OBJECTIVE: To investigate the feasibility and prognostic implications of assessing volume status during early fluid resuscitation in septic patients based on estimated plasma volume status (ePVS). METHODS: A prospective study was conducted. Patients with sepsis admitted to intensive care unit (ICU) of the First Affiliated Hospital of Kunming Medical University from March to December in 2023 were enrolled. The general information and laboratory indicators at ICU admission were recorded, and ePVS, sequential organ failure assessment (SOFA) score, acute physiology and chronic health status evaluation II (APACHE II) score were calculated. The vital signs, arterial blood gas analysis and volume status related indicators before liquid resuscitation (T0h) and 3 hours (T3h) and 6 hours (T6h) of fluid resuscitation were recorded. The diameter and variability of the inferior vena cava (IVC) were measured by ultrasound, and ePVS, percentage change value of estimated plasma volume status (ΔePVS%), difference in central venous-to-arterial partial pressure of carbon dioxide (Pcv-aCO₂), and lactate clearance rate (LCR) were calculated. Patients were divided into sepsis group and septic shock group based on the diagnosis at ICU admission, and septic patients were subdivided into survival group and death group based on their 28-day survival status. The differences in clinical data between the groups were compared. The correlation between ePVS or ΔePVS% and volume status related indicators during early liquid resuscitation was analyzed by Spearman rank sum correlation test. The predictive value of each variable for 28-day survival in patients with sepsis was analyzed by receiver operator characteristic curve (ROC curve), and 28-day death risk factors were analyzed by Logistic regression method. RESULTS: Fifty-four septic patients were enrolled in the final analysis, including 17 with sepsis and 37 with septic shock; 34 survived at 28 days and 20 died, with a 28-day survival rate of 63.0%. Compared with the sepsis group, the septic shock group had a lower venous ePVS at ICU admission [dL/g: 4.96 (3.67, 7.15) vs. 7.55 (4.36, 10.07), P < 0.05]. Compared with the death group, the survival group had higher T6h arterial and venous ΔePVS%, and albumin [Alb; T6h arterial ΔePVS% (%): 11.57% (-1.82%, 31.35%) vs. 0.48% (-5.67%, 6.02%), T6h venous ΔePVS%: 9.62% (3.59%, 25.75%) vs. 1.52% (-9.65%, 7.72%), Alb (g/L): 27.57±4.15 vs. 23.77±6.97, all P < 0.05], lower SOFA score, APACHE II score, AST, T0h Lac, and T3h and T6h norepinephrine dosage [SOFA score: 9.00 (8.00, 10.00) vs. 11.50 (9.25, 14.50), APACHE II score: 18.00 (14.75, 21.25) vs. 25.50 (21.00, 30.00), AST (U/L): 34.09 (23.20, 56.64) vs. 79.24 (25.34, 196.59), T0h Lac (mmol/L): 1.75 (1.40, 2.93) vs. 3.25 (2.33, 5.30), norepinephrine dosage (mg): 0.98 (< 0.01, 3.10) vs. 4.60 (1.05, 8.55) at T3h, 1.82 (0.38, 5.30) vs. 8.20 (2.80, 17.73) at T6h, all P < 0.05]. While there were no significantly differences in other basic data and ePVS at all of the time points before and after resuscitation between the two groups. Correlation analysis showed that T6h venous ePVS was significantly positively correlated with T6h IVC variability in septic patients (r = 0.360, P < 0.05), T0h arterial ePVS was significantly negatively correlated with T3h and T6h liquid intake volume (r₁ = -0.367, r₂ = -0.280, both P < 0.05), and venous ePVS at ICU admission was significantly positively correlated with NT-proBNP at ICU admission (r = 0.409, P < 0.05). T6h venous ΔePVS% was significantly positively correlated with T3h liquid intake volume and T6h LCR (r₁ = 0.286, r₂ = 0.286, both P < 0.05), and significantly negatively correlated with T6h urine volume and T6h change value of Pcv-aCO₂ (ΔPcv-aCO₂; r₁ = -0.321, r₂ = -0.371, both P < 0.05). ROC curve analysis showed that the area under the ROC curve (AUC) of T6h venous ΔePVS% for predicting 28-day survival in septic patients was 0.726 [95% confidence interval (95%CI) was 0.578-0.875, P = 0.006], with a sensitivity of 82.4%, a specificity of 60.0%, and an optimal cut-off value of 3.09%. Binary multifactorial Logistic regression analysis showed that an increase in T6h venous ΔePVS% was a protective factor for 28-day death in patients with sepsis on early fluid resuscitation [odds ratio (OR) = 0.900, 95%CI was 0.834-0.972, P = 0.007]. CONCLUSIONS ePVS may have potential for assessing the volume status of septic patients during early fluid resuscitation. The ΔePVS% during early fluid resuscitation may help to identify septic patients with a poor prognosis.
Humans ; Prognosis ; Fluid Therapy ; Sepsis/physiopathology* ; Prospective Studies ; Plasma Volume ; Intensive Care Units ; Resuscitation ; Male ; Female ; Middle Aged ; Shock, Septic/therapy*

OBJECTIVE: To evaluate the prognosis of septic right ventricular dysfunction (SRVD) based on bedside ultrasound and explore its risk factors. METHODS: A prospective observational study was conducted involving septic and septic shock patients admitted to the intensive care unit (ICU) of the General Hospital of Ningxia Medical University from February 2021 to January 2022. Tricuspid annular plane systolic excursion (TAPSE) was measured by M-mode ultrasound within 24 hours after ICU admission. According to the results of TAPSE, the subjects were divided into SRVD group (TAPSE < 16 mm) and non-SRVD group (TAPSE ≥ 16 mm). The gender, age, occurrence of septic shock, underlying diseases, source of patients, acute physiology and chronic health evaluation II (APACHE II) score, sequential organ failure assessment (SOFA) score, maximal body temperature within 24 hours after ICU admission, location and number of infections, duration of mechanical ventilation, and 28-day mortality were collected. Hemodynamic parameters, organ function indexes, oxygen therapy parameters and arterial blood gas analysis indexes were recorded within 24 hours after ICU admission. The differences of the above indexes between the two groups were compared. Binary multivariate Logistic regression analysis was used to screen out the independent risk factors for SRVD, and a nomogram of SRVD risk factors was drawn. RESULTS: 116 patients with sepsis and septic shock were enrolled, of which 24 (20.7%) had SRVD and 92 (79.3%) had no SRVD. Compared with the non-SRVD group, the patients in the SRVD group had higher emergency transfer and infection site ≥ 2 ratio, APACHE II score, SOFA score, higher cardiac troponin I (cTnI), myoglobin (Mb), MB isoenzyme of creatine kinase (CK-MB), N-terminal pro-brain natriuretic peptide (NT-proBNP), serum creatinine (SCr), arterial blood lactic acid (Lac) and lower left ventricular ejection fraction (LVEF), platelet count (PLT) within 24 hours after ICU admission, and higher proportion of norepinephrine application and continuous renal replacement therapy (CRRT). Binary multivariate Logistic regression analysis showed that LVEF [odds ratio (OR) = 0.918, 95% confidence interval (95%CI) was 0.851-0.991, P = 0.028], PLT (OR = 0.990, 95%CI was 0.981-0.999, P = 0.035), SCr (OR = 1.008, 95%CI was 1.001-1.016, P = 0.025), and the usage of norepinephrine (OR = 15.198, 95%CI was 1.541-149.907, P = 0.020) were independent risk factors for SRVD in patients with sepsis and septic shock. Based on the above four independent risk factors, a nomogram of SRVD risk factors was drawn. The results showed that the score was 64 when LVEF was 0.50, 18 when SCr was 100 μmol/L, 85 when PLT was 100×10⁹/L, and 39 when norepinephrine was used. When the total score reached 253, the risk of SRVD was 88%. Compared with non-SRVD group, the duration of mechanical ventilation in SRVD group was slightly longer [hours: 80.0 (28.5, 170.0) vs. 47.0 (10.0, 135.0), P > 0.05], and the 28-day mortality was significantly higher [41.7% (10/24) vs. 21.7% (20/92), P < 0.05]. CONCLUSIONS Patients with sepsis may have right ventricular dysfunction, impaired renal function and increased mortality in the early stage. The decrease in LVEF and PLT, the increase in SCr and the application of norepinephrine are independent risk factors for SRVD in patients with sepsis.
Humans ; Prognosis ; Ventricular Dysfunction, Right/diagnostic imaging* ; Risk Factors ; Prospective Studies ; Intensive Care Units ; Shock, Septic ; Male ; Ultrasonography ; Female ; Sepsis/complications* ; Middle Aged ; Point-of-Care Systems ; Aged ; Logistic Models ; APACHE

Septic shock, a prevalent critical condition in intensive care units (ICU) and a major cause of patient mortality, is fundamentally attributed to microcirculatory dysfunction. Traditional macrocirculatory parameters are often insufficiently sensitive to reflect microcirculatory status. Consequently monitoring peripheral microcirculatory function holds crucial significance for assessing disease progression and evaluating therapeutic efficacy in septic shock. The peripheral perfusion index (PPI), obtained from a standard pulse oximeter, is based on photoplethysmography (PPG). It calculates the differential absorption of red and infrared light emitted by the sensor between pulsatile arterial blood and non-pulsatile tissue, enabling real-time reflection of peripheral perfusion and thus providing non-invasive, continuous monitoring of microcirculatory function. Although often overlooked compared to other ICU monitoring parameters, PPI has demonstrated notable clinical advances in septic shock management. Specifically, in early identification, PPI combined with sequential organ failure assessment (SOFA) predicts disease progression, with its dynamic changes further aiding prognosis assessment. During fluid resuscitation, it guides fluid responsiveness evaluation and serves as a therapeutic target to optimize strategies. In circulatory support, it assists in determining vasoactive drug initiation timing and dosage titration. Additionally, PPI aids mechanical ventilation weaning and organ dysfunction evaluation. This article reviews the principles, influencing factors, and clinical application advances of PPI in septic shock, aiming to provide clinicians with a basis for individualized intervention, improved patient outcomes, and the advancement of precision medicine in septic shock management.
Humans ; Shock, Septic/therapy* ; Microcirculation ; Perfusion Index ; Prognosis ; Photoplethysmography

OBJECTIVE: To observe change in serum growth differentiation factor 11 (GDF11) and killer cell lectin-like receptor B1 (KLRB1), to construct a nomogram model for 28-day death in patients with septic shock, and to explore its predictive value. METHODS: A prospective observational study was conducted. The patients with septic shock admitted to the emergency intensive care unit (ICU) of Cangzhou Central Hospital from September 2023 to March 2025 were selected as the septic shock group, the patients with sepsis admitted to the emergency general ward during the same period were selected as the sepsis group, and healthy individuals undergoing physical examination during the same period were selected as the control group. On the day of hospital admission or physical examination for the research subjects, the levels of serum GDF11 and KLRB1 were detected by enzyme-linked immunosorbent assay (ELISA). The patients with septic shock were divided into survival and death groups based on their 28-day survival status. The patients' gender, age, past medical history, infection site, severity of illness, mechanical ventilation, blood purification, infection indicators, biochemical indicators, coagulation function indicators, and blood lactic acid (Lac) were collected. The clinical data of the patients with septic shock between the two groups with different prognoses were compared. Multivariate Logistic regression analysis was used to screen the risk factors for 28-day death in patients with septic shock, and bivariate Pearson correlation analysis was conducted. A nomogram model was constructed based on the risk factors for 28-day death in patients with septic shock. The discrimination and calibration of the nomogram model were evaluated using the receiver operator characteristic curve (ROC curve), Hosmer-Lemeshow goodness-of-fit test, and calibration curve. The clinical utility of the model was evaluated using clinical decision curve analysis (DCA). RESULTS: A total of 168 patients in the emergency ICU were enrolled in the septic shock group, 40 patients in the emergency general ward were enrolled in the sepsis group, and 40 healthy individuals were enrolled in the control group. Compared with the healthy control group, the serum GDF11 levels in the sepsis and septic shock groups were significantly increased (μg/L: 13.09±3.51, 19.28±5.36 vs. 4.17±0.92, both P < 0.05), and the serum KLRB1 levels were significantly decreased (ng/L: 57.36±11.28, 45.52±9.07 vs. 84.19±17.16, both P < 0.05), with more significant changes in the septic shock group (both P < 0.05). Among the 168 patients with septic shock, 96 survived and 72 died within 28 days. Compared with the survival group, the serum GDF11 level in the death group was significantly increased (μg/L: 24.24±4.81 vs. 15.56±4.62, P < 0.05), and the serum KLRB1 level was significantly decreased (ng/L: 28.53±8.69 vs. 58.26±9.45, P < 0.05). There were also statistically significant differences in sequential organ failure assessment (SOFA) score, acute physiology and chronic health evaluation II (APACHEII) score, procalcitonin (PCT), activated partial thromboplastin time (APTT), D-dimer, and Lac between the two groups. Multivariate Logistic regression analysis showed that SOFA score [odds ratio (OR) = 1.96, 95% confidence interval (95%CI) was 1.38-3.65), Lac (OR = 1.38, 95%CI was 1.09-2.01), GDF11 (OR = 1.54, 95%CI was 1.21-2.33) and KLRB1 (OR = 0.64, 95%CI was 0.41-0.78) were independent risk factors for 28-day death in patients with septic shock (all P < 0.05). Bivariate Pearson correlation analysis showed that SOFA score was significantly positively correlated with Lac and GDF11 (r value was 0.37 and 0.58, respectively, both P < 0.05), and significantly negatively correlated with KLRB1 (r = -0.72, P < 0.05). A nomogram model was constructed based on the risk factors for 28-day death in patients with septic shock. ROC curve analysis showed that the area under the ROC curve (AUC) of the nomogram model for predicting 28-day death in patients with septic shock was 0.963 (95%CI was 0.929-0.990), indicating that the model had good discrimination and predictive ability. The Hosmer-Lemeshow goodness-of-fit test (χ ² = 9.578, P = 0.295) and calibration curve indicated that the predicted values of the model were in good agreement with the actual values. DCA indicated that the model provided a high net benefit for clinical decision-making. CONCLUSIONS The serum GDF11 level was significantly increased and the KLRB1 level was significantly decreased in patients with septic shock. The nomogram model based on GDF11 and KLRB1 could more accurately evaluate the 28-day death of patients with septic shock.
Humans ; Shock, Septic/blood* ; Nomograms ; Prospective Studies ; Prognosis ; Male ; Female ; Middle Aged ; Aged ; Intensive Care Units

Objective To explore the effect of rehmanniae radix extract(RRE)on chondrocyte apoptosis in the rabbit model of knee osteoarthritis(KOA)by regulating the miR-485-5p/heat shock protein 90 beta family member 1(Hsp90b1)axis.Methods New Zealand rabbits were randomly assigned into control,KOA,low-dose RRE,medium-dose RRE,high-dose RRE,celecoxib,high-dose RRE+antagonist control,and high-dose RRE+miR-485-5p antagonist groups,with 12 rabbits in each group.Rabbits in other groups except the control group were modeled for KOA with the improved Hulth method.After modeling for 8 weeks,the rabbits were administrated with corresponding agents for 4 weeks.The changes in the activity rating of rabbits were recorded.ELISA was employed to measure the levels of tumor necrosis factor-α(TNF-α)and interleukin(IL)-6 in the serum.Safranine O-fast green staining was conducted to reveal the pathological changes in the cartilage tissue and Mankin scoring was performed.TUNEL was employed to detect chondrocyte apoptosis.Real-time fluorescence quantitative PCR was performed to determine the expression of miR-485-5p in the cartilage tissue.Western blot was employed to determine the protein levels of Hsp90b1,cleaved cysteinyl aspartate-specific proteinase-3(Caspase-3),and Bcl2-associated-X(Bax)in the cartilage tissue.The dual-luciferase reporter assay was employed to examine the relationship between miR-485-5p and Hsp90b1.Results Compared with the control group,the KOA group showed down-regulated expression of miR-485-5p,elevated levels of TNF-α and IL-6 in the serum,cartilage erosion and losses,and increases in activity rating,Mankin score,chondrocyte apoptosis rate,and protein levels of Hsp90b1,cleaved Caspase-3,and Bax(all P<0.001).Compared with the KOA group,RRE at low,medium,and high doses,and celecoxib up-regulated the expression of miR-485-5p,lowered the levels of TNF-α and IL-6 in the serum,alleviated the pathological damage to the cartilage tissue,and decreased the activity rating,Mankin score,chondrocyte apoptosis rate,and protein levels of Hsp90b1,cleaved Caspase-3,and Bax(all P<0.05).Compared with the high-dose RRE group and the high-dose RRE+antagonist control group,high-dose RRE+miR-485-5p antagonist down-regulated the expression of miR-485-5p,elevated the levels of TNF-α and IL-6 in the serum,exacerbated the pathological damage to the cartilage tissue,and increased the activity rating,Mankin score,chondrocyte apoptosis rate,and protein levels of Hsp90b1,cleaved Caspase-3,and Bax(all P<0.05).The results indicated that there was a targeted regulatory relationship between miR-485-5p and Hsp90b1.Conclusion RRE may inhibit the expression of Hsp90b1 by up-regulating miR-485-5p,thereby inhibiting chondrocyte apoptosis in the rabbit model of KOA.
Animals ; Rabbits ; Apoptosis/drug effects* ; Chondrocytes/pathology* ; Osteoarthritis, Knee/drug therapy* ; MicroRNAs/metabolism* ; Rehmannia/chemistry* ; Disease Models, Animal ; Tumor Necrosis Factor-alpha/blood* ; Plant Extracts/pharmacology* ; Interleukin-6/blood* ; HSP90 Heat-Shock Proteins/metabolism* ; Male ; Drugs, Chinese Herbal/pharmacology*

Mitochondrial encephalomyopathy is a multisystemic metabolic disorder caused by mutations in mitochondrial or nuclear genes. It commonly presents with stroke-like episodes or myopathy as initial symptoms. This paper reports a young male patient with mitochondrial encephalomyopathy whose early and prominent clinical manifestation was refractory shock, without typical neurological symptoms. The patient initially presented with abdominal pain and lower limb weakness, followed by severe hypotension requiring high-dose vasopressors to maintain blood pressure. His lactate level peaked at 20 mmol/L. After 10 days of symptomatic and supportive treatment, his hypotension resolved; lactate levels returned to normal by day 22. One month later, he still had difficulty weaning from mechanical ventilation and exhibited persistent limb weakness. Genetic testing of the biceps brachii revealed an m.3271T>C mutation in the mitochondrial tRNA gene. Mitochondrial encephalomyopathy may initially present with severe circulatory dysfunction. In patients with lactic acidosis not related to hypoperfusion, mitochondrial disease should be considered, and genetic testing of muscle or other peripheral tissues may improve diagnostic yield.
Humans ; Male ; Mitochondrial Encephalomyopathies/genetics* ; Mutation ; Shock/etiology*

Wunderlich Syndrome is a rare potentially life-threatening phenomenon that involves spontaneous non-traumatic retroperitoneal hemorrhage. At present, identifying the course of conservative management in these patients, especially in pregnancy, has not been clinically established. Presented here is a known case of Tuberous Sclerosis Complex with a Bilateral, 10cm Angiomyolipoma in a 31-year-old female, initially managed with active surveillance. At 27 weeks of pregnancy, she presented with a sudden onset of left flank pain with a hematocrit of 22%. Anemia was corrected with blood transfusions. A contrast-enhanced MRI of the abdomen showed a large subcapsular perirenal hematoma of the left kidney. Renal angioembolization of the bleeding segmental renal artery was done. The patient was conservatized until 37 weeks of pregnancy and underwent cesarean section delivery.

Four months after angioembolization, she had a recurrence of the left flank pain associated with gross hematuria and hypovolemic shock. The patient underwent emergency renal exploration of the left kidney via a transabdominal approach. Three liters of hemoperitoneum and a large expanding left retroperitoneal hematoma were noted intraoperatively. Early vascular control before nephrectomy of the left kidney was done. The postoperative course was unremarkable and the patient was discharged with improved condition.

This case displays a unique course in the management of a bleeding angiomyolipoma especially during pregnancy. Renal angioembolization can aid in achieving the age of viability in pregnancy. However, close monitoring for rebleeding should be kept in mind. A lower threshold for conservative management should be utilized when patients have a previous history of bleeding.

Human ; Female ; Adult: 25-44 Yrs Old ; Abdomen ; Anemia ; Angiomyolipoma ; Arteries ; Blood ; Blood Transfusion ; Cesarean Section ; Conservative Treatment ; Emergencies ; Female ; Flank Pain ; Hematocrit ; Hematoma ; Hematuria ; Hemoperitoneum ; Hemorrhage ; History ; Hypovolemia ; Insemination, Artificial, Heterologous ; Kidney ; Life ; Nephrectomy ; Pain ; Patients ; Pregnancy ; Recurrence ; Renal Artery ; Research Report ; Sclerosis ; Shock ; Syndrome ; Tuberous Sclerosis ; Watchful Waiting

OBJECTIVES: To detect prfA and hly toxin genes of Listeria monocytogenes using polymerase chain reaction (PCR) and colloidal gold technology. METHODS: L. monocytogenes DNA was extracted by boiling method. With prfA and hly of L. monocytogenes as the target genes, the 5' ends of upstream and downstream primers of prfA gene were labeled with 6-FAM and biotin, and the 5' ends of upstream and downstream primers of hly gene were labeled with digoxin and biotin, respectively, to establish the toxin gene detection method. Using cloning transformation, sequencing analysis, cloning of positive control products, the detection kid was developed and its specificity, sensitivity, reproducibility and stability were tested, followed by verification with sample testing. RESULTS: The concentration of L. monocytogenes DNA extracted by boiling method was 148.81±0.97 ng/μL, and the A₂₆₀/A₂₈₀ ratio ranged from 1.8 to 2.0. The PCR products showed a 100% homology with the gene sequences in GenBank database after cloning, transformation and sequencing. The colloidal gold strip yielded positive results only for L. monocytogenes samples without cross-reactions with Staphylococcus aureus, Escherichia coli or Bacillus cereus, and its minimum detection limit was 10^-2 ng/μL, demonstrating a 10-fold greater sensitivity of the test than agarose gel electrophoresis. The test also showed good reproducibility of the results when performed by different operators with good stability of the test strips after storage for 6 to 12 months. The test results showed that this kit could accurately and quickly detect L.monocytogenes in the test samples. CONCLUSIONS The detection kit developed in this study can simultaneously detect prfA and hly toxin genes of L. monocytogenes with good specificity, sensitivity, reproducibility and stability for use in food safety inspection.
Listeria monocytogenes/isolation & purification* ; Gold Colloid ; Bacterial Toxins/genetics* ; Polymerase Chain Reaction/methods* ; Hemolysin Proteins/genetics* ; Bacterial Proteins/genetics* ; DNA, Bacterial/genetics* ; Food Microbiology ; Heat-Shock Proteins

OBJECTIVES: To investigate the protective effects of dexmedetomidine (DEX) against heat stress (HS)-induced oncosis in human skeletal muscle cells (HSKMCs) and its underlying mechanisms. METHODS: A HSKMC model of HS-induced oncosis were established by 43 ℃ water bath for 4 h, and the effects of treatments with 30 μmol/L DEX, ML385 (a Nrf2 inhibitor) +DEX, si-Nrf2+HS, and si-Nrf2+DEX prior to modeling on cell viability was assessed using CCK-8 assay. Oncosis characteristics were evaluated using transmission electron microscopy and Annexin V-FITC/PI flow cytometry. The oxidative stress markers (GSH, GSH-Px, MDA, SOD and ROS), mitochondrial membrane potential, energy metabolism, and inflammatory cytokines (TNF-α, IL-6 and IL-1β) in the cells were quantified using standard kits, and the expressions of porimin, caspase-3 and Nrf2 pathway proteins were analyzed using Western blotting and qRT-PCR. RESULTS: HS induced typical oncotic features in HSKMCs including organelle swelling and cytoplasmic vacuolization. DEX pretreatment significantly attenuated these changes, reduced Annexin V⁺/PI⁺ cell ratio and cellular porimin expression, and lowered the levels of ROS and MDA while restoring GSH and SOD levels. DEX pretreatment also significantly increased the mitochondrial membrane potential and ATP level, upregulated the expressions of Nrf2, p-Nrf2, HO-1 and NQO1, and suppressed the expressions of TNF-α, IL-6 and IL-1β. The protective effects of DEX were obviously attenuated by interventions with ML385 or si-Nrf2. CONCLUSIONS DEX mitigates HS-induced HSKMC oncosis by activating the Nrf2/HO-1 pathway to relieve oxidative stress, mitochondrial dysfunction, and inflammatory responses.
Humans ; Dexmedetomidine/pharmacology* ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress/drug effects* ; Heat-Shock Response/drug effects* ; Signal Transduction/drug effects* ; Membrane Potential, Mitochondrial ; Muscle, Skeletal/cytology* ; Heme Oxygenase-1/metabolism* ; Apoptosis/drug effects*

OBJECTIVES: To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress. METHODS: Twenty male SD rats were randomized equally into control group and heat stress group. After exposure to 32 ℃ for 2 weeks in the latter group, the rats were examined for histopathological changes and Bmal1 expression in the thoracic aorta using HE staining and immunohistochemistry. In the cell experiments, cultured rat thoracic aortic endothelial cells (RTAECs) were incubated at 40 ℃ for 12 h with or without prior transfection with a Bmal1-specific small interfering RNA (si-Bmal1) or a negative sequence. In both rat thoracic aorta and RTAECs, the expressions of Bmal1, the cell cycle proteins CDK1, CDK4, CDK6, and cyclin B1, and apoptosis-related proteins Bax and Bcl-2 were detected using Western blotting. TUNEL staining was used to detect cell apoptosis in rat thoracic aorta, and the changes in cell cycle distribution and apoptosis in RTAECs were analyzed with flow cytometry. RESULTS: Compared with the control rats, the rats exposed to heat stress showed significantly increased blood pressures and lowered heart rate with elastic fiber disruption and increased expressions of Bmal1, cyclin B1 and CDK1 in the thoracic aorta (P<0.05). In cultured RTAECs, heat stress caused significant increase of Bmal1, cyclin B1 and CDK1 protein expression levels, which were obviously lowered in cells with prior si-Bmal1 transfection. Bmal1 knockdown also inhibited heat stress-induced increase of apoptosis in RTAECs as evidenced by decreased expression of Bax and increased expression of Bcl-2. CONCLUSIONS Heat stress upregulates Bmal1 expression and causes alterations in expressions of cyclins to trigger apoptosis of rat thoracic aorta endothelial cells, which can be partly alleviated by suppressing Bmal1 expression.
Animals ; ARNTL Transcription Factors/genetics* ; Male ; Aorta, Thoracic/metabolism* ; Rats ; Rats, Sprague-Dawley ; Endothelial Cells/metabolism* ; Apoptosis ; Cells, Cultured ; Heat-Shock Response ; Cyclin B1/metabolism* ; CDC2 Protein Kinase/metabolism* ; Cyclins/metabolism* ; RNA, Small Interfering ; bcl-2-Associated X Protein/metabolism*