STAY-GREEN Accelerates Chlorophyll Degradation in Magnolia sinostellata under the Condition of Light Deficiency.

Species of the Magnoliaceae family are valued for their ornamental qualities and are widely used in landscaping worldwide. However, many of these species are endangered in their natural environments, often due to being overshadowed by overstory canopies. The molecular mechanisms of Magnolia's sensitivity to shade have remained hitherto obscure. Our study sheds light on this conundrum by identifying critical genes involved in governing the plant's response to a light deficiency (LD) environment. In response to LD stress, Magnolia sinostellata leaves were endowed with a drastic dwindling in chlorophyll content, which was concomitant to the downregulation of the chlorophyll biosynthesis pathway and upregulation in the chlorophyll degradation pathway. The STAY-GREEN (MsSGR) gene was one of the most up-regulated genes, which was specifically localized in chloroplasts, and its overexpression in Arabidopsis and tobacco accelerated chlorophyll degradation. Sequence analysis of the MsSGR promoter revealed that it contains multiple phytohormone-responsive and light-responsive cis-acting elements and was activated by LD stress. A yeast two-hybrid analysis resulted in the identification of 24 proteins that putatively interact with MsSGR, among which eight were chloroplast-localized proteins that were significantly responsive to LD. Our findings demonstrate that light deficiency increases the expression of MsSGR, which in turn regulates chlorophyll degradation and interacts with multiple proteins to form a molecular cascade. Overall, our work has uncovered the mechanism by which MsSGR mediates chlorophyll degradation under LD stress conditions, providing insight into the molecular interactions network of MsSGR and contributing to a theoretical framework for understanding the endangerment of wild Magnoliaceae species.

Metachronous Multiple Primary Carcinoma With Acute Promyelocytic Leukemia: 2 Cases Report and Literature Review.

The co-occurrence of multiple primary cancers with hematological malignancies is uncommon, and acute promyelocytic leukemia (APL) with MPC is even rarer, with only a few cases reported in the literature. Herein, we introduce the diagnosis and treatment of 2 cases of MPC complicated with APL in our hospital and review the relevant literature. Both patients were primary solid tumor patients and were treated with surgery and chemotherapy, and had stable disease (SD). However, more than 1 year after the primary tumor was diagnosed, clinical symptoms were found and APL was diagnosed. Both patients received standard remission-induction therapy, but unfortunately died in the short term due to hemorrhagic complications. In conclusion, treatment of hematological neoplasms, especially acute leukemia combined with multiple primary cancers, is challenging. The prognostic factors and survival analysis of MPC patients with combined APL still need further clinical research and analysis.

Irisin mediates beiging of adipose-derived mesenchymal stem cells through binding to TRPC3.

BACKGROUND: Beiging of white fat plays an important role in energy metabolism. Beige adipocytes contribute to the regulation of body weight and body temperature through expenditure of chemical energy to produce heat, and they have therefore recently attracted considerable attention as potential targets for therapeutic approaches in metabolic disorders, including obesity. All adipocytes, including beige adipocytes, differentiate from mesenchymal stem cells (MSCs), which may provide an important path for clinical intervention; however, the mechanism of beiging of human adipose cell-derived MSCs is not fully understood. Here, we provide insights on the role of IRISIN, which is known to be secreted by skeletal muscle and promote beiging of white fat. RESULTS: We established an IRISIN-induced mesenchymal stem cell beiging model and found that IRISIN protein interacts with the MSC membrane protein TRPC3. This interaction results in calcium influx and consequential activation of Erk and Akt signaling pathways, which causes phosphorylation of PPARγ. The phosphorylated PPARγ enters the nucleus and binds the UCP1 promoter region. Furthermore, the role of TRPC3 in the beiging of MSCs was largely abolished in Trpc3-/- mice. We additionally demonstrate that the calcium concentration in the brain of mice increases upon IRISIN stimulation, followed by an increase in the content of excitatory amino acids and norepinephrine, while Trpc3-/- mice exhibit the reverse effect. CONCLUSIONS: We found that TRPC3 is a key factor in irisin-induced beiging of MSCs, which may provide a new target pathway in addressing metabolic disorders. Our results additionally suggest that the interaction of irisin with TRPC3 may affect multiple tissues, including the brain.

Light Deficiency Inhibits Growth by Affecting Photosynthesis Efficiency as well as JA and Ethylene Signaling in Endangered Plant Magnolia sinostellata.

The endangered plant Magnolia sinostellata largely grows in the understory of forest and suffers light deficiency stress. It is generally recognized that the interaction between plant development and growth environment is intricate; however, the underlying molecular regulatory pathways by which light deficiency induced growth inhibition remain obscure. To understand the physiological and molecular mechanisms of plant response to shading caused light deficiency, we performed photosynthesis efficiency analysis and comparative transcriptome analysis in M. sinostellata leaves, which were subjected to shading treatments of different durations. Most of the parameters relevant to the photosynthesis systems were altered as the result of light deficiency treatment, which was also confirmed by the transcriptome analysis. Gene Ontology and KEGG pathway enrichment analyses illustrated that most of differential expression genes (DEGs) were enriched in photosynthesis-related pathways. Light deficiency may have accelerated leaf abscission by impacting the photosynthesis efficiency and hormone signaling. Further, shading could repress the expression of stress responsive transcription factors and R-genes, which confer disease resistance. This study provides valuable insight into light deficiency-induced molecular regulatory pathways in M. sinostellata and offers a theoretical basis for conservation and cultivation improvements of Magnolia and other endangered woody plants.

A new strategy for accurate targeted diagnosis and treatment of cutaneous malignant melanoma: dual-mode phase-change lipid nanodroplets as ultrasound contrast agents.

BACKGROUND: Currently, effective detection and treatment of cutaneous malignant melanoma (CMM) still face severe challenges. Ultrasound molecular imaging as a noninvasive and easy-to-operate method is expected to bring improvements for tumor detection. PURPOSE: The aim of this research is to prepare novel phase-change ultrasound contrast agents, Nds-IR780, which can perform not only dual-mode molecule-targeted imaging but also targeted photothermal therapy for CMM. METHODS: A double emulsion process was used to prepare the Nds-IR780. Then, the entrapment rate and drug loading of IR-780 iodide in Nds-IR780 were detected by high-performance liquid chromatography. The biocompatibility of Nds-IR780 was evaluated by a CCK-8 assay and the characteristics and stability of that were verified through the particle size analyzer, laser scanning confocal microscopy (LSCM) and transmission electron microscopy (TEM). The abilities of dual-mode molecule-targeted imaging and targeted photothermal therapy for Nds-IR780 were confirmed via the in vitro and in vivo experiments. RESULTS: Nds-IR780 had good size distribution, polydispersity index, stability and biosafety. The in vitro and in vivo experiments confirmed that Nds-IR780 were capable of targeting CMM cells with high affinity (22.4±3.2%) and facilitating dual-mode imaging to detect the primary lesion and sentinel lymph nodes (SLNs) of CMM. Furthermore, the photothermal ablation of CMM mediated by Nds-IR780 was very effective in vivo. CONCLUSION: The newly prepared Nds-IR780 were observed to be effective targeted theranostic probe for the precise detection and targeted treatment of CMM.

FA-NBs-IR780: Novel multifunctional nanobubbles as molecule-targeted ultrasound contrast agents for accurate diagnosis and photothermal therapy of cancer.

Early accurate diagnosis and targeted therapy for cancer are essential to improve the prognosis of patients. With the emergence of molecular imaging, molecule-targeted ultrasound imaging for the non-invasive and precise detection of cancer has attracted increased attention. The investigation of molecule-targeted ultrasound contrast agents (UCAs) with excellent performance is urgently needed. In this study, we synthetized folic acid and IR-780 on self-made nanobubbles and prepared novel UCAs, named FA-NBs-IR780. The results showed that the conjugates had a uniform size distribution (591 ±â€¯52 nm). In vitro and in vivo experiments demonstrated that FA-NBs-IR780 can target tumour cells via dual molecular targeting, perform enhanced-contrast ultrasound imaging and near-infrared fluorescence (NIRF) imaging for the precise detection of tumours, and induce targeted photothermal therapy in lesions irradiated at 808 nm. Ex vivo experiments further confirmed that FA-NBs-IR780 efficiently induced tumour cell apoptosis and inhibited tumour growth. The newly fabricated FA-NBs-IR780 were observed to be molecule-targeted dual-mode UCAs and may have potential applications in early accurate diagnosis and targeted therapy of cancer in the future.

Effects of Gastric Cancer Cell-Derived Exosomes on the Immune Regulation of Mesenchymal Stem Cells by the NF-kB Signaling Pathway.

Mesenchymal stem cells (MSCs) are important components of the tumor microenvironment, which play an important role in tumor development. Exosomes derived from tumor cells can affect the biological characteristics of MSCs. Our study examined the effects of exosomes derived from gastric cancer cells on MSC immunomodulatory functions. Exosomes were extracted from gastric cancer cell line AGS (AGS-Exos) and cultured with MSCs. MSCs were then cocultured with both human peripheral blood mononuclear cells and macrophages [phorbol-12-myristate-13-acetate (PMA)-stimulated THP1 cells]. The activation levels of T cells and macrophages were detected by flow cytometry and real-time quantitative polymerase chain reaction (RT-PCR). Changes in the MSC signaling pathway after AGS-Exos stimulation were studied using RNA Chip, and the molecular mechanisms of functional change in MSCs were studied by inhibiting the signaling pathway. MSCs treated with AGS-Exos could promote macrophage phagocytosis and upregulate the secretion of proinflammatory factor, and promote the activation of CD69 and CD25 on the surface of T cells. RNA Chip results indicated the abnormal activation of the NF-kB signaling pathway in MSCs after AGS-Exos stimulation, and this was verified by the identification of key proteins in the pathway using western blot analysis. After NF-kB signaling pathway inhibition, the effect of MSCs stimulated by AGS-Exos on T cells and macrophages was markedly weakened. Therefore, AGS-Exos affected the immunomodulation function of MSCs through the NF-kB signaling pathway, which enhanced the ability of MSCs to activate immune cells, maintain the inflammatory environment, and support tumor growth.

A Novel Bimodal Imaging Agent Targeting HER2 Molecule of Breast Cancer.

Nanobubble (NB), a newly developed nanoscaled ultrasound contrast agent (UCA) for molecular imaging, has been widely researched for these years. Targeting it with functional molecule, nanobubble can adhere selectively to cellular epitopes and receptors outside the vasculature via enhanced permeability and retention (EPR) effect of tumor blood vessel. To enhance the targeting rate of our previous prepared NBs-Affibody for HER2 (+) breast cancer imaging, we introduced a near-infrared fluorescent (NIRF) dye, IR783, in this study to enhance tumor-specific targeting rate and provide a promising modality for dual-mode imaging. The prepared IR783-NBs-Affibody presented a uniform nanoscale size around 482.7 ± 54.3 nm, good biosecurity, and stability over time. The encapsulation efficiency (EE) of IR-783 was 15.09% in the conjugates leading to a successful NIR fluorescence and ultrasound enhancement imaging ex vivo. IR783-NBs-Affibody was able to automatically accumulate on BT474 cells with a highly increased targeting rate of 85.4% compared with previous NBs-Affibody of 26.6%, while Affibody-guided HER2 binding was only found in HER2-positive cell lines (BT474 and T-47D). The newly developed IR783-NBs-Affibody is characterized with favorable HER2 targeting ability and bimodal imaging capability for breast cancer. Thus, IR783-NBs-Affibody holds great potential in molecular diagnosis for patients with breast cancer.

Exosomes Derived from Hypoxia-Treated Human Adipose Mesenchymal Stem Cells Enhance Angiogenesis Through the PKA Signaling Pathway.

Angiogenesis is a complicated and sequential process that plays an important role in different physiological processes. Mesenchymal stem cells (MSCs), which are pluripotent stem cells, are widely used for the treatment of ischemic and traumatic diseases, and exosomes derived from these cells can also promote angiogenesis. Therefore, we aimed to uncover mechanisms to improve MSC exosome-mediated angiogenesis. For this study, we isolated human adipose-derived MSCs (hAD-MSCs) and assessed differentiation ability and markers. Cells were divided into hypoxia-treated MSCs (H-MSCs) and normoxia-treated MSCs (N-MSC), and exosomes were extracted by ultrafiltration. Exosomes (100 µg/mL) from H-MSCs and N-MSCs were added to human umbilical vein endothelial cells (HUVECs). Exosome uptake and the ability of endothelial cells to form tubes were detected in real time. Protein samples were collected at different time points to detect the expression of inhibitors (Vash1) and enhancers (Angpt1 and Flk1) of angiogenesis; we also assessed their related signaling pathways. We found that exosomes from the hypoxia group were more easily taken up by HUVECs; furthermore, their angiogenesis stimulatory activity was also significantly enhanced compared to that with exosomes from the normoxia group. HUVECs exposed to exosomes from H-MSCs significantly upregulated angiogenesis-stimulating genes and deregulated angiogenesis-inhibitory genes. The expression of vascular endothelial growth factor (VEGF) and activation of the protein kinase A (PKA) signaling pathway in HUVECs were significantly increased by hypoxia-exposed exosomes. Moreover, a PKA inhibitor was shown to significantly suppress angiogenesis. Finally, we concluded that hypoxia-exposed exosomes derived from hAD-MSCs can improve angiogenesis by activating the PKA signaling pathway and promoting the expression of VEGF. These results could be used to uncover safe and effective treatments for traumatic diseases.

Protection of Nerve Injury with Exosome Extracted from Mesenchymal Stem Cell.

OBJECTIVE: To investigate the protective effect of Exosomes from human adipose-derived mesenchymal stem cells (hAMSCs) in neural injury induced by glutamate and its possible mechanism. METHODS: Characteristics of Exosomes from hAMSCs were identified by electron microscopy and Western blot analysis. Cytokines that might play a major role in the protective effect were tested by enzyme-linked immunosorbent assay (ELISA). The protective action of Exosome and its possible signaling pathway were researched by the in vitro neural injury induced by glutamate, including control group (without Glu), Glu group (dealing with Glu), Glu+Exo group (dealing with Glu +100 ng/ml Exo), Glu+Exo+Akt group (dealing with Glu+100 ng/ml Exo+10 µmol/L Akt), Glu+Exo+Erk group (dealing with 100 ng/ml Glu+100 ng/ml Exo+10 µmol/L Erk), and Glu+Exo+TrkB group (dealing with Glu+100 ng/ml Exo +10 µmol/L TrkB). RESULTS: Exosomes from hAMSCs had similar sizes to those isolated from other kinds of cells, and expressed the characteristic proteins such as CD63, CD81, HSP70, and HSP90. Cytokines that had neurotrophic effects on Exosomes were mainly insulin-like growth factor and hepatocyte growth factor, with the concentration being 9336.49±258.63 and 58,645.50±16,014.62, respectively; brain derived neurotrophic factor, nerve growth factor,and vascular endothelial growth factor had lower levels, with the concentration being 1928.25±385.47, 1136.94±5.99, and 33.34±9.43, respectively. MTS assay showed that the PC12 cell survival rates were 0.842±0.047, 0.306±0.024, 0.566±0.026, 0.461±0.016, 0.497±0.003, and 0.515±0.034 in the control group, Glu group, Glu+Exo group, Glu+Exo+Akt group, Glu+Exo+Erk group, and Glu+Exo+TrkB group; obviously, it was significantly lower in Glu group than in control group (P=0.02), significantly higher in Glu+Exo group than in Glu group (P=0.01), and significantly lower in Glu+Exo+Akt group than in Glu+Exo group (P=0.01). CONCLUSION: Exosomes secreted from hAMSCs have protective effect against neuron damage induced by glutamate, which may be mediated through activating the PI3/K-Akt signalling pathway.

[Application and curative effect of plasma exchange in myasthenia gravis patients with thymectomy].

OBJECTIVE: To explore the application of plasma exchange in myasthenia gravis (MG) patients with thymectomy, and to evaluate its curative effects. METHODS: The clinical data of 50 patients with thymectomy were analyzed retrospectively, and the patients were divided into Group A (23 cases, undergoing thymectomy and plasma exchange) and Group B (27 cases, undergoing thymectomy). The difference of serum concentration of AChRab was examined by ELISA, and the time of auxiliary breath, crisis of myasthenia and clinical evaluation in the 2 groups were compared. RESULTS: Serum concentration of AChRab in Group A descended obviously after the plasma exchange. One day and one week after the operation, the AChRab concentration in Group A was obviously lower than that in Group B, but there was no difference one month after the operation. One week after the operation, the time of auxiliary breath,crisis of myasthenia and clinical evaluation in Group A were less than those in Group B. CONCLUSION: Plasma exchange together with thymectomy can improve the temporary curative effects in patients with MG. It is safe and effective for MG.