Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 415
Filter
1.
Article in English | MEDLINE | ID: mdl-38726609

ABSTRACT

Objective: Hepatocellular carcinoma (HCC) is a highly lethal cancer with significant mortality, primarily attributed to metastasis. Although Protocadherin Gamma Subfamily A, 9 (PCDHGA9) has been identified as a tumor suppressor gene in cancer metastasis, its role in HCC remains ambiguous. This study aims to clarify the role of PCDHGA9 in HCC by examining its expression, clinical significance, and molecular activities. Methods: Tissue microarray immunofluorescence analysis evaluated the expression of PCDHGA9 and its clinical relevance. In vitro experiments involved manipulating PCDHGA9 levels in SK-HEP-1 cells to assess migration through wound-healing and transwell assays. In vivo, shPCDHGA9 cell injections were utilized to observe effects on tumor growth and metastasis. Protein analysis and Western Blot validated epithelial-mesenchymal transition (EMT)-related proteins. Subsequent to TGF-ß treatment, cell proliferation and apoptosis were quantified using Cell counting kit-8 and flow cytometry, respectively, followed by investigation of TGF-ß effects on PCDHGA9 N6-methyladenosine (m6A) modification via Methylated RNA immunoprecipitation, RT-qPCR, and Western blot analysis. Results: Downregulation of PCDHGA9 expression in HCC tissues is correlated with poor prognosis. In vitro experiments demonstrated that modulating PCDHGA9 expression influenced HCC cell migration. In vivo, PCDHGA9 knockdown is correlated with increased metastasis. Furthermore, TGF-ß stimulation promoted cell proliferation and inhibited apoptosis. Mechanistically, TGF-ß-mediated m6A modification led to PCDHGA9 decay, promoting EMT in HCC cells. Conclusion: PCDHGA9 serves as a potential tumor suppressor in HCC by inhibiting EMT. During this process, TGF-ß is observed to exert regulatory control over m6A modifications of PCDHGA9.

2.
Nat Commun ; 15(1): 3149, 2024 Apr 11.
Article in English | MEDLINE | ID: mdl-38605037

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) develops through step-wise genetic and molecular alterations including Kras mutation and inactivation of various apoptotic pathways. Here, we find that development of apoptotic resistance and metastasis of KrasG12D-driven PDAC in mice is accelerated by deleting Plk3, explaining the often-reduced Plk3 expression in human PDAC. Importantly, a 41-kDa Plk3 (p41Plk3) that contains the entire kinase domain at the N-terminus (1-353 aa) is activated by scission of the precursor p72Plk3 at Arg354 by metalloendopeptidase nardilysin (NRDC), and the resulting p32Plk3 C-terminal Polo-box domain (PBD) is removed by proteasome degradation, preventing the inhibition of p41Plk3 by PBD. We find that p41Plk3 is the activated form of Plk3 that regulates a feed-forward mechanism to promote apoptosis and suppress PDAC and metastasis. p41Plk3 phosphorylates c-Fos on Thr164, which in turn induces expression of Plk3 and pro-apoptotic genes. These findings uncover an NRDC-regulated post-translational mechanism that activates Plk3, establishing a prototypic regulation by scission mechanism.


Subject(s)
Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Humans , Mice , Animals , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/metabolism , Pancreatic Neoplasms/pathology , Carcinoma, Pancreatic Ductal/pathology , Metalloendopeptidases/genetics , Metalloendopeptidases/metabolism
3.
Angew Chem Int Ed Engl ; 63(17): e202319580, 2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38433092

ABSTRACT

Transforming polyolefin waste into liquid alkanes through tandem cracking-alkylation reactions catalyzed by Lewis-acid chlorides offers an efficient route for single-step plastic upcycling. Lewis acids in dichloromethane establish a polar environment that stabilizes carbenium ion intermediates and catalyzes hydride transfer, enabling breaking of polyethylene C-C bonds and forming C-C bonds in alkylation. Here, we show that efficient and selective deconstruction of low-density polyethylene (LDPE) to liquid alkanes is achieved with anhydrous aluminum chloride (AlCl3) and gallium chloride (GaCl3). Already at 60 °C, complete LDPE conversion was achieved, while maintaining the selectivity for gasoline-range liquid alkanes over 70 %. AlCl3 showed an exceptional conversion rate of 5000 g L D P E m o l c a t - 1 h - 1 ${{{\rm g}}_{{\rm L}{\rm D}{\rm P}{\rm E}}{{\rm \ }{\rm m}{\rm o}{\rm l}}_{{\rm c}{\rm a}{\rm t}}^{-1}{{\rm \ }{\rm h}}^{-1}}$ , surpassing other Lewis acid catalysts by two orders of magnitude. Through kinetic and mechanistic studies, we show that the rates of LDPE conversion do not correlate directly with the intrinsic strength of the Lewis acids or steric constraints that may limit the polymer to access the Lewis acid sites. Instead, the rates for the tandem processes of cracking and alkylation are primarily governed by the rates of initiation of carbenium ions and the subsequent intermolecular hydride transfer. Both jointly control the relative rates of cracking and alkylation, thereby determining the overall conversion and selectivity.

4.
Gastroenterology ; 2024 Mar 11.
Article in English | MEDLINE | ID: mdl-38467382

ABSTRACT

BACKGROUND & AIMS: Pancreatic ductal adenocarcinoma (PDAC) has a desmoplastic tumor stroma and immunosuppressive microenvironment. Galectin-3 (GAL3) is enriched in PDAC, highly expressed by cancer cells and myeloid cells. However, the functional roles of GAL3 in the PDAC microenvironment remain elusive. METHODS: We generated a novel transgenic mouse model (LSL-KrasG12D/+;Trp53loxP/loxP;Pdx1-Cre;Lgals3-/- [KPPC;Lgals3-/-]) that allows the genetic depletion of GAL3 from both cancer cells and myeloid cells in spontaneous PDAC formation. Single-cell RNA-sequencing analysis was used to identify the alterations in the tumor microenvironment upon GAL3 depletion. We investigated both the cancer cell-intrinsic function and immunosuppressive function of GAL3. We also evaluated the therapeutic efficacy of GAL3 inhibition in combination with immunotherapy. RESULTS: Genetic deletion of GAL3 significantly inhibited the spontaneous pancreatic tumor progression and prolonged the survival of KPPC;Lgals3-/- mice. Single-cell analysis revealed that genetic deletion of GAL3 altered the phenotypes of immune cells, cancer cells, and other cell populations. GAL3 deletion significantly enriched the antitumor myeloid cell subpopulation with high major histocompatibility complex class II expression. We also identified that GAL3 depletion resulted in CXCL12 upregulation, which could act as a potential compensating mechanism on GAL3 deficiency. Combined inhibition of the CXCL12-CXCR4 axis and GAL3 enhanced the efficacy of anti-PD-1 immunotherapy, leading to significantly inhibited PDAC progression. In addition, deletion of GAL3 also inhibited the basal/mesenchymal-like phenotype of pancreatic cancer cells. CONCLUSIONS: GAL3 promotes PDAC progression and immunosuppression via both cancer cell-intrinsic and immune-related mechanisms. Combined treatment targeting GAL3, CXCL12-CXCR4 axis, and PD-1 represents a novel therapeutic strategy for PDAC.

5.
J Hepatol ; 2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38428643

ABSTRACT

BACKGROUND & AIMS: The PTEN-AKT pathway is frequently altered in extrahepatic cholangiocarcinoma (eCCA). We aimed to evaluate the role of PTEN in the pathogenesis of eCCA and identify novel therapeutic targets for this disease. METHODS: The Pten gene was genetically deleted using the Cre-loxp system in biliary epithelial cells. The pathologies were evaluated both macroscopically and histologically. The characteristics were further analyzed by immunohistochemistry, reverse-transcription PCR, cell culture, and RNA sequencing. Some features were compared to those in human eCCA samples. Further mechanistic studies utilized the conditional knockout of Trp53 and Aurora kinase A (Aurka) genes. We also tested the effectiveness of an Aurka inhibitor. RESULTS: We observed that genetic deletion of the Pten gene in the extrahepatic biliary epithelium and peri-ductal glands initiated sclerosing cholangitis-like lesions in mice, resulting in enlarged and distorted extrahepatic bile ducts in mice as early as 1 month after birth. Histologically, these lesions exhibited increased epithelial proliferation, inflammatory cell infiltration, and fibrosis. With aging, the lesions progressed from low-grade dysplasia to invasive carcinoma. Trp53 inactivation further accelerated disease progression, potentially by downregulating senescence. Further mechanistic studies showed that both human and mouse eCCA showed high expression of AURKA. Notably, the genetic deletion of Aurka completely eliminated Pten deficiency-induced extrahepatic bile duct lesions. Furthermore, pharmacological inhibition of Aurka alleviated disease progression. CONCLUSIONS: Pten deficiency in extrahepatic cholangiocytes and peribiliary glands led to a cholangitis-to-cholangiocarcinoma continuum that was dependent on Aurka. These findings offer new insights into preventive and therapeutic interventions for extrahepatic CCA. IMPACT AND IMPLICATIONS: The aberrant PTEN-PI3K-AKT signaling pathway is commonly observed in human extrahepatic cholangiocarcinoma (eCCA), a disease with a poor prognosis. In our study, we developed a mouse model mimicking cholangitis to eCCA progression by conditionally deleting the Pten gene via Pdx1-Cre in epithelial cells and peribiliary glands of the extrahepatic biliary duct. The conditional Pten deletion in these cells led to cholangitis, which gradually advanced to dysplasia, ultimately resulting in eCCA. The loss of Pten heightened Akt signaling, cell proliferation, inflammation, fibrosis, DNA damage, epigenetic signaling, epithelial-mesenchymal transition, cell dysplasia, and cellular senescence. Genetic deletion or pharmacological inhibition of Aurka successfully halted disease progression. This model will be valuable for testing novel therapies and unraveling the mechanisms of eCCA tumorigenesis.

6.
Toxicol Appl Pharmacol ; 485: 116876, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38437955

ABSTRACT

BACKGROUND: Olanzapine antagonizes dopamine receptors and is prescribed to treat multiple psychiatric conditions. The main side effect of concern for olanzapine is weight gain and metabolic syndrome. Olanzapine induces hyperprolactinemia, however its effect on the mammary gland is poorly documented. METHODS: Rats received olanzapine by gavage or in drinking water at 1, 3, and 6 mg/kg/day for 5-40 days or 100 days, with and without coadministration of bromocriptine or aripiprazole and using once daily or continuous administration strategies. Histomorphology of the mammary gland, concentrations of prolactin, estradiol, progesterone, and olanzapine in serum, mammary gland and adipose tissue, and mRNA and protein expressions of prolactin receptors were analyzed. RESULTS: In adult and prepubescent female rats and male rats, olanzapine induced significant development of mammary glands in dose- and time-dependent manners, with histopathological hyperplasia of mammary ducts and alveoli with lumen dilation and secretion, marked increase of mammary prolactin receptor expression, a marker of breast tissue, and with mild increase of circulating prolactin. This side effect can be reversed after medication withdrawal, but long-term olanzapine treatment for 100 days implicated tumorigenic potentials indicated by usual ductal epithelial hyperplasia. Olanzapine induced mammary development was prevented with the coaddition of the dopamine agonist bromocriptine or partial agonist aripiprazole, or by continuous administration of medication instead of a once daily regimen. CONCLUSIONS: These results shed light on the previously overlooked effect of olanzapine on mammary development and present experimental evidence to support current clinical management strategies of antipsychotic induced side effects in the breast.


Subject(s)
Antipsychotic Agents , Aripiprazole , Benzodiazepines , Bromocriptine , Mammary Glands, Animal , Olanzapine , Prolactin , Animals , Olanzapine/toxicity , Female , Mammary Glands, Animal/drug effects , Mammary Glands, Animal/pathology , Aripiprazole/toxicity , Rats , Prolactin/blood , Antipsychotic Agents/toxicity , Antipsychotic Agents/adverse effects , Benzodiazepines/toxicity , Male , Rats, Sprague-Dawley , Receptors, Prolactin/metabolism , Estradiol/blood , Dose-Response Relationship, Drug , Progesterone/blood , Quinolones/toxicity , Adipose Tissue/drug effects , Adipose Tissue/metabolism , Adipose Tissue/pathology , Piperazines/toxicity
7.
Int J Biol Macromol ; 266(Pt 1): 131113, 2024 May.
Article in English | MEDLINE | ID: mdl-38531524

ABSTRACT

In order to prevent uranium pollution and recovery uranium resources, it was necessary to find a highly efficient adsorbent for radioactive wastewater treatment. Herein, U(VI) imprinted polyethyleneimine (PEI) incorporated chitosan/layered hydrotalcite composite foam (IPCL) was synthesized by combining ion-imprinting and freeze-drying techniques. IPCL has a high amino/imino content and an ultralight macroporous structure, making it capable of efficiently adsorbing U(VI) and easy to separate; Especially after ion-imprinting, vacancies matching the size of uranyl ions were formed, significantly improving U(VI) selectivity. The adsorption isotherms and adsorption kinetics were in accordance with the Freundlich model and PSO model respectively, indicating that heterogeneous adsorption of U(VI) by the adsorbents. The adsorption capacity of IPCL-2 for U(VI) reached 278.8. mg/g (under the conditions of optimal pH 5.0, temperature of 298 K, contact time of 2 h, and adsorbent dosage of 0.2 g/L), which is almost double of that for the non-imprinted foam (PCL-2, 138.2 mg/g), indicating that IPCL-2 can intelligently recognize U(VI). The heterogeneous adsorption mechanism of U(VI) by IPCL-2 involves complexation, ion-exchange and isomorphic substitution. The adsorption of U(VI) by IPCL-2 is spontaneous and endothermic. IPCL-2 has excellent adsorption performance for U(VI), and is a promising adsorbent for radioactive pollution control.


Subject(s)
Aluminum Hydroxide , Chitosan , Magnesium Hydroxide , Polyethyleneimine , Uranium , Uranium/chemistry , Polyethyleneimine/chemistry , Chitosan/chemistry , Adsorption , Aluminum Hydroxide/chemistry , Kinetics , Magnesium Hydroxide/chemistry , Porosity , Hydrogen-Ion Concentration , Water Purification/methods , Temperature , Ions/chemistry
8.
Int J Nanomedicine ; 19: 1041-1054, 2024.
Article in English | MEDLINE | ID: mdl-38317849

ABSTRACT

Purpose: The search for effective and low-risk treatment methods for colorectal cancer (CRC) is a pressing concern, given the inherent risks and adverse reactions associated with traditional therapies. Photothermal therapy (PTT) has emerged as a promising approach for cancer treatment, offering advantages such as non-radiation, non-invasiveness, and targeted treatment. Consequently, the development of nanoparticles with high stability, biocompatibility, and photothermal effects has become a significant research focus within the field of PTT. Methods: In this study, TiO2-Ti3C2 nanocomposites were synthesized and characterized, and their photothermal conversion efficiency in the near-infrared region II (NIR-II) was determined. Then studied the in vivo and in vitro photothermal activity and anti-tumor effect of TiO2-Ti3C2 in human colorectal cancer cell lines and nude mice subcutaneous tumor model. Results: The results showed that TiO2-Ti3C2 nanocomposites have strong absorption ability in the NIR-II, and have high photothermal conversion efficiency under 1064 nm (0.5 W/cm2, 6 min) laser stimulation. In addition, in vitro experiments showed that TiO2-Ti3C2 nanocomposites significantly inhibited the invasion, migration, and proliferation of colorectal cancer cells, and induced cell apoptosis; in vivo, experiments showed that TiO2-Ti3C2 nanocomposites-mediated PTT had good biocompatibility and efficient targeted inhibition of tumor growth. Conclusion: In conclusion, TiO2-Ti3C2 nanocomposites can be used as NIR-II absorption materials in PTT to suppress the invasion, migration, and proliferation of colorectal cancer cells, induce colorectal cancer cell apoptosis, and thus inhibit the development of CRC. Therefore, TiO2-Ti3C2 nanocomposites can be used as potential anti-tumor drugs for photothermal ablation of colorectal cancer cells.


Subject(s)
Antineoplastic Agents , Colorectal Neoplasms , Nanocomposites , Neoplasms , Animals , Mice , Humans , Mice, Nude , Titanium , Neoplasms/drug therapy , Antineoplastic Agents/pharmacology , Nanocomposites/therapeutic use , Phototherapy , Colorectal Neoplasms/drug therapy , Cell Line, Tumor
9.
NPJ Precis Oncol ; 8(1): 27, 2024 Feb 03.
Article in English | MEDLINE | ID: mdl-38310130

ABSTRACT

The relevance of KRAS mutation alleles to clinical outcome remains inconclusive in pancreatic adenocarcinoma (PDAC). We conducted a retrospective study of 803 patients with PDAC (42% with metastatic disease) at MD Anderson Cancer Center. Overall survival (OS) analysis demonstrated that KRAS mutation status and subtypes were prognostic (p < 0.001). Relative to patients with KRAS wildtype tumors (median OS 38 months), patients with KRASG12R had a similar OS (median 34 months), while patients with KRASQ61 and KRASG12D mutated tumors had shorter OS (median 20 months [HR: 1.9, 95% CI 1.2-3.0, p = 0.006] and 22 months [HR: 1.7, 95% CI 1.3-2.3, p < 0.001], respectively). There was enrichment of KRASG12D mutation in metastatic tumors (34% vs 24%, OR: 1.7, 95% CI 1.2-2.4, p = 0.001) and enrichment of KRASG12R in well and moderately differentiated tumors (14% vs 9%, OR: 1.7, 95% CI 1.05-2.99, p = 0.04). Similar findings were observed in the external validation cohort (PanCAN's Know Your Tumor® dataset, n = 408).

11.
Bioresour Technol ; 397: 130504, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38423484

ABSTRACT

While wet waste hydrothermal liquefaction technology has a high biofuel yield, a significant amount of the carbon and nitrogen in the feedstock reports to the aqueous-phase product. Pretreatment of this stream before sending to a conventional wastewater plant is essential or at the very least, advisable. In this work, techno-economic and life-cycle assessments were conducted for the state-of-technology baseline and four aqueous-phase product treatment and monetization options based on experimental data. These options can cut minimum fuel selling prices by up to 13 % and life-cycle greenhouse gas emissions by up to 39 % compared to the baseline. These findings highlight the substantial influence of aqueous produce treatment strategies on the entire wet waste hydrothermal liquefaction process, demonstrating the potential for optimizing economic viability and environmental impact through further research and development of milder treatment methods and diversified by-product valorization pathways.


Subject(s)
Environment , Greenhouse Gases , Wastewater , Nitrogen , Biofuels , Biomass
12.
J Am Chem Soc ; 146(8): 5232-5241, 2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38350439

ABSTRACT

In pursuit of potent pharmaceutical candidates and to further improve their chemical traits, small ring systems can serve as a potential starting point. Small ring units have the additional merit of loaded strain at their core, making them suitable reactants as they can capitalize on this intrinsic driving force. With the introduction of cyclobutenone as a strained precursor to ketene, the photocycloaddition with another strained unit, bicyclo[1.1.0]butane (BCB), enables the reactivity of both π-units in the transient ketene. This double strain-release driven [2π+2σ]-photocycloaddition promotes the synthesis of diverse heterobicyclo[2.1.1]hexane units, a pharmaceutically relevant bioisostere. The effective reactivity under catalyst-free conditions with a high functional group tolerance defines its synthetic utility. Experimental mechanistic studies and density functional theory (DFT) calculations suggest that the [2π+2σ]-photocycloaddition takes place via a triplet mechanism.

13.
J Exp Med ; 221(4)2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38411616

ABSTRACT

Diffuse-type gastric adenocarcinoma (DGAC) is a deadly cancer often diagnosed late and resistant to treatment. While hereditary DGAC is linked to CDH1 mutations, the role of CDH1/E-cadherin inactivation in sporadic DGAC tumorigenesis remains elusive. We discovered CDH1 inactivation in a subset of DGAC patient tumors. Analyzing single-cell transcriptomes in malignant ascites, we identified two DGAC subtypes: DGAC1 (CDH1 loss) and DGAC2 (lacking immune response). DGAC1 displayed distinct molecular signatures, activated DGAC-related pathways, and an abundance of exhausted T cells in ascites. Genetically engineered murine gastric organoids showed that Cdh1 knock-out (KO), KrasG12D, Trp53 KO (EKP) accelerates tumorigenesis with immune evasion compared with KrasG12D, Trp53 KO (KP). We also identified EZH2 as a key mediator promoting CDH1 loss-associated DGAC tumorigenesis. These findings highlight DGAC's molecular diversity and potential for personalized treatment in CDH1-inactivated patients.


Subject(s)
Ascites , Carcinogenesis , Humans , Animals , Mice , Carcinogenesis/genetics , Cell Transformation, Neoplastic , Stomach , Cadherins/genetics , Enhancer of Zeste Homolog 2 Protein/genetics
15.
Nat Commun ; 15(1): 818, 2024 Jan 27.
Article in English | MEDLINE | ID: mdl-38280869

ABSTRACT

Animal studies have demonstrated the ability of pancreatic acinar cells to transform into pancreatic ductal adenocarcinoma (PDAC). However, the tumorigenic potential of human pancreatic acinar cells remains under debate. To address this gap in knowledge, we expand sorted human acinar cells as 3D organoids and genetically modify them through introduction of common PDAC mutations. The acinar organoids undergo dramatic transcriptional alterations but maintain a recognizable DNA methylation signature. The transcriptomes of acinar organoids are similar to those of disease-specific cell populations. Oncogenic KRAS alone do not transform acinar organoids. However, acinar organoids can form PDAC in vivo after acquiring the four most common driver mutations of this disease. Similarly, sorted ductal cells carrying these genetic mutations can also form PDAC, thus experimentally proving that PDACs can originate from both human acinar and ductal cells. RNA-seq analysis reveal the transcriptional shift from normal acinar cells towards PDACs with enhanced proliferation, metabolic rewiring, down-regulation of MHC molecules, and alterations in the coagulation and complement cascade. By comparing PDAC-like cells with normal pancreas and PDAC samples, we identify a group of genes with elevated expression during early transformation which represent potential early diagnostic biomarkers.


Subject(s)
Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Animals , Humans , Transcriptome , Pancreatic Neoplasms/pathology , Carcinoma, Pancreatic Ductal/pathology , Carcinogenesis/pathology , Acinar Cells/metabolism , Gene Expression Profiling , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/metabolism
16.
Cell Stem Cell ; 31(1): 52-70.e8, 2024 01 04.
Article in English | MEDLINE | ID: mdl-38181751

ABSTRACT

Human pluripotent stem cell-derived kidney organoids offer unprecedented opportunities for studying polycystic kidney disease (PKD), which still has no effective cure. Here, we developed both in vitro and in vivo organoid models of PKD that manifested tubular injury and aberrant upregulation of renin-angiotensin aldosterone system. Single-cell analysis revealed that a myriad of metabolic changes occurred during cystogenesis, including defective autophagy. Experimental activation of autophagy via ATG5 overexpression or primary cilia ablation significantly inhibited cystogenesis in PKD kidney organoids. Employing the organoid xenograft model of PKD, which spontaneously developed tubular cysts, we demonstrate that minoxidil, a potent autophagy activator and an FDA-approved drug, effectively attenuated cyst formation in vivo. This in vivo organoid model of PKD will enhance our capability to discover novel disease mechanisms and validate candidate drugs for clinical translation.


Subject(s)
Cilia , Polycystic Kidney Diseases , Humans , Kidney , Polycystic Kidney Diseases/drug therapy , Autophagy , Organoids
17.
Chembiochem ; 25(3): e202300678, 2024 02 01.
Article in English | MEDLINE | ID: mdl-38015421

ABSTRACT

Using myoglobin (Mb) as a model protein, we herein developed a facial approach to modifying the heme active site. A cavity was first generated in the heme distal site by F46 C mutation, and the thiol group of Cys46 was then used for covalently linked to exogenous ligands, 1H-1,2,4-triazole-3-thiol and 1-(4-hydroxyphenyl)-1H-pyrrole-2,5-dione. The engineered proteins, termed F46C-triazole Mb and F46C-phenol Mb, respectively, were characterized by X-ray crystallography, spectroscopic and stopped-flow kinetic studies. The results showed that both the heme coordination state and the protein function such as H2 O2 activation and peroxidase activity could be efficiently regulated, which suggests that this approach might be generally applied to the design of functional heme proteins.


Subject(s)
Heme , Myoglobin , Myoglobin/chemistry , Myoglobin/genetics , Myoglobin/metabolism , Catalytic Domain , Heme/chemistry , Kinetics , Protein Conformation , Sulfhydryl Compounds
18.
Biochem Pharmacol ; 220: 115993, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38151075

ABSTRACT

Phosphatidylinositol 4-kinases (PI4Ks) could phosphorylate phosphatidylinositol (PI) to produce phosphatidylinositol 4-phosphate (PI4P) and maintain its metabolic balance and location. PI4P, the most abundant monophosphate inositol in eukaryotic cells, is a precursor of higher phosphoinositols and an essential substrate for the PLC/PKC and PI3K/Akt signaling pathways. PI4Ks regulate vesicle transport, signal transduction, cytokinesis, and cell unity, and are involved in various physiological and pathological processes, including infection and growth of parasites such as Plasmodium and Cryptosporidium, replication and survival of RNA viruses, and the development of tumors and nervous system diseases. The development of novel drugs targeting PI4Ks and PI4P has been the focus of the research and clinical application of drugs, especially in recent years. In particular, PI4K inhibitors have made great progress in the treatment of malaria and cryptosporidiosis. We describe the biological characteristics of PI4Ks; summarize the physiological functions and effector proteins of PI4P; and analyze the structural basis of selective PI4K inhibitors for the treatment of human diseases in this review. Herein, this review mainly summarizes the developments in the structure and enzyme activity of PI4K inhibitors.


Subject(s)
Cryptosporidiosis , Cryptosporidium , Humans , 1-Phosphatidylinositol 4-Kinase , Phosphatidylinositol 3-Kinases/metabolism , Cryptosporidium/metabolism , Phosphatidylinositol Phosphates , Phosphatidylinositols/metabolism
19.
Lipids Health Dis ; 22(1): 222, 2023 Dec 13.
Article in English | MEDLINE | ID: mdl-38093311

ABSTRACT

BACKGROUND: Previous studies demonstrated that mast cells with their degranulated component heparin are the major endogenous factors that stimulate preadipocyte differentiation and promote fascial adipogenesis, and this effect is related to the structure of heparin. Regarding the structural and physiological properties of the negatively charged polymers, hexasulfonated suramin, a centuries-old medicine that is still used for treating African trypanosomiasis and onchocerciasis, is assumed to be a heparin-related analog or heparinoid. This investigation aims to elucidate the influence of suramin on the adipogenesis. METHODS: To assess the influence exerted by suramin on adipogenic differentiation of primary white adipocytes in rats, this exploration was conducted both in vitro and in vivo. Moreover, it was attempted to explore the role played by the sulfonic acid groups present in suramin in mediating this adipogenic process. RESULTS: Suramin demonstrated a dose- and time-dependent propensity to stimulate the adipogenic differentiation of rat preadipocytes isolated from the superficial fascia tissue and from adult adipose tissue. This stimulation was concomitant with a notable upregulation in expression levels of pivotal adipogenic factors as the adipocyte differentiation process unfolded. Intraperitoneal injection of suramin into rats slightly increased adipogenesis in the superficial fascia and in the epididymal and inguinal fat depots. PPADS, NF023, and NF449 are suramin analogs respectively containing 2, 6, and 8 sulfonic acid groups, among which the last two moderately promoted lipid droplet formation and adipocyte differentiation. The number and position of sulfonate groups may be related to the adipogenic effect of suramin. CONCLUSIONS: Suramin emerges as a noteworthy pharmaceutical agent with the unique capability to significantly induce adipocyte differentiation, thereby fostering adipogenesis.


Subject(s)
Adipogenesis , Suramin , Rats , Animals , Suramin/pharmacology , Antiparasitic Agents/pharmacology , Cell Differentiation , Adipocytes, White , Heparin/pharmacology
20.
J Toxicol ; 2023: 2566754, 2023.
Article in English | MEDLINE | ID: mdl-38106638

ABSTRACT

Objective: The aim of this study was to investigate the effects of sodium hydrosulfide (NaHS) on Lipopolysaccharide (LPS)-induced cardiomyocyte injury in H9c2 cells. Methods: H9c2 cardiomyocytes cultivated with medium containing 10 µg/mL LPS were used to recapitulate the phenotypes of those in sepsis. Two sequential experiments were performed. The first contained a control group, a LPS group, and a LPS + NaHS group, with the aim to assure the protective effects of NaHS on LPS-treated cardiomyocytes. The second experiment added a fourth group, the LPS + NaHS + miR-133a-3p inhibition group, with the aim to preliminarily explore whether miR-133-3p exerts a protective function downstream of NaHS. The adenosine triphosphate (ATP) kit was used to detect ATP content; real-time quantitative polynucleotide chain reaction (qPCR) was used to measure the levels of mammalian targets of rapamycin (mTOR), AMP-dependent protein kinase (AMPK), and miR-133a-3p, and Western blot (WB) was used to detect protein levels of mTOR, AMPK, myosin-like Bcl2 interacting protein (Beclin-1), microtubule-associated protein 1 light chain 3 (LC3I/II), and P62 (sequestosome-1, sqstm-1/P62). Results: Compared with the control group, the expressions of miR-133a-3p (P < 0.001), P62 (P < 0.001), and the content of ATP (P < 0.001) decreased, while the expressions of Beclin-1 (P = 0.023) and LC3I/II (P = 0.048) increased in the LPS group. Compared with the LPS group, the expressions of miR-133a-3p (P < 0.001), P62 (P < 0.001), and the content of ATP (P < 0.001) in the NaHS + LPS group increased, while the expressions of Beclin-1 (P = 0.023) and LC3I/II (P = 0.022) decreased. Compared with the NaHS + LPS group, the expression levels of miR-133a-3p (P < 0.001), P62 (P = 0.001), and the content of ATP (P < 0.001) in the LPS + NaHS + miR-133a-3p inhibition group were downregulated, and the expression levels of Beclin-1 (P = 0.012) and LC3I/II (P = 0.010) were upregulated. The difference was statistically significant. There was no significant difference in the expression of AMPK and mTOR between groups. Conclusion: Our research demonstrated that NaHS relieved LPS-induced myocardial injury in H9c2 by promoting the expression of miR-133a-3p, inhibiting autophagy in cardiomyocytes, and restoring cellular ATP levels.

SELECTION OF CITATIONS
SEARCH DETAIL
...