Background: The present clinical trial investigated the potential influences of dosage and age on the pharmacokinetic properties and safety profile of HSK3486, and whether any adjustment in dosing regimen is necessary in elderly patients.Methods: Twenty-four elderly participants (65–73 years) were apportioned to three equal cohorts to receive a single IV bolus of 0.2, 0.3, and 0.4 mg/kg HSK3486, respectively. An additional control group comprised eight non-elderly participants (21–44 years), who each received a single IV bolus dose of 0.4 mg/kg. Safety was assessed throughout the study, and the clinical effects were assessed based on modified observer’s assessment of alertness/sedation and bispectral index (BIS) monitor. Pharmacokinetic parameters were calculated.Results: The rates of drug-related adverse reactions among the elderly groups were a little higher than that of the non-elderly, and were slightly higher in the elderly receiving 0.4 mg/kg compared with the elderly given lower doses. The pharmacokinetic characteristics of 0.4 mg/kg HSK3486 in the elderly and non-elderly were comparable. The time to recovery was similar in elderly 0.3 mg/kg, elderly 0.4 mg/kg and non-elderly 0.4 mg/kg groups. In the elderly 0.2 mg/kg group, the time to loss of consciousness was a little longer, and the time to recovery was shorter, relative to the other three groups.Conclusions: Administration of 0.3 mg/kg to the elderly and 0.4 mg/kg to the non-elderly were similarly efficacious. A dose of HSK3486 of 0.3 mg/kg may be chosen for clinical use in elderly patients.

Background/Aims: Chronic respiratory conditions continue to plague millions of people worldwide. We aimed to elucidate the detailed mechanisms of microRNA-485 (miR-485) in airway smooth muscle cell (ASMC) proliferation and apoptosis in chronic asthmatic mice. Methods: A mouse model of chronic asthma was established. Ovalbumin was used to induce chronic asthma in the mice. The levels of transforming growth factor β (TGF-β), interleukin (IL)-4, IL-5, IL-13 and IL-17 in bronchoalveolar lavage fluid in mice were measured by enzyme-linked immunoassays (ELISAs). ASMCs were transfected with miR-485 mimic, miR-485 inhibitor and siRNA-Smurf2. The reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analyses were applied to detect the mRNA and protein levels of Smurf2, α-SMA, TGF-β1 and decapentaplegic homolog (Smads). The MTT assay was utilized for cell proliferation, while flow cytometry was conducted to assess cell cycle distribution and apoptosis. Results: Lower expression of miR-485 and higher expression levels of TGF-β1, IL-4, IL-5, IL-13 and IL-17 were detected in mice with chronic asthma. Smurf2 was identified as the target gene of miR-485. Upregulation of miR-485 mimic and downregulation of Smurf2 decreased expression levels of Smurf2, α-SMA, TGF-β1 and Smad3, inhibited cell proliferation and increased apoptosis, while contrary results were observed in ASMCs transfected with miR-485 inhibitor. Conclusion: Overexpressed miR-485 inhibits cell proliferation and promotes apoptosis of ASMCs through the Smurf2-mediated TGF-β/Smads signaling pathway in mice with chronic asthma.

As a chemotherapeutic agent, bortezomib (BTZ) is used for the treatment of multiple myeloma with adverse effect of painful peripheral neuropathy. Our current study was to determine the inhibitory effects of blocking microRNA-155 (miR-155) signal on BTZ-induced neuropathic pain and the underlying mechanisms. We employed real time RT-PCR and western blot analysis to examine the miR-155 and expression of pro − inflammatory tumor necrosis factor-α receptor (TNFR1) in the dorsal horn of the spinal cord. Its downstream signals p38-MAPK and JNK and transient receptor potential ankyrin 1 (TRPA1) were also determined. Mechanical pain and cold sensitivity were assessed by behavioral test. In result, inhibition of miR-155 significantly attenuated mechanical allodynia and thermal hyperalgesia in BTZ rats, which was accompanied with decreasing expression of TNFR1, p38-MAPK, JNK, and TRPA1. In contrast, miRNA-155 mimics amplified TNFR1-TRPA1 pathway and augmented mechanical pain and cold sensitivity. In addition, mechanical and thermal hypersensitivity induced by miRNA-155 mimics were attenuated after blocking TNFR1, p38-MAPK, JNK, and TRPA1. Overall, we show the key role of miR-155 in modifying BTZ-induced neuropathic pain through TNFR1-TRPA1 pathway, suggesting that miR-155 is a potential target in preventing neuropathic pain development during intervention of BTZ.

Background Pain is one of the most common and distressing symptoms suffered by patients with progression of cancer; however, the mechanisms responsible for hyperalgesia are not well understood. Since the midbrain periaqueductal gray is an important component of the descending inhibitory pathway controlling on central pain transmission, in this study, we examined the role for pro-inflammatory cytokines of the periaqueductal gray in regulating mechanical and thermal hyperalgesia evoked by bone cancer via phosphatidylinositide 3-kinase (PI3K)–mammalian target of rapamycin (mTOR) signals. Methods Breast sarcocarcinoma Walker 256 cells were implanted into the tibia bone cavity of rats to induce mechanical and thermal hyperalgesia. Western blot analysis and ELISA were used to examine PI3K/protein kinase B (Akt)/mTOR and pro-inflammatory cytokine receptors and the levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α). Results Protein expression levels of p-PI3K/p-Akt/p-mTOR were amplified in the periaqueductal gray of bone cancer rats, and blocking PI3K–mTOR pathways in the periaqueductal gray attenuated hyperalgesia responses. In addition, IL-1β, IL-6, and TNF-α were elevated in the periaqueductal gray of bone cancer rats, and expression of their respective receptors (namely, IL-1R, IL-6R, and tumor necrosis factor receptor (TNFR) subtype TNFR1) was upregulated. Inhibition of IL-1R, IL-6R, and TNFR1 alleviated mechanical and thermal hyperalgesia in bone cancer rats, accompanied with downregulated PI3K–mTOR. Conclusions Our data suggest that upregulation of pro-inflammatory cytokine signal in the periaqueductal gray of cancer rats amplifies PI3K–mTOR signal in this brain region and alters the descending pathways in regulating pain transmission, and this thereby contributes to the development of bone cancer-induced pain.

Background/Aims: Bortezomib (BTZ) is largely used as a chemotherapeutic agent for the treatment of cancer. However, one of the significant limiting complications of BTZ is painful peripheral neuropathy during BTZ therapy. Drugs preventing and/or treating the painful symptoms induced by BTZ are lacking since the underlying mechanisms leading to neuropathic pain remain largely unclear. The purposes of this study were to examine 1) the effects of blocking mammalian target of rapamycin (mTOR) on mechanical pain and cold hypersensitivity evoked by BTZ and 2) the underlying mechanisms responsible for the role of mTOR in regulating BTZ-induced neuropathic pain. Methods: Behavioral test was performed to determine mechanical pain and cold sensitivity in a rat model. Western blot analysis and ELISA were used to examine expression of mTOR and phosphatidylinositide 3-kinase (p-PI3K) signals, and the levels of substance P and calcitonin gene-related peptide (CGRP). Results: Systemic injection of BTZ significantly increased mechanical pain and cold sensitivity as compared with control animals (P<0.05 vs. control rats). The expression of p-mTOR, mTORmediated phosphorylation of p70 ribosomal S6 protein kinase 1 (p-S6K1), 4E-binding protein 4 (p-4E-BP1) as well as p-PI3K was amplified in the dorsal horn of spinal cord of BTZ rats as compared with control rats. Blocking mTOR by intrathecal infusion of rapamycin attenuated mechanical pain and cold hypersensitivity. Blocking PI3K signal also attenuated activities of mTOR, which was accompanied with decreasing neuropathic pain. Inhibition of either mTOR or PI3K blunted enhancement of the spinal substance P and CGRP in BTZ rats. Conclusions: The data for the first time revealed specific signaling pathways leading to BTZ-induced peripheral neuropathic pain, including the activation of mTOR and PI3K. Inhibition of these signal pathways alleviates pain. Targeting one or more of these signaling molecules may present new opportunities for treatment and management of peripheral painful neuropathy observed during chemotherapeutic application of BTZ.