The Immediate Intramedullary Nailing Surgery Increased the Mitochondrial DNA Release That Aggravated Systemic Inflammatory Response and Lung Injury Induced by Elderly Hip Fracture

Combined Systemic Immune-inflammatory Index (SII) and Geriatric Nutritional Risk Index (GNRI) predict survival in elderly patients with hip fractures: a retrospective study

PURPOSE

The Systemic Immune-inflammatory Index (SII) and Geriatric Nutritional Risk Index (GNRI) have undergone comprehensive examination and validation in forecasting the outcomes of diverse medical conditions. Nevertheless, the correlation between the combined use of GNRI and SII metrics and hip fractures has yet to be elucidated. This study aimed to determine whether the amalgamation of SII and GNRI scores constitutes an independent prognostic factor for elderly patients with hip fractures.

METHODS

We conducted a retrospective analysis of elderly patients admitted to our facility with hip fractures, encompassing both femoral neck and intertrochanteric fractures. Demographic information, experimental parameters, and postoperative complications were systematically recorded. The Geriatric Nutritional Risk Index (GNRI) and Systemic Immunoinflammatory Index (SII) were meticulously computed. Receiver operating characteristic (ROC) curves were generated, and optimal cutoff values for each parameter were determined. Subsequently, a multivariate Cox regression analysis was employed to assess the predictive utility of the SII-GNRI score in relation to 1-year postoperative mortality among elderly patients with hip fractures.

RESULTS

In a study involving 597 patients, 90 of whom experienced mortality within 1 year, it was observed that the SII-GNRI score in the group of patients who passed away was significantly higher compared to the group that survived. Following a multifactorial adjustment, it was established that a high SII-GNRI score served as an independent predictor of 1-year all-cause mortality in older patients with hip fractures. In addition to the SII-GNRI score, factors such as length of hospital stay, CCI > 2, and blood transfusion were also identified as independent risk factors for survival. Notably, the incidence of postoperative complications in patients with high SII-GNRI scores was significantly greater than in patients with low scores.

CONCLUSION

The SII-GNRI score proves valuable in predicting the 1-year survival rate for elderly patients with hip fractures who have undergone surgery.

The impact of preoperative single low-dose dexamethasone on in-hospital prognosis in geriatric intertrochanteric fracture patients: Analysis of secondary outcomes in a randomized controlled trial

BACKGROUND

Intertrochanteric fracture in the geriatric population is associated with poor prognosis, which may be attributed to consistent stress and the systemic inflammatory response. Dexamethasone is an exogenous glucocorticoid commonly used in clinical practice for broad anti-inflammatory action. The purpose is to investigate whether a single preoperative low-dose dexamethasone can improve the in-hospital prognosis in geriatric intertrochanteric fracture patients undergoing internal fixation surgery.

METHODS

Between June 2020 and October 2022, 219 eligible patients with intertrochanteric fractures were in this study. After meeting the inclusion and exclusion criteria, 160 patients were randomly allocated to the dexamethasone or placebo groups (80 patients who are geriatric with an intertrochanteric fracture in each group). The patients in the dexamethasone group received 10 mg (2 mL) of dexamethasone intravenously, whereas the patients in the placebo group received 2 mL of saline intravenously within 30 minutes before being sent to the operating room. The efficacy-related outcomes (the first bed-chair transfer ability, in-hospital mortality, and length of stay) and safety-related outcomes (infection events and hyperglycemia) were collected for analysis.

RESULTS

There were no significant differences in the baseline characteristics between the 2 groups. The dexamethasone group had a significantly higher rate of the first bed-chair transfer than the placebo group (65.0% [52/80] vs 48.8% [39/80], relative risk = 1.46, 95% confidence interval = 1.02 to 2.11; P = .038). One patient in the dexamethasone group and 7 patients in the placebo group died during hospitalization (1.3% [1/80] vs 8.8% [7/80], relative risk = 0.92, 95% confidence interval = 0.86 to 0.99; P = .07). No differences were found in the length of stay, infections, and hyperglycemia between the 2 groups.

CONCLUSION

A single preoperative low-dose of dexamethasone can improve the in-hospital prognosis (increase the ability of the first bed-chair transfer and potentially decrease the in-hospital mortality) in geriatric intertrochanteric fracture patients after internal fixation surgery.

Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune inflammation index (SII) to predict postoperative pneumonia in elderly hip fracture patients

PURPOSE

Investigate the association between the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) about the presence of postoperative pneumonia (POP) in geriatric patients with hip fractures. Compare the predictive value of these biomarkers for POP and assess their potential for early detection of POP.

METHODS

We retrospectively included elderly patients with hip fractures who underwent surgical treatment at our institution. POP was diagnosed according to the guidelines provided by the American Thoracic Society. We collected neutrophil, lymphocyte, and platelet counts upon admission to calculate the NLR, PLR, and SII. Receiver operating characteristic curves were utilized to establish the optimal cutoff values for each index. Multivariate logistic regression analysis and propensity score matching analysis were utilized to assess the independent association between each index and POP after adjusting for demographic, comorbidity, and surgery-related variables.

RESULTS

The study included a total of 1199 patients, among whom 111 cases (9.26%) developed POP. NLR exhibited the highest predictive value for POP in elderly patients with hip fractures compared to PLR and SII (AUC = 0.648, 95% CI 0.594-0.701). A high NLR, using the optimal cutoff value of 5.84, was significantly associated with an increased incidence of POP (OR = 2.24, 95% CI 1.43-3.51). This finding remained statistically significant even after propensity score matching (OR = 2.04, 95% CI 1.31-3.20).

CONCLUSIONS

Among the three inflammatory/immune markers considered, the NLR demonstrates the highest reliability as a predictor for POP in elderly patients with hip fractures. Therefore, it serves as a valuable tool for early identification.

Mortality in patients with trochanteric hip fractures (AO/OTA 31-A) treated with sliding hip screw versus intramedullary nail: A retrospective national registry study of 9547 patients from the Danish Fracture Database

BACKGROUND

Whether trochanteric hip fractures (AO/OTA 31-A) should be treated with an intramedullary nail (IMN) or sliding hip screw (SHS) is debated. Recent studies suggest an association between IMN and excess mortality rates compared to SHS, but higher quality studies fail to show this association. Furthermore, there is an increased usage of IMN with sparse evidence supporting this rise. Our aim was to compare mortality rates between IMN and SHS in patients with AO/OTA 31-A fractures. Secondarily, to investigate choice of implant in relation to fracture subtype.

METHODS

This national registry study is based on data from the Danish Fracture Database (DFDB). Data were retrieved on patients aged ≥65 years treated for a non-pathological AO/OTA type 31-A fracture with IMN or SHS from January 1, 2012 to December 31, 2018. Data from DFDB were merged with data from the Danish Civil Registration System (CRS) for time of death. Mortality rates were recorded at 30 days, 90 days, and 1 year and presented as crude mortality and adjusted for age, gender, ASA-class, and AO/OTA-subtype.

RESULTS

A total of 9,547 patients were included. The mean age was 83 years, 69% were female, and 55% were ASA-class 3-5. We found higher mortality rates for IMN-patients at 30 days, 90 days, and 1 year. The crude relative mortality risk for IMN was also significantly higher at both 30 days (1.20) and 90 days (1.11). Adjusted relative mortality risk for IMN was 1.12 [0.96; 1.31] at 30-days, 1.03 [0.91; 1.17] at 90-days, and 1.01 [0.92; 1.11] at 1 year. Most patients suffered a 31-A2 fracture (56%) and, overall, 74% of patients were treated with IMN.

CONCLUSION

We found significantly increased crude relative mortality risk at 30 days and 90 days in patients treated with IMN. However, when adjusting for confounders the two groups had similar mortality risks. In total, 74% of all patients in this cohort were treated with IMN.

LEVEL OF EVIDENCE

This study has level of evidence: III.

Delirium in Head Trauma: Looking for a Culprit

Head trauma and delirium are two common conditions in the elderly population. They both carry a heavy burden in terms of mortality and morbidity and are associated with one another through several environmental and clinical factors, such as comorbidities, age, and sex. One factor that may play a role in both these conditions is inflammation, which might also represent a link between them. In particular, head trauma can cause both systemic and neuroinflammation, while delirium appears to be precipitated by inflammatory conditions, while also involving a number of inflammatory pathways in its pathogenesis. Interleukin 6 and tumor necrosis factor α are only two of the main actors in this crosstalk, which also involves microglia and immune cells. An indirect proof is that anti-inflammatory drugs have proven effective in reducing post-traumatic delirium, thus demonstrating the importance of inflammation in the pathophysiology of this disease. In this paper, we have revised the available literature exploring the links between inflammation, head trauma and delirium and we will discuss the mechanisms of this relationship, paying particular attention to the possible future implications.

Risk factors and new diagnostic index for deep venous thrombosis of lower extremities in elderly patients with traumatic femoral neck fracture

Purpose

To determine the incidence and risk factors of deep vein thrombosis (DVT) of lower extremities at admission in elderly Chinese patients with femoral neck fracture, and to establish and evaluate a new DVT predictor based on these risk factors.

Methods

Patients who were hospitalized from January 2018 to December 2020 at three independent centers were reviewed. According to the results of lower extremities vascular ultrasound at admission, they were divided into DVT group and non-DVT group. Single and multivariate logistic regression analysis were applied to identify independent risk factors for DVT occurrence, and then a prediction formula for DVT based on the risk factors was developed. The new predictive index of DVT was calculated by the formula. Receiver operating characteristic (ROC) curve analysis was used to determine the diagnostic value of different factors and the new predictive index.

Results

There were 203 elder patients were included in the final analysis after application of the exclusion criteria. Thirty seven patients (18.2%) were diagnosed as DVT by ultrasound, including 33 patients (89.2%) of peripheral type, 1 patient (2.7%) of central type and 3 patients (8.1%) of mixed type.Multivariate logistic regression analysis showed that four factors including injured side, hemoglobin, fibrinogen, d-dimer were the independent risk factors for the incidence of DVT. On this basis, a new formula for DVT predictive factor was constructed: New predictive index = 0.895 * injured side (right = 1, left = 0) + 0.899 * hemoglobin (<109.5 g/L = 1, > 109.5 g/L = 0) + 1.19 * fibrinogen (>4.24 g/L = 1, < 4.24 g/L = 0) + 1.221* d-dimer (>2.4 mg/L = 1, < 2.4 mg/L = 0). The AUC value of this new developed index was 0.735.

Conclusions

This work showed that the incidence of DVT in elderly patients with femoral neck fracture in China was high at admission. New DVT predictive value can be used as an effective diagnosis strategy for evaluation of thrombosis at admission.

Whole-Blood Mitochondrial DNA Copies Are Associated With the Prognosis of Acute Respiratory Distress Syndrome After Sepsis

Acute respiratory distress syndrome (ARDS) is an inflammatory process of the lungs that develops primarily in response to pulmonary or systemic sepsis, resulting in a disproportionate death toll in intensive care units (ICUs). Given its role as a critical activator of the inflammatory and innate immune responses, previous studies have reported that an increase of circulating cell-free mitochondrial DNA (mtDNA) is a biomarker for fatal outcome in the ICU. Here we analyzed the association of whole-blood mtDNA (wb-mtDNA) copies with 28-day survival from sepsis and sepsis-associated ARDS. We analyzed mtDNA data from 687 peripheral whole-blood samples within 24 h of sepsis diagnosis from unrelated Spanish patients with sepsis (264 with ARDS) included in the GEN-SEP study. The wb-mtDNA copies were obtained from the array intensities of selected probes, with 100% identity with mtDNA and with the largest number of mismatches with the nuclear sequences, and normalized across the individual-probe intensities. We used Cox regression models for testing the association with 28-day survival. We observed that wb-mtDNA copies were significantly associated with 28-day survival in ARDS patients (hazard ratio = 3.65, 95% confidence interval = 1.39–9.59, p = 0.009) but not in non-ARDS patients. Our findings support that wb-mtDNA copies at sepsis diagnosis could be considered an early prognostic biomarker in sepsis-associated ARDS patients. Future studies will be needed to evaluate the mechanistic links of this observation with the pathogenesis of ARDS.

The effect of anesthetics on toll like receptor 9

Toll like receptors (TLRs) are critical receptors to respond to danger signals, and their functions are relevant in the perioperative period. We previously reported that volatile anesthetics directly bound to TLR2 and TLR4 and attenuated their functions. Given that TLR9 can respond to mitochondrial DNA, a danger signal that is released upon tissue injury, we examined the role of anesthetics on TLR9 function. Our reporter assay showed that volatile anesthetics isoflurane and sevoflurane increased the activation of TLR9, while propofol attenuated it. TLR9 activation occurs via its dimerization. The dimerization is facilitated by unmethylated cytosine-phosphate-guanine (CpG) DNA as well as DNA containing cytosine at the second position from 5'-end (5'-xCx DNA). Our structural analysis using photoactivable anesthetics and rigid docking simulation showed that isoflurane and sevoflurane bound to both TLR9 dimer interface and 5'-xCx DNA binding site. Propofol bound to the TLR9 antagonist binding site. This is the first illustration that anesthetics can affect the binding of nucleic acids to their receptor. This study sets the foundation for the effect of anesthetics on TLR9 and will pave the way for future studies to determine the significance of such interactions in the clinical setting.

Retrospective Analysis of Geriatric Patients Undergoing Hip Fracture Surgery: Delaying Surgery Is Associated With Increased Morbidity, Mortality, and Length of Stay

Introduction:

Hip fractures are common in elderly patients. However, this population frequently presents with significant medical comorbidities requiring extensive medical optimization.

Methods:

This study sought to elucidate optimal time to surgery and evaluate its effect on postoperative morbidity, mortality, and length of stay (LOS). We performed a retrospective analysis of data collected from 2008 to 2010 on 841 patients who underwent hip fracture surgery. Patients were classified based on time to surgery and were also classified and analyzed according to the American Society of Anesthesiologists (ASA) physical classification system.

Results:

Patients with a delay of greater than 48 hours had a significant increase in overall LOS, postoperative days, and overall postoperative complications. Patients classified as ASA 4 had an odds ratio for postoperative morbidity of 3.32 compared to the ASA 1 and 2 group (P = .0002) and 2.26 compared to the ASA 3 group (P = .0005). Delaying surgery >48 hours was also associated with increased in-hospital mortality compared to 24 to 48 hours (P = .0197). Increasing ASA classification was also associated with significantly increased mortality. Patients classified as ASA 4 had 5.52 times the odds of ASA 1 and 2 (P = .0281) of in-hospital mortality. Those classified ASA 4 had 2.97 times the odds of ASA 3 (P = .0198) of an in-house mortality. Anesthetic technique (spinal vs general) and age were not confounding variables with respect to mortality or morbidity.

Discussion:

Surgical timing and ASA classification were evaluated with regard to LOS, number postoperative days, morbidity, and mortality.

Conclusions:

Delaying surgery >48 hours, especially in those with increased ASA classification, is associated with an increase in overall LOS, postoperative days, morbidity, and mortality. However, rushing patients to surgery may not be beneficial and 24 to 48 hours of preoperative optimization may be advantageous.

The source of cell-free mitochondrial DNA in trauma and potential therapeutic strategies

Mitochondria play a key role in the pathophysiology of post-injury inflammation. Cell-free mitochondrial DNA (cf-mtDNA) is now understood to catalyse sterile inflammation after trauma. Observations in trauma cohorts have identified high cf-mtDNA in patients with systemic inflammatory response syndrome and multiple organ failure as well as following major surgery. The source of cf-mtDNA can be various cells affected by mechanical and hypoxic injury (passive mechanism) or induced by inflammatory mechanisms (active mechanism). Multiple forms of cf-mtDNA exist; mtDNA fragments, mtDNA in microparticles/vesicles and cell-free mitochondria. Trauma to cells that are rich in mitochondria are believed to release more cf-mtDNA. This review describes the current understanding of the mechanisms of cf-mtDNA release, its systemic effects and the potential therapeutic implications related to its modification. Although current understanding is insufficient to change trauma management, focussed research goals have been identified to pave the way for monitoring and manipulation of cf-mtDNA release and effects in trauma.

Specific microRNA signatures responsible for immune disturbance related to hip fracture in aged rats

Background

Hip fracture is commonly associated with an overwhelming inflammatory response, which may lead to high rates of morbidity and mortality in the elderly. MicroRNAs (miRNAs) play important roles in the functions of immune system. However, the association between miRNA dysregulation and immune disturbance (IMD) related to elderly hip fracture is largely unknown.

Methods

In this study, microarray profiling was carried out to evaluate the differential expression patterns of miRNAs in plasma of the aged hip fracture rats with IMD, those without IMD, and normal aged rats, followed by validation using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Genes and signaling pathways of the dysregulated miRNAs related to elderly hip fracture-induced IMD were investigated in silico using Gene Ontology and analysis of Kyoto Encyclopedia of Genes or Genomes.

Results

Dead or moribund rats with hip fracture exhibited significantly reduced TNF-α/IL-10 ratio compared with healthy controls and other hip fracture rats, which were therefore named as hip fracture rats with IMD. Seven serum miRNAs in hip fracture rats with IMD were significantly downregulated. qRT-PCR and in silico analysis revealed that miR-130a-3p likely participated in regulating the hip fracture-induced IMD. Furthermore, Western blot experiment demonstrated that in lung tissue, the reduction of miR-130a-3p was accompanied with the increase of the protein expression of interferon regulatory factor-1 (IRF1) and sphingosine-1-phosphate receptor 1 (SIPR1).

Conclusions

miR-130a-3p desregulation may be associated with elderly hip fracture-induced IMD, which might act as a new potential biomarker for the diagnosis and prognosis of elderly hip fracture-induced IMD and a potential therapeutic target as well.

Early surgery increases mitochondrial DNA release and lung injury in a model of elderly hip fracture and chronic obstructive pulmonary disease

Hip fractures are one of the most common injuries in elderly individuals and are associated with a high incidence of complications and mortality. Clinical guidelines recommend early reparative surgery within 24-48 h from hospital admission; however, it is currently unknown whether this principle of early surgery is applicable for patients with hip fracture and chronic obstructive pulmonary disease (COPD). To investigate the systemic inflammatory response and lung injury as a result early surgery in elderly patients with hip fracture and COPD, a COPD model was created, by daily exposure to cigarette smoke, and evaluated. Rats (5 months of age) were exposed to cigarette smoking for 37 weeks to create a COPD group. Rats not exposed to cigarette smoke formed the control group. All rats experienced hip fracture, which was subsequently treated with surgery at 24 h (early fixation; EF) or 72 h (late fixation; LF) after fracture, respectively. Serum mitochondrial DNA (mtDNA), tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-10 were measured at 2 and 24 h after surgery. Cytokine and myeloperoxidase (MPO) activity in the lung tissue were measured and assessed via bronchoalveolar lavage. The serum mtDNA, IL-6 and IL-10 levels in the control group and in the COPD group increased rapidly at 2 h and peaked at 24 h, while TNF-α levels peaked at 2 h and subsequently decreased. Rats that received EF in the COPD group demonstrated a significant increase of TNF-α (P<0.001 at 2 h), IL-6 (P<0.001 at 2 and 24 h), IL-10 (P=0.010 at 2 h and P=0.001 at 24 h) and mtDNA (P<0.001 at 24 h) compared with the rats that received LF. LF in experimental rats also significantly reduced the severity of MPO activity (P<0.001 and P=0.001) and permeability (P=0.009 and P=0.018) in pulmonary samples at 2 or 24 h, respectively, compared with EF. However, LF in the control group did not demonstrate a significant advantage at reducing MPO and permeability in serum and pulmonary samples. The present study indicated that early surgery increased mtDNA and cytokine release in a model of elderly hip fracture with COPD, and LF may reduce the severity of the inflammatory response and degree of permeability in pulmonary tissues.

Epigallocatechin Gallate Attenuates Hip Fracture-Induced Acute Lung Injury by Limiting Mitochondrial DNA (mtDNA) Release

BACKGROUND To study the protective effects and explore the mechanism of epigallocatechingallate (EGCG) on the hip fracture-induced acute lung injury. MATERIAL AND METHODS Thirty male Sprague-Dawley (SD) rats were randomly divided into the control group, hip fracture group, and hip fracture + EGCG (10 mg/Kg) group. After 24 h, blood samples, bronchoalveolar lavage fluid (BALF), and lung tissue were collected. Serum mitochondrial DNA (mtDNA) was measured by RT-PCR and BALF was used to perform cytological analysis and enzyme-linked immunosorbent assay (ELISA) assay. Lung tissue was used to evaluate the injury level. RESULTS EGCG significantly reduced the hip fracture-induced high level of serum mtDNA (p<0.05). HE staining showed protective effects of EGCG. Lower lung injury score and wet/dry ratio were identified in the hip fracture + EGCG group than in the hip fracture group (p<0.05). We found significantly lower levels of infiltration of inflammatory cells and production of inflammatory cytokines in the BALF of the hip fracture + EGCG group than in the hip fracture group (p<0.05). CONCLUSIONS Our study found that EGCG had protective effects on hip fracture-induced acute lung injury and suggests that EGCG exerts its protective effects through limiting the release of mtDNA. Our results provide a novel pharmacological agent to attenuate hip fracture-induced acute lung injury, as well as a potential theory to better explain the anti-inflammatory property of EGCG.

Plasma mitochondrial DNA levels were independently associated with lung injury in elderly hip fracture patients

INTRODUCTION

Hip fracture in the elderly can induce systemic inflammatory response (SIRS) and lung injury which increases the risk of lung infection and death. Mitochondrial DNA (mtDNA) plays a role in SIRS and lung injury in patients with multi-trauma, and also in patients with hip fractures. This study evaluated the potential value of plasma mtDNA in the early prognosis of lung injury in elderly fracture patients.

METHODS

This study enrolled 156 elderly patients with intertrochanteric fracture. Plasma mtDNA, IL-6, IL-10, prostaglandin E2 (PGE2) levels were measured at admission. Sixty-one and 31 patients were diagnosed with systemic inflammatory response syndrome (SIRS) and lung injury, respectively.

RESULTS

Plasma mtDNA levels were higher in hip fracture patients compared to healthy controls (P<0.001) and significantly higher in the lung injury subgroup compared to the lung injury absent subgroup (P<0.001). MtDNA levels were correlated with the SIRS score (r=0.446, P<0.001), IL-6 (r=0.506, P<0.001), IL-10 (r=0.523, P<0.001), and PGE2 (r=0.360, P<0.001). Logistic regression analysis revealed that plasma mtDNA, IL-6, PGE2 and SIRS score were independent predictors of the risk of lung injury.

CONCLUSION

Plasma mtDNA release induced by hip fracture in elderly patients, might be an early predictor of lung injury in these patients.

Biomarkers for patients with trauma associated acute respiratory distress syndrome

Trauma is a major factor that contributes to the risk for acute respiratory distress syndrome (ARDS). Biomarkers that predict the risk, diagnosis, treatment response and prognosis of ARDS after trauma have been widely investigated. In addition to their applications in clinical diagnosis and treatment, these biomarkers provide important insights into our understanding of the pathogenesis of ARDS. This review begins with a brief introduction regarding the incidence and pathogenesis of trauma-associated ARDS. Then, we focus on reviewing the clinical trials that have been designed to investigate the value of biomarkers in ARDS after trauma. Biomarkers with a confirmed value in ARDS have been organized on the basis of key pathogenic processes that are central to ARDS and are described in detail. Among these, angiopoietin 2 (Ang-2), L-selectin, Clara cell protein 16 (CC16), soluable receptor for advanced glycation end products (sRAGE), Surfactant protein D (SP-D), histones, mtDNAs and some biomarker panels had a certain association with the diagnosis and prognosis of trauma-related ARDS. Further investigations are needed regarding the design of trials, the best sampling approaches and the optimal combinations of the biomarker panels.

Potential Mechanism of Post-Acute Aortic Dissection Inflammatory Responses: The Role of mtDNA from Activated Platelets

BACKGROUND

Acute aortic dissection (AD) is a lethal cardiovascular disease with severe inflammatory complications. Considering the proinflammatory properties of plasma mitochondrial DNA (mtDNA), we postulate that plasma mtDNA from activated platelets may be responsible for post-acute AD inflammatory responses.

METHODS

We consecutively enrolled 68 patients with acute AD as well as matched hypertensive and healthy participants. Blood samples were collected on admission for blood routine tests, mtDNA assay, and inflammatory cytokine analysis. A computed tomography scan was used to evaluate the extent of dissections.

RESULTS

Our results demonstrate that plasma mtDNA, platelet activation, and inflammatory levels were remarkably higher in acute AD patients than in hypertensive or healthy participants. These parameters were also higher in the Stanford A group than in the Stanford B group (p < 0.05). Bivariate correlation analysis demonstrated positive associations between mtDNA and inflammatory levels (tumor necrosis factor-α: r = 0.577; interleukin-6: r = 0.632), mtDNA and platelet activation (r = 0.642), and platelet activation and the extent of dissection (r = 0.635).

CONCLUSION

Our study suggests that acute AD-induced tunica media exposure causes platelet activation, which leads to the initiation of inflammatory responses via the release of mtDNA into the circulation. Our study provides a novel fundamental basis and a potential therapeutic target for the prevention and treatment of post-AD inflammatory responses.

Dopamine D1 receptor agonist A-68930 inhibits NLRP3 inflammasome activation and protects rats from spinal cord injury-induced acute lung injury

STUDY DESIGN

Randomized experimental study.

OBJECTIVES

The study aimed to investigate the therapeutic efficacy and molecular mechanisms of A-68930 in a rat model of spinal cord injury (SCI)-induced acute lung injury (ALI).

SETTING

China.

METHODS

The influences of A-68930 on the pulmonary edema, histological changes, proinflammatory cytokines levels, myeloperoxidase (MPO) activity and NLRP3 inflammasome protein expression were estimated.

RESULTS

SCI significantly promoted NLRP3 inflammasome activation, increased proinflammatory cytokine productions and MPO activity, and induced pulmonary edema and tissue damage in the SCI group as compared with the control group. A-68930 administration significantly inhibited NLRP3 inflammasome activation and reduced inflammatory cytokines levels and MPO activity. Moreover, A-68930 administration attenuated pulmonary edema and histopathology.

CONCLUSION

Our experimental findings indicated that A-68930 exhibited a protective effect on SCI-induced ALI by the alleviations of inflammatory response with the inhibition NLRP3 inflammasome activation 72 h post injury. The present study indicated that A-68930 could be a potentially efficient therapeutic strategy for the treatment of SCI-induced ALI.