Silencing of CircTRIM25/miR-138-5p/CREB1 axis promotes chondrogenesis in osteoarthritis.

BACKGROUND: Dysregulated circular RNAs (circRNAs) are involved in osteoarthritis (OA) progression. OBJECTIVE: We aimed to explore the effect of hsa_circ_0044719 (circTRIM25) on the ferroptosis of chondrocytes. METHODS: Chondrocytes were treated with interleukin (IL)-1ß to generate cell model. Cellular behaviours were measured using cell counting kit-8, enzyme-linked immunosorbent assay, relevant kits, propidium iodide staining, and immunofluorescence assay. Quantitative real-time polymerase chain reaction was performed to examine the expression of circTRIM25, miR-138-5p, and cAMP responsive element binding protein 1 (CREB1), and their interactions were assessed using luciferase reporter analysis and RNA pull-down assay. RESULTS: CircTRIM25 was upregulated in OA tissues and IL-1ß-stimulated chondrocytes. Knockdown of circTRIM25 facilitated the viability and suppressed ferroptosis and inflammation of IL-1ß-induced cells. CircTRIM25 served as a sponge of miR-138-5p, which directly targets CREB1. Downregulation of miR-138-5p abrogated the effect induced by knockdown of circTRIM25. Furthermore, enforced CREB1 reversed the miR-138-5p induced effect. Moreover, knockdown of circTRIM25 attenuated cartilage injury in vivo. CONCLUSION: Silencing of circTRIM25 inhibited ferroptosis of chondrocytes via the miR-138-5p/CREB axis and thus attenuated OA progression.

P38-DAPK1 axis regulated LC3-associated phagocytosis (LAP) of microglia in an in vitro subarachnoid hemorrhage model.

BACKGROUND: The phagocytosis and homeostasis of microglia play an important role in promoting blood clearance and improving prognosis after subarachnoid hemorrhage (SAH). LC3-assocaited phagocytosis (LAP) contributes to the microglial phagocytosis and homeostasis via autophagy-related components. With RNA-seq sequencing, we found potential signal pathways and genes which were important for the LAP of microglia. METHODS: We used an in vitro model of oxyhemoglobin exposure as SAH model in the study. RNA-seq sequencing was performed to seek critical signal pathways and genes in regulating LAP. Bioparticles were used to access the phagocytic ability of microglia. Western blot (WB), immunoprecipitation, quantitative polymerase chain reaction (qPCR) and immunofluorescence were performed to detect the expression change of LAP-related components and investigate the potential mechanisms. RESULTS: In vitro SAH model, there were increased inflammation and decreased phagocytosis in microglia. At the same time, we found that the LAP of microglia was inhibited in all stages. RNA-seq sequencing revealed the importance of P38 MAPK signal pathway and DAPK1 in regulating microglial LAP. P38 was found to regulate the expression of DAPK1, and P38-DAPK1 axis was identified to regulate the LAP and homeostasis of microglia after SAH. Finally, we found that P38-DAPK1 axis regulated expression of BECN1, which indicated the potential mechanism of P38-DAPK1 axis regulating microglial LAP. CONCLUSION: P38-DAPK1 axis regulated the LAP of microglia via BECN1, affecting the phagocytosis and homeostasis of microglia in vitro SAH model. Video Abstract.

The D-Dimer/Albumin Ratio Is a Prognostic Marker for Aneurysmal Subarachnoid Hemorrhage.

Background: Aneurysmal subarachnoid hemorrhage (aSAH) is a severe neurological event with limited treatment options, and little is known about its pathophysiology. There are few objective tools for predicting outcomes of aSAH patients and further aiding in directing clinical therapeutic programs. This study aimed to determine whether an elevated serum D-dimer/albumin ratio (DAR) reflects disease severity and predicts aSAH outcomes. Methods: We included 178 patients with aSAH. Data included demographics; clinical severity of aSAH (World Federation of Neurological Societies (WFNS) grade and Hunt-Hess grade); levels of D-dimer, albumin, and c-reactive protein (CRP); leukocyte counts on admission; and three-month outcomes. The outcomes were dichotomized into good and poor. The predictive ability of DAR for outcomes was determined using receiver operating characteristic (ROC) curve analysis. Results: Serum DAR showed a positive correlation with disease severity. Univariate analysis revealed that DAR, WFNS grade, Hunt-Hess grade, delayed cerebral infarction (DCI), age, neutrophil-to-lymphocyte ratio (NLR), and CRP/albumin ratio (CAR) were associated with unfavorable outcomes. Multivariate regression analysis further revealed that elevated DAR predicted poor outcomes after adjusting for WFNS grade, Hunt-Hess grade, DCI, age, NLR, and CRP/albumin ratio. Receiver operating characteristic curve analysis revealed that DAR predicted outcomes at a level comparable with NLR and CAR and had superior predictivity than D-dimer alone. Conclusion: DAR is a promising objective tool for aSAH outcome prediction. A high content DAR was associated with disease severity and unfavorable short-term outcomes.

Elevated MFG-E8 in CSF in the Early Stage Indicates Rapid Recovery of Mild Aneurysmal SAH Patients.

Background: Aneurysmal subarachnoid hemorrhage (aSAH) can impair blood perfusion in brain tissue and cause adverse effects. Microglia, which are the inherent immune cells of the brain, significantly activate and play a role in phagocytosis, anti-inflammatory, proinflammatory, and damage repair in this process. Milk fat globule epidermal growth factor 8 (MFG-E8) is the bridging molecule of this process and mediates the activation and biological effects of microglia. Methods: We obtained cerebrospinal fluid (CSF) from patients with aSAH at various times (the third day, seventh day, and ninth day) as well as from patients in the control cohort. MFG-E8 protein levels in CSF were measured by enzyme-linked immunosorbent assay (ELISA). Meanwhile, we evaluated the GCS and GOS of aSAH patients on admission and on the third day, seventh day, ninth day, and at discharge. Then, we analyzed the association between the levels of MFG-E8 and the changes in GCS and GOS. Results: MFG-E8 expression rose in the early stage on the third day and reached equilibrium around day 7 and day 9. The levels of MFG-E8 on the third day were associated with the change in GOS on the seventh day (r = 0.644, p = 0.018) and ninth day (r = 0.572, p = 0.041) compared with admission but were not correlated with the change on day 3 or at discharge. The levels of MFG-E8 were not correlated with any change in GCS. Conclusions: We found that aSAH resulted in an upregulation of MFG-E8 in CSF. Moreover, high MFG-E8 levels in the early stage indicated a rapid recovery of mild aSAH patients.

Long-Term Elevated Siglec-10 in Cerebral Spinal Fluid Heralds Better Prognosis for Patients with Aneurysmal Subarachnoid Hemorrhage.

The presence of aneurysmal subarachnoid hemorrhage (aSAH) is usually accompanied by excessive inflammatory response leading to damage of the central nervous system, and the sialic acid-binding Ig-like lectin 10 (Siglec-10) is a recognized factor being able to modify the inflammatory reaction. To investigate the potential role of Siglec-10 in aSAH, we collected the cerebrospinal fluid (CSF) of control (n = 11) and aSAH (n = 14) patients at separate times and measured the Siglec-10 concentration utilizing the enzyme-linked immunosorbent assay (ELISA) and evaluated the alterations of GOS and GCS during the disease process. In accordance with the STROBE statement, results showed that Siglec-10 in CSF rose quickly in response aSAH attack and then fell back to a slightly higher range above baseline, while it remained at relative high concentration and last longer in several severely injured patients. In general, higher Siglec-10 expression over a longer period usually indicated a better clinical prognosis. This prospective cohort study suggested that Siglec-10 could possibly be used as a biomarker for predicting prognosis of aSAH due to its ability to balance aSAH-induced nonsterile inflammation. Additionally, these findings might provide novel therapeutic perspectives for aSAH and other inflammation-related diseases.

Astrocytic CD24 Protects Neuron from Recombinant High-Mobility Group Box 1 Protein(rHMGB1)-Elicited Neuronal Injury.

Endogenous host-derived molecules named damage-associated molecular patterns (DAMPs) can induce excessive non-sterile inflammatory responses on recognition of specific membrane-tethered receptors. Here in this study, we aimed to explore the role of DAMP molecule HMGB1 in astrocyte-mediated sterile neuroinflammation and the resultant influences on neurons. In vitro cultured astrocytes were challenged with rHMGB1 and then harvested at 6 h, 12 h, 24 h, 36 h, and 48 h, respectively. The astrocytic CD24 expression was determined by quantitative real-time polymerase chain reaction (qPCR), Western blot analysis and immunofluorescence, nuclear factor kappa B (NF-κB) binding activity was detected by electrophoretic mobility shift assay (EMSA), and the proinflammatory factors, tumor necrosis factor-α (TNF-α), and interleukin 1ß (IL-1ß), were measured by qPCR. The neuronal morphology was assessed with phase-contrast microscopy. The results showed that astrocytic mRNA and protein CD24 expression began to rise at 24 h, peaked at 36 h, and remained elevated at 48 h after rHMGB1 stimulation, accompanied with enhanced NF-κB binding activity and augmented expression of TNF-α and IL-1ß. Furthermore, rHMGB1 caused cocultured neuron damage and was aggregated upon CD24 knockdown. Taken together, these novel findings suggested that rHMGB1 could promote astrocytic CD24 expression, the inhibition of which could aggregate neuronal damage.

Efficacy of Liquid Embolic Agent Treatment in Hemorrhagic Peripheral Intracranial Aneurysms: A Single-Center Experience.

Objective: To evaluate the efficacy of liquid embolization agents for treating various hemorrhagic peripheral intracranial aneurysms. Methods: We retrospectively analyzed 38 patients who suffered from hemorrhagic peripheral intracranial aneurysms and were treated with liquid embolization agents. We used the modified Rankin scale for follow-up at 6 months postoperatively, and digital subtraction angiography follow-up was performed 6 months postoperatively. Results: Of the 38 patients (ten of simple peripheral intracranial aneurysms, six of Moyamoya disease (MMD), and 22 of arteriovenous malformation (AVM)), posterior circulation accounted for the most significant proportion (57.9%), followed by anterior circulation (21.1%) and intranidal aneurysms (21.1%). Intraoperative hemorrhage occurred in four cases, postoperative cerebral infarction occurred in four cases, two patients encountered microcatheter retention, and intraoperative thrombosis took place in the basilar artery of a patient with an arteriovenous malformation. A postoperative hemorrhage occurred in only one patient. At 6-month follow-up, 84.2% of patients had good prognosis outcomes, and 13.5% had poor outcomes. Conclusion: Liquid embolization agents are effective for hemorrhagic peripheral intracranial aneurysms; however, safety depends on the subtypes. For peripheral hemorrhagic aneurysms in MMD, the vessel architecture must be carefully evaluated before embolization.

High Expression of PDK4 Could Play a Potentially Protective Role by Attenuating Oxidative Stress after Subarachnoid Hemorrhage.

Pyruvate dehydrogenase (PDH), a key enzyme on the mitochondrial outer membrane, has been found to decrease activity notably in early brain injury (EBI) after subarachnoid hemorrhage (SAH). It has been demonstrated that PDH is associated with the production of reactive oxygen species (ROS) and apoptosis. Hence, in this study, we aimed to determine the cause of the decreased PDH activity and explore the potential role of PDH in EBI. We investigated the expression changes of PDH and pyruvate dehydrogenase kinase (PDK) in vivo and in vitro. Then, we explored the possible effects of PDH and ROS after SAH. The results showed that early overexpression of PDK4 promoted the phosphorylation of PDH, inhibited PDH activity, and may play a protective role after SAH in vivo and in vitro. Finally, we investigated the levels of PDK4 and pyruvate, which accumulated due to decreased PDH activity, in the cerebrospinal fluid (CSF) of 34 patients with SAH. Statistical analysis revealed that PDK4 and pyruvate expression was elevated in the CSF of SAH patients compared with that of controls, and this high expression correlated with the degree of neurological impairment and long-term outcome. Taken together, the results show that PDK4 has the potential to serve as a new therapeutic target and biomarker for assisting in the diagnosis of SAH severity and prediction of recovery.

Human adipose and synovial mesenchymal stem cells improve osteoarthritis in rats by reducing chondrocyte reactive oxygen species and inhibiting inflammatory response.

BACKGROUND: We explored the therapeutic effects of Adipose-derived mesenchymal stem cells (ADMSCs) and Synovial-derived mesenchymal stem cells (SDMSCs) on osteoarthritis (OA). METHODS: SDMSCs and ADMSCs were co-cultured with chondrocytes and stimulated with interleukin (IL)-1ß. An OA model was established on rats by intra-articular injection with ADMSCs and SDMSCs. After 8 weeks, the joint diameter difference was detected, and histological staining was used to observe the pathological changes in cartilage tissue. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expressions of IL-6, tumor necrosis factor (TNF)-α and IL-1ß in joint fluid. The expressions of COL2A1, Aggrecan, Matrix metalloproteinase (MMP)-13, SOX9, IL-6, TNF-α and IL-1ß were detected by qRT-PCR and Western blotting in cartilage tissue. Reactive oxygen species (ROS) content in cells and cartilage tissues was detected by ROS kit. RESULTS: SDMSCs and ADMSCs co-cultured with chondrocytes could reduce MMP-13 expression, increase the expressions of COL2A1, Aggrecan and SOX9, as well as reverse the effects of IL-1ß on promoting ROS content and inflammatory factors levels. After the OA model was established, the injection of ADMSCs and SDMSCs reduced the differences in joint diameter and tissue lesions in OA rats. The OA model led to increased levels of IL-6, TNF-α and IL-1ß in joint fluid and cartilage tissue, while the injection of ADMSCs and SDMSCs inhibited the inflammatory factor levels in OA rats, and increased the expressions of COL2A1, Aggrecan and SOX9 in OA rats. CONCLUSION: ADMSCs and SDMSCs improve osteoarthritis in rats by reducing chondrocyte ROS and inhibiting inflammatory response.

Fucoxanthin Mitigates Subarachnoid Hemorrhage-Induced Oxidative Damage via Sirtuin 1-Dependent Pathway.

Oxidative stress is a key component of the pathological cascade in subarachnoid hemorrhage (SAH). Fucoxanthin (Fx) possesses a strong antioxidant property and has shown neuroprotective effects in acute brain injuries such as ischemic stroke and traumatic brain injury. Here, we investigated the beneficial effects of Fx against SAH-induced oxidative insults and the possible molecular mechanisms. Our data showed that Fx could significantly inhibit SAH-induced reactive oxygen species production and lipid peroxidation, and restore the impairment of endogenous antioxidant enzymes activities. In addition, Fx supplementation improved mitochondrial morphology, ameliorated neural apoptosis, and reduced brain edema after SAH. Moreover, Fx administration exerted an improvement in short-term and long-term neurobehavior functions after SAH. Mechanistically, Fx inhibited oxidative damage and brain injury after SAH by deacetylation of forkhead transcription factors of the O class and p53 via sirtuin 1 (Sirt1) activation. EX527, a selective Sirt1 inhibitor, significantly abated Fx-induced Sirt1 activation and abrogated the antioxidant and neuroprotective effects of Fx after SAH. In primary neurons, Fx similarly suppressed oxidative insults and improved cell viability. These effects were associated with Sirt1 activation and were reversed by EX527 treatment. Taken together, our study explored that Fx provided protection against SAH-induced oxidative insults by inducing Sirt1 signaling, indicating that Fx might serve as a potential therapeutic drug for SAH.

Utility of serum tartrate-resistant acid phosphatase isoform 5b, bone alkaline phosphatase and osteocalcin in osteoporotic fractures in Chinese patients.

BACKGROUND: The goal was to find out the clinical significances of tartrate-resistant acid phosphatase isoform 5b (TRACP 5b), a biomarker of bone resorption, and bone alkaline phosphatase (BAP) and osteocalcin, two markers of bone formation, in evaluating the osteoporotic fracture risk in Chinese patients. METHODS: Thirty six Chinese osteoporotic fracture patients and 32 Chinese healthy subjects were included in the study. Bone mineral density (BMD) of lumbar spine and total body were determined by dual-energy X-ray absorptiometry in all subjects. Fasting blood samples were collected from all subjects and the serum concentrations of TRACP 5b, BAP, and osteocalcin were analyzed with enzyme-linked immunosorbent assay or immunoradiometric assay. RESULTS: With lower BMD, the osteoporotic fracture patients had elevated levels of TRACP 5b and BAP, compared with the healthy controls. No difference in serum osteocalcin level was observed between the fracture patients and the control. CONCLUSIONS: Elevated serum TRACP 5b and BAP, combined with or without increased osteocalcin, are valuable tools for the assessment of osteoporotic fracture risk in Chinese patients.