The ex vivo generation of platelets from human-induced pluripotent cells (hiPSCs) is expected to compensate donor-dependent transfusion systems. However, manufacturing the clinically required number of platelets remains unachieved due to the low platelet release from hiPSC-derived megakaryocytes (hiPSC-MKs). Here, we report turbulence as a physical regulator in thrombopoiesis in vivo and its application to turbulence-controllable bioreactors. The identification of turbulent energy as a determinant parameter allowed scale-up to 8 L for the generation of 100 billion-order platelets from hiPSC-MKs, which satisfies clinical requirements. Turbulent flow promoted the release from megakaryocytes of IGFBP2, MIF, and Nardilysin to facilitate platelet shedding. hiPSC-platelets showed properties of bona fide human platelets, including circulation and hemostasis capacities upon transfusion in two animal models. This study provides a concept in which a coordinated physico-chemical mechanism promotes platelet biogenesis and an innovative strategy for ex vivo platelet manufacturing.
Background: The discovery and development of novel biomarkers that could facilitate early diagnosis and thus prevent the progression of atherosclerosis-related diabetes mellitus (DM), cerebral infarction (CI), and cardiovascular disease (CVD) has garnered much research interest. Notably, recent reports have described a number of highly sensitive antibody markers. In this study, we aimed to identify additional antibody markers that would facilitate screening. Methods:The amplified luminescent proximity homogeneous assay (AlphaLISA) method, which incorporates glutathione-or streptavidin-donor beads and anti-human-IgG-acceptor beads, was used to evaluate serum antibody levels in serum samples. The protein array method was used for the initial screening, and peptide arrays were used to identify epitope sites. Results:The protein array identified SH3 domain-binding protein 5 (SH3BP5) as a target antigen of serum IgG antibodies in the sera of patients with atherosclerosis. We prepared recombinant glutathione S-transferase (GST)-fused SH3BP5 protein. Peptide arrays revealed that the epitope site recognized by serum antibodies is located within amino acids 161-174 of SH3BP5. AlphaLISA revealed significantly higher serum antibody levels against both the SH3BP5 protein and peptide in patients with DM, acute-phase CI, transient ischemic attack, CVD or chronic kidney disease (CKD), than in healthy donors. Furthermore, areas under the receiver operating characteristic curves of these antibodies were higher in patients with CKD and DM than in other patients. Spearman correlation analysis revealed associations between the serum antibody levels against SH3BP5 peptide and artery stenosis, hypertension, and smoking. Conclusions:The serum anti-SH3BP5 antibody marker appears to be useful for estimating the progress of atherosclerosis and may discriminate atherosclerosis associated with hypertension and/or habitual smoking.
Summary We previously identified mutations in Nardilysin (dNrd1) in a forward genetic screen designed to isolate genes whose loss causes neurodegeneration in Drosophila photoreceptor neurons. Here we show that NRD1 is localized to mitochondria where it recruits mitochondrial chaperones and assists in the folding of α-ketoglutarate dehydrogenase (OGDH), a rate-limiting enzyme in the Krebs cycle. Loss of Nrd1 or Ogdh leads to an increase in α-ketoglutarate, a substrate for OGDH, which in turn leads to mTORC1 activation and a subsequent reduction in autophagy. Inhibition of mTOR activity by rapamycin or partially restoring autophagy delays neurodegeneration in dNrd1 mutant flies. In summary, this study reveals a novel role for NRD1 as a mitochondrial co-chaperone for OGDH, and provides a mechanistic link between mitochondrial metabolic dysfunction, mTORC1 signaling, and impaired autophagy in neurodegeneration.
Axonal maturation and myelination are essential processes for establishing an efficient neuronal signaling network. We found that nardilysin (N-arginine dibasic convertase, also known as Nrd1 and NRDc), a metalloendopeptidase enhancer of protein ectodomain shedding, is a critical regulator of these processes. Nrd1-/- mice had smaller brains and a thin cerebral cortex, in which there were less myelinated fibers with thinner myelin sheaths and smaller axon diameters. We also found hypomyelination in the peripheral nervous system (PNS) of Nrd1-/- mice. Neuron-specific overexpression of NRDc induced hypermyelination, indicating that the level of neuronal NRDc regulates myelin thickness. Consistent with these findings, Nrd1-/- mice had impaired motor activities and cognitive deficits. Furthermore, NRDc enhanced ectodomain shedding of neuregulin1 (NRG1), which is a master regulator of myelination in the PNS. On the basis of these data, we propose that NRDc regulates axonal maturation and myelination in the CNS and PNS, in part, through the modulation of NRG1 shedding.
Transient ischemic attack (TIA) is a predictor for cerebral infarction (CI), and early diagnosis of TIA is extremely important for the prevention of CI. We set out to identify novel antibody biomarkers for TIA and CI, and detected matrix metalloproteinase 1 (MMP1), chromobox homolog 1 (CBX1), and chromobox homolog 5 (CBX5) as candidate antigens using serological identification of antigens by recombinant cDNA expression cloning (SEREX) and Western blotting to confirm the presence of serum antibodies against the antigens. Amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) revealed that serum antibody levels were significantly higher in patients with TIA or acute-phase CI (aCI) compared with healthy donors (P < 0.01). Spearman’s correlation analysis and multivariate logistic regression analysis demonstrated that levels of anti-MMP1, anti-CBX1, and anti-CBX5 antibodies were associated with age, cigarette-smoking habits, and blood pressure. Thus, serum levels of antibodies against MMP1, CBX1, and CBX5 could potentially serve as useful tools for diagnosing TIA and predicting the onset of aCI.
Amyloid-b (Ab) peptide, the principal component of senile plaques in the brains of patients with Alzheimer's disease, is derived from proteolytic cleavage of amyloid precursor protein (APP) by b-and c-secretases. Alternative cleavage of APP by a-secretase occurs within the Ab domain and precludes generation of Ab peptide. Three members of the ADAM (a disintegrin and metalloprotease) family of proteases, ADAM9, 10 and 17, are the main candidates for a-secretases. However, the mechanism that regulates a-secretase activity remains unclear. We have recently demonstrated that nardilysin (EC 3.4.24.61, N-arginine dibasic convertase; NRDc) enhances ectodomain shedding of heparin-binding epidermal growth factor-like growth factor through activation of ADAM17. In this study, we show that NRDc enhances the a-secretase activity of ADAMs, which results in a decrease in the amount of Ab generated. When expressed with ADAMs in cells, NRDc dramatically increased the secretion of a-secretase-cleaved soluble APP and reduced the amount of Ab peptide generated. A peptide cleavage assay in vitro also showed that recombinant NRDc enhances ADAM17-induced cleavage of the peptide substrate corresponding to the a-secretase cleavage site of APP. A reduction of endogenous NRDc by RNA interference was accompanied by a decrease in the cleavage by a-secretase of APP and increase in the amount of Ab generated. Notably, NRDc is clearly expressed in cortical neurons in human brain. Our results indicate that NRDc is involved in the metabolism of APP through regulation of the a-secretase activity of ADAMs, which may be a novel target for the treatment of Alzheimer's disease. Keywords: a disintegrin and metalloprotease proteases, a-secretase, Alzheimer's disease, amyloid-b, ectodomain shedding, nardilysin. Alzheimer's disease (AD), a progressive neurodegenerative disorder, is characterized by a variety of pathological features in the brain such as extracellular senile plaques and intracellular neurofibrillary tangles. The main component of the extracellular senile plaques is amyloid b (Ab) peptide, which is derived from amyloid precursor protein (APP), a type I transmembrane protein, by two sequential proteolytic cleavages. The initial cleavage is mediated by b-secretase, b-site APP-cleaving enzyme 1, at the N-terminus of the Ab domain, which generates a soluble N-terminal fragment (bsecretase-cleaved soluble APP; sAPPb) and a transmembrane C-terminal fragment (C99). C99 is susceptible to a second intramembrane cleavage by c-secretase, releasing the 4-kDa
Nardilysin (NRDc), a metalloendopeptidase of the M16 family, promotes ectodomain shedding of the precursor forms of various growth factors and cytokines by enhancing the protease activities of ADAM proteins. Here, we show the growth-promoting role of NRDc in gastric cancer cells. Analyses of clinical samples demonstrated that NRDc protein expression was frequently elevated both in the serum and cancer epithelium of gastric cancer patients. After NRDc knockdown, tumour cell growth was suppressed both in vitro and in xenograft experiments. In gastric cancer cells, NRDc promotes shedding of pro-tumour necrosis factor-alpha (pro-TNF-α), which stimulates expression of NF-κB-regulated multiple cytokines such as interleukin (IL)-6. In turn, IL-6 activates STAT3, leading to transcriptional upregulation of downstream growth-related genes. Gene silencing of ADAM17 or ADAM10, representative ADAM proteases, phenocopied the changes in cytokine expression and cell growth induced by NRDc knockdown. Our results demonstrate that gastric cancer cell growth is maintained by autonomous TNF-α–NF-κB and IL-6–STAT3 signalling, and that NRDc and ADAM proteases turn on these signalling cascades by stimulating ectodomain shedding of TNF-α.
Cerebral infarction (CI), cardiovascular disease (CVD), diabetes mellitus (DM) and chronic kidney disease (CKD) are atherosclerosis-related diseases, which are major causes of health damage. For early and sensitive diagnosis, development of novel biomarkers is expected and of significant practical importance. First screening was carried out by phage expression cloning to identify antigen proteins recognized by serum IgG antibodies in patients with atherosclerosis. RPA2, LRPAP1, EEF1A1, SPOCK1, LOC729260, tubulin beta 2C (TUBB2C) and KIAA0020 markers were identified. We then compared the serum antibody levels against the candidate proteins between healthy donors (HD) and patients with CI, CVD, DM, or CKD by Alpha (amplified luminescent proximity homogeneous assay)-LISA method. The results showed that the serum TUBB2C antibody levels were significantly higher in patients with CI, DM, or CKD than those in HD. Using the average + 2SD of HD as the cut-off value, the positive thresholds of TUBB2C antibody markers were 14.8% in CI, 25.8% in DM, and 18.3% in CKD. TUBB2C antibody levels were well correlated with artery stenosis degrees such as plaque score, maximum intima-media thickness and cardio ankle vascular index. Consequently, TUBB2C antibody markers are useful to diagnose atherosclerosis, DM, and CKD, and can be applied to the prediction of the onset of CI. The serum anti-TUBB2C antibody markers are useful for the diagnosis of DM and CKD.
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