Lactate administration improves laboratory parameters in murine models of iron overload.

ABSTRACT: Current iron overload therapeutics have inherent drawbacks including perpetuated low hepcidin. Here, we unveiled that lactate, a potent hepcidin agonist, effectively reduced serum and hepatic iron levels in mouse models of iron overload with an improved erythropoiesis in ß-thalassemic mice.

Zonated iron deposition in the periportal zone of the liver is associated with selectively enhanced lipid synthesis.

BACKGROUND AND AIMS: Disorders in liver lipid metabolism have been implicated in a range of metabolic conditions, including fatty liver and liver cancer. Altered lipid distribution within the liver, shifting from the pericentral to the periportal zone under pathological circumstances, has been observed; however, the underlying mechanism remains elusive. Iron, an essential metal, exhibits a zonal distribution in the liver similar to that of lipids. Nevertheless, the precise relationship between iron and lipid distribution, especially in the pericentral and periportal zones, remains poorly understood. METHODS: We conducted comprehensive in vitro and in vivo experiments, combining with in situ analysis and RNA sequencing, aiming for a detailed exploration of the causal relationship between iron accumulation and lipid metabolism. RESULTS: Our research suggests that iron overload can disrupt the normal distribution of lipids within the liver, particularly in the periportal zone. Through meticulous gene expression profiling in both the pericentral and periportal zones, we identified pyruvate carboxylase (PC) as a pivotal regulator in iron overload-induced lipid accumulation. Additionally, we revealed that the activation of cyclic adenosine monophosphate response element binding protein (CREB) was indispensable for Pc gene expression when in response to iron overload. CONCLUSIONS: In summary, our investigation unveils the crucial involvement of iron overload in fostering hepatic lipid accumulation in the periportal zone, at least partly mediated by the modulation of Pc expression. These insights offer new perspectives for understanding the pathogenesis of fatty liver diseases and their progression.

Synergistic/antagonistic toxicity characterization and source-apportionment of heavy metals and organophosphorus pesticides by the biospectroscopy-bioreporter-coupling approach.

Many anthropogenic chemicals are manufactured and eventually enter the surrounding environment, threatening food security and human health. Considering the additive or synergistic effects of pollutant mixtures, there is an expanding need for rapid, cost-effective and field-portable screening methods in environmental monitoring. This study used a recently developed biospectroscopy-bioreporter-coupling (BBC) approach to investigate the binary toxicity of Ag(I), Cr(VI) and four organophosphorus pesticides (dichlorvos, parathion, omethoate and monocrotophos). Ag(I) and Cr(VI) altered the toxicity mechanisms of pesticides, explained by the synergistic or antagonistic effect of Ag/Cr-induced cytotoxicity and pesticide-induced genotoxicity. The discriminating Raman spectral peaks associated with organophosphorus pesticides were 1585 and 1682 cm-1, but 750, 1004, 1306 and 1131 cm-1 were found in heavy metal and pesticide mixtures. More spectral alterations were related to pesticides rather than Ag(I) or Cr(VI), hinting at the dominant toxicity mechanisms of pesticides in mixtures. Ag(I) supplement significantly increased the levels of reactive oxygen species induced by organophosphorus pesticides, attributing to the increased permeability of cell membrane and entrance of toxic substances into the cells by the oligodynamic actions. This study lends deeper insights into the interactions between microbes and pollutant mixtures, offering clues to assess the cocktail effects of multiple pollutants comprehensively.

Radiotherapy for Primary Tracheal Carcinoma: Experience at a Single Institution.

BACKGROUND: There is limited understanding of tracheal carcinoma (TC) because of its rarity. We examined the efficacy of radiotherapy (RT) for patients with primary TC. METHODS: We analyzed the records of 32 patients with primary TC who received RT at our center between November 1996 and December 2016. RESULTS: Thirteen patients received adjuvant RT and 18 received definitive RT. Eight patients achieved complete remission (CR) after definitive RT. Among all patients, the 5-year overall survival (OS) rate was 46.9% and the locoregional progression free survival (LRPFS) rate was 68.1%. Univariate analysis indicated the 5-year OS was better in those with adenoid cystic adenocarcinoma than squamous cell carcinoma (P = 0.001); the 5-year LRPFS was better in patients who received surgical resection than those who did not (92.9% vs 46.4%, P = 0.013) and in patients who received postoperative RT than in those who received definitive RT (91.7% vs 50.1%, P = 0.038). A sub-group univariate analysis indicated the 5-year PFS was better for those who received at least 68 Gy of radiation (44.4% vs 13.0%, P = 0.044). Patients who achieved CR had a better 5-year PFS than those who did not (57.1% vs 10%, P = 0.006). No patients had a toxicity of grade 3 or more. CONCLUSIONS: Adjuvant and definitive RT are safe and effective treatments for TC. Patients who received dosages of 68 Gy or more and who had complete tumor regression following definitive RT seemed to have better long-term survival.

The cardinal roles of ferroportin and its partners in controlling cellular iron in and out.

In mammals, ferroportin (FPN) is the only known iron exporter, and it functions as a "water tap" in controlling iron absorption from the diet, iron egress from macrophages and other cells. However, its function is implemented not by itself but by a complex with many partners involved. In the current study, we elaborate on the direct partners in calibrating the capability of FPN in exporting iron out of cells, such as ceruloplasmin (CP), hephaestin (HP) and poly(rC)-binding protein 2 (PCBP2). We also recapitulate the current understandings of the regulation of FPN concentration at the post-transcriptional level. Considering the importance of FPN in finetuning iron homeostasis, a few therapeutic options are pursued to target FPN and its partners in treating iron diseases. Nonetheless, limited knowledge has been obtained on direct and indirect partners of FPN, so that more efforts should be invested including their therapeutic values.

In Search of Zonation Markers to Identify Liver Functional Disorders.

A substantial amount of research is being conducted on zonation markers to identify hepatic injuries and disorders based on the structural and functional zonation of the liver. In contrast to metabolic zonation, hepatocyte ploidy reflects the capability of liver regenerative turnover. Nonetheless, many knowledge gaps remain in the understanding of the links between liver disorders and altered zonation and ploidy, partially owing to the lack of sufficient zonation markers. Under this setting, we recapitulated the currently known and prospective markers used to identify normal and altered liver zonation in different disorders. Furthermore, we discussed new findings from studies that have used advanced methodologies to identify potential markers with greater accuracy. We also elaborated on the perspectives and future applications of zonation research in the early detection of various liver diseases.

Protein target identification and toxicological mechanism investigation of silver nanoparticles-induced hepatotoxicity by integrating proteomic and metallomic strategies.

BACKGROUND: Silver nanoparticles (AgNPs), as promising anti-microbials and anti-cancer therapeutics, the toxicological effect and killing efficiency towards cells need in-depth investigation for better applications in daily life and healthcare fields. Thus far, limited studies have yet elucidated the protein targets of AgNPs and silver ions (Ag+) released from intracellular AgNPs dissolution in hepatocytes, as well as potential interaction mechanism. RESULTS: Through integrating proteomic and metallomic methodologies, six intracellular protein targets (i.e. glutathione S-transferase (GST), peroxiredoxin, myosin, elongation factor 1, 60S ribosomal protein and 40S ribosomal protein) were ultimately identified and confirmed as AgNPs- and Ag+ -binding proteins. Toward a deep understanding the direct interaction mechanism between AgNPs and these protein targets, GST was chosen as a representative for toxicological investigation. The results revealed that AgNPs could remarkably deplete the enzyme activity of GST but did not depress the expressions, resulting in elevated intracellular oxidative stress and cell death. Finally, both "Ag+ effect" and "particle-specific effect" were demonstrated to concomitantly account for the overall cytotoxicity of AgNPs, and the former relatively contributed more via activity depletion of GST. CONCLUSIONS: Collectively, our major contribution is the development of an efficient strategy to identify the intracellular AgNPs-targeted protein (e.g. GST) through integrating proteomic and metallomic methodologies, which is helpful to accelerate the interpretation of underlying toxicological mechanism of AgNPs.

The bromodomain protein BRD4 positively regulates necroptosis via modulating MLKL expression.

Necroptosis is a programmed form of necrotic cell death, which is tightly regulated by the necroptotic signaling pathway containing receptor-interacting protein (RIP)1, RIP3, and mixed-lineage kinase domain-like (MLKL) protein. In addition to the RIP1-RIP3-MLKL axis, other factors regulating necroptosis are still largely unknown. Here a cell-based small-molecule screening led to the finding that BET inhibitors protected cells from necroptosis in the TNFα/Smac-mimetic/Z-VAD-FMK (TSZ)-induced cell necroptosis model. Mechanistic studies revealed that BET inhibitors acted by downregulating MLKL expression. Further research demonstrated that BRD4, IRF1, P-TEFb, and RNA polymerase II formed a transcription complex to regulate the expression of MLKL, and BET inhibitors interfered with the transcription complex formation. In necroptosis-related disease model, the BET inhibitor JQ-1 showed promising therapeutic effects. Collectively, our studies establish, for the first time, BRD4 as a new epigenetic factor regulating necroptosis, and highlight the potential of BET inhibitors in the treatment of necroptosis-related diseases.

Preliminary investigation on cytotoxicity of fluorinated polymer nanoparticles.

As well-known persistent organic pollutants (POPs), organofluorine pollutants such as perfluorooctane sulfonate (PFOS) have been proven to be bioaccumulated and harmful to health. However, toxicological assessment of organofluorinated nanoparticles, which have emerged as a novel tool for biomedical and industrial applications, is lacking, to the best of our knowledge. To assess the biological effects and health risk of fluorinated nanoparticles, trifluoroethyl aryl ether-based fluorinated poly(methyl methacrylate) nanoparticles (PTFE-PMMA NPs) were synthesized with various fluorine contents (PTFE-PMMA-1 NPs 12.0wt.%, PTFE-PMMA-2 NPs 6.1wt.% and PTFE-PMMA-3 NPs 5.0wt.%), and their cytotoxicity was investigated in this study. The in vitro experimental results indicated that the cytotoxicity of PTFE-PMMA NPs was mild, and was closely related to their fluorine (F) contents and F-containing side chains. Specifically, the cytotoxicity of PTFE-PMMA NPs decreased with increasing F content and F-containing side chains. After exposure to PTFE-PMMA NPs at a sublethal dose (50µg/mL) for 24hr, the phospholipid bilayer was damaged, accompanied by increasing permeability of the cell membrane. Meanwhile, the intracellular accumulation of reactive oxygen species (ROS) occurred, resulting in the increase of DNA damage, cell cycle arrest and cell death. Overall, the PTFE-PMMA NPs were found to be relatively safe compared with typical engineered nanomaterials (ENMs), such as silver nanoparticles and graphene oxide, for biomedical and industrial applications.

Structural optimization and structure-activity relationship studies of N-phenyl-7,8-dihydro-6H-pyrimido[5,4-b][1,4]oxazin-4-amine derivatives as a new class of inhibitors of RET and its drug resistance mutants.

The RET tyrosine kinase is an important therapeutic target for medullary thyroid cancer (MTC), and drug resistance mutations of RET, particularly V804M and V804L, are a main challenge for the current targeted therapy of MTC based on RET inhibitors. In this investigation, we report the structural optimization and structure-activity relationship studies of N-phenyl-7,8-dihydro-6H-pyrimido[5,4-b][1,4]oxazin-4-amine derivatives as a new class of RET inhibitors. Among all the obtained kinase inhibitors, 1-(5-(tert-butyl)isoxazol-3-yl)-3-(4-((6,7,8,9-tetrahydropyrimido[5,4-b][1,4]oxazepin-4-yl)amino)phenyl)urea (17d) is a multi-kinase inhibitor and potently inhibits RET and its drug resistance mutants. It showed IC50 (half maximal inhibitory concentration) values of 0.010 µM, 0.015 µM, and 0.009 µM against RET-wild-type, RET-V804M, and RET-V804L, respectively. 17d displayed significant anti-viability potencies against various RET-driving tumor cell lines. In a xenograft mouse model of NIH3T3-RET-C634Y, 17d exhibited potent in vivo anti-tumor activity, and no obvious toxicity was observed. Mechanisms of action were also investigated by Western blot and immunohistochemical assays. Collectively, 17d could be a promising agent for the treatment of MTC, hence deserving a further investigation.

Geographic characteristics of sable (Martes zibellina) distribution over time in Northeast China.

Understanding historical context can help clarify the ecological and biogeographic characteristics of species population changes. The sable (Martes zibellina) population has decreased dramatically in Northeast China since the l950s, and understanding the changes in its distribution over time is necessary to support conservation efforts. To achieve this goal, we integrated ecological niche modeling and historical records of sables to estimate the magnitude of change in their distribution over time. Our results revealed a 51.71% reduction in their distribution in 2000-2016 compared with the potential distribution in the 1950s. This reduction was related to climate change (Pearson's correlation: Bio1, -.962, p < .01; Bio2, -.962, p < .01; Bio5, .817, p < .05; Bio6, .847, p < .05) and human population size (-.956, p < .01). The sable population tended to migrate in different directions and elevations over time in different areas due to climate change: In the Greater Khingan Mountains, they moved northward and to lower elevations; in the Lesser Khingan Mountains, they moved northward; and in the Changbai Mountains, they move southward and to higher elevations. Active conservation strategies should be considered in locations where sable populations have migrated or may migrate to.

Discovery of KDM5A inhibitors: Homology modeling, virtual screening and structure-activity relationship analysis.

Herein we report the discovery of a series of new KDM5A inhibitors. A three-dimensional (3D) structure model of KDM5A jumonji domain was firstly established based on homology modeling. Molecular docking-based virtual screening was then performed against commercial chemical databases. A number of hit compounds were retrieved. Further structural optimization and structure-activity relationship (SAR) analysis were carried out to the most active hit compound, 9 (IC50: 2.3 µM), which led to the discovery of several new KDM5A inhibitors. Among them, compound 15e is the most potent one with an IC50 value of 0.22 µM against KDM5A. This compound showed good selectivity for KDM5A and considerable ability to suppress the demethylation of H3K4me3 in intact cells. Compound 15e could be taken as a good lead compound for further studies.

Optimal cleavage and oxidative folding of α-conotoxin TxIB as a therapeutic candidate peptide.

Alpha6beta2 nicotinic acetylcholine receptors (nAChRs) are potential therapeutic targets for the treatment of several neuropsychiatric diseases, including addiction and Parkinson's disease. Alpha-conotoxin (α-CTx) TxIB is a uniquely selective ligand, which blocks α6/α3ß2ß3 nAChRs only, but does not block the other subtypes. Therefore, α-CTx TxIB is a valuable therapeutic candidate peptide. Synthesizing enough α-CTx TxIB with high yield production is required for conducting wide-range testing of its potential medicinal applications. The current study optimized the cleavage of synthesized α-CTx TxIB resin-bounded peptide and folding of the cleaved linear peptide. Key parameters influencing cleavage and oxidative folding of α-CTx TxIB were examined, such as buffer, redox agents, pH, salt, co-solvent and temperature. Twelve conditions were used for cleavage optimization. Fifty-four kinds of one-step oxidative solution were used to assess their effects on each α-CTx TxIB isomers' yield. The result indicated that co-solvent choices were particularly important. Completely oxidative folding of globular isomer was achieved when the NH4HCO3 or Tris-HCl folding buffer at 4 °C contained 40% of co-solvent DMSO, and GSH:GSSG (2:1) or GSH only with pH 8~8.7.