Objective:To observe any regulatory effect of a pulsed electromagnetic field (PEMF) on A2A adenosine receptors (A2ARs) in the nucleus pulposus of rats with intervertebral disc degeneration (IDD), and to explore any combination with the A2ARs′ agonist-mediating ROS/PI3K/Akt signaling pathway.Methods:Fifty Sprague-Dawley rats were randomly divided into a control group, an intervertebral disc degeneration group (the model group), an A2AR agonist CGS-21680 treatment group (the agonist group), a PEMF group and a PEMF combined with CGS-21680 treatment group (the observation group). IDD was modeled in all except the rats in the control group. 100μL of CGS-21680 (100μg/kg) was injected into the L 5-6 intervertebral discs of the agonist group, while the PEMF group was given 30 minutes of PEMF intervention daily for 14 days at 1.5mT and 75Hz with a pulse width of 150μs. The observation group was injected with CGS-21680 and then given the same PEMF intervention. Primary nucleus pulposus cells from each group (50ng/mL) were cultured and the expressions of 8-OHDG, SOD, MDA and ROS were detected by immunohistochemistry, immunofluorescence or with an ELISA kit. The A2AR, PI3K, AKT and p-AKT protein levels were detected using western blotting. Results:The nucleus pulposus cells and the annulus fibrosus were obviously wrinkled, necrotic and broken in the model group but the annulus fibrosus was intact and the nucleus pulposus was almost normal in the observation group. Compared with the model group, the levels of SOD and A2AR, PI3K, p-AKT and AKT protein were higher in the agonist, PEMF and observation groups, while the expressions of MDA, ROS and 8-OHDG were weaker. The ROS level in the observation group was significantly lower than that in the agonist and PEMF groups, and the phosphorylation level of p-AKT in the observation group was significantly higher than in the agonist and PEMF groups. The average levels of SOD, A2AR, PI3K, p-AKT and AKT protein in the nucleus pulposus cells of the agonist, PEMF and observation groups were significantly higher than the IL-1β group′s average, while the average levels of MDA, ROS and 8-OHDG were significantly lower. The ROS levels in the observation group were significantly lower than in the agonist and PEMF groups, while the A2AR protein content and p-AKT phosphorylation in the observation group were significantly greater. The average Bax levels in the nucleus pulposus cells of the agonist, PEMF and observation groups were significantly lower than that in the IL-1β group, and the expression of Bcl-2 was significantly increased. There was significantly less apoptosis observed in the observation group than in the agonist and PEMF groups, while the expression of Bcl-2 was significantly higher.Conclusions:PEMF plays an anti-oxidative stress role by up-regulating A2AR activity and reducing ROS generation. Treatment with PEMF and A2AR agonist could further activate the phosphorylation of PI3K/Akt, down-regulate Bax and up-regulate Bcl-2, thus inhibiting the apoptosis of nucleus pulposus cells and alleviating the malignant progression of IDD.

Objective:To explore any effect of pulsed electromagnetic field (PEMF) stimulation on intervertebral disc degeneration (IDD).Methods:Forty Sprague-Dawley rats were randomly divided into a control group, an IDD model group, a PEMF group and an observation group. An IDD model was induced in all except those in the control group. Both the PEMF and observation groups were given PEMF stimulation, while the latter was additionally injected with the A2AR agonist CGS-21680. Eight weeks after the modelling any pathological changes in the morphology of the rats′ intervertebral disc tissues were evaluated using saffron solid green staining. The expression of A2AR, cyclic adenosine phosphate (cAMP), protein kinase A (PKA), cysteine aspartate proteolytic enzyme-3 (Caspase-3), type II collagen (COL-II) and matrix metalloproteinase-3 (MMP3) in the intervertebral discs were evaluated.Results:The nucleus pulposus had shrunk, while fibrous tissues and chondrocytes had increased in the IDD model group. In the observation group the nucleus pulposus was intact and of basically normal shape. A2AR mRNA and protein levels were higher in the intervertebral disc tissue of the model group than among the control group, on average, while the levels in the observation group were significantly higher than in the other groups. In the PEMF and observation groups cAMP and PKA mRNA were significantly higher than in the IDD model group. The p38 MAPK and P-P38 MAPK levels of the IDD model group and its average P-P38 MAPK/p38 MAPK ratio were significantly higher than in the control group. In the PEMF and observation groups those indices had decreased to varying degrees, with those of the observation group significantly lower than among the model and PEMF groups on average, except for the p38 MAPK values. Caspase-3 and its mRNA were significantly higher in the model group than in the control group, on average, and those values were significantly lower in the PEMF and observation groups than in the IDD model group. The average MMP3 contents of the IDD model group had increased significantly compared with the control group, while the Col-Ⅱ level had decreased significantly. Compared with the IDD model group, the MMP3 level had decreased but Col-Ⅱ expression had increased in both the PEMF and observation groups, with significant differences between the IDD model and observation groups.Conclusions:The activation of the p38 MAPK signaling pathway by inflammatory factors to induce apoptosis is one of the important reasons for the aggravation of IDD lesions. PEMF combined with A2AR agonists can activate the A2AR/cAMP/PKA signaling pathway, inhibit p38 MAPK phosphorylation, reduce apoptosis of nucleus pulposus cells, and relieve IDD damage.

Objective:To report our experience in the emergent foot and ankle surgery in the epidemic of COVID-19.Methods:The data of 18 patients with acute foot and ankle injury were reviewed who had been admitted to the Department of Foot and Ankle Surgery, Wuhan Fourth Hospital from 20th January, 2020 to 26th February, 2020. They were 11 men and 7 women, aged from 18 to 70 years (average, 42.5 years). There were 5 cases of acute open injury and 13 ones of acute closed injury. COVID-19 infection was diagnosed or suspected in 5 cases but not in the other 13 cases. Emergency operation was carried out for 2 patients with open injury plus COVID-19 infection and one with complicated pilon fracture plus COVID-19 infection, one of whom received secondary operation. One patient with closed fracture of the left calcaneus plus COVID-19 infection was hospitalized from emergency department for secondary surgery, and another with closed fracture of the right lateral malleolus was referred to the isolation ward after emergency plaster fixation. Of the 10 patients with closed injury but without COVID-19 infection, 3 received conventional secondary surgery after admission and the others conservative treatment at the outpatient department. Recorded were COVID-19 infections in the patients after admission and in the medical staff. The measures taken and experience in control and prevention of COVID-19 infection after outbreak of the epidemic were reviewed.Results:Of the 11 patients who had been hospitalized for foot and ankle injury in emergency, 5 were definitely diagnosed of or suspected of COVID-19 infection and 6 free of COVID-19 infection. During hospitalization, COVID-19 infection was confirmed in the 5 cases and no COVID-19 infection occurred in the other 6 patients. No COVID-19 infection occurred in the medical staff; no cross infection was observed between the patients and the medical staff.Conclusions:Reasonable strategies are advised to balance the foot and ankle surgery and epidemic prevention. A simplified management is not advised for all the cases. The operative procedures in emergent foot and ankle surgery should be optimized in line with the epidemic control and prevention principles to facilitate functional rehabilitation for the patients.

Many human genetic diseases, including Hutchinson-Gilford progeria syndrome (HGPS), are caused by single point mutations. HGPS is a rare disorder that causes premature aging and is usually caused by a de novo point mutation in the LMNA gene. Base editors (BEs) composed of a cytidine deaminase fused to CRISPR/Cas9 nickase are highly efficient at inducing C to T base conversions in a programmable manner and can be used to generate animal disease models with single amino-acid substitutions. Here, we generated the first HGPS monkey model by delivering a BE mRNA and guide RNA (gRNA) targeting the LMNA gene via microinjection into monkey zygotes. Five out of six newborn monkeys carried the mutation specifically at the target site. HGPS monkeys expressed the toxic form of lamin A, progerin, and recapitulated the typical HGPS phenotypes including growth retardation, bone alterations, and vascular abnormalities. Thus, this monkey model genetically and clinically mimics HGPS in humans, demonstrating that the BE system can efficiently and accurately generate patient-specific disease models in non-human primates.
Animals ; Disease Models, Animal ; Female ; Gene Editing ; Humans ; Lamin Type A/metabolism* ; Macaca fascicularis ; Progeria/pathology*