1.The impact of different chest compression frequencies on cardiopulmonary resuscitation outcomes in domestic pigs.
Nana XU ; Jiabi ZHANG ; Jialin LUO ; Li WANG ; Yong CHEN ; Lijun ZHOU ; Bihua CHEN ; Lan LUO ; Xiaolu LIU ; Shuju LUO ; Yong WANG ; Zunwei LUO ; Li DING ; Mei LI ; Manhong ZHOU
Chinese Critical Care Medicine 2025;37(5):472-476
OBJECTIVE:
To compare the effects of different chest compression rates (60-140 times/min) on hemodynamic parameters, return of spontaneous circulation (ROSC), resuscitation success, and survival in a porcine model of cardiac arrest (CA) followed by cardiopulmonary resuscitation (CPR).
METHODS:
Forty healthy male domestic pigs were randomly divided into five groups based on chest compression rate: 60, 80, 100, 120, and 140 times/min (n = 8). All animals underwent standard anesthesia and tracheal intubation. A catheter was inserted via the left femoral artery into the thoracic aorta to monitor aortic pressure (AOP), and another via the right external jugular vein into the right atrium to monitor right atrial pressure (RAP). In each group, animals were implanted with a stimulating electrode via the right external jugular vein to the endocardium, and ventricular fibrillation (VF) was induced by delivering alternating current stimulation, resulting in CA. After a 1-minute, manual chest compressions were performed at the assigned rate with a compression depth of 5 cm. The first defibrillation was delivered after 2 minutes of CPR. No epinephrine or other pharmacologic agents were administered during the entire resuscitation process. From 1 minute before VF induction to 10 minutes after ROSC, dynamic monitoring of AOP, coronary perfusion pressure (CPP), and partial pressure of end-tidal carbon dioxide (PETCO2). Cortical ultrastructure was examined 24 hours post-ROSC using transmission electron microscopy.
RESULTS:
With increasing compression rates, both the total number of defibrillations and cumulative defibrillation energy significantly decreased, reaching their lowest levels in the 120 times/min group. The number of defibrillations decreased from (4.88±0.83) times in the 60 times/min group to (2.25±0.71) times in the 120 compressions/min group, and energy from (975.00±166.90)J to (450.00±141.42)J. However, both parameters increased again in the 140 times/min group [(4.75±1.04)times, (950.00±207.02)J], the differences among the groups were statistically significant (both P < 0.01). As compression frequency increased, PETCO2, pre-defibrillation AOP and CPP significantly improved, peaking in the 120 times/min group [compared with the 60 times/min group, PETCO2 (mmHg, 1 mmHg≈0.133 kPa): 18.69±1.98 vs. 8.67±1.30, AOP (mmHg): 95.13±7.06 vs. 71.00±6.41, CPP (mmHg): 14.88±6.92 vs. 8.57±3.42]. However, in the 140 times/min group, these values declined significantly again [PETCO2, AOP, and CPP were (10.59±1.40), (72.38±11.49), and (10.36±4.57) mmHg, respectively], the differences among the groups were statistically significant (all P < 0.01). The number of animals achieving ROSC, successful resuscitation, and 24-hour survival increased with higher compression rates, reaching a peak in the 120 times/min group (compared with the 60 times/min group, ROSC: 7 vs. 2, successful resuscitation: 7 vs. 2, 24-hour survival: 7 vs.1), then decreased again in the 140 times/min group (the animals that ROSC, successfully recovered and survived for 24 hours were 3, 3, and 2, respectively). Transmission electron microscopy revealed that in the 60, 80, and 140 times/min groups, nuclear membranes in cerebral tissue were irregular and incomplete, nucleoli were indistinct, and mitochondria were swollen with reduced cristae and abnormal morphology. In contrast, the 100 times/min and 120 times/min groups exhibited significantly attenuated ultrastructural damage.
CONCLUSIONS
Among the tested chest compression rates of 60-140 times/min, a chest compressions frequency of 120 times/min is the most favorable hemodynamic profile and outcomes during CPR in a porcine CA model. However, due to the wide spacing between groups, further investigation is needed to determine the optimal compression rate range more precisely.
Animals
;
Cardiopulmonary Resuscitation/methods*
;
Swine
;
Male
;
Heart Arrest/therapy*
;
Heart Massage/methods*
;
Hemodynamics
2.Mechanism of auraptene in improving acute liver injury induced by diquat poisoning in mice.
Renyang OU ; Shan HUANG ; Lihong MA ; Zhijie ZHAO ; Shengshan LIU ; Yuanliang WANG ; Yezi SUN ; Nana XU ; Lijun ZHOU ; Mei LI ; Manhong ZHOU ; Guosheng RAO
Chinese Critical Care Medicine 2025;37(6):590-594
OBJECTIVE:
To investigate whether auraptene (AUR) exerts a protective effect on acute diquat (DQ)-induced liver injury in mice and explore its underlying mechanisms.
METHODS:
Forty SPF-grade healthy male C57BL/6 mice were randomly divided into normal control group (Control group), DQ poisoning model group (DQ group), AUR treatment group (DQ+AUR group), and AUR control group (AUR group), with 10 mice in each group. The DQ poisoning model was established via a single intraperitoneal injection of 40 mg/kg DQ aqueous solution (0.5 mL); Control group and AUR group received an equal volume of pure water intraperitoneally. Four hours post-modeling, DQ+AUR group and AUR group were administered 0.5 mg/kg AUR aqueous solution (0.2 mL) by gavage once daily for 7 consecutive days, while Control group and DQ group received pure water. Blood and liver tissues were collected after anesthesia on day 7. Liver ultrastructure was observed by transmission electron microscopy. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured via enzyme-linked immunosorbent assay (ELISA). Hepatic glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) levels were detected using WST-1, thiobarbituric acid (TBA), and enzymatic reaction methods, respectively. Protein expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Kelch-like ECH-associated protein 1 (Keap1), and activated caspase-9 in liver tissues was analyzed by Western blotting.
RESULTS:
Transmission electron microscopy revealed that mitochondria in the Control group exhibited mild swelling, uneven distribution of matrix, and a small number of cristae fractures. In the AUR group, mitochondria showed mild swelling, with no obvious disruption of cristae structure. In the DQ group, mitochondria demonstrated marked swelling and increased volume, matrix dissolution, loss and fragmentation of cristae, and extensive vacuolization. In contrast, the DQ+AUR group showed significantly reduced mitochondrial swelling, volume increase, matrix dissolution, cristae loss and fragmentation, and vacuolization compared to the DQ group. Compared with the DQ group, the DQ+AUR group exhibited significantly lower serum AST levels (U/L: 173.45±23.60 vs. 255.33±41.51), ALT levels (U/L: 51.77±21.63 vs. 100.70±32.35), and hepatic MDA levels (μmol/g: 12.40±2.76 vs. 19.74±4.10), along with higher hepatic GSH levels (mmol/g: 37.65±14.95 vs. 20.58±8.52) and SOD levels (kU/g: 124.10±33.77 vs. 82.81±22.00), the differences were statistically significant (all P < 0.05). Western blotting showed upregulated Nrf2 expression (Nrf2/β-actin: 0.87±0.37 vs. 0.53±0.22) and HO-1 expression (HO-1/β-actin: 1.06±0.22 vs. 0.49±0.08), and downregulated Keap1 expression (Keap1/β-actin: 0.82±0.12 vs. 1.52±0.76) and activated caspase-9 expression (activated caspase-9/β-actin: 1.16±0.28 vs. 1.71±0.30) in the DQ+AUR group compared to the DQ group (all P < 0.05).
CONCLUSION
AUR attenuates DQ-induced acute liver injury in mice by activating the Keap1/Nrf2 signaling pathway.
Animals
;
Male
;
Mice
;
Mice, Inbred C57BL
;
Liver/pathology*
;
Chemical and Drug Induced Liver Injury/drug therapy*
;
Diquat/poisoning*
;
NF-E2-Related Factor 2/metabolism*
;
Oxidative Stress
;
Apoptosis
;
Coumarins
3.Protective effect and mechanism of quercetin on acute liver injury induced by diquat poisoning in mice
Shan HUANG ; Jianhong WANG ; Renyang OU ; Guosheng RAO ; Zhijie ZHAO ; Nana XU ; Manhong ZHOU
Chinese Critical Care Medicine 2024;36(6):604-608
Objective:To investigate the protective effect of quercetin (QR) on acute liver injury induced by diquat (DQ) poisoning in mice and its mechanism.Methods:Eighty healthy male C57BL/6 mice with SPF grade were randomly divided into control group, DQ model group, QR treatment group, and QR control group, with 20 mice in each group. The DQ poisoning model was established by a one-time intraperitoneal injection of DQ solution (40 mg/kg); the control and QR control groups received equivalent amounts of distilled water through intraperitoneal injection. Four hours after modeling, the QR treatment group and the QR control group received 0.5 mL QR solution (50 mg/kg) through gavage. Meanwhile, an equivalent amount of distilled water was given orally to the control group and the DQ model group. The treatments above were administered once daily for seven consecutive days. Afterwards, the mice were anesthetized, blood and liver tissues were collected for following tests: changes in the structure of mice liver tissue were observed using transmission electron microscopy; the levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected using enzyme linked immunosorbent assay (ELISA); the levels of glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) in liver tissues were measured using the water-soluble tetrazolium-1 (WST-1) method, the thiobarbituric acid (TBA) method, and enzymatic methods, respectively; the protein expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Kelch-like ECH-associated protein 1 (Keap1), and activated caspase-9 in liver tissues were detected using Western blotting.Results:Severe mitochondrial damage was observed in the liver tissues of mice in the DQ model group using transmission electron microscopy, yet mitochondrial damage in the QR treatment group showed significant alleviation. Compared to the control group, the DQ model group had significantly increased levels of MDA in liver tissue, serum AST, and ALT, yet had significantly decreased levels of GSH and SOD in liver tissue. In comparison to the DQ model group, the QR treatment group exhibited significant reductions in serum levels of ALT and AST, as well as MDA levels in liver tissue [ALT (U/L): 52.60±6.44 vs. 95.70±8.00, AST (U/L): 170.45±19.33 vs. 251.10±13.09, MDA (nmol/mg): 12.63±3.41 vs. 18.04±3.72], and notable increases in GSH and SOD levels in liver tissue [GSH (μmol/mg): 39.49±6.33 vs. 20.26±3.96, SOD (U/mg): 121.40±11.75 vs. 81.67±10.01], all the differences were statistically significant (all P < 0.01). Western blotting results indicated that the protein expressions of Nrf2 and HO-1 in liver tissues of the DQ model group were significantly decreased compared to the control group. On the other hand, the protein expressions of Keap1 and activated caspase-9 were conspicuously higher when compared to the control group. In comparison to the DQ model group, the QR treatment group showed a significant increase in the protein expressions of Nrf2 and HO-1 in liver tissues (Nrf2/β-actin: 1.17±0.08 vs. 0.92±0.45, HO-1/β-actin: 1.53±0.17 vs. 0.84±0.09). By contrast, there was a notable decrease in the protein expressions of Keap1 and activated caspase-9 (Keap1/β-actin: 0.48±0.06 vs. 1.22±0.09, activated caspase-9/β-actin: 1.17±0.12 vs. 1.59±0.30), the differences were statistically significant (all P < 0.01). Conclusion:QR may reduce acute liver injury induced by DQ poisoning in mice via activating Keap1/Nrf2 signaling pathway.
4.Sulforaphane alleviates acute liver injury induced by diquat in mice by activating Keap1/Nrf2 signaling pathway
Jianhong WANG ; Liang PENG ; Liaozhang WU ; Shan HUANG ; Guoli HE ; Pei SHEN ; Jing LIANG ; Tingting HUANG ; Jiaming HUANG ; Hong ZHONG ; Manhong ZHOU
Chinese Critical Care Medicine 2024;36(11):1183-1189
Objective:To investigate the protective effect and possible mechanism of sulforaphane (SFN) on acute liver injury in mice induced by diquat (DQ) poisoning.Methods:Forty-eight male C57BL/6 mice were divided into Control group, DQ model group (DQ group), SFN intervention group (DQ+SFN group), and SFN control group (SFN group) using a random number table method, with 12 mice in each group. Acute liver injury mice model was established by one-time intraperitoneal injection of 1 mL of 40 mg/kg DQ solution at once. SFN group was injected with 1 mL of ddH 2O. After 4 hours of molding, 0.5 mL of 5 mg/kg SFN solution was injected into the peritoneal cavity of the DQ+SFN group and SFN group, once daily for 7 consecutive days. DQ group and Control group were injected with an equal amount of ddH 2O. Then, the mice were euthanized to collect liver tissue and blood samples, and the levels of plasma biomarkers alanine aminotransferase (ALT) and aspartate aminotransferase (AST), as well as oxidative stress indicators such as superoxide dismutase (SOD), glutathione (GSH), and malondialdehyde (MDA) in liver tissue were measured. The changes of liver structure were observed under transmission electron microscopy. The apoptosis and reactive oxygen species (ROS) level in liver tissue were observed under fluorescence microscope. Western blotting was used to detect the protein expressions of nuclear factor E2-related factor 2 (Nrf2), hemeoxygenase-1 (HO-1), Kelch-like ECH-associated protein 1 (Keap1), and cleaved caspase-9 in liver tissue. Results:Compared with the Control group, the liver mitochondria in the DQ group showed severe swelling, partial dissolution of the matrix, and cristae rupture and loss; the levels of plasma AST and ALT significantly increased, the MDA content in the liver increased, the activities of SOD and GSH decreased, the level of ROS significantly increased, the number of apoptotic cells in the liver significantly increased, the protein expressions of Nrf2 and HO-1 significantly decreased, and the protein expressions of Keap1 and cleaved caspase-9 significantly increased. Compared with the DQ group, the mitochondrial damage in the DQ+SFN group was reduced, the levels of plasma AST and ALT were significantly reduced [ALT (U/L): 58.22±4.39 vs. 79.94±3.32, AST (U/L): 177.64±8.40 vs. 219.62±11.60, both P < 0.01], the liver MDA content decreased, and the activities of SOD and GSH increased [MDA (μmol/g: 5.63±0.18 vs. 5.96±0.29, SOD (kU/g): 102.05±4.01 vs. 84.34±5.34, GSH (mmol/g): 16.32±1.40 vs. 13.12±1.84, all P < 0.05], the production of ROS in liver tissue was significantly reduced [ROS (fluorescence intensity): 115.90±10.89 vs. 190.70±10.16, P < 0.05], and apoptotic cells were significantly reduced (cell apoptosis index: 4.39±1.00 vs. 10.71±0.56, P < 0.01), the protein expressions of Nrf2 and HO-1 were significantly increased, while the protein expressions of Keap1 and cleaved caspase-9 were significantly decreased (Nrf2/β-actin: 1.15±0.04 vs. 0.93±0.05, HO-1/β-actin: 1.75±0.12 vs. 0.78±0.04, Keap1/β-actin: 1.00±0.14 vs. 1.28±0.13, cleaved caspase-9/β-actin: 1.31±0.12 vs. 1.81±0.09, all P < 0.05). However, there was no statistically significant difference in various indicators between the SFN group and the Control group. Conclusion:SFN can activate the Keap1/Nrf2 signaling pathway to alleviate DQ induced acute liver injury in mice.
5.Optical coherence tomography imaging features of Coats disease and their correlation with macular fibrosis
Ziyi ZHOU ; Guorui DOU ; Hongxiang YAN ; Guoheng ZHANG ; Jinting ZHU ; Dongjie SUN ; Zifeng ZHANG ; Manhong LI ; Yusheng WANG
Chinese Journal of Experimental Ophthalmology 2024;42(5):436-441
Objective:To analyze the optical coherence tomography (OCT) imaging characteristics in patients with Coats disease and their value in predicting macular fibrosis.Methods:A nested case-control study was performed.A total of 43 patients (43 eyes) diagnosed with Coats disease through color fundus photography, ocular B-scan ultrasonography, fundus fluorescein angiography, and spectral-domain OCT examination were enrolled from January 2008 to October 2021 at the Xijing Hospital.Among them, there were 40 males and 3 females, aged from 2 to 60 years old, with a median age of 13 years.Macular fibrosis was used as an indicator of poor prognosis, and patients were divided into two groups based on whether macular fibrosis occurred at the end of follow-up.The differences in OCT characteristics between two groups were compared and logistic regression analysis was used to identify the risk factors for macular fibrosis.This study adhered to the Declaration of Helsinki and was approved by the Ethics Committee of Xijing Hospital of Fourth Military Medical University (No.KY20202009-C-1).Results:The OCT clinical features of 43 cases of Coats disease included intraretinal hard exudates in 43 eyes (100%), subretinal fluid in 21 eyes (48.8%), macular cysts in 17 eyes (27.9%), subretinal exudates in 9 eyes (20.9%), anterior retinal hyperreflective dots in 7 eyes (16.3%), epiretinal membrane in 21 eyes (48.8%), and intraretinal fluid in 22 eyes (51.2%).In color fundus photos of 41 eyes, 38 eyes (93.0%) had hard exudates distributed in the posterior pole and 27 eyes (65.9%) had the mid-peripheral region.OCT examination showed that hard exudates were distributed in the inner nuclear layer in 35 eyes (81.4%) and the outer nuclear layer in 33 eyes (76.7%).Among 21 eyes with exudative retinal detachment detected by OCT, 9 eyes (42.9%) were detected by fundus photography and 18 eyes (85.7%) were detected by B-scan ultrasonography.The proportions of eyes with subretinal fluid and subretinal exudates were higher in the macular fibrosis group than in the non-macular fibrosis group, and the differences were statistically significant ( χ2=20.755, P<0.001; χ2=6.133, P=0.013).Logistic regression analysis showed that the presence of subretinal fluid was a risk factor for macular fibrosis (odds ratio=48.345, 95% confidence interval: 4.272-547.066, P=0.002). Conclusions:OCT examination can detect subretinal fluid, subretinal exudates, macular cysts, macular exudates, and hyperreflective spots in the retina of patients with Coats disease.Subretinal fluid is a risk factor for macular fibrosis.
6.Protective effect of tumor necrosis factor receptor-associated factor 6 inhibitor C25-140 on acute kidney injury induced by diquat poisoning in mice.
Tingting HUANG ; Guosheng RAO ; Zhijie ZHAO ; Nana XU ; Manhong ZHOU ; Renyang OU
Chinese Critical Care Medicine 2024;36(12):1273-1278
OBJECTIVE:
To investigate the protective effect and mechanism of tumor necrosis factor receptor-associated factor 6 (TRAF6) inhibitor C25-140 on acute kidney injury (AKI) induced by acute diquat (DQ) poisoning in mice.
METHODS:
A total of 80 SPF grade healthy male C57BL/6 mice were randomly divided into the normal control group, DQ model group, C25-140 intervention group, and C25-140 control group, with 20 mice in each group. The DQ poisoning mouse model was established by using one-time intraperitoneal injection of 1 mL of 40 mg/kg DQ solution. The normal control group and C25-140 control group were injected with an equal amount of pure water into the peritoneal cavity. After 4 hours of model establishment, the C25-140 intervention group and C25-140 control group were given intraperitoneal injection of C25-140 5 mg/kg. The normal control group and DQ model group were given equal amounts of pure water, once a day for 7 consecutive days. After 7 days, the mice were anesthetized, eye blood was collected, and renal tissue was collected after sacrifice. The pathological changes of renal tissue were observed under a light microscope and renal tissue structure and mitochondrial changes were observed under transmission electron microscopy. The levels of serum creatinine (SCr) and blood urea nitrogen (BUN) were measured. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of serum interleukins (IL-6, IL-1β) and tumor necrosis factor-α (TNF-α). Western blotting was used to detect the protein expression levels of TRAF6, myeloid differentiation factor 88 (MyD88), and nuclear factor-κB (NF-κB) in renal tissue. Chemical method was used to determine the content of serum malondialdehyde (MDA) and superoxide dismutase (SOD).
RESULTS:
During the observation period, there were no abnormal behaviors in the normal control group mice. The DQ model group mice gradually showed symptoms such as mental fatigue, fluffy fur, reduced activity, and low food intake after being exposed to the toxin, and severe cases resulted in death. The above symptoms were alleviated in the C25-140 intervention group compared to the DQ model group. Under light microscopy, HE staining showed infiltration of inflammatory cells, glomerulosclerosis, proximal tubular dilation, and vacuolization in the DQ model group, while the inflammatory response was reduced in the C25-140 intervention group compared to the DQ model group. Under transmission electron microscopy, the DQ model group showed relatively high levels of mitochondrial damage, severe swelling, increased volume, matrix dissolution, ridge fracture and loss. The degree of mitochondrial damage in the C25-140 intervention group was reduced compared to the DQ model group. Compared with the normal control group, the levels of serum SCr, BUN, IL-6, IL-1β, TNF-α, and MDA in the DQ model group were significantly increased, while the serum SOD level was significantly decreased. Compared with the DQ model group, the levels of serum SCr, BUN, IL-6, IL-1β, TNF-α, and MDA in the C25-140 intervention group were significantly reduced [SCr (μmol/L): 59.07±13.11 vs. 83.61±20.13, BUN (mmol/L): 25.83±9.95 vs. 40.78±11.53, IL-6 (ng/L): 40.76±7.03 vs. 83.33±21.83, IL-1β (ng/L): 53.87±7.82 vs. 91.74±12.53, TNF-α (ng/L): 102.52±32.13 vs. 150.92±31.75, MDA (μmol/L): 3.57±1.06 vs. 5.75±1.83], and the serum SOD level was significantly increased (kU/g: 162.52±36.13 vs. 122.72±22.13), and the differences were statistically significant (all P < 0.01). Western blotting results showed that the protein expression levels of TRAF6, NF-κB, and MyD88 in the renal tissue of DQ model group mice were significantly higher than those in the normal control group. The expression levels of the above-mentioned proteins in the C25-140 intervention group of mice were significantly lower than those in the DQ model group (TRAF6/β-actin: 1.05±0.36 vs. 1.74±0.80, NF-κB/β-actin: 0.57±0.07 vs. 1.03±0.75, MyD88/β-actin: 0.58±0.07 vs. 1.03±0.33, all P < 0.05).
CONCLUSIONS
TRAF6 inhibitor C25-140 can alleviate AKI induced by DQ poisoning in mice by regulating the Toll-like receptor 4 (TLR4)/TRAF6/NF-κB signaling pathway and downregulating the levels of inflammatory cytokines IL-1β, IL-6, and TNF-α.
Animals
;
Male
;
Acute Kidney Injury/prevention & control*
;
Mice
;
Mice, Inbred C57BL
;
Diquat
;
TNF Receptor-Associated Factor 6/metabolism*
;
Interleukin-6/blood*
;
Kidney/pathology*
;
NF-kappa B/metabolism*
;
Peptide Fragments
7.Protective effect of metformin on pulmonary fibrosis caused by paraquat through activating AMP-activated protein kinase pathway.
Tongying LIU ; Lihong GAO ; Jianhong WANG ; Liaozhang WU ; Manhong ZHOU
Chinese Critical Care Medicine 2023;35(12):1309-1315
OBJECTIVE:
To observe whether metformin (MET) inhibits transforming growth factor-β1 (TGF-β1)/Smad3 signaling pathway by activating adenosine activated protein kinase (AMPK), so as to alleviate the pulmonary fibrosis caused by paraquat (PQ) poisoning in mice.
METHODS:
Male C57BL/6J mice were randomly divided into the Control group, PQ poisoning model group (PQ group), MET intervention group (PQ+MET group), AMPK agonist group (PQ+AICAR group), and AMPK inhibitor group (PQ+MET+CC group), according to a random number table method. A mouse model of PQ poisoning was established by one-time peritoneal injection of 1 mL PQ solution (20 mg/kg). The Control group was injected with the same volume of normal saline. After 2 hours of modeling, the PQ+MET group was given 2 mL of 200 mg/kg MET solution by gavage, the PQ+AICAR group was given 2 mL of 200 mg/kg AICAR solution by intraperitoneal injection, the PQ+MET+CC group was given 2 mL of 200 mg/kg MET solution by gavage and then 1 mL complex C (CC) solution (20 mg/kg) was intraperitoneally injected, the Control group and PQ group were given 2 mL of normal saline by gavage. The intervention was given once a day for 21 consecutive days. The 21-day survival rate of ten mice in each group was calculated, and the lung tissues of remaining mice were collected at 21 days after modeling. The pathological changes of lung tissues were observed under light microscope after hematoxylin-eosin (HE) staining and Masson staining, and the degree of pulmonary fibrosis was evaluated by Ashcroft score. The content of hydroxyproline in lung tissue and oxidative stress indicators such as malondialdehyde (MDA) and superoxide dismutase (SOD) were detected. The protein expressions of E-cadherin, α-smooth muscle actin (α-SMA), phosphorylated AMPK (p-AMPK), TGF-β1 and phosphorylated Smad3 (p-Smad3) in lung tissue were detected by Western blotting.
RESULTS:
Compared with the Control group, the 21 days survival rate was significantly reduced, lung fibrosis and Ashcroft score were significantly increased in PQ group. In addition, the content of hydroxyproline, MDA and the protein expressions of α-SMA, TGF-β1 and p-Smad3 in lung tissue were significantly increased, while the activity of SOD and the protein expressions of E-cadherin and p-AMPK were significantly decreased in PQ group. Compared with the PQ group, the 21 days survival rates of mice were significantly improved in the PQ+MET group and PQ+AICAR group (70%, 60% vs. 20%, both P < 0.05). The degree of pulmonary fibrosis and the Ashcroft score were significantly reduced (1.50±0.55, 2.00±0.63 vs. 6.67±0.52, both P < 0.05). The content of hydroxyproline and MDA in lung tissue, as well as α-SMA, TGF-β1 and p-Smad3 protein expressions were significantly reduced [hydroxyproline (mg/L): 2.03±0.11, 3.00±0.85 vs. 4.92±0.65, MDA (kU/g): 2.06±1.48, 2.10±1.80 vs. 4.06±1.33, α-SMA/GAPDH: 0.23±0.06, 0.16±0.06 vs. 1.00±0.09, TGF-β1/GAPDH: 0.28±0.03, 0.53±0.05 vs. 0.92±0.06 p-Smad3/GAPDH: 0.52±0.04, 0.69±0.06 vs. 1.11±0.10, all P < 0.05], SOD activity and the protein expressions of E-cadherin and p-AMPK were significantly increased [SOD (μmol/g): 39.76±1.35, 33.03±1.28 vs. 20.08±1.79, E-cadherin/GAPDH: 0.91±0.08, 0.72±0.08 vs. 0.26±0.04, p-AMPK/GAPDH: 0.62±0.04, 0.60±0.01 vs. 0.20±0.04, all P < 0.05]. However, these protective effects of MET were inhibited by the addition of AMPK inhibitor CC solution.
CONCLUSIONS
MET can effectively alleviate the degree of pulmonary fibrosis in mice poisoned with PQ, and its mechanism may be related to the activation of AMPK and inhibition of TGF-β1/Smad3 signaling pathway, which can be inhibited by AMPK inhibitor CC.
Mice
;
Male
;
Animals
;
Pulmonary Fibrosis/drug therapy*
;
Paraquat
;
AMP-Activated Protein Kinases/pharmacology*
;
Metformin/pharmacology*
;
Hydroxyproline/pharmacology*
;
Saline Solution
;
Mice, Inbred C57BL
;
Lung/metabolism*
;
Transforming Growth Factor beta1/pharmacology*
;
Cadherins
;
Superoxide Dismutase
8.Research progress on the relationship between diquat poisoning and nuclear factor E2-related factor 2 signaling pathway
Jianhong WANG ; Tongying LIU ; Manhong ZHOU
Chinese Critical Care Medicine 2022;34(4):444-448
Since the production and use of paraquat was banned in China in 2016, the use of diquat (DQ) has been increasing and the clinical cases of DQ poisoning have also shown an increasing trend every year. The treatment of DQ poisoning is a worldwide medical problem, and there is no specific antidote. Studies have found that oxidative stress, lipid peroxidation, neurotoxicity, reproductive and developmental toxicity play an important role in DQ poisoning. Nuclear factor E2-related factor 2 (Nrf2) can inhibit oxidative stress, lipid peroxidation and inflammation by regulating the protein expression of upstream and downstream signaling molecules. Therefore, the role of Nrf2 signaling pathway in the poisoning and treatment of DQ has become a hot spot of attention for emergency critical care researchers in recent years. This paper reviews the relationship between Nrf2 signal pathway and DQ poisoning, in order to provide a theoretical basis for improving the treatment strategy for DQ poisoning.
9.Advances in the study of optimum chest compression point for adult cardiopulmonary resuscitation
Hong ZHONG ; Bihua CHEN ; Jing LIANG ; Tingting HUANG ; Jianhong WANG ; Manhong ZHOU
Chinese Critical Care Medicine 2022;34(6):670-672
Chest compressions are a key component of cardiopulmonary resuscitation (CPR). The determination of the optimal compression point (OCP) in adult CPR is an indispensable critical factor for high quality chest compressions (CCs). At present, the OCP for adult CPR is still controversial, which still needs further research and discussion. To provide theoretical reference for determining the OCP, this paper reviews the research progress of the OCP of adult CPR from the development process of compression point and hemodynamic mechanism, so as to improve the quality of CCs and the outcome of cardiac arrest (CA) patients.
10.Research progress of S-nitrosoglutathione reductase inhibitors in the regulation of cerebral injury after cardiac arrest-cardiopulmonary resuscitation
Chinese Critical Care Medicine 2022;34(9):995-998
The cerebral ischemia-reperfusion injury (CIRI) after the cardiac arrest (CA)-cardiopulmonary resuscitation (CPR) was a complex pathophysiology process. Nitric oxide (NO) is a small molecule that mediates cell signal transduction in vivo and plays an important role in the regulation of brain function during ischemia/reperfusion (I/R). S-nitrosoglutathione reductase (GSNOR) inhibitor can regulate the synthesis and release of NO in vivo and has a protective effect on CIRI. Therefore, early administration of GSNOR to CA-CPR patients could be the main treatment method to improve the prognosis of those patients. A large number of studies have been done to improve the prognosis of CA-CPR in recent years. In order to provide reference for further research on the treatment and brain protection of CIRI after CA-CPR, the article reviewed the main mechanisms of brain injury after CA-CPR, the protective effect and mechanism of NO on cerebral I/R injury, the production and regulation of NO, in vivo, and the protective effect of GSNOR inhibitors on CIRI, especially the research progress of GSNOR inhibitors.

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