ability to compete with calcium for specific binding sites on proteins and cell membranes. Over 300 enzyme reactions rely on magnesium. The concentration of free magnesium within cells determines the magnesium content of these enzymes. Magnesium influences myocardial contraction and the electrical activity of myocardial cells, as well as the specialized conduction systems of the fetus, by modulating the transmembrane movements of ions like sodium, potassium, and calcium. Furthermore, magnesium can affect the contractility of vascular smooth muscle, and alterations in intracellular magnesium levels may impact cell proliferation or contraction. Magnesium is involved in nucleic acid and protein metabolism, intermediary metabolism, energy production, and consumption reactions, and it plays specific roles in various physiological systems such as the neuromuscular and cardiovascular systems. Our research aims to assess the analytical accuracy of the serum magnesium assay method utilizing an Abbott kit on the Architect ci8200 automated system in the biochemistry laboratory of Mohammed VI University Hospital of Oujda. The evaluation of the kit's analytical accuracy was conducted within the flexible scope A by conducting a performance analysis on the Architect ci8200. We examined repeatability, reproducibility, measurement imprecision, and compared results between two Architect ci8200 instruments. All findings align with the acceptability criteria recommended by the supplier and the Valtec protocol of the Société Française de Biologie Clinique (SFBC), indicating overall satisfactory outcomes for the study. The Architect ci8200 automated system demonstrated satisfactory analytical performance for reliably determining serum magnesium levels. Method verification in medical laboratories is essential to guarantee the accuracy, precision, and reliability of test results. Verification entails confirming that the test method used is suitable for its intended purpose, yields result consistent with the claimed performance characteristics, and meets the laboratory's quality control and quality assurance standards.

Regulation of the mouse ventral tegmental area by melanin-concentrating hormone.

Melanin-concentrating hormone (MCH) acts via its sole receptor MCHR1 in rodents and is an important regulator of homeostatic behaviors like feeding, sleep, and mood to impact overall energy balance. The loss of MCH signaling by MCH or MCHR1 deletion produces hyperactive mice with increased energy expenditure, and these effects are consistently associated with a hyperdopaminergic state. We recently showed that MCH suppresses dopamine release in the nucleus accumbens, which principally receives dopaminergic projections from the ventral tegmental area (VTA), but the mechanisms underlying MCH-regulated dopamine release are not clearly defined. MCHR1 expression is widespread and includes dopaminergic VTA cells. However, as the VTA is a neurochemically diverse structure, we assessed Mchr1 gene expression at glutamatergic, GABAergic, and dopaminergic VTA cells and determined if MCH inhibited the activity of VTA cells and/or their local microcircuit. Mchr1 expression was robust in major VTA cell types, including most dopaminergic (78%) or glutamatergic cells (52%) and some GABAergic cells (38%). Interestingly, MCH directly inhibited dopaminergic and GABAergic cells but did not regulate the activity of glutamatergic cells. Rather, MCH produced a delayed increase in excitatory input to dopamine cells and a corresponding decrease in GABAergic input to glutamatergic VTA cells. Our findings suggested that MCH may acutely suppress dopamine release while disinhibiting local glutamatergic signaling to restore dopamine levels. This indicated that the VTA is a target of MCH action, which may provide bidirectional regulation of energy balance.Significance Statement Role of melanin-concentrating hormone (MCH) on energy balance may converge on the dopamine system via the mesolimbic pathway, as loss of MCH or MCH receptor (MCHR1) signaling increases hyperactivity and energy expenditure associated with a hyperdopaminergic state. MCH can suppress dopamine release within the mesolimbic pathway, but its underlying mechanism is not known. We thus determined if MCH could inhibit dopamine release through direct actions within the ventral tegmental area (VTA). We found that MCH directly inhibited dopaminergic VTA cells, but MCH also disinhibited excitatory input to dopamine cells. Therefore, we showed that the VTA is a putative target site supporting dopamine-dependent actions of MCH.

Discovery and Optimization of N-Arylated Tetracyclic Dicarboximides That Target Primary Glioma Stem-like Cells.

We recently discovered a novel N-aryl tetracyclic dicarboximide MM0299 (1) with robust activity against glioma stem-like cells that potently and selectively inhibits lanosterol synthase leading to the accumulation of the toxic shunt metabolite 24(S),25-epoxycholesterol. Herein, we delineate a systematic and comprehensive SAR study that explores the structural space surrounding the N-aryl tetracyclic dicarboximide scaffold. A series of 100 analogs were synthesized and evaluated for activity against the murine glioma stem-like cell line Mut6 and for metabolic stability in mouse liver S9 fractions. This study led to several analogs with single-digit nanomolar activity in Mut6 glioblastoma cells that were metabolically stable in S9 fractions. In vivo pharmacokinetic analysis of selected analogs identified compound 52a (IC50 = 63 nM; S9 T1/2 > 240 min) which was orally available (39% plasma; 58% brain) and displayed excellent brain exposure. Chronic oral dosing of 52a during a 2-week tolerability study indicated no adverse effect on body weight nor signs of hematologic, liver, or kidney toxicity.

Heterogeneous distribution of mitochondria and succinate dehydrogenase activity in human airway smooth muscle cells

AbstractSuccinate dehydrogenase (SDH) is a key mitochondrial enzyme involved in the tricarboxylic acid cycle, where it facilitates the oxidation of succinate to fumarate, and is coupled to the reduction of ubiquinone in the electron transport chain as Complex II. Previously, we developed a confocal‐based quantitative histochemical technique to determine the maximum velocity of the SDH reaction (SDHmax) in single cells and observed that SDHmax corresponds with mitochondrial volume density. In addition, mitochondrial volume and motility varied within different compartments of human airway smooth muscle (hASM) cells. Therefore, we hypothesize that the SDH activity varies relative to the intracellular mitochondrial volume within hASM cells. Using 3D confocal imaging of labeled mitochondria and a concentric shell method for analysis, we quantified mitochondrial volume density, mitochondrial complexity index, and SDHmax relative to the distance from the nuclear membrane. The mitochondria within individual hASM cells were more filamentous in the immediate perinuclear region and were more fragmented in the distal parts of the cell. Within each shell, SDHmax also corresponded to mitochondrial volume density, where both peaked in the perinuclear region and decreased in more distal parts of the cell. Additionally, when normalized to mitochondrial volume, SDHmax was lower in the perinuclear region when compared to the distal parts of the cell. In summary, our results demonstrate that SDHmax measures differences in SDH activity within different cellular compartments. Importantly, our data indicate that mitochondria within individual cells are morphologically heterogeneous, and their distribution varies substantially within different cellular compartments, with distinct functional properties.

Adenovirus-mediated expression of MOAP-1, Bax and RASSF1A antagonizes chemo-drug resistance of human breast cancer cells expressing cancer stem cell markers

Cancer is one of the major leading causes of mortality globally and chemo-drug-resistant cancers pose significant challenges to cancer treatment by reducing patient survival rates and increasing treatment costs. Although the mechanisms of chemoresistance vary among different types of cancer, cancer cells are known to share several hallmarks, such as their resistance to apoptosis as well as the ability of cancer stem cells to produce metastatic daughter cells that are resistant to chemotherapy. To address the issue of chemo-drug resistance in cancer cells, a tetracistronic expression construct, Ad-MBR-GFP, encoding adenovirus-mediated expression of MOAP-1, Bax, RASSSF1A, and GFP, was generated to investigate its potential activity in reducing or inhibiting the chemo-drug resistant activity of the human breast cancer cells, MCF-7-CR and MDA-MB-231. When infected by Ad-MBR-GFP, the cancer cells exhibited round cell morphology and nuclei condensation with positive staining for annexin-V. Furthermore, our results showed that both MCF-7-CR and MDA-MB-231 cells stained positively for CD 44 and negatively for CD 24 (CD44+/CD24-) with high levels of endogenous ALDH activity whereas SNU-1581 breast cancer cells were identified as CD 44-/CD 24- cells with relatively low levels of endogenous ALDH activity and high sensitivity toward chemo-drugs, suggesting that both CD 44 and ALDH activity contribute to chemo-drug resistance. Moreover, both MCF-7-CR and MDA-MB-231 cells showed strong chemo-drug sensitivity to cisplatin when the cells were infected by Ad-MBR-GFP, leading to 9-fold and 2-fold reduction in the IC 50 values when compared to cisplatin treatment alone, respectively. The data were further supported by 3D (soft agar) and spheroid cell models of MCF-7-CR and MDA-MB-231 cells which showed a 2-fold reduction of a number of cell colonies and spheroid size when treated with both Ad-MBR-GFP and cisplatin, and compared to control. Other than chemo-sensitivity, Ad-MBR-GFP-infected cancer cells retarded cell migration. Flow cytometry analysis showed that the mechanism of action of Ad-MBR-GFP involved cell cycle arrest at the G1 phase and inhibition of cellular DNA synthesis. Taken together, our investigation showed that Ad-MBR-GFP mediated chemo-drug sensitization in the infected cancer cells involved the activation of apoptosis signaling, cell cycle arrest, and inhibition of DNA synthesis, suggesting that Ad-MBR-GFP is potentially efficacious for the treatment of chemo-drug resistant cancers.

Lysophosphatidic Acid Stimulates Mitogenic Activity and Signaling in Human Neuroblastoma Cells through a Crosstalk with Anaplastic Lymphoma Kinase

Lysophosphatidic acid (LPA) is a well-documented pro-oncogenic factor in different cancers, but relatively little is known on its biological activity in neuroblastoma. The LPA effects and the participation of the tyrosine kinase receptor anaplastic lymphoma kinase (ALK) in LPA mitogenic signaling were studied in human neuroblastoma cell lines. We used light microscopy and [3H]-thymidine incorporation to determine cell proliferation, Western blot to study intracellular signaling, and pharmacological and molecular tools to examine the role of ALK. We found that LPA stimulated the growth of human neuroblastoma cells, as indicated by the enhanced cell number, clonogenic activity, and DNA synthesis. These effects were curtailed by the selective ALK inhibitors NPV-TAE684 and alectinib. In a panel of human neuroblastoma cell lines harboring different ALK genomic status, the ALK inhibitors suppressed LPA-induced phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2), which are major regulators of cell proliferation. ALK depletion by siRNA treatment attenuated LPA-induced ERK1/2 activation. LPA enhanced ALK phosphorylation and potentiated ALK activation by the ALK ligand FAM150B. LPA enhanced the inhibitory phosphorylation of the tumor suppressor FoxO3a, and this response was impaired by the ALK inhibitors. These results indicate that LPA stimulates mitogenesis of human neuroblastoma cells through a crosstalk with ALK.

The phosphate starvation response regulator PHR2 antagonizes arbuscule maintenance in Medicago.

Phosphate starvation response (PHR) transcription factors play essential roles in regulating phosphate uptake in plants through binding to the P1BS cis-element in the promoter of phosphate starvation response genes. Recently, PHRs were also shown to positively regulate arbuscular mycorrhizal colonization in rice and lotus by controlling the expression of many symbiotic genes. However, their role in arbuscule development has remained unclear. In Medicago, we previously showed that arbuscule degradation is controlled by two SPX proteins that are highly expressed in arbuscule-containing cells. Since SPX proteins bind to PHRs and repress their activity in a phosphate-dependent manner, we investigated whether arbuscule maintenance is also regulated by PHR. Here, we show that PHR2 is a major regulator of the phosphate starvation response in Medicago. Knockout of phr2 showed reduced phosphate starvation response, symbiotic gene expression, and fungal colonization levels. However, the arbuscules that formed showed less degradation, suggesting a negative role for PHR2 in arbuscule maintenance. This was supported by the observation that overexpression of PHR2 led to enhanced degradation of arbuscules. Although many arbuscule-induced genes contain P1BS elements in their promoters, we found that the P1BS cis-elements in the promoter of the symbiotic phosphate transporter PT4 are not required for arbuscule-containing cell expression. Since both PHR2 and SPX1/3 negatively affect arbuscule maintenance, our results indicate that they control arbuscule maintenance partly via different mechanisms. While PHR2 potentiates symbiotic gene expression and colonization, its activity in arbuscule-containing cells needs to be tightly controlled to maintain a successful symbiosis in Medicago.

Radiation-induced exosomes promote oral squamous cell carcinoma progression via enhancing SLC1A5-glutamine metabolism.

Radiotherapy (RT) can drive cancer cells to enter a state of cellular senescence in which cells can secrete senescence-associated secretory phenotype (SASP) and produce small extracellular vesicles (sEVs) to interact with cells in the tumor microenvironment (TME). Tumor-derived sEVs that are taken up by recipient cells contribute to cancer cell metabolic plasticity, resistance to anticancer therapy, and adaptation to the TME. However, how radiation-induced sEVs support oral squamous cell carcinoma (OSCC) progression remains unclear. Beta-galactosidase staining and SASP mRNA expression analysis were used to evaluate the senescence-associated activity of OSCC cells after irradiation. Nanoparticle tracking analysis was performed to identify radiation-induced sEVs. Liquid chromatography-tandem mass spectrometry (LC-MS) was used to explore changes in the levels of proteins in radiation-induced sEVs. Cell Counting Kit-8 and colony formation assays were performed to investigate the function of radiation-induced SASP and sEVs in vitro. A xenograft tumor model was established to investigate the functions of radiation-induced sEVs and V-9302 in vivo as well as the underlying mechanisms. Bioinformatics analysis was performed to determine the relationship between glutamine metabolism and OSCC recurrence. We determined that the radiation-induced SASP triggered OSCC cell proliferation. Additionally, radiation-induced sEVs exacerbated OSCC cell malignancy. LC-MS/MS and bioinformatics analyses revealed that SLC1A5, which is a cellular receptor that participates in glutamine uptake, was significantly enriched in radiation-induced sEVs. In vitro and in vivo, inhibiting SLC1A5 could block the oncogenic effects of radiation-induced sEVs in OSCC. Radiation-induced sEVs might promote the proliferation of unirradiated cancer cells by enhancing glutamine metabolism; this might be a novel molecular mechanism underlying radiation resistance in OSCC patients.

Dihydroartemisinin suppresses the tumorigenesis of esophageal carcinoma by elevating DAB2IP expression in a NFIC-dependent manner.

Dihydroartemisinin (DHA) has been identified to have the anticancer and anti-inflammatory activities. Disabled homolog 2 interacting protein (DAB2IP) is a well-recognized tumor suppressor. Both DHA and DAB2IP were proven to have suppressing effects on esophageal carcinoma (ESCA) tumorigenesis. However, whether DHA regulated ESCA cells via DAB2IP and its mechanism are still vague. Functional analyses were conducted using MTT, tube formation, sphere formation, and transwell assays in vitro as well as Tumor formation experiments in mice. Levels of genes and proteins were assayed by qRT-PCR and western blotting analyses. The interaction between DAB2IP and Nuclear Factor I C (NFIC) was confirmed using bioinformatics analysis and dual-luciferase reporter assay.DHA treatment suppressed ESCA cell angiogenesis, stemmess, migration, and invasion. DAB2IP level was decreased in ESCA tissues and cells, and DHA elevated DAB2IP expression in ESCA cells. Functionally, DAB2IP overexpression impaired ESCA cell angiogenesis, stemmess, migration and invasion. Mechanistically, NFIC had binding sites on the promoter region and directly targeted DAB2IP. DHA could up-regulate DAB2IP expression via NFIC. Moreover, NFIC was also decreased in ESCA tissues and cells, and its overexpression had anticancer activity in ESCA cells. In addition, DAB2IP knockdown reversed the anticancer effects of NFIC or DHA on ESCA cells. In further in vivo analysis, DHA also suppressed ESCA growth by regulating DAB2IP expression.DHA suppressed the tumorigenesis of ESCA by elevating DAB2IP expression in an NFIC-dependent manner, suggesting the potential clinical application of DHA in ESCA treatment.

Platelet microparticles influence gene expression and modulate biological activities of chronic myeloid leukemia cells (K562).

The current understanding emphasizes the intricate interplay between the Leukemic cell and its environment. Platelet-derived microparticles play a crucial role in facilitating intercellular communication and contribute to the complex landscape of cancer pathology. This study aimed to investigate the influence of platelet-derived microparticles on cell proliferation, apoptosis, and the expression of key genes, including P53, P21, Cyclin D1, Bax, and Bcl-2, within the context of a chronic myeloid leukemia cell line (K562). Platelet-derived microparticles were obtained through centrifugation at various speeds, and their concentration was quantified using the BCA assay. To determine the size and immunophenotypic characteristics of the PMPs, both the DLS technique and flow cytometry were employed. Cell proliferation was assessed using the MTT assay and hemocytometer, and cell cycle analysis was conducted through DNA content evaluation. Real-time PCR was utilized for gene expression analysis of Bax, Bcl-2, Cyclin D1, P53, and P21. Flow cytometry was employed to examine cell apoptosis. The findings revealed that platelet-derived microparticles have the ability to decrease proliferation of the K562 cell line, while not exerting an impact on apoptosis and cell cycle progression. Analysis through real-time PCR indicated an upregulation in the gene expression of P53, P21, and Bcl-2, accompanied by a downregulation in Bax and Cyclin D1. This investigation sheds light on the intricate relationship between chronic myeloid leukemia and its microenvironment, particularly the involvement of platelet-derived microparticles. The study underscores the potential of platelet-derived microparticles to influence cell behavior and gene expression, providing a deeper understanding of their role in CML and its therapeutic implications.

Coordination of actin plus-end dynamics by IQGAP1, formin, and capping protein.

Cell processes require precise regulation of actin polymerization that is mediated by plus-end regulatory proteins. Detailed mechanisms that explain plus-end dynamics involve regulators with opposing roles, including factors that enhance assembly, e.g., the formin mDia1, and others that stop growth (capping protein, CP). We explore IQGAP1's roles in regulating actin filament plus-ends and the consequences of perturbing its activity in cells. We confirm that IQGAP1 pauses elongation and interacts with plus ends through two residues (C756 and C781). We directly visualize the dynamic interplay between IQGAP1 and mDia1, revealing that IQGAP1 displaces the formin to influence actin assembly. Using four-color TIRF, we show that IQGAP1's displacement activity extends to formin-CP "decision complexes," promoting end-binding protein turnover at plus-ends. Loss of IQGAP1 or its plus-end activities disrupts morphology and migration, emphasizing its essential role. These results reveal a new role for IQGAP1 in promoting protein turnover on filament ends and provide new insights into how plus-end actin assembly is regulated in cells.

Antioxidative Potential and Ameliorative Effects of Rice Bran Fermented with Lactobacillus against High-Fat Diet-Induced Oxidative Stress in Mice

Rice bran is an important byproduct of the rice polishing process, rich in nutrients, but it is underutilized and often used as feed or discarded, resulting in a huge amount of waste. In this study, rice bran was fermented by Lactobacillus fermentum MF423 to obtain a product with high antioxidant activity. First, a reliable and efficient method for assessing the antioxidant capacity of the fermentation products was established using high-performance liquid chromatography (HPLC), which ensured the consistency of the batch fermentation. The fermented rice bran product (FLRB) exhibited significant antioxidant activity in cells, C. elegans, and hyperlipidemic mice. Transcriptome analysis of mouse livers showed that the expression of plin5 was upregulated in diabetic mice administered FLRB, thereby preventing the excessive production of free fatty acids (FFAs) and the subsequent generation of large amounts of reactive oxygen species (ROS). These studies lay the foundation for the application of rice bran fermentation products.

Regulation of YAP and Wnt signaling by the endosomal protein MAMDC4.

Maintenance of the intestinal epithelium requires constant self-renewal and regeneration. Tight regulation of proliferation and differentiation of intestinal stem cells within the crypt region is critical to maintaining homeostasis. The transcriptional co-factors β-catenin and YAP are required for proliferation during normal homeostasis as well as intestinal regeneration after injury: aberrant signaling activity results in over proliferation and tumorigenesis. Although both YAP and β-catenin activity are controlled along canonical pathways, it is becoming increasingly clear that non-canonical regulation of these transcriptional regulators plays a role in fine tuning their activity. We have shown previously that MAMDC4 (Endotubin, AEGP), an integral membrane protein present in endosomes, regulates both YAP and β-catenin activity in kidney epithelial cells and in the developing intestinal epithelium. Here we show that MAMDC4 interacts with members of the signalosome and mediates cross-talk between YAP and β-catenin. Interestingly, this cross-talk occurs through a non-canonical pathway involving interactions between AMOT:YAP and AMOT:β-catenin.

Erratum for the Research Article: "TREM2 inhibition triggers antitumor cell activity of myeloid cells in glioblastoma" by Sun et al.

Erratum for the Research Article: "TREM2 inhibition triggers antitumor cell activity of myeloid cells in glioblastoma" by Sun et al.

#1225 Lactate aggravates mitochondrial dysfunction via ALDH2 lactylation in acute kidney injury

Abstract Background and Aims Elevated lactate levels have been recognized as an independent risk factor in acute kidney injury (AKI) contributed by mitochondrial dysfunction. We previously proved the crucial role of acetaldehyde dehydrogenase 2 (ALDH2) in AKI but not focused on the lactate and lactylation of ALDH2. Method We first established a maleic acid (MA) induced AKI model (MA-AKI) in C57BL/6J mice, administrating 2-DG i.p. (a glycolysis inhibitor) or oxamate (a lactate dehydrogenase A inhibitor) to suppress the lactate production. We measured the renal function, mitochondrial function, and lactate in serum and urine, then evaluated the ALDH2 lactylation by co-immunoprecipitation assays, and identified the specific lactation site by mass spectrum. The role of ALDH2 lactylation was explored through point mutation in HEK293 cells. Furthermore, an ALDH2 lactylation eraser was identified, and its function was elucidated in mice and HK-2 cells. Results The elevated lactate in the kidney, serum, and urine showed a significant positive correlation to the serum creatinine (Scr, R2 = 0.83, P < 0.0001) in MA-induced mice. Both 2-DG and oxamate partly abolished the Scr increasing and the proximal tubular histopathological injuries. Increased pan-lactylation in AKI mice was effectively inhibited by oxamate, parallel with increased ALDH2 lactylation in MA-stimulated HK-2 cells. Mass spectrometry identified a single lactylate lysine residue in ALDH2 (K52). The introduction of a point mutation (K52 to R) in ALDH2, mimicking the delactylated state, led to partial recovery of ALDH2 activity (1.11 ± 0.07 vs. 0.68 ± 0.15, P = 0.0029) and mitochondrial function in MA-stimulated HK-2 cells. Additionally, sirt3 was identified as an ALDH2 lactylation eraser, and Honokiol (a sirt3 activator) demonstrated enhanced renal function and mitigation of mitochondrial dysfunction in both MA-induced mice and HK-2 cells. Conclusion Lactate played a crucial role in mitochondrial dysfunction in AKI partly via induction of ALDH2 lactylation, which shed light on the potential target for the therapy.

Effects of rearing systems (cage versus floor) on the microbial composition and transcriptome of goose ileum

There is a gradual transition from water to dryland rearing of geese. In this study, we performed 16S rRNA sequencing (16S rRNA-seq) and transcriptome sequencing (RNA-seq) to reveal the effects of cage rearing (CR) and floor rearing (FR) systems on the microbial composition and transcriptome of the goose ileum. Through 16S rRNA-seq, Linear Discriminant Analysis Effect Size (LEfSe) analysis identified 2 (hgcI_clade and Faecalibacterium) and 14 (Bacteroides, Proteiniphilum, Proteiniclasticum, etc.) differential microbiota in CR and FR, respectively. The rearing system influenced 4 pathways including biosynthesis of amino acids in ileal microbiota. Moreover, we identified 1,198 differentially expressed genes (DEGs) in the ileum mucosa, with 957 genes up-regulated in CR and 241 genes up-regulated in FR. In CR, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed the significant enrichment (p < 0.05) of 28 KEGG pathways, most of which were associated with amino acid metabolism. In FR, up-regulated DEGs were mainly enriched in KEGG pathways associated with cellular processes, including apoptosis, necroptosis, and cellular senescence. Spearman correlation analysis of differential microbiota and amino acid metabolism-related DEGs in CR showed a significant positive correlation. Additionally, differential microbiota of FR, Phascolarctobacterium and Sutterella, were positively correlated with FGF10 (p < 0.05) and PIK3R1 (p < 0.01), respectively. In conclusion, there might be differences in ileal amino acid metabolism levels between CR and FR geese, and the observed increase in harmful bacterial species in FR might impact the activity of ileal cells.