Neuroprotective effects of pravastatin in cerebral venous infarction in a rat model

The biological efficacy of Apelin against focal transient cerebral ischemia-reperfusion injury. A systematic review and meta-analysis of animal studies

BACKGROUND

Apelin has been extensively studied, and emerging experimental evidence suggests that Apelin may have effects on stroke by reducing infarct volume and neurological deficits, inhibiting the apoptosis process and reducing brain water content. However, the credibility of the evidence is uncertain. Thus, we aimed to perform a systematic review and meta-analysis to evaluate preclinical studies that used Apelin for the treatment of transient focal cerebral ischemia.

METHODS

Electronic bibliographic databases including PubMed, EMBASE, Scopus, and Google Scholar were searched for finding relevant studies from January 2000 to July 2023. The methodological quality and risk of bias scores for animal studies were calculated based on the CAMARADES and the SYRCLE's RoB tools, respectively. The effect sizes were assessed using Comprehensive Meta-Analysis (CMA) software.

RESULTS

A total of twelve eligible studies were used for the systematic review and meta-analysis. The median scores of study quality and risk of bias were 7.5 out of 10, and 5 out of 10, respectively. Apelin treatment effectively decreased infarct volume (primary outcome) [Hedges' g = 2.72, 95 % CI (1.93, 3.51), p < 0.001], neurological deficit [Hedges' g = 1.76, 95 % CI (0.96, 2.55), p < 0.001], cleaved caspase 3 [Hedges' g = 2.16, 95 % CI (0.87, 3.44), p = 0.001], and apoptotic cell number [Hedges' g = 4.07, 95 % CI (1.25,6.89), p = 0.005] compared with the control group. According to subgroup analysis, more notable neuroprotective effects were observed with intravenous administration than with intracerebroventricular (ICV) administration. Moreover, we determined that effect size of infarct volume was markedly related to the species. The combined measurement of two studies demonstrated that Apelin could reduce BCL2 and TNF-α levels as well as brain water content compared with the control group. However, pooled measurement of two studies showed that no relevancy was discovered between CHOP and altering infarct volume.

CONCLUSION

The present meta-analysis was conducted to assess preclinical studies related to Apelin treatment in rodent ischemic stroke. Apelin can exert promising neuroprotective effects by reducing infarct volume, neurological deficit, caspase 3, apoptotic cell number, TNF- α and brain water content and increasing BCL2. The current evidence supports the anti-apoptotic and anti-inflammatory properties of Apelin, but its effectiveness in decreasing CHOP level in animal models of ischemic stroke needs further elucidation. This study was registered within the International Prospective Register of Systematic Reviews (PROSPERO) as number CRD42023460926.

Protein inhibitor of activated STAT1 (PIAS1) alleviates cerebral infarction and inflammation after cerebral ischemia in rats

Background

Ischemic stroke is a severe disorder with high incidence, disability rate and mortality. Multiple pathogenesis mechanisms are involved in ischemic stroke, such as inflammation and neuronal cell apoptosis. Protein inhibitor of activated signal transducer and activators of transcription 1 (PIAS1) plays a crucial role in various biological processes, including inflammation. PIAS1 is also downregulated in ischemia-reperfusion injury and involved in the disease processes. However, the role of PIAS1 in cerebral ischemia is unclear.

Methods

Sprague-Dawley (SD) rats were induced with middle cerebral artery occlusion (MCAO). The role and mechanisms of PIAS1 in ischemic cerebral infarction were explored by Longa test, 2,3,5-triphenyltetrazolium chloride (TTC) staining, Morris water maze (MWM) test, hematoxylin-eosin (HE) staining, quantification of brain water content, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL), Western blot and immunofluorescence assays.

Results

The expression of PIAS1 in MCAO-induced rat was declined compared to sham rats. Overexpression of PIAS1 reduced the Longa neurological scores, the percent of infarction area, the pathological abnormality, the escape latency of swimming and the percent of brain water content, and increased the number of platform crossings and time in the target quadrant in the MCAO-induced rats. Besides, overexpression of PIAS1 decreased the MCAO-induced the contents of IL-1β, IL-6 and TNF-α, but further elevated the concentrations of IL-10 in both sera and brain tissues. Moreover, overexpression of PIAS1 reversed the MCAO-induced apoptosis rate and the relative protein level of Bax, cleaved caspase3 and Bcl-2. Overexpression of PIAS1 also reversed the level of proteins involved in NF-κB pathway.

Conclusion

PIAS1 reduced inflammation and apoptosis, thereby alleviating ischemic cerebral infarction in MCAO-induced rats through regulation NF-κB pathway.

Chemokine‑like receptor 1‑positive cells are present in the odontoblast layer in tooth tissue in rats and humans

Cluster of differentiation (CD)44 is a marker of dental pulp stem cells and is involved in odontoblast differentiation and calcification. Chemokine-like receptor 1 (CMKLR1), also known as chemerin receptor 23 (ChemR23) is also expressed in odontoblasts and dental pulp stem cells and is involved in inflammation suppression and tooth regeneration. Resolvin E1, a bioactive lipid, is a CMKLR1 ligand that mediates the chemerin-CMKLR1 interaction and suppresses pulpal inflammation. The present study clarified the intracellular and tissue localization of CD44 and CMKLR1 by immunohistochemical staining of normal pulp and pulp with pulpitis from 12-week-old male Wistar rat teeth or human teeth. In addition, the localization of CD44 and CMKLR1 in human dental pulp stem cells was observed by immunofluorescence staining. The present study also examined the involvement of resolvin E1 in inhibiting inflammation and calcification by western blotting. CD44- and CMKLR1-positive cells were confirmed in the odontoblast layer in normal dental pulp of rats and humans. CD44 was mainly localized in the cell membrane and CMKLR1 was mainly found in the cytoplasm of human dental pulp stem cells. CMKLR1 was also confirmed in the odontoblast layer in rats and humans with pulpitis but CD44 was not present. Following treatment of dental pulp stem cells with lipoteichoic acid, which imitates Gram-positive bacterial infection, resolvin E1 did not suppress the expression of cyclooxygenase-2 or of the odontoblast differentiation marker, dentin sialophosphoprotein. Furthermore, resolvin E1 induced the differentiation of dental pulp stem cells into odontoblasts even in the presence of the inflammatory stimulus.

SRSF3 Alleviates Ischemic Cerebral Infarction Damage by Activating the PI3K/AKT Pathway

BACKGROUND

Ischemic cerebral infarction is one of cerebrovascular diseases with high incidence, disability rate, and mortality globally, and neuronal cell apoptosis is a crucial cause of brain injury during cerebral infarction.

METHODS

A middle cerebral artery occlusion (MCAO) model was built in Sprague-Dawley rats to simulate ischemic cerebral infarction. An in vitro model of ischemic cerebral infarction was constructed in BV2 cells with the treatment of oxygen-glucose deprivation (OGD). The role and mechanism of serine/arginine-rich splicing factor 3 (SRSF3) in ischemic cerebral infarction were investigated both in animal and cell models.

RESULTS

The expression of SRSF3 was downregulated in MCAO-treated rats. Overexpression of SRSF3 reduced the neurological scores, brain water content, and infarct volume in MCAO-induced rats. Increased apoptosis in neurons accompanied with the abnormal expressions of apoptosis-related proteins in MCAO-induced rats were revised with the upregulation of SRSF3. Also, a diminished cell viability and elevated apoptosis rate were indicated in OGD-induced BV2 cells, which were reversed with the overexpression of SRSF3. Besides, OGD induced an enhancement in the relative protein expression of programmed cell death protein 4 (PDCD4) and a reduction in the relative expression of p-PI3K/PI3K and p-AKT/AKT, which were inverted with the upregulation of SRSF3 in BV2 cells. Overexpression of PDCD4 abolished the role of SRSF3 in cell viability, apoptosis rate, and the level of the PI3K/AKT pathway in OGD-induced BV2 cells.

CONCLUSION

SRSF3 improved ischemic cerebral infarction via PDCD4 in vivo and in vitro, which was closely associated with the PI3K/AKT signaling pathway.