Over the past few decades, two-dimensional (2D) and layered materials have emerged as new fields. Due to the zero-band-gap nature of graphene and the low photocatalytic performance of MoS2, more ...advanced semiconducting 2D materials have been prompted. As a result, semiconductor black phosphorus (BP) is a derived cutting-edge post-graphene contender for nanoelectrical application, because of its direct-band-gap nature. For the first time, we report on robust BP@TiO2 hybrid photocatalysts offering enhanced photocatalytic performance under light irradiation in environmental and biomedical fields, with negligible affected on temperature and pH conditions, as compared with MoS2@TiO2 prepared by the identical synthesis method. Remarkably, in contrast to pure few layered BP, which, due to its intrinsic sensitivity to oxygen and humidity was readily dissolved after just several uses, the BP@TiO2 hybrid photocatalysts showed a ~92% photocatalytic activity after 15 runs. Thus, metal-oxide-stabilized BP photocatalysts can be practically applied as a promising alternative to graphene and MoS2.
Many studies have been conducted to improve economically important livestock traits such as feed efficiency and muscle growth. Genome editing technologies represent a major advancement for both basic ...research and agronomic biotechnology development. The clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technical platform is a powerful tool used to engineer specific targeted loci. However, the potential occurrence of off‐target effects, including the cleavage of unintended targets, limits the practical applications of Cas9‐mediated genome editing. In this study, to minimize the off‐target effects of this technology, we utilized D10A‐Cas9 nickase to generate myostatin‐knockout (MSTN KO) chickens via primordial germ cells. D10A‐Cas9 nickase (Cas9n)‐mediated MSTN KO chickens exhibited significantly larger skeletal muscles in the breast and leg. Degrees of skeletal muscle hypertrophy and hyperplasia induced by myostatin deletion differed by sex and muscle type. The abdominal fat deposition was dramatically lower in MSTN KO chickens than in wild‐type chickens. Our results demonstrate that the D10A‐Cas9 technical platform can facilitate precise and efficient targeted genome engineering and may broaden the range of applications for genome‐edited chickens in practical industrialization and as animal models of human diseases.
Life expectancy has dramatically increased around the world over the last few decades, and staying healthier longer, without chronic disease, has become an important issue. Although understanding ...aging is a grand challenge, our understanding of the mechanisms underlying the degeneration of cell and tissue functions with age and its contribution to chronic disease has greatly advanced during the past decade. As our immune system alters with aging, abnormal activation of immune cells leads to imbalance of innate and adaptive immunity and develops a persistent and mild systemic inflammation, inflammaging. With their unique therapeutic properties, such as immunomodulation and tissue regeneration, mesenchymal stem cells (MSCs) have been considered to be a promising source for treating autoimmune disease or as anti-aging therapy. Although direct evidence of the role of MSCs in inflammaging has not been thoroughly studied, features reported in senescent MSCs or the aging process of MSCs are associated with inflammaging; MSC niche-driven skewing of hematopoiesis toward the myeloid lineage or oncogenesis, production of pro-inflammatory cytokines, and weakening their modulative property on macrophage polarization, which plays a central role on inflammaging development. This review explores the role of senescent MSCs as an important regulator for onset and progression of inflammaging and as an effective target for anti-aging strategies. BMB Reports 2020; 53(2): 65-73.
•The electrochemical supercapacitor electrode was fabricated using CuS nanoplatelets.•CuS electrodes shows better electrochemical properties in aqueous LiClO4 electrolyte.•The heat treated CuS ...electrode shows an excellent pseudocapacitance performance than bare CuS electrode.
Copper sulfide (CuS) nanoplatelets have been fabricated by simple low temperature chemical bath deposition technique for electrochemical supercapacitor electrodes. The morphology and structural properties of the electrodes were analyzed using scanning electron microscopy and X-ray diffraction. The effect of heat treatment on electrochemical properties of CuS electrodes were examined by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge tests. Results show that bare and heat treated CuS has pseudocapacitive characteristic within the potential range of −0.6 to 0.3V (vs. Ag/AgCl) in aqueous 1M LiClO4 solution. The pseudocapacitance is induced mainly by lithium ions insertion/extraction with the CuS electrodes. The specific capacitance of 72.85Fg−1 was delivered by heat treated CuS film at a scan rate of 5mVs−1 with an energy and power density of 6.23Whkg−1 and 1.75kWkg−1 at 3Ag−1 constant discharge current which is comparatively higher than that of as deposited CuS electrode.
Identification of the immunomodulatory and regenerative properties of mesenchymal stem cells (MSCs) have made them an attractive alternative therapeutic option for diseases with no effective ...treatment options. Numerous clinical trials have followed; however, issues such as infusional toxicity and cellular rejection have been reported. To address these problems associated with cell-based therapy, MSC exosome therapy was developed and has shown promising clinical outcomes. MSC exosomes are nanosized vesicles secreted from MSCs and represent a non-cellular therapeutic agent. MSC exosomes retain therapeutic features of the cells from which they originated including genetic material, lipids, and proteins. Similar to MSCs, exosomes can induce cell differentiation, immunoregulation, angiogenesis, and tumor suppression. MSC exosomes have therefore been employed in several experimental models and clinical studies. Here, we review the therapeutic potential of MSC-derived exosomes and summarize currently ongoing clinical trials according to disease type. In addition, we propose several functional enhancement strategies for the effective clinical application of MSC exosome therapy.
Mesenchymal stem cell (MSC) is a promising tool for the therapy of immune disorders. However, their efficacy and mechanisms in treating allergic skin disorders are less verified. We sought to ...investigate the therapeutic efficacy of human umbilical cord blood-derived MSCs (hUCB-MSCs) against murine atopic dermatitis (AD) and to explore distinct mechanisms that regulate their efficacy. AD was induced in mice by the topical application of Dermatophagoides farinae. Naïve or activated-hUCB-MSCs were administered to mice, and clinical severity was determined. The subcutaneous administration of nucleotide-binding oligomerization domain 2 (NOD2)-activated hUCB-MSCs exhibited prominent protective effects against AD, and suppressed the infiltration and degranulation of mast cells (MCs). A β-hexosaminidase assay was performed to evaluate the effect of hUCB-MSCs on MC degranulation. NOD2-activated MSCs reduced the MC degranulation via NOD2-cyclooxygenase-2 signaling. In contrast to bone marrow-derived MSCs, hUCB-MSCs exerted a cell-to-cell contact-independent suppressive effect on MC degranulation through the higher production of prostaglandin E2 (PGE2 ). Additionally, transforming growth factor (TGF)-β1 production from hUCB-MSCs in response to interleukin-4 contributed to the attenuation of MC degranulation by downregulating FcεRI expression in MCs. In conclusion, the subcutaneous application of NOD2-activated hUCB-MSCs can efficiently ameliorate AD, and MSC-derived PGE2 and TGF-β1 are required for the inhibition of MC degranulation.
Abstract
Mesenchymal stem cells (MSCs) have recently been considered a promising alternative treatment for diverse immune disorders due to their unique biomedical potentials including the ...immunomodulatory property and ability to promote tissue regeneration. However, despite many years of pre-clinical studies in the research field, results from clinical trials using these cells have been diverse and conflicting. This discrepancy is caused by several factors such as poor engraftment, low survival rate, and donor-dependent variation of the cells. Enhancement of consistency and efficacy of MSCs remains a challenge to overcome the current obstacles to MSC-based therapy and subsequently achieve an improved therapeutic outcome. In this review, we investigated function enhancement strategies by categorizing as preconditioning, genetic manipulation, usage of supportive materials, and co-administration with currently used drugs. Preconditioning prior to MSC application makes up a large proportion of improvement strategies and preconditioning reagents include bioactive substances (cytokines, growth factors, and innate immune receptor agonists), hypoxia, and modification in culture method. With the piled results from previous studies using each method, disease- or patient-specific therapy has become more important than ever. On the other hand, genetic manipulation targeting therapeutic-associated factors or co-administration of biocompatible materials has also arisen as other therapeutic strategies. Thus, we summarized several specialized tactics by analyzing up-to-date results in the field and proposed some promising enhancement methods to improve the clinical outcomes for MSC therapy.
There is a growing appreciation for a fundamental connection between lipid metabolism and the immune response. Macrophage phagocytosis is a signature innate immune response to pathogen exposure, and ...cytoplasmic membrane expansion is required to engulf the phagocytic target. The sterol regulatory element binding proteins (SREBPs) are key transcriptional regulatory proteins that sense the intracellular lipid environment and modulate expression of key genes of fatty acid and cholesterol metabolism to maintain lipid homeostasis. In this study, we show that TLR4-dependent stimulation of macrophage phagocytosis requires mTORC1-directed SREBP-1a–dependent lipid synthesis. We also show that the phagocytic defect in macrophages from SREBP-1a–deficient mice results from decreased interaction between membrane lipid rafts and the actin cytoskeleton, presumably due to reduced accumulation of newly synthesized fatty acyl chains within major membrane phospholipids. We show that mTORC1-deficient macrophages also have a phagocytic block downstream from TLR4 signaling, and, interestingly, the reduced level of phagocytosis in both SREBP-1a– and mTORC1-deficient macrophages can be restored by ectopic SREBP-1a expression. Taken together, these observations indicate SREBP-1a is a major downstream effector of TLR4–mTORC1 directed interactions between membrane lipid rafts and the actin cytoskeleton that are required for pathogen-stimulated phagocytosis in macrophages.
Background & Aims Decreased levels or function of nucleotide-binding oligomerization domain 2 (NOD2) are associated with Crohn's disease. NOD2 regulates intestinal inflammation, and also is expressed ...by human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs), to regulate their differentiation. We investigated whether NOD2 is required for the anti-inflammatory activities of MSCs in mice with colitis. Methods Colitis was induced in mice by administration of dextran sulfate sodium or trinitrobenzene sulfonic acid. Mice then were given intraperitoneal injections of NOD2-activated hUCB-MSCs; colon tissues and mesenteric lymph nodes were collected for histologic analyses. A bromodeoxyuridine assay was used to determine the ability of hUCB-MSCs to inhibit proliferation of human mononuclear cells in culture. Results Administration of hUCB-MSCs reduced the severity of colitis in mice. The anti-inflammatory effects of hUCB-MSCs were greatly increased by activation of NOD2 by its ligand, muramyl dipeptide (MDP). Administration of NOD2-activated hUCB-MSCs increased anti-inflammatory responses in colons of mice, such as production of interleukin (IL)-10 and infiltration by T regulatory cells, and reduced production of inflammatory cytokines. Proliferation of mononuclear cells was inhibited significantly by co-culture with hUCB-MSCs that had been stimulated with MDP. MDP induced prolonged production of prostaglandin (PG)E2 in hUCB-MSCs via the NOD2–RIP2 pathway, which suppressed proliferation of mononuclear cells derived from hUCB. PGE2 produced by hUCB-MSCs in response to MDP increased production of IL-10 and T regulatory cells. In mice, production of PGE2 by MSCs and subsequent production of IL-10 were required to reduce the severity of colitis. Conclusions Activation of NOD2 is required for the ability of hUCB-MSCs to reduce the severity of colitis in mice. NOD2 signaling increases the ability of these cells to suppress mononuclear cell proliferation by inducing production of PGE2.
The omnidirectional circularly polarized (CP) antenna using a circular mushroom structure with curved branches is proposed. The antenna is based on the zeroth-order resonance (ZOR) mode of epsilon ...negative (ENG) transmission line (TL) to obtain a vertical polarization and an omnidirectional radiation pattern. Also, the horizontal polarization is obtained by the curved branches. The 90° phase difference between two orthogonal polarizations is inherently provided by the zeroth-order resonator. Therefore, the antenna has an omnidirectional CP radiation pattern in the azimuthal plane. In addition, this antenna is planar type and simply designed without a dual feeding structure and 90° phase shifter. The measured average axial ratio and left-hand (LH) CP gain are 2.03 dB and - 0.40 dBic, respectively, in the azimuthal plane.
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