Objective:To explore the molecular mechanism for bone mass loss caused by staphylococcus aureus infection.Methods:Thirty 8-week-old male C57BL/6 mice were randomly divided into 3 groups ( n=10): control, infection and infection+JAK inhibitor (JAKi) ones. The mice were killed 2 weeks later for sampling from the femur and tibia. Micro-CT reconstruction was performed for analyses of BV/TV, Tb.N, Tb.Th and Tb.Sp to detect changes in bone mass; OCN immunohistochemistry and Goldner's trichrome staining were used to quantify osteoblasts; TRAP staining was used to quantify osteoclasts; the GSE166522 data set was downloaded and analyzed to explore the relationships between staphylococcus aureus infection and bone cell senescence and JAK/STAT pathway. Senescence β-Galactosidase staining, Osterix and P16 immunofluorescence colocalization were used to observe the changes in number of senescent cells. Results:MicroCT results showed a statistically significant difference in the loss of cancellous bone in the target area in the infection group compared with the control group ( P<0.05). The results of osteocalcin immunohistochemistry and Goldner's trichrome staining indicated that the number of osteoblasts in the infection group was significantly reduced ( P<0.05). TRAP staining indicated no significant difference in the number of osteoclasts between the infection and control groups ( P>0.05). Bioinformatics analysis found that staphylococcus aureus infection caused bone cell senescence and the JAK/STAT pathway was activated after the infection. Senescence β-Galactosidase staining suggested that senescent cells increased in the infection group compared with the control group. The number of Osterix and P16 positive senescent osteoprogenitor cells in the infection group was increased significantly compared with the control group. The number of senescent osteoprogenitor cells in the infection+JAKi group was significantly reduced and the bone loss was partially reversed after treatment of JAK inhibitor, compared with the infection group. Conclusion:Staphylococcus aureus may induce osteoprogenitor cell senescence through the JAK/STAT pathway and eventually lead to bone mass loss.

Objective To investigate the change in NF-κB activity in astrocytes in spinal dorsal horn in a rat model of neuropathic pain and the underlying mechanism. Methods Sixteen male SD rats aged 2-3 months weighing 220-280 g were randomly divided into 2 groups ( n = 8 each) : sham operation group (group S) and CCI group. Neuropathic pain was induced by chronic constrictive injury (CCI) . Right sciatic nerve was exposed and 4 loose ligatures were placed on the sciatic nerve at 1 mm intervals with 4-0 chromic catgut. In group S the right sciatic nerve was exposed but not ligated. The paw withdrawal threshold (PWT) to von Frey filament stimulation and paw withdrawal latency (PWL) to radiant heat stimulation were measured at 1 d before (baseline) and 7 d after operation. The animals were then killed and the lumbar segment of the spinal cord (L_(4-6)) was removed. The expression of NF-κB in the astrocytes in spinal dorsal horn was determined by immuno-histochemistry. Results PWT and PWL to mechanical and thermal stimuli were significantly decreased after operation as compared with the baseline before operation in group CCI. The number of NF-κBp65 immunoreaction positive cells in the spinal dorsal horn on the operated side was significantly larger in group CCI than in group S. Conclusion NF-κB signal transduction pathway in the astrocytes in the spinal dorsal hom may be involved in neuropathic pain.

ObjectiveTo investigate the effect of modified Simiaosan on miR-223-3p and NOD-like receptor thermal protein domain associated protein 3 （NLRP3）/interleukin-1β （IL-1β） signaling pathway in rat model with acute gouty arthritis （AGA） and explore the anti-inflammatory mechanism of modified Simiaosan on AGA. MethodA total of 72 8-week-old male SD rats were selected. They were divided into blank group， model group， colchicine group （0.3 mg·kg^-1）， high-dose modified Simiaosan group （31.75 g·kg^-1）， medium-dose modified Simiaosan group （15.75 g·kg^-1）， and low-dose modified Simiaosan group （7.875 g·kg^-1） according to random number table method， with 12 rats in each group. Except for the blank group， monosodium urate （MSU） crystal suspension was injected into the right ankle joint of rats by the Coderre method in other groups to replicate the rat model with AGA. The drug administration groups were given the corresponding drug solution by gavage， and the model group and the blank group were given an equal volume of sterile sodium chloride solution by gavage for one week. The circumference of the rats' ankle joint was measured， and the swelling degree of the ankle joint was calculated. Hematoxylin-eosin （HE） staining was used to detect the pathological morphological changes in the synovial tissue of the ankle joint. The levels of IL-1β， tumor necrosis factor-α （TNF-α）， and interleukin-6 （IL-6） in the serum of rats in each group were detected by enzyme-linked immunosorbent assay （ELISA）. Western blot was used to detect the protein expressions of NLRP3， Caspase-1， and apoptosis-related spot-like protein （ASC） in synovial tissue of rats in each group， and real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the mRNA expressions of NLRP3， Caspase-1， and ASC and the expression of miR-223-3p in synovial tissue of rats. ResultCompared with that in the normal group， the swelling degree of the ankle joint in the model group was higher （P<0.01）， and the synovial tissue structure was disordered. Synovial cells proliferated obviously， and a large number of inflammatory cells were infiltrated. The levels of IL-1β， IL-6， and TNF-α in the serum of the model group increased significantly （P<0.01）， and the protein and mRNA expressions of NLRP3， Caspase-1， and ASC increased， while expression of miR-223-3 decreased. Compared with the model group， the swelling degree of ankle joint in the colchicine group and high-dose and medium-dose modified Simiaosan groups was lower （P<0.05）. Synovial cell proliferation and inflammatory cell infiltration of the colchicine group and high-dose， medium-dose， and low-dose modified Simiaosan groups were reduced to varying degrees， among which the colchicine group and high-dose modified Simiaosan group improved most obviously. The levels of IL-1β， IL-6， and TNF-α in the serum of rats in different dose groups of modified Simiaosan and colchicine group decreased significantly （P<0.01）， while the protein and mRNA expressions of NLRP3， Caspase-1， and ASC increased （P<0.01）. The expression of miR-223-3p in synovial tissue of the medium-dose and high-dose modified Simiaosan groups and colchicine group increased significantly （P<0.01）. Compared with those in the colchicine group， the levels of IL-1β， IL-6， and TNF-α in the low-dose modified Simiaosan group increased greatly （P<0.01）. In the medium-dose modified Simiaosan group， the protein expressions of NLRP3， Caspase-1， and ASC increased， and the expression of miR-223-3p decreased （P<0.05）. In the low-dose modified Simiaosan group， the levels of IL-1β， IL-6， and TNF-α increased greatly （P<0.01）， as well as the protein and mRNA expressions of NLRP3， Caspase-1， and ASC， while the expression of miR-223-3p was decreased （P<0.01）. ConclusionModified Simiaosan may play an anti-inflammatory role by intervening in the NLRP3/IL-1β signaling pathway via regulating miR-223-3p.

Studies have suggested that the nucleus accumbens (NAc) is implicated in the pathophysiology of major depression; however, the regulatory strategy that targets the NAc to achieve an exclusive and outstanding anti-depression benefit has not been elucidated. Here, we identified a specific reduction of cyclic adenosine monophosphate (cAMP) in the subset of dopamine D1 receptor medium spiny neurons (D1-MSNs) in the NAc that promoted stress susceptibility, while the stimulation of cAMP production in NAc D1-MSNs efficiently rescued depression-like behaviors. Ketamine treatment enhanced cAMP both in D1-MSNs and dopamine D2 receptor medium spiny neurons (D2-MSNs) of depressed mice, however, the rapid antidepressant effect of ketamine solely depended on elevating cAMP in NAc D1-MSNs. We discovered that a higher dose of crocin markedly increased cAMP in the NAc and consistently relieved depression 24 h after oral administration, but not a lower dose. The fast onset property of crocin was verified through multicenter studies. Moreover, crocin specifically targeted at D1-MSN cAMP signaling in the NAc to relieve depression and had no effect on D2-MSN. These findings characterize a new strategy to achieve an exclusive and outstanding anti-depression benefit by elevating cAMP in D1-MSNs in the NAc, and provide a potential rapid antidepressant drug candidate, crocin.