Uric acid (UA) is well known as the end product of purine metabolism in human. Hyperuricemia is defined as a serum UA level of ≥ 7.0 mg/dl (416 µM) in Japanese guideline for the management of ...hyperuricemia and gout (second edition), which is known as a risk factor for cardiovascular disease. Recently, it has been reported that low UA levels as well as high UA levels are predictive markers of increased mortality in epidemiologic studies. Hence, the aim of this study is to assess the role of UA at physiological concentration (conc) in normal cells. Normal human dermal fibroblasts were treated with UA conc at 62.5 - 500 µM (1.1 - 8.4 mg/dl). Cell viability of UA treated groups within the normal range was higher than that of control group. There was no change in cell number among groups, but total protein levels in UA treated groups increased at 72 hours. On the other hand, UA is known to have the potential antioxidant effects. Physiological conc of UA treatment decreased reactive oxygen species in the present study. Additionally, the expression of an oxidative stress-related protein was increased by UA treatment. Taken together, these findings suggest that physiological conc of UA in normal cells is probably implicated in cell viability.
Extracellular vesicles (EVs) including exosomes act as intercellular communicators by transferring protein and microRNA cargoes, yet the role of EV lipids remains unclear. Here, we show that the ...pro-tumorigenic action of lymphoma-derived EVs is augmented via secreted phospholipase A2 (sPLA2)-driven lipid metabolism. Hydrolysis of EV phospholipids by group X sPLA2, which was induced in macrophages of Epstein-Barr virus (EBV) lymphoma, increased the production of fatty acids, lysophospholipids, and their metabolites. sPLA2-treated EVs were smaller and self-aggregated, showed better uptake, and increased cytokine expression and lipid mediator signaling in tumor-associated macrophages. Pharmacological inhibition of endogenous sPLA2 suppressed lymphoma growth in EBV-infected humanized mice, while treatment with sPLA2-modified EVs reversed this phenotype. Furthermore, sPLA2 expression in human large B cell lymphomas inversely correlated with patient survival. Overall, the sPLA2-mediated EV modification promotes tumor development, highlighting a non-canonical mechanistic action of EVs as an extracellular hydrolytic platform of sPLA2.
Display omitted
•sPLA2-X is induced in EBV-induced B cell lymphoma in humanized mice•sPLA2-X hydrolyzes EV membranes to increase lipid mediator cargo•sPLA2-X alters the morphology and function of EVs•sPLA2-X facilitates EBV lymphomagenesis via a lipid-driven non-canonical mechanism
EVs act as intercellular communicators by transferring miRNAs and proteins. Kudo et al. find the importance of EV lipids in EBV lymphoma development. Hydrolysis of phospholipids in tumor-cell-derived EVs by sPLA2-X increases vesicle aggregation, produces immunoregulatory lipid mediators, and facilitates EV uptake by recipient macrophages, thereby exacerbating lymphomagenesis.
Induced pluripotent stem cells (iPS cells) are a promising source for a cell-based therapy to treat Parkinson's disease (PD), in which midbrain dopaminergic neurons progressively degenerate. However, ...long-term analysis of human iPS cell-derived dopaminergic neurons in primate PD models has never been performed to our knowledge. Here we show that human iPS cell-derived dopaminergic progenitor cells survived and functioned as midbrain dopaminergic neurons in a primate model of PD (Macaca fascicularis) treated with the neurotoxin MPTP. Score-based and video-recording analyses revealed an increase in spontaneous movement of the monkeys after transplantation. Histological studies showed that the mature dopaminergic neurons extended dense neurites into the host striatum; this effect was consistent regardless of whether the cells were derived from patients with PD or from healthy individuals. Cells sorted by the floor plate marker CORIN did not form any tumours in the brains for at least two years. Finally, magnetic resonance imaging and positron emission tomography were used to monitor the survival, expansion and function of the grafted cells as well as the immune response in the host brain. Thus, this preclinical study using a primate model indicates that human iPS cell-derived dopaminergic progenitors are clinically applicable for the treatment of patients with PD.
"Antibody-breeding" approach potentially generates therapeutic/diagnostic antibody mutants with greater performance than native antibodies. Therein, antibody fragments (e.g., single-chain Fv ...fragments; scFvs) with a variety of mutations are displayed on bacteriophage to generate diverse phage-antibody libraries. Rare clones with improved functions are then selected via panning against immobilized or tagged target antigens. However, this selection process often ended unsuccessful, mainly due to the biased propagation of phage-antibody clones and the competition with a large excess of undesirable clones with weaker affinities. To break radically from such panning-inherent problems, we developed a novel method, clonal array profiling of scFv-displaying phages (CAP), in which colonies of the initial bacterial libraries are examined one-by-one in microwells. Progenies of scFv-displaying phages generated are, if show sufficient affinity to target antigen, captured in the microwell via pre-coated antigen and detected using a luciferase-fused anti-phage scFv. The advantage of CAP was evidenced by its application with a small error-prone-PCR-based library (~ 10
colonies) of anti-cortisol scFvs. Only two operations, each surveying only ~ 3% of the library (9,400 colonies), provided five mutants showing 32-63-fold improved K
values (> 10
M
), compared with the wild-type scFv (K
= 3.8 × 10
M
), none of which could be recovered via conventional panning procedures operated for the entire library.
Parathyroid carcinoma (PC) is a rare type of endocrine cancer. Recurrence and metastasis are common after surgery, and refractory hypercalcemia often leads to a poor prognosis. However, there are ...currently no specific strategies for PC recurrence. We herein report a 61-year-old Japanese man with metastatic PC who was treated with sorafenib, a multikinase inhibitor. In this case, the serum calcium level was under control for 10 months after the initiation of sorafenib. This case suggests that combination therapy with sorafenib, evocalcet, and denosumab may be an alternative, stronger management option for refractory hypercalcemia in recurrent PC.
The emu is the second largest ratite; thus, their sera and egg yolks, obtained after immunization, could provide therapeutic and diagnostically important immunoglobulins with improved production ...efficiency. Reliable purification tools are required to establish a pipeline for supplying practical emu-derived antibodies, the majority of which belongs to the immunoglobulin Y (IgY) class. Therefore, we generated a monoclonal secondary antibody specific to emu IgY. Initially, we immunized an emu with bovine serum albumin multiply haptenized with 2,4-dinitrophenyl (DNP) groups. Polyclonal emu anti-DNP antibodies were partially purified using conventional precipitation method and used as antigen for immunizing a BALB/c mouse. Splenocytes were fused with myeloma cells and a hybridoma clone secreting a desirable secondary antibody (mAb#2-16) was established. The secondary antibody bound specifically to emu-derived IgY, distinguishing IgYs from chicken, duck, ostrich, quail, and turkey, as well as human IgGs. Affinity columns immobilizing the mAb#2-16 antibodies enabled purification of emu IgY fractions from sera and egg yolks via simple protocols, with which we succeeded in producing IgYs specific to the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) spike protein with a practical binding ability. We expect that the presented purification method, and the secondary antibody produced in this study, will facilitate the utilization of emus as a novel source of therapeutic and diagnostic antibodies.
Small intestinal mononuclear cells that express CX3CR1 (CX3CR1
cells) regulate immune responses
. CX3CR1
cells take up luminal antigens by protruding their dendrites into the lumen
. However, it ...remains unclear how dendrite protrusion by CX3CR1
cells is induced in the intestine. Here we show in mice that the bacterial metabolites pyruvic acid and lactic acid induce dendrite protrusion via GPR31 in CX3CR1
cells. Mice that lack GPR31, which was highly and selectively expressed in intestinal CX3CR1
cells, showed defective dendrite protrusions of CX3CR1
cells in the small intestine. A methanol-soluble fraction of the small intestinal contents of specific-pathogen-free mice, but not germ-free mice, induced dendrite extension of intestinal CX3CR1
cells in vitro. We purified a GPR31-activating fraction, and identified lactic acid. Both lactic acid and pyruvic acid induced dendrite extension of CX3CR1
cells of wild-type mice, but not of Gpr31b
mice. Oral administration of lactate and pyruvate enhanced dendrite protrusion of CX3CR1
cells in the small intestine of wild-type mice, but not in that of Gpr31b
mice. Furthermore, wild-type mice treated with lactate or pyruvate showed an enhanced immune response and high resistance to intestinal Salmonella infection. These findings demonstrate that lactate and pyruvate, which are produced in the intestinal lumen in a bacteria-dependent manner, contribute to enhanced immune responses by inducing GPR31-mediated dendrite protrusion of intestinal CX3CR1
cells.
PDF
