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Objective To identify the effects of interleukin-6 (IL-6) on astrocytes activation, and the regulation of the expression of inwardly rectifying potassium 4.1 (Kir4.1) channels in astrocytes. Methods Astrocytes were separated from the cerebral cortex of newborn SD rats, and cultured in the presence of IL-6 or combined with interleukin-6 receptor antagonist (IL-6Ra). CCK-8 assay was performed to measure cell viability. The expression level of Kir4.1 channels in astrocytes was measured using quantitative real-time PCR and Western blot analysis. Results IL-6 promoted the proliferation of astrocytes in a dose- (0-30 ng/mL) and time- (0-24 hours) dependent manner. After astrocytes were treated with IL-6 (30 ng/mL) for 24 hours, the levels of Kir4.1 mRNA and protein decreased significantly, and this down-regulation could be attenuated by IL-6Ra. Conclusion IL-6 promotes the activation of astrocyte and down-regulation of the expression of Kir4.1 channel.

Phlomis medicinalis Diels, an important perennial herbal plant unique to the Qinghai-Tibet Plateau, is often used as Tibetan Materia Medicine Radix Phlomii for the treatment of cold, cough, and convergence trauma. In order to efficiently extract the iridoid glycosides from P. medicinalis, an ultrasound-assisted deep eutectic solvent extraction technique was employed. The main parameters influencing the extraction process were studied through single-factor tests and the extraction was optimized by using response surface methodology. The hemostasis activity of total iridoid glycosides (TIG) from P. medicinalis was evaluated in vitro and in mice. The optimization results revealed that the optimal process parameters were liquid-solid ratio 20 : 1, choline chloride-lactic acid concentration 79 %, and sonication time 34 min, under which a TIG extraction yield of 20.73 % was obtained. Meanwhile, high-performance liquid chromatography-photodiode array/mass spectrometry (HPLC-PDA/MS) was employed to characterize the optimized extract and indicated that TIG from P. medicinalis mainly consisted of sixteen reported iridoid glycosides with a total content of 91.22 %. The experimental results in vivo and in vitro indicated that TIG from P. medicinalis had strong hemostasis activities, which may be achieved by increasing the fibrinogen levels. Therefore, the ultrasound-assisted deep eutectic solvent extraction is an effective method to extract iridoid glycosides from P. medicinalis and they will be promising candidates to be developed for medical hemostasis agents.

Chitosan-based thermosensitive hydrogels have been widely used in drug delivery and tissue engineering, but their poor bioactivity has limited their further applications. Integral active oyster peptide microspheres (OPM) with an average particle diameter of 3.9 μm were prepared with high encapsulation efficiency (72.8%) and loading capacity (11.9%), exhibiting desirable sustained release effects. Using catechol functionalized chitosan (CS-C) as the polymeric matrix, OPM as the filler, and β-sodium glycerophosphate (β-GP) as a thermal sensitizer, the thermosensitive hydrogel CS-C/OPM/β-GP was prepared. Besides, the application of the hydrogel on wound healing was studied, and its biosafety was evaluated. The results of cell migration in vitro showed that the cell migration rate of CS-C/OPM/β-GP reached 97.47 ± 5.41% within 48 h, indicating that the hydrogel accelerated the migration of L929 cells. As demonstrated in the mouse skin wound experiment, CS-C/OPM/β-GP hydrogel not only inhibited the aggregation of diversified inflammatory cells and accelerated the generation of collagen fibers and new blood vessels of the wound, but also enhanced the synthesis of total protein (TP) in granulation tissue, and up-regulated the expression of Ki-67 and VEGF in the injury, thereby achieving fast wound healing. Safety evaluation results showed that CS-C/OPM/β-GP hydrogel was not cytotoxic to L929 cells, and the hemolysis ratio was less than 5% within 1 mg/mL. In conclusion, CS-C/OPM/β-GP hydrogel is expected as a promising medical dressing for wound healing.

Based on Stephen Paget's well-established theory, both cell-autonomous and non-cell-autonomous mechanisms are crucial for metastasis. Although the mitochondrial calcium uniporter (MCU) has been suggested to be involved in breast cancer (BC) progression via cell-autonomous mechanisms, whether it assists the metastasis of BC cells through non-cell-autonomous mechanisms remains unclear. This study aimed to demonstrate that the MCU regulates BC metastatic colonization via non-cell-autonomous mechanisms. The results suggested that extracellular vesicles (EVs) derived from MCU-downregulated MDA-MB-231 cells suppressed angiogenesis in the metastatic niche in a nude mouse model, thereby hindering the colonization of BC cells. Mechanistically, we revealed that the MCU negatively correlated with miR-4488 in EVs derived from BC cells. Significantly, miR-4488 was determined to suppress angiogenesis of vascular endothelial cells by directly targeting angiogenic CX3CL1. Furthermore, we identified miR-4488 as being significantly downregulated in serum EVs from patients with triple-negative BC. Hence, this study suggests that MCU-dependent negative sorting of miR-4488 to EVs enhances angiogenesis in the metastatic niche and, thus, favors the metastatic colonization of BC cells.

Objective To investigate the effect of insulin-like growth factor 1 (IGF-1) on the phagocytic activity of mouse BV-2 microglial cells. Methods Western blotting was performed to detect the protein levels of IGF-1 and IGF-1 receptor (IGF-1R) in the murine brain after the establishment of acute central nervous system inflammation models by intraperitoneal lipopolysaccharide (LPS) injection (10 mg/kg). The protein level of IGF-1R on BV-2 microglial cells that had been stimulated by 500 ng/mL LPS for 4, 12 and 24 hours was measured by Western blotting. To assess the phagocytic activity of microglial cells in response to IGF-1, BV-2 microglial cells were stimulated by IGF-1 at different concentrations for 24 hours after pretreated with or without wortmannin (PI3K/AKT signaling pathway blocker), and then incubated with fluorescent microbeads for 2 hours followed by measurement of phagocytosis of the fluorescent microbeads by flow cytometry. After treatment of IGF-1 (50 ng/mL), p-AKT and AKT signaling pathways in the BV-2 microglial cells were detected by Western blotting. Results Intraperitoneal LPS injection caused increased levels of IGF-1 and IGF-1R in the mouse brain. LPS upregulated the protein expression of IGF-1R on BV-2 microglial cells. The activity of BV-2 microglial cells to phagocytose fluorescent microbeads gradually increased with IGF-1 concentration rising and peaked in the IGF-1 treatment at 50 ng/mL, and gradually decreased thereafter. And IGF-1 induced the phosphorylation of AKT in BV-2 microglial cells. However, after the PI3K/AKT signaling pathway was blocked via wortmannin, the effect of IGF-1 on the activity of BV-2 microglial cells to phagocytose fluorescent microbeads was significantly alleviated. Conclusion IGF-1 can promote phagocytic activity of BV-2 cells via activating PI3K/AKT signaling pathway, which suggests a potential role of IGF-1 in regulating the cerebral inflammation.

18β-Glycyrrhetinic acid (GA) is often topically applied in clinical treatment of inflammatory skin diseases. However, GA has poor solubility in water, which results in poor skin permeability and low bioavailability. Nanocrystallization of drugs can enhance their permeability and improve bioavailability. We prepared GA nanocrystals (Nano GA) by high-pressure homogenization. These nanocrystals were characterized by photon correlation spectroscopy, scanning electron microscopy, thermogravimetric analysis, and X-ray diffractometry. The ability of Nano GA to improve dermal permeability was investigated ex vivo using Franz diffusion vertical cells and mouse skin. The topical anti-inflammatory activity of Nano GA was assessed in vivo by a 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced model in mouse ears. The average particle size of a GA nanocrystalline suspension was 288.6 ± 7.3 nm, with a narrow particle-size distribution (polydispersity index ∼0.13 ± 0.10), and the particle size of the lyophilized powder increased (552.0 ± 9.8 nm). After nanocrystallization, the thermal stability and crystallinity decreased but solubility increased significantly. Nano GA showed higher dermal permeability than Coarse GA. Macroscopic and staining-based observations of mouse ears and the levels of proinflammatory factors and myeloperoxidase revealed that the Nano GA hydrogel exhibited better anti-edema ability and more strongly inhibited inflammation development than the Coarse GA hydrogel and indomethacin hydrogel (positive drug). These results suggest that Nano GA could be an efficacious topical therapeutic agent for skin inflammation.

Long-term excessive alcohol intake can easily lead to gastritis, gastric ulcer, and gastric bleeding. In this paper, the gastric acid-responsive hydrogel of CS-NAC/alginate/tilapia collagen peptide (CS-NAC/ALG/TCP) was developed. Its structure and properties were determined. The alcohol-induced gastric mucosal injury models in mice were established to evaluate the protective effects of CS-NAC/ALG/TCP. The results showed that CS-NAC/ALG/TCP was successfully fabricated, and it showed a sustained release of TCP, strong mucoadhesion, and excellent biodegradability in vitro. In the animal experiments, CS-NAC/ALG/TCP improved the oxidative stress status of the gastric mucosa by increasing the levels of SOD, GSH, and CAT in tissues. It also down-regulated the expression of MPO, TNF-α, IL-1β, and IL-6, and increased the production of gastric protective factors such as PGE2 and NO in mouse stomach, thereby reducing the alcohol-induced inflammation and protecting the gastric mucosal injury. Besides, CS-NAC/ALG/TCP can also increase the activities of alcohol metabolism enzymes to improve alcohol metabolism, thereby reducing alcoholic damage. In conclusion, CS-NAC/ALG/TCP is a promising candidate for the treatment of alcohol-induced gastric injury.

Uncontrolled bleeding has always been a sudden accident, which is the main cause of casualties in war trauma, emergency events and surgical operations. Rapid hemostatic materials can effectively reduce casualties and save lives. In this paper, marine collagen peptide grafted carboxymethyl chitosan (CMCS-MCP) was synthesized by 1-ethyl-(dimethylaminopropyl) carbodiimide (EDC)-mediated coupling reaction. To obtain CMCS-MCP conjugates with different degrees of substitution (DS), the reaction conditions were investigated by single-factor tests and optimized by response surface methodology. And the sponges of CMCS-MCP were prepared by freeze-thaw cycling and freeze-drying and characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), and X-ray diffraction (XRD). To evaluate the hemostatic properties of CMCS-MCP sponges, in vitro and in vivo hemostasis tests were carried out. The results showed that the optimum preparation conditions were the mass ratio of MCP to CMCS (MMCP/MCMCS) 6:1, reaction temperature 41 °C, and reaction time 16 h. And under which the DS of 58.86% was obtained. Structure analysis showed that MCP had been successfully grafted onto the CMCS molecular chain, and the CMCS-MCP sponges were of high porosity. In vitro and in vivo hemostasis tests showed that the CMCS-MCP sponges had significant procoagulant activities, especially the one with high DS of 58.86%. The hemostasis mechanism may be that the synergistic effects of MCP and CMCS accelerated coagulation through multiple approaches. The CMCS-MCP sponges give a new insight into biomedical hemostasis materials.

Lung metastasis is a primary obstacle in the clinical treatment of metastatic breast cancer. Most patients with lung metastasis eventually die of recurrence. Recurrence may be related to self-seeding, which occurs when circulating tumor cells re-seed into the tumors they originated from (metastasis or carcinoma in situ). Tumor-derived exosomes have been intensively revealed to promote the progression of various cancers. However, whether tumor-derived exosomes play roles in tumor self-seeding has not yet been identified. By establishing a self-seeding nude mouse model, we found that exosomes derived from MDA231-LM2 cells (subpopulations of breast cancer lung metastasis) potentiate the growth of MDA-MB-231 xenografts. More importantly, laser confocal microscopy and flow cytometry results identified that MDA231-LM2-secreted exosomes promote the seeding of MDA231-LM2 cells into MDA-MB-231 xenografts. These findings suggest MDA231-LM2-secreted exosomes as a promising target to treat breast cancer lung metastasis.

Burns are physically debilitating and potentially fatal injuries. Two marine biomaterials, carboxymethyl chitosan (CMC) and collagen peptides (COP), have emerged as promising burn dressings. In this paper, sponges of carboxymethyl chitosan grafted with collagen peptide (CMC&ndash, COP) were prepared by covalent coupling and freeze drying. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy were then used to characterize the prepared sponges. To evaluate the wound healing activity of the CMC&ndash, COP sponges, in vitro tests including cell viability scratch wound healing and scald wound healing experiments were performed in rabbits. Appearance studies revealed the porous nature of sponges and FTIR spectroscopy demonstrated the successful incorporation of COP into CMC. The in vitro scratch assay showed that treatment with CMC&ndash, COP sponges (at 100 &mu, g/mL) had significant effects on scratch closure. For burn wounds treated with CMC&ndash, COP, regeneration of the epidermis and collagen fiber deposition was observed on day 7, with complete healing of the epidermis and wound on days 14 and 21, respectively. Based on the pathological examination by hematoxylin and eosinstaining, the CMC&ndash, COP group demonstrated pronounced wound healing efficiencies. These results confirmed that the CMC&ndash, COP treatment enhanced cell migration and promoted skin regeneration, thereby highlighting the potential application of these sponges in burn care.

Background Stromal interaction molecule (STIM) 2 is a key calcium-sensing molecule that regulates the stabilization of calcium ions (Ca2+) and therefore regulates downstream Ca2+-associated signaling and cellular events. We hypothesized that STIM2 regulates epithelial-mesenchymal transition (EMT) to promote breast cancer metastasis. Methods We determined the effects of gain, loss, and rescue of STIM2 on cellular motility, levels of EMT-related proteins, and secretion of transforming growth factor-β (TGF-β). We also conducted bioinformatics analyses and in vivo assessments of breast cancer growth and metastasis using xenograft models. Results We found a significant association between STIM2 overexpression and metastatic breast cancer. STIM2 overexpression activated the nuclear factor of activated T cells 1 (NFAT1) and TGF-β signaling. Knockdown of STIM2 inhibited the motility of breast cancer cells by inhibiting EMT via specific suppression of NFAT1 and inhibited mammary tumor metastasis in mice. In contrast, STIM2 overexpression promoted metastasis. These findings were validated in human tissue arrays of 340 breast cancer samples for STIM2. Conclusion Taken together, our results demonstrated that STIM2 specifically regulates NFAT1, which in turn regulates the expression and secretion of TGF-β1 to promote EMT in vitro and in vivo, leading to metastasis of breast cancer. Electronic supplementary material The online version of this article (10.1186/s13058-019-1185-1) contains supplementary material, which is available to authorized users.

Effective hemostasis is vital to reduce the pain and mortality of patients, and the research and development of hemostatic materials are prerequisite for effective hemostasis. Chitosan (CS), with good biodegradability, biocompatibility and non-toxicity, has been widely applied in bio-medicine, the chemical industry, the food industry and cosmetics. The excellent hemostatic properties of CS have been extensively studied. As a result, chitosan-based composite hemostatic materials have been emerging. In this review, the hemostatic mechanism of chitosan is briefly discussed, and then the progress of research on chitosan-based composite hemostatic materials with multiple forms such as films, sponges, hydrogels, particles and fibers are introduced. Finally, future perspectives of chitosan-based composite hemostatic materials are given. The objective of this review is to provide a reference for further research and development of effective hemostatic materials.

Hemorrhea is one of the major problems in war, trauma care, and surgical operation that threaten the life of the injured and patients. As a novel polymeric hemostatic agent, biodegradable chitosan can stop bleeding through a variety of approaches. In this paper, chitosan with various molecular parameters was prepared from chitin as raw material through deacetylation, oxidative degradation, hydrophilic modification, and salt formation reactions. The influence of different polymer parameters on the hemostatic effects of chitosan was investigated by in vitro coagulation time and dynamic coagulation assay. The results showed that when the molecular weights were high (105&ndash, 106) and approximate, the coagulation effect of chitosan improved with a decrease of the deacetylation degree and achieved a prominent level in a moderate degree of deacetylation (68.36%). With the same degree of deacetylation, the higher the molecular weight of chitosan, the better the procoagulant effect. The substituent derivatives and acid salts of chitosan showed significant procoagulant effects, especially the acid salts of chitosan. In addition, the hemostasis mechanism of chitosan with various parameters was preliminarily explored by analyzing the plasma recalcification time (PRT). The efforts in this paper laid a basis for further study of the structure&ndash, activity relationship and the mechanism of chitosan hemostasis.