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A disintegrin and metalloproteinases 10 (ADAM10) and ADAM17 are transmembrane metalloproteinases that cleave the membrane-anchored proteins. They act as α-secretase that cleaves amyloid precursor protein (APP), precluding the production of amyloid-β, thus protecting against the onset of Alzheimer's disease (AD). However, the degradation pathway of ADAM10 and ADAM17 remains unknown. In this study, we show that ADAM10 and ADAM17 are degraded through the lysosomal pathway. The lysosomal cysteine protease, AEP, plays an important role in the degradation of ADAM10/17. AEP directly cleaves ADAM10/17. Knockout of AEP increases the content of ADAM10/17 in the brain. Given the protective role of ADAM10 and ADAM17 against AD, AEP-mediated degradation of ADAM10/17 may be involved in the pathogenesis of AD. • ADAM10 and ADAM17 were degraded by the lysosome pathway. • The lysosome enzyme, AEP, degraded ADAM10 and ADAM17 in vitro and in vivo. • Knockout of AEP elevated the content of ADAM10 and ADAM17. [ABSTRACT FROM AUTHOR]

Abstract Long noncoding RNA (OGFRP1) has been reported to be involved in the progression of non-small cell lung cancer (NSCLC). However, the expression pattern, functions and molecular mechanisms of OGFRP1 in NSCLC remains unclear. In the present study, we found that OGFRP1 expression was significantly up-regulated in both NSCLC tissues and cell lines, and the upregulation of OGFRP1 expression is a powerful predictor of advanced clinical stage, lymph nodes metastasis and poor prognosis for NSCLC patients. Loss-of-function assay indicated that knockdown of OGFRP1 inhibited proliferation, migration and invasion, and induced apoptosis in vitro. Mechanistically, OGFRP1 could directly bind to miR-124-3p and effectively act as a competing endogenous RNA (ceRNA) for miR-124-3p to promote the expression of the target gene LYPD3. Taken together, OGFRP1 contributed to progression of NSCLC at least partly through upregulating LYPD3 expression by sponging miR-124-3p, indicating that OGFRP1 may be a novel prognostic biomarker and therapeutic target in NSCLC. Highlights • The expression levels of lncRNA OGFRP1 was up-regulated in NSCLC tissues and cell lines. • Overexpression of lncRNA OGFRP1 was associated with advanced clinical features and poor prognosis in NSCLC patients. • LncRNA OGFRP1 promoted NSCLC cells proliferation, migration and invasion by regulation of miR-124-3p-LYPD3 pathway. [ABSTRACT FROM AUTHOR]

Melanoma is the most aggressive type of skin cancer. Melanoma has an extremely poor prognosis because of its high potential for vascular invasion, metastasis and recurrence. The mechanism of melanoma metastasis is not well understood. ATP-binding cassette sub-family B member 5 (ABCB5) plays a key role in melanoma growth. However, it is uncertain what function ABCB5 may exert in melanoma metastasis. In this report, we for the first time demonstrate ABCB5 as a crucial factor that promotes melanoma metastasis. ABCB5 positive (ABCB5 + ) malignant melanoma initiating cells (MMICs) display a higher metastatic potential compared with ABCB5 negative (ABCB5 - ) melanoma subpopulation. Knockdown of ABCB5 expression reduces melanoma cell migration and invasion in vitro and melanoma pulmonary metastasis in tumor xenograft mice. ABCB5 and NF-κB p65 expression levels are positively correlated in both melanoma tissues and cell lines. Consequently, ABCB5 activates the NF-κB pathway by inhibiting p65 ubiquitination to enhance p65 protein stability. Our finding highlights ABCB5 as a novel pro -metastasis factor and provides a potential therapeutic target for melanoma. [ABSTRACT FROM AUTHOR]

Background Microglia microvesicles (MVs) has shown to have significant biological functions under normal conditions. A diversity of miRNAs is involved in neuronal development, survival, function, and plasticity, but the exact functional role of NDRG2 and secreted miR-375 in MVs in neuron damage is poorly understood. We investigated the effect of NDRG2 and secreted miR-375 in MVs shed from M1 microglia on neuron damage. Methods Expression of Nos2, Arg-1, miR-375, syntaxin-1A, NDRG2 and Pdk 1 were evaluated using RT-PCR or western blotting. Cell viability of N2A neuron was quantified by a MTT assay. Results Microglia can be polarized into different functional phenotypes. Expression of NDRG2 and Nos2 were significantly increased by LPS treatment on N9 cells, whereas treatment with IL-4 dramatically suppressed the expression of NDRG2 and remarkably elevated expression of Arg-1. Besides, MVs shed from LPS-treated N9 microglia significantly inhibited cell viability of N2A neurons and expression of syntaxin-1A, and NDRG2 interference reversed the up-regulated miR-375 in LPS-treated N9 microglia and MVs shed from LPS-treated N9 cells. Furthermore, NDRG2 could modulate miR-375 expression in N9 microglia and MVs. And miR-375 inhibitor remarkably elevated Pdk1 expression in N2A neurons. Finally, miR-375 inhibitor could reverse suppression effect of NDRG2 overexpression on cell viability of N2A neurons and expression of syntaxin-1A. Conclusion Our results demonstrated that NDRG2 promoted secreted miR-375 in microvesicles shed from M1 microglia, which induced neuron damage. The suppression of NDRG2 and secreted miR-375 in MVs shed from M1 microglia may be potential targets for alleviation of neuron damage. [ABSTRACT FROM AUTHOR]

The growth of cells and tissues is regulated by stress. When body is injured, it manifests a large spectrum of metabolic, endocrine, and immune alterations, which is named stress reaction. Among them, the production of growth factors may play a critical role. For osteoblasts and myoblasts, IGF-I has been shown to be involved in the process of cells in response to overloads. There are two splicing forms, one is IGF-Ea, the other is the IGF-IEb in the rodents and corresponds to IGF-IEc in humans. The latter is markedly up-regulated in response to overloads. Therefore, it has been named mechanogrowth factor. The link between the mechanical stimulus and the gene expression represents a new and important area in cell science. Understanding the process of splicing in IGF-I helps one to investigate the mechanotransduction of cells in response to mechanical stimulation at molecular level. [Copyright &y& Elsevier]

Homeodomain (HD)-containing proteins are typically recognized as transcription factors. Engrailed 2 (EN2) is an HD-containing protein that is highly expressed in various types of cancers, however, the mechanism underlying the biological function of EN2 is not fully understood. Here, we report a transcription-independent function of EN2 in addition to its role as a transcription factor. EN2 expression leads to the activation of multiple signaling pathways mediated by phosphorylation cascades. A phosphoproteomic analysis revealed that the phosphorylation status of numerous protein sites was altered after EN2 is expressed. Notably, EN2 was shown to interact with a myriad of proteins implicated in phosphorylation signaling cascades, as determined by immunoprecipitation–mass spectrometry (IP–MS). We validated the interaction between EN2 and B55α, the regulatory subunit of the PP2A-B55α complex, and confirmed that the phosphatase activity of the complex was suppressed by EN2 binding. To target EN2-induced malignancy, two kinds of small molecules were utilized to inhibit the EN2-activated NF-κB and AKT signaling pathways. A clear synergistic effect was observed when the activation of the two pathways was simultaneously blocked. Collectively, the data show that EN2 functions in a transcription-independent manner in addition to its role as a transcription factor. This finding may have therapeutic implications in treating esophageal squamous cell carcinoma (ESCC). • EN2 activates multiple oncogenic signaling pathways. • EN2 alters the expression of numerous genes related to the signaling pathways, indicating a transcription-dependent manner. • EN2 interacts with the proteins involved in the signaling pathways, suggesting a transcription-independent mechanism. • EN2 interacts with B55α and consequently inhibits its phosphatase activity. • The perturbation of the EN2-induced signaling pathways inhibits the malignant phenotype in ESCC. [ABSTRACT FROM AUTHOR]

KDM2A is a histone demethylase, which primarily catalyzes the demethylation of H3K36me2. Abnormal expression of KDM2A is observed in many types of cancers; however, the molecular events connected to KDM2A expression remain unclear. We report that KDM2A performs an oncogenic function in esophageal squamous cell carcinoma (ESCC) and is robustly expressed in ESCC cells. ShRNA-mediated knockdown of KDM2A resulted in a significant inhibition of the malignant phenotype of ESCC cell lines, whereas ectopic expression of KDM2A showed the opposite effect. We also analyzed the function of KDM2A using a CRISPR-CAS9 depletion system and subsequent rescue experiment, which also indicated a cancerous role of KDM2A. Interestingly, analysis of the gene expression network controlled by KDM2A using RNA-seq revealed an unexpected feature: KDM2A could induce expression of a set of well-documented oncogenic genes, including IL6 and LAT2, while simultaneously suppressing another set of oncogenes, including MAT2A and HMGCS1. Targeted inhibition of the upregulated oncogene in the KDM2A-depleted cells led to a synergistic suppressive effect on the malignant phenotype of ESCC cells. Our results revealed the dual role of KDM2A in ESCC cells, which may have therapeutic implications. • Ablation of KDM2A attenuates the malignant phenotype of ESCC cell lines. • Augmented expression of KDM2A promotes the malignant phenotype of ESCC cells. • KDM2A activates one set of oncogenic genes and represses another set of cancerous genes simultaneously. • Inhibition of activated oncogenes generates a synergistic antitumor effect in KDM2A-deficient ESCC cells. • The dual role of KDM2A may be used to develop a combination treatment for ESCC. [ABSTRACT FROM AUTHOR]

Acetaminophen (APAP) overdose induces acute liver injury (ALI), even acute liver failure (ALF). There is a significant unmet need to furtherly elucidate the mechanisms and find new therapeutic target. Recently, emerging evidence indicates that nicotinamide adenine dinucleotide (NAD+) plays a crucial role in APAP-induced ALI. Herein, we firstly investigated the protein expression of NAD kinase (NADK), as the rate-limiting enzyme converting NAD+ to nicotinamide adenine dinucleotide phosphate (NADP+), and found it was positively correlated with APAP-induced ALI in a dose- and time-dependent manner. Additionally, supplementation of N-acetylcysteine (NAC), known as an antidote of APAP, mitigated the ALI and downregulated the expression of NADK which was also in a dose-dependent manner. Moreover, pretreatment with methotrexate (MTX), the inhibitor of NADK, attenuated the levels of transaminases, alleviated morphological abnormalities, and improved oxidative stress triggered by APAP overdose, which was attributed to elevated hepatic NAD+ pool. Subsequently, the increased NAD+ upregulated the expression of Sirt1, SOD2 and attenuated DNA damage. Collectively, elevated expression of NADK is related to APAP-induced ALI, and inhibition of NADK alleviates the ALI through elevating liver NAD+ level and improving antioxidant capacity. • The expression of NADK was positively correlated with APAP-induced ALI. • Inhibition of NADK alleviated APAP-induced ALI. • Inhibition of NADK increased the level of NAD+ and activated Sirt1/SOD2. [ABSTRACT FROM AUTHOR]

High-altitude de-acclimatization (HADA) significantly impacts physiological functions when individuals acclimatize to high altitudes return to lower altitudes. This study investigates HADA's effects on renal function and structure in rats, focusing on oxidative and endoplasmic reticulum stress as potential mechanisms of renal injury. To elucidate the pathophysiological mechanisms of renal damage in HADA and evaluate the efficacy of antioxidants Vitamin C (Vit C) and tauroursodeoxycholic acid (TUDCA) in mitigating these effects. 88 male Sprague-Dawley rats were randomly divided into a control group, a high-altitude (HA) group, a high-altitude de-acclimatization (HADA) group, and a treatment group. The control group was housed in a sea level environment (500 m), while the HA, HADA, and treatment groups were placed in a simulated high-altitude chamber (5000 m) for 90 days. After this period, the HA group completed the modeling phase; the HADA group was further subdivided into four subgroups, each continuing to be housed in a sea level environment for 3, 7, 14, and 30 days, respectively. The treatment group was split into the Vit C group, the TUDCA group, and two placebo groups, receiving medication for 3 consecutive days, once daily upon return to the sea level. The Vit C group received 100 mg/kg Vit C solution via intravenous injection, the TUDCA group received 250 mg/kg TUDCA solution via intraperitoneal injection, and the placebo groups received an equivalent volume of saline similarly. Serum, urine, and kidney tissues were collected immediately after the modeling phase. Renal function and oxidative stress levels were assessed using biochemical and ELISA methods. Renal histopathology was observed with H&E, Masson's trichrome, PAS, and PASM staining. Transmission electron microscopy was used to examine the ultrastructure of glomeruli and filtration barrier. TUNEL staining assessed cortical apoptosis in the kidneys. Metabolomics was employed for differential metabolite screening and pathway enrichment analysis. Compared to the control and HA groups, the HADA 3-day group (HADA-3D) exhibited elevated renal function indicators, significant pathological damage, observable ultrastructural alterations including endoplasmic reticulum expansion and apoptosis. TUNEL-positive cells significantly increased, indicating heightened oxidative stress levels. Various differential metabolites were enriched in pathways related to oxidative and endoplasmic reticulum stress. Early intervention with Vit C and TUDCA markedly alleviated renal injury in HADA rats, significantly reducing the number of apoptotic cells, mitigating endoplasmic reticulum stress, and substantially lowering oxidative stress levels. This study elucidates the pivotal roles of oxidative and endoplasmic reticulum stress in the early-stage renal injury in rats undergoing HADA. Early intervention with the Vit C and TUDCA significantly mitigates renal damage caused by HADA. These findings provide insights into the pathophysiological mechanisms of HADA and suggest potential therapeutic strategies for its future management. • Study on renal effects of high-altitude de-acclimatization (HADA) in rats. • Vitamin C and TUDCA reduce oxidative stress and kidney damage from HADA. • Identifies key metabolites and pathways in HADA-related kidney damage. • Advances understanding of physiological impacts in high-altitude medicine. [ABSTRACT FROM AUTHOR]

Angiogenesis plays a vital role in tumor progression and metastasis. To better understand the role of anesthesia in tumor biology, we previously reported that bupivacaine displayed the inhibitory effects in endothelial cells. In this work, we demonstrated that fentanyl, an opioid medication commonly used in cancer patients, stimulated tumor angiogenesis. We found that fentanyl at nanomolar concentrations significantly stimulated capillary network formation of human lung tumor-associated endothelial cell (HLT-EC) in a similar manner as vascular endothelial growth factor (VEGF), and furthermore that the stimulatory effect of fentanyl was mainly involved in early stage of HLT-EC vascular structure assembly. Particularly, fentanyl significantly increased HLT-EC growth and migration. Fentanyl also protected HLT-EC from apoptosis induced by growth factor withdrawal. In contrast, the same concentrations of fentanyl did not affect human lung cancer cell growth and survival. Fentanyl stimulated migration of some but not all tested human lung cancer cells. Mechanism analysis suggested that fentanyl activates multiple pro-angiogenic signaling pathways, including VEGFR2/FAK/PI3K/Akt and small GTPases. Our work systematically demonstrates that fentanyl stimulates tumor angiogenesis via activating multiple pro-angiogenic signaling pathways. Our findings highlight the potential adverse effect of fentanyl in cancer patients. • Fentanyl stimulates early stage of lung tumor angiogenesis. • Fentanyl increases HLT-EC migration, growth and survival. • Fentanyl activates VEGFR2/FAK, small GTPases and PI3K/Akt in HLT-EC. • Fentanyl increases lung cancer cell migration but not proliferation. [ABSTRACT FROM AUTHOR]

The regulatory mechanism of tautomycetin (TMC) biosynthesis remains largely unknown, although it has been of great interest to the pharmaceutical industry. Our previous study showed that intracellular adenosine triphosphate (inATP) level is negatively correlated with secondary metabolite biosynthesis in various Streptomyces spp. In this study, by exogenous treatment of ATP, we also found a negative correlation between TMC biosynthesis and inATP level in Streptomyces griseochromogenes ( S. griseochromogenes ). However, the underlying mechanism remains unclear. TmcN, a pathway-specific transcriptional regulator of TMC biosynthetic genes, was previously revealed as a large ATP-binding LuxR (LAL) family protein. The predicted amino acid sequence of TmcN shows highly conserved Walker A and B binding motifs, which suggest an ATPase function of TmcN. We therefore hypothesized that the ATPase domain of TmcN may play a role in sensing endogenous pool of ATP, and is thus involved in the ATP regulation of TMC biosynthesis. To test the hypothesis, we first explored the key residue that affects the ATPase activity of TmcN by amino acid sequence alignment and structural simulation. After that, we disrupted tmcN gene in S. griseochromogenes , and the tmcN or site-direct-mutated tmcN were re-introduced to get the complementary and ATPase domain disrupted strains. The transcription level of tmcN , TMC yield, and inATP, as well as the effect of ATP on TMC production of different mutants were evaluated. Deletion of tmcN or site-direct mutation of ATPase domain of TmcN in S. griseochromogenes significantly reduced the TMC production, and it was not affected by exogenous ATP treatment. In addition, a relatively high level of inATP was detected in tmcN deletion and site-direct mutation strains. Our results here suggested that TmcN, especially its ATPase domain, is involved in consuming of endogenous ATP pool and thus plays pivotal role in connecting the primary and secondary metabolite in S. griseochromogenes . [ABSTRACT FROM AUTHOR]

Accumulating evidence has indicated that natural killer cells (NK cells) play an important role in immune responses generated in the liver. However, the underlying molecular basis for local immune regulation is poorly understood. Mice were intraperitoneally injected with polyinosinic-polycytidylic acid (PolyI:C) at a dose of 20 mg/kg body wt. The percentage and absolute number of NK cells in the liver were analysed with flow cytometry. LSECtin knockout mice and LSECtin cDNA plasmids were used for analyze the role of LSECtin in hepatic NK cell regulation in vivo. Here, we show that the C-type lectin LSECtin, a member of the DC-SIGN family, is a novel liver regulator for NK cells. LSECtin could bind to NK cells in a carbohydrate-dependent manner and could regulate the number of hepatic NK cells. In the NK cell-mediated acute liver injury model induced with PolyI:C, the exogenous expression of LSECtin accelerated NK cell-induced liver injury, whereas the absence of LSECtin ameliorated this condition. Our results reveal that LSECtin is a novel, liver-specific NK cell regulator that may be a target for the treatment of inflammatory diseases in the liver. [ABSTRACT FROM AUTHOR]