Salidroside Inhibits Ganglion Cell Apoptosis by Suppressing the Müller Cell Inflammatory Response in Diabetic Retinopathy.

PURPOSE: This study aimed to investigate the role of salidroside (SAL) in the cellular communication between Müller cells and retinal ganglion cells in diabetic mice. METHODS: The diabetes mellitus (DM) animal models were established by the intraperitoneal injection of streptozotocin and treatment with SAL via gavage or by the injection of IL-22BP into the vitreous cavity. Immunohistochemistry was used to measure the expression of the glial fibrillary acidic protein in Müller cells. The expression of IL-22 and IL-22Rα1 in retinal tissues was assessed by immunofluorescence. Western blotting was used to measure the expression of inflammatory and apoptosis-related proteins. Hematoxylin-eosin staining, TUNEL staining, and flow cytometry were used to analyze the apoptosis of retinal ganglion cells. The effect of cellular interactions was explored by Transwell assays. RESULTS: Western blotting showed that glial fibrillary acidic protein, IL-22 protein expression was significantly upregulated in the DM animal models compared with the control mice. Immunofluorescence showed that IL-22 was highly expressed in Müller cells and IL-22Rα1 was expressed in ganglion cells in the retina of DM mice. Hematoxylin-eosin and TUNEL staining results showed an increase in the number of ganglion cells apoptotic in DM. However, SAL reversed these phenomena. Meanwhile, after coculture with Müller cells, Western blotting suggested that ganglion cells secreted p-STAT3, and c-caspase3 protein expression was increased. More interestingly, the treatment of IL-22BP and SAL inhibited the expression of the p-STAT3 and c-caspase3 proteins. Flow cytometry indicates that compared with the control group, the apoptosis rate of ganglion cells was increased in the high glucose group, while the apoptosis rate of cells in the recombinant IL-22 protein group was significantly increased, while the SAL inhibited ganglion cells apoptosis. CONCLUSION: SAL inhibits the apoptosis of retinal ganglion cells via the IL-22/STAT3 pathway in Müller cells.

Salidroside Alleviates Diabetic Cognitive Dysfunction Via B3galt2/F3/Contactin Signaling Pathway in Mice.

Diabetes is frequently accompanied by cognitive impairment with insidious onset, and progressive cognitive and behavioral changes. ß-1, 3-galactosyltransferase 2 (B3galt2) contributes to glycosylation, showing a clue for neuronal apoptosis, proliferation and differentiation. However, the role of B3galt2 in diabetic cognitive dysfunction (DCD) has not been investigated. In the present study, we aimed to explore the role of B3galt2 in DCD. Additionally, the potential therapeutic effects of salidroside on DCD was also explored. Diabetic C57BL/6J mice showed cognitive dysfunction together with down-regulated B3galt2. Overexpression of B3galt2 reversed the cognitive decline of diabetic C57BL/6J. Moreover, cognitive impairment was aggravated in B3galt2+/- diabetic mice compared with C57BL/6J diabetic mice. Immunohistochemistry fluorescence indicated that B3galt2 and F3/Contactin were co-localized in the hippocampal regions. Importantly, the expression of F3/Contactin can be regulated by the manipulation of B3galt2, overexpression of which assuaged hippocampal neuronal damage, protected the synapsin, and reduced neuronal apoptosis in diabetic mice. Interestingly, SAL alleviated DCD and reversed the expression of B3galt2 in diabetic C57BL/6J mice. These findings indicate that inhibition of B3galt2/F3/Contactin pathway contributes to DCD, and participates in SAL reversed DCD.

Th22 cells induce Müller cell activation via the Act1/TRAF6 pathway in diabetic retinopathy.

T helper 22 (Th22) cells have been implicated in diabetic retinopathy (DR), but it remains unclear whether Th22 cells involve in the pathogenesis of DR. To investigate the role of Th22 cells in DR mice, the animal models were established by intraperitoneal injection of STZ and confirmed by fundus fluorescein angiography and retinal haematoxylin-eosin staining. IL-22BP was administered by intravitreal injection. IL-22 level was measured by ELISA in vivo and in vitro. The expression of IL-22Rα1 in the retina was assessed by immunofluorescence. We assessed GFAP, VEGF, ICAM-1, inflammatory-associated factors and the integrity of blood-retinal barrier in control, DR, IL-22BP, and sham group. Müller cells were co-cultured with Th22 cells, and the expression of the above proteins was measured by immunoblotting. Plasmid transfection technique was used to silence Act1 gene in Müller cells. Results in vivo and in vitro indicated that Th22 cells infiltrated into the DR retinal and IL-22Rα1 expressed in Müller cells. Th22 cells promoted Müller cells activation and inflammatory factor secretion by secreting IL-22 compared with high-glucose stimulation alone. In addition, IL-22BP ameliorated the pathological alterations of the retina in DR. Inhibition of the inflammatory signalling cascade through Act1 knockdown alleviated DR-like pathology. All in all, the results suggested that Th22 cells infiltrated into the retina and secreted IL-22 in DR, and then IL-22 binding with IL-22Rα1 activated the Act1/TRAF6 signal pathway, and promoted the inflammatory of Müller cells and involved the pathogenesis of DR.

Rheological Characterization and Accumulation Tests for Strong Thixotropic Engineering Slurry.

Underground void subsidence hazards, especially mine goaf, have now become one of the major social problems affecting the well-being of civilians and development in China. The objective of this study was to propose a kind of strong thixotropic engineering slurry and filling treatment for use in underground void subsidence hazards. The optimal agent ratio for thixotropic cement slurry/mortar was obtained by indoor tests, where the rheological agent is 7.5% compared to the weight of cement, the water-solid ratio is in the range of 0.7~0.8, and the aeolian sand ratio can be 0~1.5 times that of cement. The rheological properties of slurry and mortar were tested using a Brookfield RST-SST rheometer. The results show that aeolian sand can be used as thixotropic cement mortar for a backfilling treatment for underground voids (mine goaf). The static yield stress increases non-linearly compared to existing thixotropic models. The stress decays sharply with shearing (the shear rate is more or less 10 s-1) and then the stress increases with the increase in shear rate (the shear rate is more than 10 s-1). The increase in the stress of the slurry is greater than in the mortar. A natural logarithmic function between yield stress and rest time (only 1 parameter), an exponential function with two parts for stress-shear rate (a rheology model, with only 3 parameters), and an exponential function for the accumulation law (only 2 parameters) were proposed in turn.

Porous Core/Dense Shell PLA Microspheres Embedded with High Drug Loading of Bupivacaine Crystals for Injectable Prolonged Release.

Objective of the study was to design an injectable microsphere preparation with high drug loading of bupivacaine for prolonged release and local anesthetic. PLA or PLGA was used as the biodegradable matrix material to fabricate microspheres with the o/w emulsification-solvent evaporation method. The characterization of bupivacaine microspheres was observed by SEM, DSC, and XRPD. The microsphere preparation and extended drug release, as well as the plasma drug concentration and sciatic nerve blockade after injection of the microsphere formulation to rats were investigated. High drug-loading microspheres of more than 70% were successfully obtained with extended drug release over 5 days in vitro depending on the type of matrix and the feed ratio of drug to polymer. SEM, DSC, and XRPD results verified a novel microsphere structure characterized as the porous core composed of PLA material and form II bupivacaine crystals and dense shell formed of PLA layer. The mechanism that bupivacaine was dissolved inside the microsphere and diffused across the dense shell was suggested for drug release in vitro. The optimized PLA microsphere formulation showed low and steady plasma drug concentration over 5 days and prolonged duration of sensory and motor blockade of sciatic nerve lasted more than 3 days. Results indicated that the porous core-shell structure of PLA microsphere formulation would provide enormous potential as an injectable depot for locally prolonged delivery of bupivacaine and control of postoperative pain.

Atractylenolide II Inhibits Proliferation, Motility and Induces Apoptosis in Human Gastric Carcinoma Cell Lines HGC-27 and AGS.

Atractylenolide II (AT-II) exhibits several biological and pharmacological functions, especially anti-cancer activity as the major sesquiterpene lactones isolated from Atractylodes macrocephala (also named Baizhu in Chinese). However, the effects and mechanisms of AT-II on human gastric cancer remain unclear. Cell Counting Kit-8 (CCK-8) assay, morphological changes, flow cytometry, wound healing assay and Western blot analysis were used to investigate the effects of AT-II on cell proliferation, apoptosis and motility of human gastric carcinoma cell lines HGC-27 and AGS. Our results indicated that AT-II could significantly inhibit cell proliferation, motility and induce apoptosis in a dose and time-dependent manner. Western blot analysis showed that the expression level of Bax was upregulated and the expression levels of B-cell lymphoma-2 (Bcl-2), phosphorylated-protein kinase B (p-Akt) and phosphorylated-ERK (p-ERK) were downregulated compared to control group. In conclusion, the findings suggested that AT-II exerted significant anti-tumor effects on gastric carcinoma cells by modulating Akt/ERK signaling pathway, which might shed light on therapy of gastric carcinoma.

The anti-melanoma efficiency of the intratumoral injection of cucurbitacin-loaded sustained release carriers: in situ-forming implants.

Our previous studies revealed that the PLGA-based particulate systems loaded with cucurbitacin showed limited anti-melanoma efficiency in xenograft animal models after intratumoral injection, which was due to the undesirable initial burst release and the leakage of the particulate carriers from the injection site through the pinhole. In this paper, two categories of in situ-forming implants (ISFIs) for intratumoral injection, PLGA ISFIs and SAIB ISFIs, were systemically evaluated for their potentials for on solid tumor treatment via intratumoral injection. The in vitro drug release profiles of these two ISFIs were different due to the different sol-gel transition properties. The pharmacodynamics results revealed that SAIB ISFIs displayed obvious therapeutic efficiencies to melanoma, and multi-points injection of SASIB ISFIs displayed better efficiency than single-point injection. The different sol-gel transition properties and mechanism for PLGA ISFIs and SAIB ISFIs affected both the drug release and strongly impacted the pharmacokinetic parameters and pharmacodynamic effectiveness. Also, the adhesive property of SAIB to the local tissue could extend the retention and inhibit the leakage of the SAIB ISFIs, thus enhanced the anticancer effectiveness. Comparison of the various intratumoral injection systems, appropriate drug release profiles (lower initial burst and steady release) and good retention (minimum leakage from the injection site) would benefit to the antitumor effects of the intratumoral depots.