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Erythroleukemia disease is caused by over production of malignant blood and immature large number of blood cells enters into peripheral compartment. Biophysical and biochemical changes in plasma and erythrocyte membrane in erythroleukemia treated rats were identified. Our study, leukemia is experimentally exposed in rats were injecting erythroleukemia cells (FLC) (H-2d) intravenously in adult rats and normal control rats were maintained. Significant increase in the activity of blood glucose, proteins levels, aspartate transaminase (AST) and alanine transaminase (ALT) values and significant decrease in haemoglobin (Hb), albumin levels in erythroleukemia treated rats were observed when compared with control rats. Cholesterol and low density liproprotein (LDL) levels increased significantly in erythroleukemia treated rats but triglycerides, high density lipoprotein (HDL) and very low density lipoprotein (VLDL) levels decreased significantly. Levels of red cell membrane cholesterol decreased in erythroleukemia treated rats in comparison with control while levels of phospholipids and proteins increased in erythrocytes of erythroleukemia treated rats. Red blood cell (RBC) and white blood cell (WBC) counts increased significantly and platelet count decreased. C/P (cholesterol/phospholipid) ratio decreased significantly in erythroleukemia treated rats. This study has been undertaken for the first time to investigate the effect of (FLC) (H-2d) erythroleukemia cells (treated) in intravenously in adult rats and normal control rats. Results indicate biophysical and biochemical alterations at molecular level in plasma and erythrocyte membrane. [ABSTRACT FROM AUTHOR]

Approximately 30% of metastatic breast cancers harbor estrogen receptor α (ERα) mutations associated with resistance to endocrine therapy and reduced survival. Consistent with their constitutive proliferation, T47D and MCF7 cells in which wild-type ERα is replaced by the most common mutations, ERαY537S and ERαD538G, exhibit partially estrogen-independent gene expression. A novel invasion/dissociation/rebinding assay demonstrated that the mutant cells have a higher tendency to dissociate from invasion sites and rebind to a second site. Compared to ERαD538G breast tumors, ERαY537S tumors exhibited a dramatic increase in lung metastasis. Transcriptome analysis showed that the ERαY537S and ERαD538G mutations each elicit a unique gene expression profile. Gene set enrichment analysis showed Myc target pathways are highly induced in mutant cells. Moreover, chromatin immunoprecipitation showed constitutive, fulvestrant-resistant, recruitment of ERα mutants to the Myc enhancer region, resulting in estrogen-independent Myc overexpression in mutant cells and tumors. Knockdown and virus transduction showed Myc is necessary and sufficient for ligand-independent proliferation of the mutant cells but had no effect on metastasis-related phenotypes. Thus, Myc plays a key role in aggressive proliferation-related phenotypes exhibited by breast cancer cells expressing ERα mutations. [ABSTRACT FROM AUTHOR]

The onco-protein epidermal growth factor (EGF) initiates a cascade that includes activation of the ERK and AKT signaling pathways and alters gene expression. We describe a new action of EGF–EGF receptor (EGFR), rapid anticipatory activation of the endoplasmic reticulum stress sensor, the unfolded protein response (UPR). Within 2 min, EGF elicits EGFR dependent activation of phospholipase C γ (PLCγ), producing inositol triphosphate (IP 3 ), which binds to IP 3 receptor (IP 3 R), opening the endoplasmic reticulum IP 3 R Ca 2+ channels, resulting in increased intracellular Ca 2+ . This calcium release leads to transient and moderate activation of the IRE1α and ATF6α arms of the UPR, resulting in induction of BiP chaperone. Knockdown or inhibition of EGFR, PLCγ or IP 3 R blocks the increase in intracellular Ca 2+ . While blocking the increase in intracellular Ca 2+ by locking the IP 3 R calcium channel with 2-APB had no effect on EGF activation of the ERK or AKT signaling pathways, it abolished the rapid EGF-mediated induction and repression of gene expression. Knockdown of ATF6α or XBP1, which regulate UPR-induced chaperone production, inhibited EGF stimulated cell proliferation. Supporting biological relevance, increased levels of EGF receptor during tumor progression were correlated with increased expression of the UPR gene signature. Anticipatory activation of the UPR is a new role for EGF. Since UPR activation occurs in <2 min, it is an initial cell response when EGF binds EGFR. [ABSTRACT FROM AUTHOR]

Abstract: 3-Nitropropionic acid (3-NP), an irreversible inhibitor of succinate dehydrogenase, produces selective lesions in striatal neurons that resemble those observed in Huntington''s disease neuropathology. In this study, we evaluated the role of peripheral bone marrow-derived cells (BMDCs) in the 3-NP-induced striatal damage by transplanting bone marrow cells with human SOD1 G93A mutation (mSOD1G93A) which induces amyotrophic lateral sclerosis through an unknown gain of toxicity and mitochondrial dysfunction. We assessed striatal damage after 3-NP treatment in the recipient C57BL/6 wild-type (WT) mice that received bone marrow cells from WT or mSOD1G93A transgenic donor mice (WT→WT or mSODG93A →WT). After intraperitoneal injection of 3-NP, six of the eight mSOD1G93A →WT mice had bilateral striatal lesions while only one out of eight WT→WT mice had a striatal lesion. The lesion volume was significantly higher in the mSOD1G93A →WT mice than in the WT→WT mice. However, following an intrastriatal injection of 3-NP, there was no significant difference in the lesion volumes between the WT→WT mice and mSOD1G93A →WT mice. Thus, the exacerbation of 3-NP-induced striatal damage in mSODG93A →WT mice was only seen after systemic administration of 3-NP, but not after intrastriatal injection. These results demonstrate that altered SOD1 activity (mSODG93A) in BMDCs affects striatal damage probably through a mechanism involving a systemic factor. [Copyright &y& Elsevier]

Abstract: The adenosine A2A receptor has recently emerged as a leading non-dopaminergic therapeutic target for Parkinson''s disease, largely due to the restricted distribution of the receptor in the striatum and the profound interaction between adenosine and dopamine receptors in brain. Two lines of research in particular have demonstrated the promise of the A2A receptor antagonists as novel anti-parkinsonian drugs. First, building on extensive preclinical animal studies, the A2A receptor antagonist KW6002 has demonstrated its potential to increase motor activity in PD patients of the advanced stage in a recent clinical phase IIB trial. Second, recently two prospective epidemiological studies of large cohorts have firmly established the inverse relationship between the consumption of caffeine (a non-specific adenosine antagonist) and the risk of developing PD. The potential neuroprotective effect of caffeine and A2A receptor antagonists in PD is further substantiated by the demonstration that pharmacological blockade (by caffeine or specific A2A antagonists) or genetic depletion of the A2A receptor attenuated dopaminergic neurotoxicity and neurodegeneration in animal models of PD. Moreover, A2A receptor antagonism-mediated neuroprotection goes beyond PD models and can be extended to a variety of other brain injuries induced by stroke, excitotoxicity and mitochondrial toxins. Intensive investigations are under way to dissect out common cellular mechanisms (such as A2A receptor modulation of neuroinflammation) which may underlie the broad spectrum of neuroprotection by A2A receptor inactivation in brain. [Copyright &y& Elsevier]

Abstract: Adenosine A2A receptor (A2AR) antagonists, including the non-specific adenosine antagonist caffeine, have been proposed as a novel, non-dopaminergic treatment strategy for Parkinson''s disease (PD). However, the long-term interaction between caffeine and l-dopa treatment in PD models has not been characterized. We examined the interaction between caffeine and l-dopa following a repeated treatment paradigm in hemiparkinsonian mice. In contrast to the progressively sensitized rotational behavior induced by daily l-dopa (2.0mg/kg) treatment, tolerance for the rotational response to daily caffeine (2.5 or 10mg/kg) treatment tended to develop over several weeks. However, after a subsequent two-week washout, challenge with same drug demonstrated an extinction of the sensitized l-dopa-induced rotation, but a sensitization of the caffeine-induced rotation. In a cross-challenge paradigm, daily treatment of mice with l-dopa (compared to daily saline) produced a three-fold enhancement in the rotational response to a subsequent re-challenge with caffeine. Similarly, daily treatment of mice with caffeine produced a six-fold enhancement in the rotational response to a subsequent re-challenge with l-dopa. Furthermore, daily co-administration of caffeine plus l-dopa produced enhanced rotational behavior, compared to caffeine or l-dopa alone, indicating an additive or synergistic interaction between caffeine and l-dopa during repeated treatment. Cross-sensitization between caffeine and l-dopa following repeated treatment and their positive interaction during chronic co-adminstration in hemiparkinsonian mice suggest that repeated exposure to caffeine may alter l-dopa responses in PD. [Copyright &y& Elsevier]

The adenosine A2A receptor (A2AR) is abundantly expressed in brain and emerging as an important therapeutic target for Parkinson''s disease and potentially other neuropsychiatric disorders. To understand the molecular mechanisms of A2AR gene expression, we have characterized the genomic organization of the mouse and human A2AR genes by molecular and bioinformatic analyses. Three new exons (m1A, m1B and m1C) encoding the 5′ untranslated regions (5′-UTRs) of mouse A2AR mRNA were identified by rapid amplification of 5′ cDNA end (5′ RACE), RT-PCR analysis and genome sequence analyses. Similar bioinformatics analysis also suggested six variants of the non-coding “exon 1” (h1A, h1B, h1C, h1D, h1E and h1F) in the human A2AR gene, which were confirmed by RT-PCR analysis, while three of the human exon 1 variants (h1D, h1E and h1F) were likewise verified by 5′ oligonucleotide capping analysis suggesting multiple transcription start sites. Importantly, RT-PCR and quantitative PCR analysis demonstrated that the A2AR transcripts with different exon 1 variants displayed tissue-specific expression patterns. For instance, the mouse exon m1A mRNA was detected only in brain (specifically striatum) and the human exon h1D mRNA in lymphoreticular system. Furthermore, the determination of the three new transcription start sites of human A2AR gene by 5′ oligonucleotide capping and bioinformatics analyses led to the identification of three corresponding promoter regions which contain several important cis elements, providing additional target for further molecular dissection of A2AR gene expression. Finally, our analysis indicates that A2AR mRNA and a novel transcript partially overlapping with the 3′ exon h3, but in opposite orientation to the A2AR gene, could conceivably form duplexes to mutually regulate transcript expression. Thus, combined molecular and bioinformatics analyses revealed a new A2AR genomic structure, with conserved coding exons 2 and 3 and divergent, tissue-specific exon 1 variants encoding for 5′-UTR. This raises the possibility of generating multiple tissue-specific A2AR mRNA species by alternative promoters with varying regulatory susceptibility. [Copyright &y& Elsevier]

Accumulation of unfolded protein, or other stresses, activates the classical reactive unfolded protein response (UPR). In the recently characterized anticipatory UPR, receptor-bound estrogen, progesterone and other mitogenic hormones rapidly elicit phosphorylation of phospholipase C γ (PLCγ), activating the anticipatory UPR. How estrogen and progesterone activating their receptors couples to PLCγ phosphorylation and anticipatory UPR activation was unknown. We show that the oncogene c-Src is a rate-limiting regulator whose tyrosine kinase activity links estrogen and progesterone activating their receptors to anticipatory UPR activation. Supporting Src coupling estrogen and progesterone to anticipatory UPR activation, we identified extranuclear complexes of estrogen receptor α (ERα):Src:PLCγ and progesterone receptor:Src:PLCγ. Moreover, Src inhibition protected cancer cells against cell death. To probe Src's role, we used the preclinical ERα biomodulator, BHPI, which kills cancer cells by inducing lethal anticipatory UPR hyperactivation. Notably, Src inhibition blocked BHPI-mediated anticipatory UPR activation and the resulting rapid increase in intracellular calcium. After unbiased long-term selection for BHPI-resistant human breast cancer cells, 4/11 BHPI-resistant T47D clones, and nearly all MCF-7 clones, exhibited reduced levels of normally growth-stimulating Src. Notably, Src overexpression by virus transduction restored sensitivity to BHPI. Furthermore, in wild type cells, several-fold knockdown of Src, but not of ERα, strongly blocked BHPI-mediated UPR activation and subsequent HMGB1 release and necrotic cell death. Thus, Src plays a previously undescribed pivotal role in activation of the tumor-protective anticipatory UPR, thereby increasing the resilience of breast cancer cells. This is a new role for Src and the anticipatory UPR in breast cancer. Unlabelled Image • Src regulates estrogen and progesterone activation of the anticipatory UPR. • Inhibiting Src blocks the Ca2+ increase that triggers anticipatory UPR activation. • Src levels control cancer cell death by the anticipatory UPR hyperactivator, BHPI. • Breast cancer cell lines selected for BHPI resistance often down-regulate Src. [ABSTRACT FROM AUTHOR]

To identify new pathways of estrogen action and novel estrogen receptor α (ERα) biomodulators, we performed high throughput screening and used follow on assays and bioinformatics to identify small molecule ERα inhibitors with a novel mode of action. These studies led to identification of rapid extranuclear activation of the endoplasmic reticulum stress sensor, the unfolded protein response (UPR), as a new pathway of estrogen-ERα action. Moreover, increasing evidence indicates that the mechanism underlying anticipatory activation of the UPR is shared among steroid and peptide hormones and is conserved from insects to humans. It is likely that this newly unveiled extranuclear pathway is used by diverse mitogenic hormones to prepare cells for the increased protein folding load that will occur during subsequent cell proliferation. Demonstrating biological relevance, elevated expression of a UPR gene signature in ERα positive breast cancer is a powerful new prognostic marker tightly correlated with subsequent resistance to tamoxifen, tumor recurrence and poor survival. In addition, overexpression of epidermal growth factor receptor and HER2/neu is positively correlated with increased UPR activation in breast cancer. This review describes recent research that demonstrates the importance of anticipatory UPR activation in therapy resistant tumors and discusses a promising small molecule biomodulator that inhibits tumor growth by tuning this UPR signaling pathway. [ABSTRACT FROM AUTHOR]

The endoplasmic reticulum (EnR) stress sensor, the unfolded protein response (UPR), plays a key role in regulating intracellular protein homeostasis. The extensively studied reactive mode of UPR activation is characterized by unfolded protein, or other EnR stress, triggering UPR activation. Here we focus on the emerging anticipatory mode of UPR activation in which mitogenic steroid and peptide hormones and other effectors preactivate the UPR and anticipate a future need for increased protein folding capacity. Mild UPR activation in breast cancer can be protective and contributes to antiestrogen resistance. Hyperactivation of the anticipatory UPR pathway in cancer cells with a small molecule converts it from cytoprotective to cytotoxic, highlighting its potential as a therapeutic target in estrogen receptor-positive breast cancer. [ABSTRACT FROM AUTHOR]

Spinal cord injury (SCI) triggers interconnected malignant pathological cascades culminating in structural abnormalities and composition changes of neural tissues and impairs spinal cord tissue function. Cellulose nanofibers (CNF) have considerable potential in mimicking tissue microstructure for nerve regeneration, but the effectiveness of CNF in repairing SCI remains poorly understood. In this study, we designed a Mg–Fe layered double hydroxide (LDH)-doped cellulose nanofiber (CNF) scaffold with aligned intact microchannels and homogeneously distributed pores (CNF-LDH), loaded with retinoic acid and sonic hedgehog (CNF-LDH-RS) for neuroregeneration. The aligned microchannel structure and chemical cues in the scaffold were designed further to enhance the differentiation of neural stem cells towards neurons and promote axon growth while inhibiting differentiation to astrocytes. Transplanting the scaffolds into a completely transected SCI mice model dramatically improved behavioral and electrophysiological outcomes underpinned by robust neuronal regeneration, significant axonal growth and orderly neural circuit remodeling. RNA-seq analysis revealed the pivotal roles of the RhoA/Rock/Myosin II pathway and neuroactive ligand-receptor interaction pathway in SCI repair by CNF-LDH-RS. Particularly, Myosin II emerged as a key gene for functional recovery, and its effect on negative regulation of axon growth was suppressed by the scaffolds, resulting in a distinctly oriented growth of the axons along the microchannel structure. The results indicate that CNF-LDH scaffolds rationally combined with physical and biochemical cues create promising tissue-engineered substrates to facilitate the repair of spinal cord injury. [ABSTRACT FROM AUTHOR]