BACKGROUND:Human umbilical cord mesenchymal stem cell-derived exosomes were found to be effective in promoting neural repair in spinal cord injury.OBJECTIVE:To investigate whether exosomes derived from human umbilical cord mesenchymal stem cells are able to attenuate neuroinflammation and promote recovery of motor function by promoting polarization of microglia toward the M2 type.METHODS:Totally 48 SD rats were randomly divided into a sham operation group,a model group,and an exosome group(n=16 per group).A rat spinal cord injury model was established using the modified Allen method.The exosome group was injected with 20 μL of human umbilical cord mesenchymal stem cell-derived exosomes intrathecally via neuroendoscopy 24 hours after injury.At 3,7,14,and 21 days after modeling,the recovery of the motor function of the hind limbs of the rats was assessed by BBB scoring method combined with Rivlin's slant plate test.The damage of spinal cord tissues was detected by using hematoxylin-eosin staining and Nissl staining.The expression levels of brain-derived neurotrophic factor and vascular endothelial growth factor A proteins were detected by western blot assay.The expression proportion of M1-type markers(inducible nitric oxide synthase)and M2 markers(arginase-1)in the spinal cord tissues was detected by immunofluorescence method.qRT-PCR and western blot assay were used to detect the expression levels of inducible nitric oxide synthase and arginase-1 in spinal cord tissues.ELISA was utilized to detect the levels of pro-inflammatory factors(tumor necrosis factor α,interleukin 1β,and interleukin 6)and anti-inflammatory factors(interleukin 10)levels in spinal cord tissues.RESULTS AND CONCLUSION:(1)At 3,7,and 14 days postoperatively,the BBB scores of the exosome group were better than those of the model group(P＜0.05).The angles of the Rivlin slanting plate experiments of the exosome group were significantly higher than those of the model group at 7 and 14 days postoperatively(P＜0.05).The results of hematoxylin-eosin staining and Nissl staining indicated that the spinal cord tissues and nerve injuries of the exosome group were reduced in comparison with those of the model group,and the levels of brain-derived neurotrophic factor and vascular endothelial growth factor A in spinal cord tissues of the exosome group were higher than those in the model group at 7 days postoperatively(P＜0.05).(2)Immunofluorescence experiments showed that the number of inducible nitric oxide synthase-positive microglial cells in the lesion area of the exosome group was significantly reduced and the level of Arg1-positive microglial cells increased in the lesion area of the exosome group compared with the model group at 7 days postoperatively(P＜0.05).qRT-PCR and western blot assay also confirmed the results of immunofluorescence experiments.(3)The secretion of pro-inflammatory factors tumor necrosis factor α,interleukin 1β,and interleukin 6 in spinal cord tissues of the exosome group was reduced compared with the model group(P＜0.05),whereas the secretion of the inflammation-suppressing factor interleukin 10 was increased compared with the model group(P＜0.05).These findings conclude that human umbilical cord mesenchymal stem cell-derived exosomes could promote the polarization of microglial cells from the M1 to the M2 type and decrease the release of pro-inflammatory factors,thereby reducing the secondary damage of neuroinflammation in spinal cord injury.

Objective:To explore the clinical efficacy of "four-step" aortic valve anatomic repair for bicuspid aortic valve(BAV) with aortic regurgitation(AR).Methods:From August 2021 to November 2024, a total of 298 consecutive patients with BAV-AR underwent aortic valve anatomic repair(AVr) in Shanghai Zhongshan Hospital Fudan University, 266 males and 32 females, with age of 39(29.5, 48.5) years. All patients underwent " four-step" three-dimensional anatomic repair of the aortic annulus and leaflets, 129(43.3%) patients via upper mini-sternotomy and 169(56.7%) patients via conventional median sternotomy, with the main steps including: (1) deep dissecting and annuloplasty of the virtual basal ring(VBR); (2) symmetrical repairing of leaflets; (3) replacement or remodeling of the sinus of Valsalva; (4) annuloplasty of the sinotubular junction(STJ). Basal and perioperative data were retrospectively collected, and statistical analysis was performed in conjunction with follow-up data.Results:All patients successfully underwent anatomical repair without transferring to valve replacement during operation. Among them, 43 patients underwent aortic root reimplantation technique(Reimplantation group), while 255 patients underwent modified aortic root sleeve remodeling technique(Sleeve group). The median cardiopulmonary bypass time for the Reimplantation and Sleeve groups were 154(134, 169) minutes and 111(95, 129) minutes, respectively( P<0.05); the median aortic cross-clamp time were 112(100, 131) minutes and 80(67, 94) minutes, respectively( P<0.05). Preoperative TEE showed 35 patients(81.4%) and 229 patients(89.8%) with moderate and severe AR in Reimplantation and Sleeve groups, respectively. Postoperative TEE showed 41 patients(95.3%) with no/trace AR and 2 patients(4.7%) with central mild AR in Reimplantation group, while 212 patients(83.1%) with no/trace AR and 43 patients(16.9%) with central mild AR in Sleeve group. Follow-up was completed in all patients, with a median follow-up of 12.9(4.7, 21.2) months. Echocardiography was obtained in 271 patients(90.9%) at the latest follow-up, including no/trace AR in 167 patients(56.0%), mild AR in 89 patients(29.9%), moderate AR in 14 patients(4.7%), and severe AR in 1 patient(0.3%). Conclusion:Aortic valve anatomic repair by standardized "four-step" approach is safe and reproducible. Satisfied short- and mid-term outcome have obtained in selected BAV-AR patients.

Objective:To investigate the effects of oral propranolol on the heart rate and blood glucose levels in children with hemangiomas receiving hospital care.Methods:A total of 259 children [77 males and 182 females, aged (125.2±85.4) days, weighted (6.3±1.6) kg], who were treated with oral propranolol for the first time under hospital care from January 2013 to August 2021, were retrospectively analyzed. After fasting, the patients administered the same dose of propranolol once daily (0.5-2.5 mg/kg). Fasting blood glucose and heart rate were measured in all children before propranolol administration and after 2 h. Heart rate was measured at 1, 3 and 6 h after propranolol administration for three consecutive days. Adverse reactions were observed and recorded.Results:Within three days of oral propranolol administration, the heart rates at 1, 3 and 6 h after propranolol administration were lower than those before propranolol administration (all P<0.001). Within three days after taking propranolol and 2 h after taking propranolol daily, blood glucose levels reduced in all children (all P<0.001). During the hospitalization period, the incidence of adverse reactions was 5.4% (14/259), including lesion ulcers in four cases, upper respiratory tract infection with fever in four, reduced eating in two, nausea and vomiting in one, lethargy in one, sinus tachycardia in one, and hyperkalemia in one. No serious adverse reactions were life-threatening. Conclusion:After oral administration of propranolol, the heart rate and blood sugar of the children decrease to different degrees compared with those before propranolol administration.

The rapid emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants that evade immunity elicited by vaccination has posed a global challenge to the control of the coronavirus disease 2019 (COVID-19) pandemic. Therefore, developing countermeasures that broadly protect against SARS-CoV-2 and related sarbecoviruses is essential. Herein, we have developed a lipid nanoparticle (LNP)-encapsulated mRNA (mRNA-LNP) encoding the full-length Spike (S) glycoprotein of SARS-CoV-2 (termed RG001), which confers complete protection in a non-human primate model. Intramuscular immunization of two doses of RG001 in Rhesus monkey elicited robust neutralizing antibodies and cellular response against SARS-CoV-2 variants, resulting in significantly protected SARS-CoV-2-infected animals from acute lung lesions and complete inhibition of viral replication in all animals immunized with low or high doses of RG001. More importantly, the third dose of RG001 vaccination elicited effective neutralizing antibodies against current epidemic XBB and JN.1 strains and similar cellular response against SARS-CoV-2 Omicron variants (BA.1, XBB.1.16, and JN.1) were observed in immunized mice. All these results together strongly support the great potential of RG001 in preventing the infection of SARS-CoV-2 variants of concern (VOCs).

OBJECTIVE: To elucidate the role and mechanism of microRNA-145-5p (miR-145-5p) in hypoxia-induced pyroptosis of human alveolar epithelial cells. METHODS: In vitro, human alveolar epithelial cell line BEAS-2B was cultured. Cells in the logarithmic growth phase were cultured to 80% confluence and then used for the experiment. (1) BEAS-2B cells were cultured under 1% O₂ hypoxic condition, with a normoxic control group. Western blotting was employed to detect the expressions of pyroptosis marker proteins [NOD-like receptor protein 3 (NLRP3), Gasdermin D N-terminal domain (GSDMD-N), and caspase-1] in cells cultured for 24 hours. Real-time fluorescent quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expression of miR-145-5p in cells cultured for 6 hours and 12 hours. (2) Cells were transfected with 30 nmol/L miR-145-5p mimic to overexpress miR-145-5p expression under normoxic condition or 30 nmol/L miR-145-5p inhibitor to suppress miR-145-5p expression under hypoxic condition. Control group and negative control group were respectively set up. After 24 hours of cell culture, Western blotting was used to detect the expressions of pyroptosis marker proteins and nuclear factor-E2-related factor 2 (Nrf2) in cells. Flow cytometry was applied to detect the level of reactive oxygen species (ROS) in cells. The target genes of miR-145-5p were predicted by miR target gene prediction software miRWalk and verified by Western blotting. (3) Under hypoxic condition, cells were transfected with 6.94 ng/μL silent information regulator 5 (Sirt5) overexpression plasmid or pretreated with 12.5 mmol/L N-acetyl-L-cysteine (NAC) as an ROS inhibitor. The empty plasmid group and control group were set up. After 24 hours of cell culture, Western blotting was used to detect the expressions of Sirt5, Nrf2, and pyroptosis marker proteins in cells. Flow cytometry was used to detect the level of ROS in cells. RESULTS: (1) Compared with the normoxic control group, the expression levels of pyroptosis marker proteins in the 24-hour hypoxia group was significantly increased, indicating that hypoxia could induce pyroptosis in BEAS-2B cells. The expression level of miR-145-5p in cells gradually increased with the extension of hypoxia induction time, indicating that hypoxia could cause the increase of miR-145-5p expression level. (2) The expression levels of pyroptosis marker proteins in cells of miR-145-5p mimic group significantly increased under normoxic condition as compared with the control and negative control groups [NLRP3 protein (NLRP3/β-actin): 1.58±0.07 vs. 1.00±0.01, 0.98±0.07, GSDMD-N protein (GSDMD-N/β-actin): 1.71±0.03 vs. 1.01±0.01, 0.85±0.03, caspase-1 protein (caspase-1/β-actin): 2.33±0.04 vs. 1.01±0.01, 1.05±0.04, all P < 0.05], Nrf2 protein expression level was significantly decreased (Nrf2/β-actin: 0.79±0.03 vs. 1.00±0.01, 1.03±0.04, both P < 0.05), ROS level was significantly up-regulated (fluorescence intensity: 1.74±0.03 vs. 1.00±0.01, 0.92±0.03, both P < 0.05). Under hypoxia condition, compared with control group and negative control group, the expression levels of pyroptosis marker proteins in miR-145-5p inhibitor group were significantly decreased [NLRP3 protein (NLRP3/β-actin): 0.21±0.04 vs. 1.70±0.02, 1.63±0.04; GSDMD-N protein (GSDMD-N/β-actin): 1.32±0.02 vs. 2.51±0.02, 2.72±0.03; caspase-1 protein (caspase-1/β-actin): 0.56±0.01 vs. 2.77±0.02, 3.12±0.03; all P < 0.05], Nrf2 protein expression level was significantly increased (Nrf2/β-actin: 1.57±0.04 vs. 1.22±0.01, 1.28±0.04, both P < 0.05), ROS level was significantly down-regulated (fluorescence intensity: 0.64±0.05 vs. 1.87±0.04, 1.70±0.07, both P < 0.05). The results indicated that miR-145-5p could promote cell pyrodeath. The predictive result of miRWalk showed that the 3' untranslated region (3'UTR) of Sirt5 had complementary base binding sites with miR-145-5p. The expression level of Sirt5 protein in cells of miR-145-5p mimic group was significantly lower than that of control group and negative control group under normoxic condition (Sirt5/β-actin: 0.59±0.03 vs. 1.00±0.01, 1.01±0.03, both P < 0.05), which verified that Sirt5 was the target gene of miR-145-5p. (3) The occurrence of pyrodeath could be partially reversed by transfection with Sirt5 overexpression plasmid or adding ROS inhibitor NAC into cells, and Sirt5 overexpression could also up-regulate Nrf2 expression and eliminate intracellular ROS. CONCLUSION In human alveolar epithelial cells, miR-145-5p can down-regulate Nrf2 by targeting Sirt5, thereby increasing ROS expression and inducing pyrodeath.
Humans ; MicroRNAs ; Pyroptosis ; Cell Hypoxia ; Alveolar Epithelial Cells/cytology* ; Cell Line ; NLR Family, Pyrin Domain-Containing 3 Protein ; Caspase 1/metabolism* ; Epithelial Cells/metabolism* ; Gasdermins ; Phosphate-Binding Proteins

OBJECTIVE: To investigate the effect of stretch on long non-coding RNA taurine upregulated gene 1 (TUG1)-mediated miR-545-3p/cannbinoida receptor 2 (CNR2) pathway regulating bone regeneration in the distraction area of rats during distraction osteogenesis. METHODS: Thirty-six 10-week-old male Sprague Dawley rats were randomly divided into 3 groups ( n=12 in each group): group A (femoral fracture+injection of interfering RNA), group B (distraction osteogenesis+injection of interfering RNA), and group C (distraction osteogenesis+injection of TUG1). Groups A and B were injected with 60 μg of interfering RNA at the beginning of incubation period (immediate after operation), the beginning of distraction phase (7 days after operation), and the end of distraction phase (21 days after operation), and group C was injected with 60 μg of synthetic TUG1 in vivo interfering sequence at the same time. The general situation of rats in each group was observed during the experiment. The mineralization of fracture space or distraction area was observed by X-ray films at 21, 35, and 49 days after operation. At 49 days after operation, the samples of the distraction area were taken for HE staining to observe the mineralization, and real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the expressions of osteoblast-related genes such as TUG1, miR-545-3p, CNR2, alkaline phosphatase (ALP), osteocalcin (OCN), and osteopontin (OPN). Blood samples were collected from the abdominal aorta of the rats, and the expressions of ALP and C terminal telopeptide of type Ⅰ (CTX-Ⅰ) protein were detected by ELISA assay. RESULTS: The results of X-ray film and HE staining observations showed that osteogenesis in group C was superior to groups A and B at the same time point. The results of qRT-PCR showed that the relative mRNA expressions of TUG1, CNR2, ALP, OCN, and OPN in group C were significantly higher than those in group A and group B, and the relative mRNA expression of miR-545-3p in group C was significantly lower than that in group A and group B ( P<0.05). The relative mRNA expressions of TUG1 and ALP in group B were significantly higher than those in group A, and the relative mRNA expression of miR-545-3p in group B was significantly lower than that in group A ( P<0.05). There was no significant difference in the relative mRNA expressions of CNR2, OCN, and OPN between group A and group B ( P>0.05). The results of ELISA showed that the expressions of ALP and CTX-Ⅰ protein were significantly higher in group C than in group A and group B, and in group B than in group A ( P<0.05). CONCLUSION Under the action of stretch, the expression of TUG1 in the femoral distraction area of rats increases, which promotes the expression of CNR2 by inhibiting the expression of miR-545-3P, which is helpful to the mineralization of the extension area and osteogenesis.
Animals ; MicroRNAs/genetics* ; Rats, Sprague-Dawley ; Male ; Osteogenesis, Distraction/methods* ; Rats ; RNA, Long Noncoding/metabolism* ; Osteopontin/genetics* ; Osteogenesis ; Bone Regeneration ; RNA, Small Interfering/genetics* ; Osteocalcin/genetics* ; Alkaline Phosphatase/metabolism* ; Osteoblasts/cytology* ; Signal Transduction ; Femoral Fractures/surgery*

BACKGROUND:Human umbilical cord mesenchymal stem cell-derived exosomes were found to be effective in promoting neural repair in spinal cord injury.OBJECTIVE:To investigate whether exosomes derived from human umbilical cord mesenchymal stem cells are able to attenuate neuroinflammation and promote recovery of motor function by promoting polarization of microglia toward the M2 type.METHODS:Totally 48 SD rats were randomly divided into a sham operation group,a model group,and an exosome group(n=16 per group).A rat spinal cord injury model was established using the modified Allen method.The exosome group was injected with 20 μL of human umbilical cord mesenchymal stem cell-derived exosomes intrathecally via neuroendoscopy 24 hours after injury.At 3,7,14,and 21 days after modeling,the recovery of the motor function of the hind limbs of the rats was assessed by BBB scoring method combined with Rivlin's slant plate test.The damage of spinal cord tissues was detected by using hematoxylin-eosin staining and Nissl staining.The expression levels of brain-derived neurotrophic factor and vascular endothelial growth factor A proteins were detected by western blot assay.The expression proportion of M1-type markers(inducible nitric oxide synthase)and M2 markers(arginase-1)in the spinal cord tissues was detected by immunofluorescence method.qRT-PCR and western blot assay were used to detect the expression levels of inducible nitric oxide synthase and arginase-1 in spinal cord tissues.ELISA was utilized to detect the levels of pro-inflammatory factors(tumor necrosis factor α,interleukin 1β,and interleukin 6)and anti-inflammatory factors(interleukin 10)levels in spinal cord tissues.RESULTS AND CONCLUSION:(1)At 3,7,and 14 days postoperatively,the BBB scores of the exosome group were better than those of the model group(P＜0.05).The angles of the Rivlin slanting plate experiments of the exosome group were significantly higher than those of the model group at 7 and 14 days postoperatively(P＜0.05).The results of hematoxylin-eosin staining and Nissl staining indicated that the spinal cord tissues and nerve injuries of the exosome group were reduced in comparison with those of the model group,and the levels of brain-derived neurotrophic factor and vascular endothelial growth factor A in spinal cord tissues of the exosome group were higher than those in the model group at 7 days postoperatively(P＜0.05).(2)Immunofluorescence experiments showed that the number of inducible nitric oxide synthase-positive microglial cells in the lesion area of the exosome group was significantly reduced and the level of Arg1-positive microglial cells increased in the lesion area of the exosome group compared with the model group at 7 days postoperatively(P＜0.05).qRT-PCR and western blot assay also confirmed the results of immunofluorescence experiments.(3)The secretion of pro-inflammatory factors tumor necrosis factor α,interleukin 1β,and interleukin 6 in spinal cord tissues of the exosome group was reduced compared with the model group(P＜0.05),whereas the secretion of the inflammation-suppressing factor interleukin 10 was increased compared with the model group(P＜0.05).These findings conclude that human umbilical cord mesenchymal stem cell-derived exosomes could promote the polarization of microglial cells from the M1 to the M2 type and decrease the release of pro-inflammatory factors,thereby reducing the secondary damage of neuroinflammation in spinal cord injury.

Objective:To explore the clinical efficacy of "four-step" aortic valve anatomic repair for bicuspid aortic valve(BAV) with aortic regurgitation(AR).Methods:From August 2021 to November 2024, a total of 298 consecutive patients with BAV-AR underwent aortic valve anatomic repair(AVr) in Shanghai Zhongshan Hospital Fudan University, 266 males and 32 females, with age of 39(29.5, 48.5) years. All patients underwent " four-step" three-dimensional anatomic repair of the aortic annulus and leaflets, 129(43.3%) patients via upper mini-sternotomy and 169(56.7%) patients via conventional median sternotomy, with the main steps including: (1) deep dissecting and annuloplasty of the virtual basal ring(VBR); (2) symmetrical repairing of leaflets; (3) replacement or remodeling of the sinus of Valsalva; (4) annuloplasty of the sinotubular junction(STJ). Basal and perioperative data were retrospectively collected, and statistical analysis was performed in conjunction with follow-up data.Results:All patients successfully underwent anatomical repair without transferring to valve replacement during operation. Among them, 43 patients underwent aortic root reimplantation technique(Reimplantation group), while 255 patients underwent modified aortic root sleeve remodeling technique(Sleeve group). The median cardiopulmonary bypass time for the Reimplantation and Sleeve groups were 154(134, 169) minutes and 111(95, 129) minutes, respectively( P<0.05); the median aortic cross-clamp time were 112(100, 131) minutes and 80(67, 94) minutes, respectively( P<0.05). Preoperative TEE showed 35 patients(81.4%) and 229 patients(89.8%) with moderate and severe AR in Reimplantation and Sleeve groups, respectively. Postoperative TEE showed 41 patients(95.3%) with no/trace AR and 2 patients(4.7%) with central mild AR in Reimplantation group, while 212 patients(83.1%) with no/trace AR and 43 patients(16.9%) with central mild AR in Sleeve group. Follow-up was completed in all patients, with a median follow-up of 12.9(4.7, 21.2) months. Echocardiography was obtained in 271 patients(90.9%) at the latest follow-up, including no/trace AR in 167 patients(56.0%), mild AR in 89 patients(29.9%), moderate AR in 14 patients(4.7%), and severe AR in 1 patient(0.3%). Conclusion:Aortic valve anatomic repair by standardized "four-step" approach is safe and reproducible. Satisfied short- and mid-term outcome have obtained in selected BAV-AR patients.

Objective:To investigate the effects of oral propranolol on the heart rate and blood glucose levels in children with hemangiomas receiving hospital care.Methods:A total of 259 children [77 males and 182 females, aged (125.2±85.4) days, weighted (6.3±1.6) kg], who were treated with oral propranolol for the first time under hospital care from January 2013 to August 2021, were retrospectively analyzed. After fasting, the patients administered the same dose of propranolol once daily (0.5-2.5 mg/kg). Fasting blood glucose and heart rate were measured in all children before propranolol administration and after 2 h. Heart rate was measured at 1, 3 and 6 h after propranolol administration for three consecutive days. Adverse reactions were observed and recorded.Results:Within three days of oral propranolol administration, the heart rates at 1, 3 and 6 h after propranolol administration were lower than those before propranolol administration (all P<0.001). Within three days after taking propranolol and 2 h after taking propranolol daily, blood glucose levels reduced in all children (all P<0.001). During the hospitalization period, the incidence of adverse reactions was 5.4% (14/259), including lesion ulcers in four cases, upper respiratory tract infection with fever in four, reduced eating in two, nausea and vomiting in one, lethargy in one, sinus tachycardia in one, and hyperkalemia in one. No serious adverse reactions were life-threatening. Conclusion:After oral administration of propranolol, the heart rate and blood sugar of the children decrease to different degrees compared with those before propranolol administration.

Objective To explore the relationship between preoperative coronary angiography and postoperative acute kidney injury (AKI) in cardiac surgery. Methods The clinical data of patients who underwent coronary angiography within 30 days before cardiac surgery in the First Affiliated Hospital of Xi’an Jiaotong University from January 2015 to April 2019 were retrospectively analyzed. Univariate analysis and multivariate logistic regression analyses were used to explore the relationship between the interval from preoperative coronary angiography to cardiac surgery and postoperative AKI. Results Finally 1 112 patients were collected, including 700 males and 412 females, with a median age of 61 (55, 66) years. The incidence of postoperative AKI was 40.8% (454/1 112), of which grade 2-3 AKI accounted for 11.9%. Multivariate analysis showed that age (OR=1.049, 95%CI 1.022-1.077, P<0.001), body mass index (OR=1.065, 95%CI 1.010-1.123, P=0.020) and time interval between preoperative coronary angiography and cardiac surgery within 24 hours (OR=1.625, 95%CI 1.116-2.364, P=0.011) were independent predictors of postoperative AKI. Patients who underwent coronary angiography within 24 hours before surgery had a 10.6% higher incidence of postoperative AKI compared to those who underwent angiography ≥24 hours before surgery (P=0.004). Patients who underwent valve surgery with or without coronary artery bypass grafting (CABG) had a higher risk of AKI than those who only underwent CABG. The in-hospital stay of patients who developed AKI was 2 days longer than those without AKI. However, undergoing coronary angiography within 24 hours before cardiac surgery did not prolong the length of ICU stay or hospital stay, nor did it increase the risk of death or renal failure after the operation. Conclusion Undergoing coronary angiography within 24 hours before cardiac surgery increases the risk of postoperative AKI.