Phosphodiesterase 4 Inhibitor Roflupram Suppresses Inflammatory Responses Using Reducing Inflammasome in Microglia After Spinal Cord Injury.

Context: Neuroinflammation after spinal cord injury (SCI) can lead to long-term damage in neural tissue, which can cause the destruction and dysfunction of the neurological system. Roflupram (ROF), a selective phosphodiesterase 4 inhibitor, may play a protective role against neuropathological diseases, but the specific role of ROF in SCI treatment is unknown. Objective: The study intended to investigate the anti-inflammatory mechanism and therapeutic effects of ROF to determine if it can attenuate lipopolysaccharide (LPS)-induced microglia that induces neuroinflammation and decrease neural-tissue damage following an SCI. Design: The research team performed an animal study. Setting: The study took place at the Fourth Affiliated Hospital of Harbin Medical University in Harbin, China. Animals: The animals were female C57BL/6 mice, aged 8 weeks and weighing approximately 20 g. Intervention: For the in-vitro study, the research team divided BV2 microglial cells into three groups: (1) the control group, which received no LPS stimuli and no ROF treatment, (2) the LPS group, which received LPS stimuli but no ROF treatment, and (3) LPS+ROF group, which received both LPS stimuli and ROF treatment. For the in-vivo study, the research team randomly divided the mice into three groups: (1) the sham group, for which the team didn't induce SCI and which received no ROF treatment (2) the SCI group, for which the team induced SCI but which received no ROF treatment, and (3) the SCI+ROF group, for which the team induced SCI and which received the ROF treatment. Outcome Measures: The research team evaluated: (1) the cell viability of the BV2 microglia cells after five doses of ROF and the RNA levels of inflammatory-activation-related factors, the inflammatory pathway; (2) in-vitro inhibition of inflammation in LPS-activated microglia; (3) the anti-neuroinflammatory role of ROF after SCI induction in vitro; and (4) the role of ROF in neural-structure protection and locomotor-function recovery in vitro. Results: In the in-vitro study, the ROF attenuated microglial inflammation through the inhibition of the NLRP3 inflammasome in vitro, reduced neuroinflammation, and protected against neuronal loss. In the in-vivo study with mice, the ROF: (1) improved the functional recovery of locomotor skills after induction of SCI; (2) acted in an anti-inflammatory role in SCI, restraining microglial inflammation by inhibition of the "nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3" (NLRP3) inflammasome and reduction of caspase-1-dependent, interleukin-1 beta (IL)-1ß; and (3) reduced neuronal death and protected against tissue loss, improving functional recovery after an SCI. Conclusions: The current study demonstrated that ROF can reduce the levels of inflammation in the tissue after spinal cord injury by modulating the AMPK/NLRP3 signaling pathway, thereby promoting the recovery of motor function in mice. ROF is a promising drug for prevention of neural-tissue damage following neural injury.

Zileuton Ameliorates Neuronal Ferroptosis and Functional Recovery After Spinal Cord Injury.

Context: Ferroptosis is a novel type of cell-death pattern characterized by iron-dependent, oxidative stress, and lipid peroxidation. Neurological pathology, especially in spinal cord injury (SCI), may involve a trace amount of ferroptosis. However, it's uncertain whether zileuton (ZIL), a selective 5-lipoxygenase (5-LO) inhibitor, can inhibit ferroptosis in SCI. Objective: The study intended to investigate the etiology of neuronal ferroptosis and the ameliorative effects of ZIL against it for SCI mice. Design: The research team performed an animal study. Setting: The study took place at the Fourth Affiliated Hospital of Harbin Medical University in Harbin, China. Animals: The animals were adult, male, C57BL/6 mice, about 20 to 25 g in weight. Intervention: The research team: (1) stimulated HT22 cells, an immortalized mouse hippocampal neuronal cell line treated with erastin, and mice induced spinal cord trauma using a moderate hit, and (2) treated the cells and mice with ZIL. Outcome measures: The research team measured: (1) motor function, (2) neurological damage, (3) iron content, (4) lipid oxidation, and (5) neuroinflammation and glial response. Results: ZIL administration attenuated ferroptosis and lipid peroxidation in the HT22 cells. Moreover, ZIL mitigated the ferroptosis and inflammation in the injured spinal cords. Hence, ZIL can decrease neurological damage and improve recovery of motor function, indicating an ameliorative role for ZIL in SCI. Conclusions: ZIL has anti-ferroptosis and anti-oxidative effects in neurons, which can contribute to recovery of motor function after induction of SCI. ZIL is a promising drug for inhibiting ferroptosis and protecting neurological functions after induction of SCI.

Inhibition of microRNA-495 suppresses chondrocyte apoptosis through activation of the NF-κB signaling pathway by regulating CCL4 in osteoarthritis.

As a common form of arthritis, osteoarthritis (OA) represents a degenerative disease, characterized by articular cartilage damage and synovium inflammation. Recently, the role of various microRNAs (miRs) and their specific expression in OA has been highlighted. Therefore, the aim of the current study was to elucidate the role by which miR-495 and chemokine ligand 4 (CCL4) influence the development and progression of OA. OA mice models were established, after which the CCL4 and collagen levels as well as cell apoptosis were determined in cartilage tissue of OA mice. The chondrocytes of the OA mice models were subsequently treated with a series of miR-495 mimic, inhibitor, and siRNA against CCL4. Afterwards, miR-495 expressions as well as the levels of CCL4, p50, p65, and IkBa and the extent of IkBa phosphorylation in addition to the luciferase activity of NF-kB were measured accordingly. Finally, cell apoptosis and cell cycle distribution were detected. miR-495 was highly expressed while NF-κB, CCL4, and collagen II were poorly expressed. Cell apoptosis was elevated in the cartilage tissue of the OA mice. CCL4 was a potential target gene of miR-495. Downregulation of miR-495 led to accelerated chondrocyte proliferation accompanied by diminished cell apoptosis among the OA mice. Taken together, the results of the current study demonstrated that inhibition of miR-495 suppressed chondrocyte apoptosis and promoted its proliferation through activation of the NF-κB signaling pathway by up-regulation of CCL4 in OA.

Downregulation of long noncoding RNA LOC101928134 inhibits the synovial hyperplasia and cartilage destruction of osteoarthritis rats through the activation of the Janus kinase/signal transducers and activators of transcription signaling pathway by upregulating IFNA1.

Osteoarthritis (OA) is the most common disease of arthritis, a chronic joint disease that is always correlated with massive destruction such as cartilage destruction, inflammation of the synovial membrane, and so on. This study aims to explore the role of long noncoding RNA (lncRNA) LOC101928134 in the synovial hyperplasia and cartilage destruction, more specifically, in the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway in an OA rat model. Microarray-based gene expression analysis was conducted to screen out the lncRNA differentially expressed in OA and predict the target gene of the lncRNA with the involvement of the signaling pathway through Kyoto encyclopedia of genes and genomes (KEGG) analysis. A model of OA was established and treated with the small interfering RNA LOC101928134/inhibitor of JAK/STAT signaling pathway to investigate the relationship among LOC101928134, IFNA1, and the JAK/STAT signaling pathway in OA. The effect of LOC101928134 on the serum levels of IFNA1, interleukin-1ß, and tumor necrosis factor-α, and the apoptosis of synovial and cartilage cells was evaluated. LOC101928134, which was found to be highly expressed in knee joint synovial tissues of OA rats, regulated the expression of IFNA1 gene and inhibited JAK/STAT signaling pathway. Downregulation of LOC101928134 resulted in reduced knee joint synovitis, relived inflammatory damage, and knee joint cartilage damage of OA rats. Besides, synovial cell apoptosis was enhanced upon LOC101928134 downregulation, while cartilage cell apoptosis of OA rats was suppressed. These results demonstrate that downregulation of LOC101928134 suppresses the synovial hyperplasia and cartilage destruction of OA rats via activation of JAK/STAT signaling pathway by upregulating IFNA1, providing a new candidate for the treatment of OA.

P15, MDM2, NF-κB, and Bcl-2 expression in primary bone tumor and correlation with tumor formation and metastasis.

Primary bone tumor is one of the most common malignant tumors in skeletal system. It seriously affected bone movement and development with unclear pathogenesis. In this paper, rabbit VX-2 malignant bone tumor model was applied to explore apoptotic genes P15, MDM2, NF-κB and Bcl-2 correlation with primary bone tumor occurrence and metastasis. 0.3 ml rabbit VX-2 tumor cell suspension (1×10(6)/ml) was injected to the marrow cavity of the right tibia condyle to establish the rabbit malignant bone tumor model, while equal amount of the saline was injected to the left tibia as control. Real-time PCR was applied to determine P15, MDM2, NF-κB and Bcl-2 expression level. Immunohistochemistry was performed to detect the abovementioned genes expression in lung, stomach, kidney and bladder. Compared with control, P15 expression level in the inoculation site surrounding tissues decreased obviously following the inoculate time elongation (P<0.05), while Bcl-2, MDM2 and NF-κB expression significantly increased (P<0.05). Bcl-2 showed significant correlation with MDM2 and NF-κB (P<0.05). At the 2, 4, 6 weeks, Bcl-2, MDM2 and NF-κB in lung, Bcl-2 in kidney, and Bcl-2 and MDM2 in bladder positively expressed (P<0.05), whereas P15 gene exhibited no significant positive expression in these tissues (P>0.05). P15, MDM2, NF-κB, and Bcl-2 genes expression levels can effectively reflect malignant bone tumor growth of rabbit tibia. MDM2, NF-κB and Bcl-2 genes involved in primary bone tumors metastasis directly. It has important clinical significance for early diagnosis and treatment of primary bone tumor.