Contrasting Iron Metabolism in Undifferentiated Versus Differentiated MO3.13 Oligodendrocytes via IL-1ß-Induced Iron Regulatory Protein 1.

Parkinson's disease (PD) is a prevalent neurodegenerative disorder characterized by the loss of dopaminergic neurons and the accumulation of iron in the substantia nigra. While iron accumulation and inflammation are implicated in PD pathogenesis, their impact on oligodendrocytes, the brain's myelin-forming cells, remains elusive. This study investigated the influence of interleukin-1ß (IL-1ß), an elevated proinflammatory cytokine in PD, on iron-related proteins in MO3.13 oligodendrocytes. We found that IL-1ß treatment in undifferentiated MO3.13 oligodendrocytes increased iron regulatory protein 1 and transferrin receptor 1 (TfR1) expression while decreasing ferroportin 1 (FPN1) expression. Consequently, iron uptake was enhanced, and iron release was reduced, leading to intracellular iron accumulation. Conversely, IL-1ß treatment in differentiated MO3.13 oligodendrocytes exhibited the opposite effect, with decreased TfR1 expression, increased FPN1 expression, and reduced iron uptake. These findings suggest that IL-1ß-induced dysregulation of iron metabolism in oligodendrocytes may contribute to the pathological processes observed in PD. IL-1ß can increase the iron content in undifferentiated oligodendrocytes, thus facilitating the differentiation of undifferentiated MO3.13 oligodendrocytes. In differentiated oligodendrocytes, IL-1ß may facilitate iron release, providing a potential source of iron for neighboring dopaminergic neurons, thereby initiating a cascade of deleterious events. This study provides valuable insights into the intricate interplay between inflammation, abnormal iron accumulation, and oligodendrocyte dysfunction in PD. Targeting the IL-1ß-mediated alterations in iron metabolism may hold therapeutic potential for mitigating neurodegeneration and preserving dopaminergic function in PD.

Research on preparation and antitumor activity of redox-responsive polymer micelles co-loaded with sorafenib and curcumin.

A novel redox-responsive mPEG-SS-PLA (PSP) polymeric micelle was synthesized and prepared for the delivery of sorafenib (SAF) and curcumin (CUR). And a series of validations were conducted to confirm the structure of the synthesized polymer carriers. Using the Chou-Talalay approach, the combination indexes (CI) of SAF and CUR were determined, and explore the inhibitory effects of the two drugs on HepG2R cells at different ratios. SAF/CUR-PSP polymeric micelles were prepared by thin film hydration method, and the physicochemical properties of nanomicelles were evaluated. The biocompatibility, cell uptake, cell migration, and cytotoxicity assays were assessed in HepG2R cells. The expression of the phosphoinositol-3 kinase (PI3K)/serine/threonine kinase (Akt) signaling pathway was detected by Western blot assay. Additionally, the tumor suppressive effect of SAF/CUR-PSP micelles was clearly superior to free drug monotherapy or their physical combination in HepG2 cell-induced tumor xenografts. The current study revealed that mPEG-SS-PLA polymer micelles loaded with SAF and CUR showed the enhanced therapeutic effects against hepatocellular carcinoma in vitro and in vivo models. It has promising applications for cancer therapy.

Glucosamine-Modified Reduction-Responsive Polymeric Micelles for Liver Cancer Therapy.

In this work, glucose transporter-1 (GLUT-1) and glutathione (GSH) over-expression in liver cancer was utilized to design a reduction-responsive and active targeting drug delivery system AG-PEG-SS-PCL (APSP) for the delivery of sorafenib (SF). The SF-APSP micelles were prepared using the thin film hydration method and characterized by various techniques. In vitro release experiments showed that the cumulative release of SF-APSP micelles in the simulated tumor microenvironment (pH 7.4 with GSH) reached 94.76 ± 1.78% at 48 h, while it was only 20.32 ± 1.67% in the normal physiological environment (pH 7.4 without GSH). The in vitro study revealed that glucosamine (AG) enhanced the antitumor effects of SF, and SF-APSP micelles inhibited proliferation by targeting HepG2 cells and suppressing cyclin D1 expression. The in vivo antitumor efficacy study further confirmed that the SF-APSP micelles had excellent antitumor effects and better tolerance against nude mouse with HepG2 cells than other treatment groups. All in all, these results indicated that SF-APSP micelles could be a promising drug delivery system for anti-hepatoma treatment.

Diketopyrrolopyrrole-based fluorescence probes for the imaging of lysosomal Zn2+ and identification of prostate cancer in human tissue.

A series of diketopyrrolopyrrole-based fluorescent probes (DPP-C2, LysoDPP-C2, LysoDPP-C3, and LysoDPP-C4) have been developed for the detection of low pH and Zn2+ in an AND logic fashion. The chelation of Zn2+ or the protonation of a morpholine moiety within these probes results in a partial increase in the fluorescence intensity, an effect ascribed to suppression of one possible photo-induced electron transfer (PET) pathway. In contrast, a large increase in the observed fluorescence intensity is observed at low pH and in the presence of Zn2+; this is rationalized in terms of both possible PET pathways within the probes being blocked. Job plots, fluorescence titration curves, and isothermal titration calorimetry proved consistent with a 1 : 1 Zn2+ complexation stoichiometry. Each probe demonstrated an excellent selectivity towards Zn2+ and the resulting Zn2+ complexes demonstrated pH sensitivity over the 3.5-9 pH range. Fluorescence imaging experiments confirmed that LysoDPP-C4 was capable of imaging lysosomal Zn2+ in live cells. Little evidence of cytotoxicity was seen. LysoDPP-C4 was successfully applied to the bioimaging of nude mice, wherein it was shown capable of imaging the prostate. Histological studies using a human sample revealed that LysoDPP-C4 can discriminate cancerous prostate tissue from healthy prostate tissue.

A novel fluorescent probe for the early detection of prostate cancer based on endogenous zinc sensing.

BACKGROUND: The early detection of prostate cancer can significantly optimize the prognosis, prolong patient lifespan, and improve quality of life. It has been well documented that prostate cancer tissues have lower zinc content than normal prostate tissues due to an impairment of the zinc accumulation mechanism. METHODS: A novel diketopyrrolopyrrole (DPP)-based fluorescent zinc ion probe named DPP-C2 was prepared. The fluorescent intensity of this novel molecule is in direct proportion to environmental zinc concentration. Malignant (DU145 and PC3 cells) and normal prostate epithelial RWPE-1 cells were tested. Prostate cancer tissues were also cultured and observed as tissue sections. The probe was also intravenously administered to tumor-bearing (DU145 and PC3 cells) nude mice and observed under a whole-body fluorescence live-imaging system. RESULTS: The probe showed minimal cytotoxicity to malignant and normal prostate cells. The RWPE-1 cells showed not only stronger baseline fluorescence but also a significant increase in signal intensity after culturing in a zinc-supplemented medium. In human prostate sections, the pathologically confirmed cancer tissues exhibited weaker fluorescence signals than normal and benign hyperplastic tissues. With proper excitation, prostate tissues revealed more intense fluorescence signals than tumor tissues, whereas other surrounding tissues showed almost no fluorescence. CONCLUSIONS: The novel zinc ion fluorescent probe DPP-C2 is low toxic and showed potential application for the early detection of prostate cancer based on endogenous zinc sensing.

Downregulation of cystathionine ß-synthase/hydrogen sulfide contributes to rotenone-induced microglia polarization toward M1 type.

Microglia-mediated neuroinflammation is implicated in the pathogenesis of several neurodegenerative disorders. Microglia can be activated and polarized to exert pro- or anti-inflammatory roles in response to specific stimulus. Rotenone is an environmental toxin that has been shown to activate microglia and neuroinflammation. However, the effects and mechanisms of rotenone on microglia polarization are poorly studied. In the present study, we demonstrated that rotenone enhanced the levels of M1 phenotypic genes including TNF-α, iNOS and COX-2/PGE2 but reduced that of M2 markers such as Ym1/2 and IL-10 in mouse primary and immortalized microglia. Moreover, the transcription and protein expression of cystathionine-ß-synthase (CBS), as well as hydrogen sulfide (H2S) production were decreased in rotenone-treated primary microglia. Elevating endogenous H2S via CBS over-expression in immortalized microglia not only reduced the expression of pro-inflammatory M1 genes, but also enhanced the anti-inflammatory M2 marker IL-10 production in response to rotenone stimulation as compared to vector-transfected cells. Similarly, pretreatment with H2S donor NaHS (50, 100 and 500µmol/L) attenuated the increases of M1 gene expression triggered by rotenone treatment, and enhanced the M2 gene Ym1/2 expression in mouse primary microglia. In addition, we observed reactive oxygen species (ROS) scavenger N-acetyl-l-cysteine reversed the down-regulation of CBS and H2S generation caused by rotenone in microglia. NaHS pretreatment also decreased the ROS formation in rotenone-stimulated microglia. Taken together, these results reveal that probably via triggering ROS formation, rotenone suppressed the CBS-H2S pathway and thus promoted microglia polarization toward M1 pro-inflammatory phenotype.