Massive retroperitoneal hematoma caused by intercostal artery bleeding after blunt trauma: a case report.

BACKGROUND: The occurrence of massive retroperitoneal hematoma caused by intercostal artery bleeding is exceedingly uncommon. CASE PRESENTATION: A middle-aged male presented to the hospital after a fall. Computed tomography scan revealed a massive retroperitoneal hematoma without any evidence of organ or major vessel rupture. The angiogram revealed extravasation from a branch of the twelfth intercostal artery, and successful transcatheter arterial embolization was performed on this specific artery. CONCLUSIONS: The possibility of intercostal artery rupture should be considered in cases of retroperitoneal hematomas, and accurate diagnosis can be achieved through imaging studies. Transcatheter arterial embolization represents an effective treatment modality.

Paracrine secretion of IL8 by breast cancer stem cells promotes therapeutic resistance and metastasis of the bulk tumor cells.

BACKGROUND: Breast tumors consist of heterogeneous cellular subpopulations that differ in molecular properties and functional attributes. Cancer stem cells (CSCs) play pivotal roles in cancer therapeutic failure and metastasis. However, it remains indeterminate how CSCs determine the progression of the bulk cancer cell population. METHODS: Co-culture systems in vitro and co-implantation systems in vivo were designed to characterize the interactions between breast cancer stem cells (BCSCs) and bulk cancer cells. RNA sequencing was performed to study the functional and mechanistic implications of the BCSC secretome on bulk cancer cells. A cytokine antibody array was employed to screen the differentially secreted cytokines in the BCSC secretome. Tail vein injection metastatic models and orthotopic xenograft models were applied to study the therapeutic potential of targeting IL8. RESULTS: We identified that the BCSC secretome potentiated estrogen receptor (ER) activity in the bulk cancer cell population. The BCSC secretome rendered the bulk cancer cell population resistant to anti-estrogen and CDK4/6 inhibitor therapy; as well as increased the metastatic burden attributable to bulk cancer cells. Screening of the BCSC secretome identified IL8 as a pivotal factor that potentiated ERα activity, endowed tamoxifen resistance and enhanced metastatic burden by regulation of bulk cancer cell behavior. Pharmacological inhibition of IL8 increased the efficacy of fulvestrant and/or palbociclib by reversing tamoxifen resistance and abrogated metastatic burden. CONCLUSION: Taken together, this study delineates the mechanism by which BCSCs determine the therapeutic response and metastasis of bulk cancer cells; and thereby suggests potential therapeutic strategies to ameliorate breast cancer outcomes. Video Abstract.

Cancer stem cell regulated phenotypic plasticity protects metastasized cancer cells from ferroptosis.

Cancer cells display phenotypic equilibrium between the stem-like and differentiated states during neoplastic homeostasis. The functional and mechanistic implications of this subpopulation plasticity remain largely unknown. Herein, it is demonstrated that the breast cancer stem cell (BCSC) secretome autonomously compresses the stem cell population. Co-implantation with BCSCs decreases the tumor-initiating capacity yet increases metastasis of accompanying cancer cells, wherein DKK1 is identified as a pivotal factor secreted by BCSCs for such functions. DKK1-promotes differentiation is indispensable for disseminated tumor cell metastatic outgrowth. In contrast, DKK1 inhibitors substantially relieve the metastatic burden by restraining metastatic cells in the dormant state. DKK1 increases the expression of SLC7A11 to protect metastasizing cancer cells from lipid peroxidation and ferroptosis. Combined treatment with a ferroptosis inducer and a DKK1 inhibitor exhibits synergistic effects in diminishing metastasis. Hence, this study deciphers the contribution of CSC-regulated phenotypic plasticity in metastatic colonization and provides therapeutic approaches to limit metastatic outgrowth.

Hypermethylation of Mitochondrial Cytochrome b and Cytochrome c Oxidase II Genes with Decreased Mitochondrial DNA Copy Numbers in the APP/PS1 Transgenic Mouse Model of Alzheimer's Disease.

Alzheimer's disease (AD) is the most common cause of dementia. Increasing evidence shows that mitochondrial DNA (mtDNA) methylation plays an essential role in many diseases related to mitochondrial dysfunction. Since mitochondrial impairment is a key feature of AD, mtDNA methylation may also contribute to AD, but few studies have addressed this issue. Methylation changes of the mitochondrial cytochrome b (CYTB) and cytochrome c oxidase II (COX II) genes in AD have not been reported. We analyzed mtDNA methylation changes of the CYTB and COX II genes in an APP/PS1 transgenic mouse model of AD using pyrosequencing. We examined mtDNA copy numbers and the levels of expression by quantitative real-time PCR. Average methylation levels of different CpG sites were ≤ 4.0%. Methylated mtDNA accounted for only a small part of the total mtDNA. We also observed hypermethylation of mitochondrial CYTB and COX II genes with decreased mtDNA copy numbers and expression in the hippocampi of APP/PS1 transgenic mice. mtDNA methylation may play an important role in AD pathology, which may open a new window for AD therapy.

Vascular endothelial growth factor alleviates mitochondrial dysfunction and suppression of mitochondrial biogenesis in models of Alzheimer's disease.

PURPOSE: Mitochondrial dysfunction is a prominent feature of Alzheimer's disease (AD). As vascular endothelial growth factor (VEGF) has been shown to be protective in AD, the aim of this study was to investigate the effects of VEGF on mitochondrial function in models of AD. MATERIALS AND METHODS: Adeno associated virus (AAV)-VEGF was injected into the hippocampus of APP/PS1 mice. Cognitive function was assessed in these mice with use of the Morris water maze (MWM) and ß-amyloid (Aß) levels in the hippocampus were also measured. Cell viability and reactive oxygen species (ROS) levels were determined in the SH-SY5Y cells treated with Aß25-35 which served as a cell model of AD. Transmission electron microscopy (TEM) was used to evaluate structural changes in mitochondria and mitochondrial DNA (mtDNA) copy number and mitochondrial membrane potential (MMP) were also recorded. Finally, we investigated the effects of VEGF upon mitochondrial biogenesis, autophagy and mitochondrial autophagy (mitophagy) as determined both in vivo and in vitro with western blots. RESULTS: VEGF treated mice showed improvements in spatial learning and memory along with reduced Aß levels. VEGF protected SH-SY5Y cells against Aß25-35 induced neurotoxicity as demonstrated by increased cell viability and decreased ROS production. Associated with these effects were improvements in mitochondrial structure and function, and increased numbers of mitochondria resulting from stimulation of mitochondrial biogenesis. CONCLUSIONS: VEGF alleviates Aß related patholoy in models of AD. In part, these beneficial effects of VEGF result from protection of mitochondria and stimulation of mitochondrial biogenesis.

Abnormality of m6A mRNA Methylation Is Involved in Alzheimer's Disease.

Alzheimer's disease (AD), the most common form of dementia, is highly prevalent in older adults. The main clinical feature is the progressive decline of memory function, which eventually leads to the decline of cognitive function. At present, the pathogenesis of AD is unclear. In the disease process, synaptic changes are the key. Recent studies have shown that the dysregulation of RNA methylation is related to many biological processes, including neurodevelopment and neurodegenerative diseases. N6-methyladenosine (m6A) is the most abundant modification in eukaryotic RNA. In this study, RNA m6A methylation was quantified in APP/PS1 transgenic mice, which is an AD mouse model, and C57BL/6 control mice, and data showed that m6A methylation was elevated in the cortex and the hippocampus of APP/PS1 transgenic mice. Next, the alterations of m6A RNA methylation in AD and in C57BL/6 mice were investigated using high-throughput sequencing. Genome-wide maps of m6A mRNA showed that the degrees of m6A methylation were higher in many genes and lower in others in AD mice. Interestingly, the expression of the m6A methyltransferase METTL3 was elevated and that of the m6A demethylase FTO was decreased in AD mice. The data were analyzed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, and pathways that might be related to synaptic or neuron development and growth were constructed. The related pathways and genes predicted the potential roles of the differentially expressed m6A methylation RNA in AD. Collectively, our findings demonstrate that the m6A methylation of RNA promotes the development of AD.

Transplantation of IFN-γ Primed hUCMSCs Significantly Improved Outcomes of Experimental Autoimmune Encephalomyelitis in a Mouse Model.

The aim of this study was to investigate potential therapeutic effects of IFN-γ primed human umbilical cord mesenchymal stem cell (IFN-γ-hUCMSCs) transplantation on experimental autoimmune encephalomyelitis (EAE) in mice. In this study, EAE mouse model was established by MOG35-55 immunization method. Outcomes of the EAE mice in terms of body weight and clinical symptoms were analyzed. Electromyography (EMG) was performed to evaluate nerve conduction. ELISA was applied to quantify inflammatory cytokine levels in serum. Our results showed that IFN-γ could up-regulate protein expression of indoleamine 2, 3-dioxygenease 1 (IDO1), an important molecule released by MSCs to exert their immune suppressive activity (p < 0.01). In this study treatment efficacy for EAE was compared between transplantation of hUCMSCs alone and the IFN-γ-hUCMSCs which were cultured in the presence of IFN-γ for 48 h prior to be harvested for transplantation. Compared with hUCMSCs alone and control (PBS transfusion) group, transplantation of the IFN-γ-hUCMSCs could significantly alleviate the body weight loss and clinical symptoms of EAE mice (p < 0.05). Consistently EMG latency was significantly improved in treatment groups (p < 0.001), and the IFN-γ-hUCMSCs group was even better than the hUCMSCs group (p < 0.05). Moreover, the concentrations of IL-17A and TNF-α in serum of the mice treated by IFN-γ-hUCMSCs were significantly lower than hUCMSCs alone and controls, respectively (p < 0.05). In few of the roles of IL-17A and TNF-α in the pathogenesis of EAE, IFN-γ-hUCMSCs treatment associated-suppression of IL-17A and TNF-α expression may contribute in part to their therapeutic effects on EAE. In sum, our study highlights a great clinical potential of IFN-γ-hUCMSCs for multiple sclerosis (MS) treatment.

Orexin-A aggravates cytotoxicity and mitochondrial impairment in SH-SY5Y cells transfected with APPswe via p38 MAPK pathway.

BACKGROUND: Alzheimer's disease (AD) is one of the common neurodegenerative diseases and is characterized by the accumulation of amyloid-ß (Aß). Orexin-A is a neuropeptide produced in the hypothalamus and thought to be involved in the pathogenesis of AD. However, its underlying mechanism and signaling pathway remains unclear. The aim of this work was to investigate the effect of Orexin-A on AD, and to explore its potential mechanism and signaling pathway. METHODS: SH-SY5Y cells that were stably transfected with the Swedish mutant amyloid precursor protein (APPswe), a cell model of AD with excessive Aß production, were used in this study. Cells were treated with Orexin-A, and with or without SB203580, an inhibitor of the p38 mitogen-activated protein kinase (MAPK) pathway, one of the key MAPK pathways associated with cell death. Following treatment, cells were collected and analyzed by western blotting, ELISA, electron microscopy, real-time PCR, fluorescence microscopy, and other biochemical assays. RESULTS: Orexin-A increased the level of Aß1-40 and Aß1-42 in the cell medium, and activated the p38 MAPK pathway. As evidenced by the CCK-8 and ELISA BrdU assays, Orexin-A decreased cell viability and cell proliferation. Electron microscopic analysis used to observe the morphology of mitochondria, showed that Orexin-A increased the percentage of abnormal mitochondria. Further, decreased activity of cytochrome c oxidase (CCO), level of ATP, and mitochondrial DNA (mtDNA) copy number following Orexin-A treatment showed that Orexin-A exacerbated mitochondrial dysfunction. The level of intracellular reactive oxygen species (ROS), which is mainly generated in mitochondria and reflects mitochondrial dysfunction, was also increased by Orexin-A. SB203580 blocked the cytotoxicity and mitochondrial impairment aggravated by Orexin-A. CONCLUSIONS: These findings demonstrate that Orexin-A aggravates cytotoxicity and mitochondrial impairment in SH-SY5Y cells transfected with APPswe through the p38 MAPK pathway, and suggest that Orexin-A participates in the pathogenesis of AD, which may provide a new treatment target in the future.

Orexin-A exacerbates Alzheimer's disease by inducing mitochondrial impairment.

Alzheimer's disease (AD) is a progressive neurodegenerative disease which is characterized by the accumulation of amyloid-ß peptide (Aß). Orexin-A is a neuropeptide which has been reported to participate in the pathogenesis of AD. Thus, we aimed to investigate the possible mechanism by which Orexin-A acts in AD. APP/PS1 transgenic mice, an animal model of AD, were intracerebroventricularly injected with Orexin-A. Aß-treated SH-SY5Y cells were used as a cell model of AD and treated with Orexin-A. The Morris water maze test, fluorescence microscopy, enzyme-linked immunosorbent assay (ELISA), electron microscopy, real-time PCR, and other biochemical assays were conducted. The Morris water maze test showed that Orexin-A aggravated cognitive deficit in APP/PS1 mice. Using thioflavine-S staining and ELISA, we found that Orexin-A promoted Aß accumulation in APP/PS1 mice. By evaluating mitochondrial morphology, cytochrome c oxidase activity, ATP level, mitochondrial DNA copy number, and reactive oxygen species, we found that Orexin-A aggravated mitochondrial impairment in APP/PS1 mice and Aß-treated SH-SY5Y cells. Our results indicate that Orexin-A exacerbates AD by inducing mitochondrial impairment. This is a new mechanism that explains how Orexin-A participates in the pathogenesis of AD.

Altered mitochondrial DNA methylation and mitochondrial DNA copy number in an APP/PS1 transgenic mouse model of Alzheimer disease.

Alzheimer's disease (AD) is a chronic neurodegenerative disease and mitochondrial impairment is a key feature of AD. The mitochondrial DNA (mtDNA) epigenetic mechanism is a relatively new field compared to nuclear DNA. The relationship between mtDNA epigenetic mechanism and AD hasn't been established. So we analyzed the mtDNA methylation in D-loop region and 12 S rRNA gene in the hippocampi in amyloid precursor protein/presenilin 1 (APP/PS1) transgenic mice by bisulfite pyrosequencing. Mitochondrial DNA copy number and gene expression were studied by quantitative real-time PCR (qRT-PCR). We observed a decrease in the displacement loop (D-loop) methylation and an increase in 12 S rRNA gene methylation, while both the mtDNA copy number and the mitochondrial gene expression were reduced in APP/PS1 transgenic mice. In summary, the present finding suggest that mtDNA methylation may play a role in AD pathology, which warrants larger future investigations.

Activation of Mitochondrial Unfolded Protein Response in SHSY5Y Expressing APP Cells and APP/PS1 Mice.

Alzheimer disease (AD) is the most common form of dementia. Amyloid ß-peptide (Aß) deposition is a major neuropathologic feature of AD. When unfolded or misfolded proteins accumulate in mitochondria, the unfolded protein responses (UPRmt) is initiated. Numerous lines of evidence show that AD pathogenesis involves mitochondrial dysfunction. However little is known about whether the UPRmt is engaged in the process of AD development. In this study, we investigated the UPRmt in mouse and cell models of AD. We found that UPRmt was activated in the brain of 3 and 9 months old APP/PS1 mice, and in the SHSY5Y cells after exposure to Aß25-35, Aß25-35 triggered UPRmt in SHSY5Y cells could be attenuated upon administration of simvastatin or siRNA for HMGCS-1 to inhibit the mevalonate pathway, and or upon knocking down Serine palmitoyltransferase long chain subunit 1 (SPTLC-1) to lower sphingolipid biosynthesis. We observed that inhibition of UPRmt aggravated cytotoxic effects of Aß25-35 in SHSY5Y cells. Our research suggests that the UPRmt activation and two pathways necessary for this response, and further provides evidence for the cytoprotective effect of UPRmt during the AD process.

Mitochondrial biogenesis mediated by melatonin in an APPswe/PS1dE9 transgenic mice model.

Alzheimer's disease (AD) is a chronic progressive neurodegenerative disease, but the pathogenesis is unclear. Damaged mitochondrial biogenesis has been observed in AD. Increasing evidence suggests that mitochondrial biogenesis is involved in the pathogenesis of AD, but the exact mechanism is unclear. In this study, we used the amyloid precursor protein Swedish mutations K594N/M595L (APPswe)/presenilin 1 with the exon-9 deletion (PS1dE9) transgenic mouse model of AD, which was successfully established by the expression of amyloid ß precursor protein and presenilin 1 (PS1). Then, we compared APPswe/PS1dE9 transgenic mice with and without melatonin (MT) in drinking water for 4 months (estimated 0.5 mg/day) and control C57BL/6J mice without MT for expression of mitochondrial biogenesis factors (mitochondrial transcription factor A, nuclear respiratory factor 1 and 2, peroxisome proliferator-activated receptor γ coactivator 1-α), mitochondrial structure, mitochondrial DNA to nuclear DNA ratio, behavioral changes, and amyloid ß (Aß) deposition and soluble Aß levels in the cerebral cortex and hippocampus. Compared with controls, APPswe/PS1dE9 mice with long-term MT intake showed increased levels of mitochondrial biogenesis factors, alleviated mitochondrial impairment, enhanced mitochondrial DNA copy number, improved spatial learning and memory deficits, and reduced Aß deposition and soluble Aß levels. Defective mitochondrial biogenesis may contribute toward the damaged mitochondrial structure and function in AD. MT may alleviate AD by promoting mitochondrial biogenesis.