Sepantronium Bromide (YM155), A Small Molecule Survivin Inhibitor, Promotes Apoptosis by Induction of Oxidative Stress, Worsens the Behavioral Deficits and Develops an Early Model of Toxic Demyelination: In Vivo and In-Silico Study

TNF-α/STAT1/CXCL10 mutual inflammatory axis that contributes to the pathogenesis of experimental models of multiple sclerosis: A promising signaling pathway for targeted therapies

BACKGROUND

Identifying mutual neuroinflammatory axis in different experimental models of multiple sclerosis (MS) is essential to evaluate the de- and re-myelination processes and improve therapeutic interventions' reproducibility.

METHODS

The expression profile data set of EAE (GSE47900) and cuprizone (GSE100663) models were downloaded from the Gene Expression Omnibus database. The R package and GEO2R software processed these raw chip data. Gene Ontology (GO) functional analysis, KEGG pathway analysis, and protein-protein interaction network analysis were performed to investigate interactions between common differentially expressed genes (DEGs) in all models. Finally, the ELISA method assessed the protein level of highlighted mutual cytokines in serum.

RESULTS

Our data introduced 59 upregulated [CXCL10, CCL12, and GBP6 as most important] and 17 downregulated [Serpinb1a, Prr18, and Ugt8a as most important] mutual genes. The signal transducer and activator of transcription 1 (STAT1) and CXCL10 were the most crucial hub proteins among mutual upregulated genes. These mutual genes were found to be mainly involved in the TNF-α, TLRs, and complement cascade signaling, and animal models shared 26 mutual genes with MS individuals. Finally, significant upregulation of serum level of TNF-α/IL-1β/CXCL10 cytokines was confirmed in all models in a relatively similar pattern.

CONCLUSION

For the first time, our study revealed the common neuroinflammatory pathway in animal models of MS and introduced candidate hub genes for better evaluating the preclinical efficacy of pharmacological interventions and designing prospective targeted therapies.

Prophylactic effects of cucurbitacin B in the EAE Model of multiple sclerosis by adjustment of STAT3/IL-23/IL-17 axis and improvement of neuropsychological symptoms

Multiple sclerosis (MS) is an autoimmune disease that affects the central nervous system. Although remarkable progress has been made in treating MS, current therapies are less effective in protecting against the progression of the disease. Since cucurbitacins have shown an extreme range of pharmacological properties, in this study, we aimed to investigate the prophylactic effect of cucurbitacin B (CuB) in the experimental MS model. Experimental autoimmune encephalomyelitis (EAE) induced by subcutaneous immunization of MOG35-55 in C57BL/6 mice. CuB interventions (0.5 and 1 mg/kg, i.p.) were performed every other day from the first day of EAE induction. Assessment of clinical scores and motor function, inflammatory responses, and microglial activation were assessed by qRT-PCR, western blotting, and immunohistochemical (IHC) analyses. CuB (1 mg/kg) significantly decreased the population of CD45⁺ (P < 0.01), CD11b⁺ (P < 0.01) and CD45⁺/CD11b⁺ (P < 0.05) cells in cortical lesions of EAE mice. In addition, activation of STAT3 (P < 0.001), expression of IL-17 A and IL-23 A (both mRNA and protein), and transcription of Iba-1 significantly decreased. On the contrary, CuB (1 mg/kg) significantly increased the transcription of MBP and Olig-2. Furthermore, a significant decrease in the severity of EAE (P < 0.05), and an improvement in motor function (P < 0.05) and coordination (P < 0.05) were observed after treatment with a high dose of CuB. Our results suggest that CuB may have a wide-ranging effect on autoimmune responses in MS via a reduction in STAT3 activation, microgliosis, and adaptation of the IL-23/IL-17 axis. Further studies are needed to investigate the exact effect of CuB in glial cells and its efficiency and bioavailability in other neuroinflammatory diseases.

Effects of YM155 on the proliferation and apoptosis of pulmonary artery smooth muscle cells in a rat model of high pulmonary blood flow-induced pulmonary arterial hypertension

INTRODUCTION

Proliferation and apoptosis of pulmonary artery smooth muscle cells (PASMCs) play an important role in the occurrence and development of pulmonary arterial hypertension (PAH). The purpose of this study was to investigate the effects of survivin inhibitor YM155 on the proliferation and apoptosis of PASMCs in rats with PAH induced by high pulmonary blood flow.

METHODS

Thirty male Sprague-Dawley (SD) rats were randomly divided into control, model, and YM155 intervention groups. A rat model of PAH induced by high pulmonary blood flow was established, and it was confirmed by assessments of right-ventricular pressure (RVP) and right ventricular hypertrophy index (RVHI). Immunohistochemical staining and western blot analysis were used to detect the expression of survivin, and the proliferation and apoptosis of PASMCs. Lastly, the effects of in vivo treatment of YM155 were tested.

RESULTS

The increased expression of survivin mRNA and protein were observed in the model group, accompanied by pulmonary arteriolar wall thickening, lumen stenosis, and perivascular inflammatory cell infiltration. Elevated expression of survivin and pulmonary vascular remodeling were significantly mitigated after YM155 treatment. Specifically, the YM155 intervention group had a significantly lower PASMC proliferation rate and a higher PASMC apoptotic rate.

CONCLUSION

YM155 suppressed PASMC proliferation and promoted PASMC apoptosis by inhibiting survivin expression and thereby reducing pulmonary vascular remodeling in high pulmonary blood flow-induced PAH in vivo.

Rg1 exerts protective effect in CPZ-induced demyelination mouse model via inhibiting CXCL10-mediated glial response

Myelin damage and abnormal remyelination processes lead to central nervous system dysfunction. Glial activation-induced microenvironment changes are characteristic features of the diseases with myelin abnormalities. We previously showed that ginsenoside Rg1, a main component of ginseng, ameliorated MPTP-mediated myelin damage in mice, but the underlying mechanisms are unclear. In this study we investigated the effects of Rg1 and mechanisms in cuprizone (CPZ)-induced demyelination mouse model. Mice were treated with CPZ solution (300 mg· kg^-1· d^-1, ig) for 5 weeks; from week 2, the mice received Rg1 (5, 10, and 20 mg· kg^-1· d^-1, ig) for 4 weeks. We showed that Rg1 administration dose-dependently alleviated bradykinesia and improved CPZ-disrupted motor coordination ability in CPZ-treated mice. Furthermore, Rg1 administration significantly decreased demyelination and axonal injury in pathological assays. We further revealed that the neuroprotective effects of Rg1 were associated with inhibiting CXCL10-mediated modulation of glial response, which was mediated by NF-κB nuclear translocation and CXCL10 promoter activation. In microglial cell line BV-2, we demonstrated that the effects of Rg1 on pro-inflammatory and migratory phenotypes of microglia were related to CXCL10, while Rg1-induced phagocytosis of microglia was not directly related to CXCL10. In CPZ-induced demyelination mouse model, injection of AAV-CXCL10 shRNA into mouse lateral ventricles 3 weeks prior CPZ treatment occluded the beneficial effects of Rg1 administration in behavioral and pathological assays. In conclusion, CXCL10 mediates the protective role of Rg1 in CPZ-induced demyelination mouse model. This study provides new insight into potential disease-modifying therapies for myelin abnormalities.

BNIP3L-mediated mitophagy is required for mitochondrial remodeling during the differentiation of optic nerve oligodendrocytes

Retinal ganglion cell axons are heavily myelinated (98%) and myelin damage in the optic nerve (ON) severely affects vision. Understanding the molecular mechanism of oligodendrocyte progenitor cell (OPC) differentiation into mature oligodendrocytes will be essential for developing new therapeutic approaches for ON demyelinating diseases. To this end, we developed a new method for isolation and culture of ON-derived oligodendrocyte lineage cells and used it to study OPC differentiation. A critical aspect of cellular differentiation is macroautophagy/autophagy, a catabolic process that allows for cell remodeling by degradation of excess or damaged cellular molecules and organelles. Knockdown of ATG9A and BECN1 (pro-autophagic proteins involved in the early stages of autophagosome formation) led to a significant reduction in proliferation and survival of OPCs. We also found that autophagy flux (a measure of autophagic degradation activity) is significantly increased during progression of oligodendrocyte differentiation. Additionally, we demonstrate a significant change in mitochondrial dynamics during oligodendrocyte differentiation, which is associated with a significant increase in programmed mitophagy (selective autophagic clearance of mitochondria). This process is mediated by the mitophagy receptor BNIP3L (BCL2/adenovirus E1B interacting protein 3-like). BNIP3L-mediated mitophagy plays a crucial role in the regulation of mitochondrial network formation, mitochondrial function and the viability of newly differentiated oligodendrocytes. Our studies provide novel evidence that proper mitochondrial dynamics is required for establishment of functional mitochondria in mature oligodendrocytes. These findings are significant because targeting BNIP3L-mediated programmed mitophagy may provide a novel therapeutic approach for stimulating myelin repair in ON demyelinating diseases.Abbreviations: A2B5: a surface antigen of oligodendrocytes precursor cells, A2B5 clone 105; ACTB: actin, beta; APC: an antibody to label mature oligodendrocytes, anti-adenomatous polyposis coli clone CC1; ATG5: autophagy related 5; ATG7: autophagy related 7; ATG9A: autophagy related 9A; AU: arbitrary units; BafA1: bafilomycin A1; BCL2: B cell leukemia/lymphoma 2; BECN1: beclin 1, autophagy related; BNIP3: BCL2/adenovirus E1B interacting protein 3; BNIP3L/NIX: BCL2/adenovirus E1B interacting protein 3-like; CASP3: caspase 3; CNP: 2',3'-cyclic nucleotide 3'-phosphodiesterase; Ctl: control; COX8: cytochrome c oxidase subunit; CSPG4/NG2: chondroitin sulfate proteoglycan 4; DAPI: 4'6-diamino-2-phenylindole; DNM1L: dynamin 1-like; EGFP: enhanced green fluorescent protein; FACS: fluorescence-activated cell sorting; FIS1: fission, mitochondrial 1; FUNDC1: FUN14 domain containing 1; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GFAP: glial fibrillary growth factor; GFP: green fluorescent protein; HsESC: human embryonic stem cell; IEM: immunoelectron microscopy; LAMP1: lysosomal-associated membrane protein 1; LC3B: microtubule-associated protein 1 light chain 3; MBP: myelin basic protein; MFN2: mitofusin 2; Mito-Keima: mitochondria-targeted monomeric keima-red; Mito-GFP: mitochondria-green fluorescent protein; Mito-RFP: mitochondria-red fluorescent protein; MitoSOX: red mitochondrial superoxide probe; MKI67: antigen identified by monoclonal antibody Ki 67; MMP: mitochondrial membrane potential; O4: oligodendrocyte marker O4; OLIG2: oligodendrocyte transcription factor 2; ON: optic nerve; OPA1: OPA1, mitochondrial dynamin like GTPase; OPC: oligodendrocyte progenitor cell; PDL: poly-D-lysine; PINK1: PTEN induced putative kinase 1; PRKN/Parkin: parkin RBR E3 ubiquitin protein ligase; RFP: red fluorescent protein; RGC: retinal ganglion cell; ROS: reactive oxygen species; RT-PCR: real time polymerase chain reaction; SEM: standard error of the mean; SOD2: superoxide dismutase 2, mitochondrial; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscopy; TMRM: tetramethylrhodamine methyl ester; TOMM20: translocase of outer mitochondrial membrane 20; TUBB: tubulin, beta; TUBB3: tubulin, beta 3 class III.

Cigarette smoke-induced toxicity consequences of intracellular iron dysregulation and ferroptosis

Despite numerous studies on the mechanisms of cigarette smoking toxicity over the past three decades, some aspects remain obscure. Recent developments have drawn attention to some hopeful indicators that allow us to advance our awareness of cigarette-induced cell death. Ferroptosis is considered a type of governed death of cells distinguished by the iron-dependent lipid hydroperoxide deposition to fatal concentrations. Ferroptosis has been linked with pathological settings such as neurodegenerative diseases, cancer, heart attack, hemorrhagic stroke, traumatic brain injury, ischemia-reperfusion injury, and renal dysfunction. This review tries to explain the causal role of ferroptosis cascade in cigarette smoke-mediated toxicity and cell death, highlighting associations on potential action mechanisms and proposing suggestions for its detoxifying and therapeutic interventions.

Licochalcone A inhibits EGFR signalling and translationally suppresses survivin expression in human cancer cells

Dysfunction of epidermal growth factor receptor (EGFR) signalling plays a critical role in the oncogenesis of non–small‐cell lung cancer (NSCLC). Here, we reported the natural product, licochalcone A, exhibited a profound anti‐tumour efficacy through directly targeting EGFR signalling. Licochalcone A inhibited in vitro cell growth, colony formation and in vivo tumour growth of either wild‐type (WT) or activating mutation EGFR‐expressed NSCLC cells. Licochalcone A bound with L858R single‐site mutation, exon 19 deletion, L858R/T790M mutation and WT EGFR ex vivo, and impaired EGFR kinase activity both in vitro and in NSCLC cells. The in silico docking study further indicated that licochalcone A interacted with both WT and mutant EGFRs. Moreover, licochalcone A induced apoptosis and decreased survivin protein robustly in NSCLC cells. Mechanistically, we found that treatment with licochalcone A translationally suppressed survivin through inhibiting EGFR downstream kinases ERK1/2 and Akt. Depletion of the translation initiation complex by eIF4E knockdown effectively inhibited survivin expression. In contrast, knockdown of 4E‐BP1 showed the opposite effect and dramatically enhanced survivin protein level. Overall, our data indicate that targeting survivin might be an alternative strategy to sensitize EGFR‐targeted therapy.

Cognitive disturbances in the cuprizone model of multiple sclerosis

Cognitive problems frequently accompany neurological manifestations of multiple sclerosis (MS). However, during screening of preclinical candidates, assessments of behaviour in mouse models of MS typically focus on locomotor activity. In the present study, we analysed cognitive behaviour of 9 to 10-week-old female C57Bl/6J mice orally administered with the toxin cuprizone that induces demyelination, a characteristic feature of MS. Animals received 400 mg/kg cuprizone daily for 2 or 4 weeks, and their performance was compared with that of vehicle-treated mice. Cuprizone-treated animals showed multiple deficits in short touchscreen-based operant tasks: they responded more slowly to visual stimuli, rewards and made more errors in a simple rule-learning task. In contextual/cued fear conditioning experiments, cuprizone-treated mice showed significantly lower levels of contextual freezing than vehicle-treated mice. Diffusion tensor imaging showed treatment-dependent changes in fractional anisotropy as well as in axial and mean diffusivities in different white matter areas. Lower values of fractional anisotropy and axial diffusivity in cuprizone-treated mice indicated developing demyelination and/or axonal damage. Several diffusion tensor imaging measurements correlated with learning parameters. Our results show that translational touchscreen operant tests and fear conditioning paradigms can reliably detect cognitive consequences of cuprizone treatment. The suggested experimental approach enables screening novel MS drug candidates in longitudinal experiments for their ability to improve pathological changes in brain structure and reverse cognitive deficits.