PO-132 Exogenous VD3 alleviates chronic fatigue syndrome by activating MEKs/ERKs-SIRT1 signaling pathway in skeletal muscle

Objective To investigate the effects of exogenous VD3 on exercise-induced chronic fatigue syndrome (CFS) and its mechanism. Methods 80 male mice were randomly divided into 5 groups（n=16）. One group was named as quiet control group (C) while the other four were used to build CFS model by forced swimming. Among the four groups, three were selected for feeding VD3 1 h before exercise (bVD), 15 min after starting exercise (mVD) and 1 h after exercise (aVD) respectively, and the group without VD3 feeding was CFS model group (CFS). The behavior and condition of mice was observed during the whole process. After the training was completed totally, the tail suspension test and the forced swimming test were implemented, and then the blood and quadriceps were dissected. Serum testosterone and corticosterone content, as well as the antioxidant system indexes in the quadriceps, including malondialdehyde (MDA), total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-PX) and total superoxide dismutase (T-SOD), were measured. Routine western blotting experimentation was used to measure signal pathway indicators, containing SIRT1, SIRT3, ERK1/2, p-ERK1/2 and MEK1/2. Results Compared with C group, CFS group appeared serious damage caused by fighting, and the concentration of serum testosterone decreased significantly (p<0.01 or p<0.05) while cortisol concentration increased significantly (p<0.01 or p<0.05). Regarding antioxidant stress system indexes, the expression of MDA, T-SOD and GSH-PX significantly increased (p<0.05). The concentration of MEK and SIRT3 decreased significantly (p<0.01 or p<0.05). Compared with CFS group, VD intervention group (bVD, mVD and aVD) showed less damage caused by fighting and significantly lighter body weight (p<0.05), and the concentration of serum testosterone increased significantly (p<0.05) while that of cortisol decreased significantly (p<0.01 or p<0.05). The expression of MDA decreased significantly (p<0.05), on the countrary, T-AOC, T-SOD and GSH-PX increased significantly (p<0.05). The expressions of MEK, p-ERK/ERK, SIRT1 and SIRT3 were significantly upregulated (p<0.01 or p<0.05). Conclusions Exogenous VD3 could alleviate CFS, which probably related to activate the MEKs/ERKs-SIRT1 signal transduction axis and hence regulate the expression of SIRT3

Role of Chitinase-3-like Protein 1 in Cardioprotection and Angiogenesis by Post-Infarction Exercise Training

Chitinase-3-like protein 1 (CHI3L1) is a myokine involving tissue remodeling and inflammatory processes. CHI3L1 and its receptor protease-activated receptor 2 (PAR2) are induced by exercise in skeletal muscles. However, it remains unknown if CHI3L1/PAR2 signaling also mediates exercise-induced cardioprotection after myocardial infarction. Twenty-four adult male rats were divided into three groups (n = 8/group), receiving: (1) a sham operation; (2) permanent ligation of left anterior descending coronary artery; and (3) post-MI exercise training with one-week adaptive treadmill exercise for seven days followed by four weeks of aerobic exercise. Left ventricular systolic and end-diastolic pressure indices were measured and cardiac fibrosis, and angiogenesis were examined. Furthermore, HUVEC cells were treated in vitro with AMPK agonist—AICAR (a putative pharmacological memetic of exercise), recombinant human CHI3L1, PAR2 receptor blocker (AZ3451), and PI3K inhibitor (LY294002), respectively. We found that post-MI exercise significantly upregulated CHI3L1, PAR2, pPI3K/PI3K, pAKT/AKT, pERK/ERK, improved cardiac function, and diminished fibrosis. AICAR increased HUVEC tubules formation and upregulated CHI3L1 and PAR2 and these changes were attenuated by PAR2 blocker. In conclusion, post-MI exercise training can effectively activate CHI3L1/PAR2 signaling, which led to the improved myocardial function and enhanced cardiac angiogenesis in the infarcted heart

Highly Stable and NIR Luminescent Ru–LPMSN Hybrid Materials for Sensitive Detection of Cu²⁺ in Vivo

Herein, new near-infrared (NIR) luminescent ruthenium complexes were prepared for detecting Cu²⁺ ions. Then, ruthenium complex hybrid nanomaterials (Ru–LPMSNs) were fabricated successfully by imbedding the ruthenium complex into mesoporous silica nanoparticles. Benefiting from the novel large-pore mesoporous structure and good adsorbility of LPMSNs, Ru–LPMSN hybrid materials showed a significantly enhanced fluorescence intensity and stability. NIR fluorescence of Ru–LPMSNs was rapidly quenched by Cu²⁺ ions. Ru–LPMSNs also showed high Cu²⁺ ion selectivity and sensitivity as a sensor. The detection limit of Cu²⁺ ions was 10 nM with a wide linear relationship between the fluorescence intensity of Ru–LPMSNs and the concentration of Cu²⁺ ions. The mechanism of fluorescence quenching might be that the combination of the ruthenium complex and Cu²⁺ ions constrained the photoinduced electron-transfer process. Furthermore, Ru–LPMSNs dramatically increased the fluorescence signals in cells and achieved Cu²⁺-ion detection. Ru–LPMSNs had different tissue affinities and could monitor distribution of exogenous Cu²⁺ ions in vivo. Moreover, Ru–LPMSNs realized direct and rapid detection of Cu²⁺-ion content in serum. These results indicated the potential applications of the prepared nanomaterials as Cu²⁺ detection agents

Characterization and Evaluation of Rapamycin-Loaded Nano-Micelle Ophthalmic Solution

Rapamycin-loaded nano-micelle ophthalmic solution (RAPA-NM) offers a promising application for preventing corneal allograft rejection; however, RAPA-NM has not yet been fully characterized. This study aimed to evaluate the physicochemical properties, biocompatibility, and underlying mechanism of RAPA-NM in inhibiting corneal allograft rejection. An optimized RAPA-NM was successfully prepared using a polyvinyl caprolactam–polyvinyl acetate–polyethylene glycol (PVCL-PVA-PEG) graft copolymer as the excipient at a PVCL-PVA-PEG/RAPA weight ratio of 18:1. This formulation exhibited high encapsulation efficiency (99.25 ± 0.55%), small micelle size (64.42 ± 1.18 nm), uniform size distribution (polydispersity index = 0.076 ± 0.016), and a zeta potential of 1.67 ± 0.93 mV. The storage stability test showed that RAPA-NM could be stored steadily for 12 weeks. RAPA-NM also displayed satisfactory cytocompatibility and high membrane permeability. Moreover, topical administration of RAPA-NM could effectively prevent corneal allograft rejection. Mechanistically, a transcriptomic analysis revealed that several immune- and inflammation-related Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were significantly enriched in the downregulated genes in the RAPA-NM-treated allografts compared with the rejected allogenic corneal grafts. Taken together, these findings highlight the potential of RAPA-NM in treating corneal allograft rejection and other ocular inflammatory diseases

Structural Characteristics of Polysaccharide GP2a in Gardenia jasminoides and Its Immunomodulatory Effect on Macrophages

Here, we elucidated the structural characteristics of a polysaccharide isolated from Gardenia jasminoides Ellis (labeled as GP2a) and its immunomodulatory activity. GP2a is an acidic polysaccharide with a molecular weight of 44.8 kDa, mostly comprising galacturonic acid. Methylation analysis revealed 4-GalpA (74.8%) to be the major sugar residue in GP2a. Nuclear magnetic resonance analysis indicated that its main chain comprised →4)-α-D-GalpA-6-OMe-(1→4)-α-D-GalpA-(1→ and →4)-α-D-GalpA-6-OMe-(1→2)-α-L-Rhap-(1→, with galactan and arabinans linked to the C-4 position of →2)-α-L-Rhap-(1→ residue as branched chains. Furthermore, GP2a showed no obvious toxicity to macrophages (RAW 264.7) while enhancing cell viability in a dose- and time-dependent manner. Compared with untreated cells, nitric oxide production and secretion of cytokines, such as tumor necrosis factor-α, interferon-γ, interleukin (IL)-1β, IL-6, and granulocyte macrophage colony stimulating factor, in GP2a-treated cells significantly increased after 48 h. At 300 µg/mL GP2a concentration, there was no significant difference in the cytokine levels in GP2a- and lipopolysaccharide-treated cells (the positive control). In summary, GP2a is a pectic polysaccharide with homogalacturonan and rhamnogalacturonan-I structural regions in the main chain. Based on its immunomodulatory effects in vitro, GP2a may have potential uses in functional food and medicine