TNFAIP1 Is Upregulated in APP/PS1 Mice and Promotes Apoptosis in SH-SY5Y Cells by Binding to RhoB

Insights into the Neuroprotective Potential of Epicatechin: Effects against Aβ-Induced Toxicity in Caenorhabditis elegans

Medical therapies to avoid the progression of Alzheimer's disease (AD) are limited to date. Certain diets have been associated with a lower incidence of neurodegenerative diseases. In particular, the regular intake of foods rich in polyphenols, such as epicatechin (EC), could help prevent or mitigate AD progression. This work aims to explore the neuroprotective effects of EC using different transgenic strains of Caenorhabditis elegans, which express human Aβ1-42 peptides and contribute to elucidating the mechanisms involved in the effects of EC in AD. The performed assays indicate that this flavan-3-ol was able to reduce the signs of β-amyloid accumulation in C. elegans, improving motility and chemotaxis and increasing survival in transgenic strain peptide producers compared to nematodes not treated with EC. The neuroprotective effects exhibited by EC in C. elegans could be explained by the modulation of inflammation and stress-associated genes, as well as autophagy, microgliosis, and heat shock signaling pathways, involving the regulation of cpr-5, epg-8, ced-7, ZC239.12, and hsp-16 genes. Overall, the results obtained in this study support the protective effects of epicatechin against Aβ-induced toxicity.

Neuronal-specific TNFAIP1 ablation attenuates postoperative cognitive dysfunction via targeting SNAP25 for K48-linked ubiquitination

BACKGROUND

Synaptosomal-associated protein 25 (SNAP25) exerts protective effects against postoperative cognitive dysfunction (POCD) by promoting PTEN-induced kinase 1 (PINK1)/Parkin-mediated mitophagy and repressing caspase-3/gasdermin E (GSDME)-mediated pyroptosis. However, the regulatory mechanisms of SNAP25 protein remain unclear.

METHODS

We employed recombinant adeno-associated virus 9 (AAV9)-hSyn to knockdown tumor necrosis factor α-induced protein 1 (TNFAIP1) or SNAP25 and investigate the role of TNFAIP1 in POCD. Cognitive performance, hippocampal injury, mitophagy, and pyroptosis were assessed. Co-immunoprecipitation (co-IP) and ubiquitination assays were conducted to elucidate the mechanisms by which TNFAIP1 stabilizes SNAP25.

RESULTS

Our results demonstrated that the ubiquitin ligase TNFAIP1 was upregulated in the hippocampus of mice following isoflurane (Iso) anesthesia and laparotomy. The N-terminal region (residues 1-96) of TNFAIP1 formed a conjugate with SNAP25, leading to lysine (K) 48-linked polyubiquitination of SNAP25 at K69. Silencing TNFAIP1 enhanced SH-SY5Y cell viability and conferred antioxidant, pro-mitophagy, and anti-pyroptosis properties in response to Iso and lipopolysaccharide (LPS) challenges. Conversely, TNFAIP1 overexpression reduced HT22 cell viability, increased reactive oxygen species (ROS) accumulation, impaired PINK1/Parkin-dependent mitophagy, and induced caspase-3/GSDME-dependent pyroptosis by suppressing SNAP25 expression. Neuron-specific knockdown of TNFAIP1 ameliorated POCD, restored mitophagy, and reduced pyroptosis, which was reversed by SNAP25 depletion.

CONCLUSIONS

In summary, our findings demonstrated that inhibiting TNFAIP1-mediated degradation of SNAP25 might be a promising therapeutic approach for mitigating postoperative cognitive decline. Video Abstract.

Knocking down TNFAIP1 alleviates inflammation and oxidative stress in pediatric pneumonia through PI3K/Akt/Nrf2 pathway

BACKGROUND

Pneumonia is an acute respiratory infection with increasing global incidences. Children are more susceptible to pneumonia than adults, and its incidences grow extremely high during peak seasons. Thus, it is necessary to investigate the pathogenesis and molecular mechanism of childhood pneumonia.

METHODS

This study examined the role of tumor necrosis factor alpha-inducible protein 1 (TNFAIP1) in lipopolysaccharide (LPS)-induced pneumonia mice. After LPS exposure, lung function, TNFAIP1 activation, infarction volume, oxidative stress, lung tissue apoptosis ratio, and inflammatory response were assessed by immunohistochemistry staining, hematoxylin and eosin staning, Western blot analysis, terminal deoxynucleotidyl transferase dUTP nick end labelling assay, and enzyme-linked-immunosorbent serologic assay, respectively. The mechanism of TNFAIP1 regulating phosphoinositide 3-kinases (PI3K)-protein kinase B (Akt)-nuclear factor erythroid 2-related factor 2 (Nrf2) pathway was analyzed by Western blot analysis.

RESULTS

TNFAIP1 expression was enhanced in the LPS-induced pneumonia mice but was negatively correlated with the LPS-induced lung injury. Silencing TNFAIP1 alleviated inflammatory response, production of reactive oxygen species (ROS), and cellular apoptosis in LPS-induced pneumonia. Moreover, PI3K/Akt/Nrf2 signaling pathways were predominantly involved in the TNFAIP1-mediated lung injury, which also played a role in the process of LPS-induced pneumonia.

CONCLUSION

This study suggested that TNFAIP1 acted as a negative regulator of acute pneumonia by attenuating inflammatory response, production of ROS, and cellular apoptosis via PI3K/Akt/Nrf2 pathway. The findings suggested that TNFAIP1 is a potential candidate for pneumonia therapy.

LncRNA NKILA Exacerbates Alzheimer's Disease Progression by Regulating the FOXA1-Mediated Transcription of TNFAIP1

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases in the world, which seriously affects AD patients' life quality. Recently, long non-coding RNAs (lncRNAs) have been reported to play a key role in AD pathogenesis, however, the specific mechanism remains unclear. Herein, we aimed to investigate the role of lncRNA NKILA in AD. The learning and memory performance of rats from streptozotocin (STZ)-treated or other treated groups were tested by Morris water maze test. Relative levels of genes and proteins were measured using RT-qPCR and Western blotting. Mitochondrial membrane potential was tested by JC-1 staining. Levels of ROS, SOD, MDA, GSH-Px, and LDH were measured using corresponding commercial kits. Apoptosis was evaluated by TUNEL staining or Flow cytometry assay. RNA Immunoprecipitation (RIP), RNA pulldown, Chromatin immunoprecipitation (ChIP), and dual-luciferase reporter assays were utilized to test the interaction between indicated molecules. STZ treatment caused learning and memory impairment in rats and oxidative stress damage in SH-SY5Y cells. LncRNA NKILA was found to be elevated in the hippocampal tissues of rats and SH-SY5Y cells after STZ exposure. Knockdown of lncRNA NKILA alleviated STZ-induced neuronal damage. Furthermore, lncRNA NKILA could bind to ELAVL1, which regulate the stability of FOXA1 mRNA. Moreover, TNFAIP1 transcription process was controlled by FOXA1, which targeted the promoter of TNFAIP1. In vivo results demonstrated that lncRNA NKILA accelerated STZ-induced neuronal damage and oxidative stress by FOXA1/TNFAIP1 axis. Our findings indicated that knockdown of lncRNA NKILA inhibited the neuronal damage and oxidative stress induced by STZ through the FOXA1/TNFAIP1 axis, thereby alleviating the development of AD, revealing a promising therapeutic axis for AD treatment.

CRISPR/Cas9-Mediated Knockout of tnfaip1 in Zebrafish Plays a Role in Early Development

TNF α-induced protein 1 (TNFAIP1) was first identified in human umbilical vein endothelial cells and can be induced by tumor necrosis factor α (TNFα). Early studies have found that TNFAIP1 is involved in the development of many tumors and is closely associated with the neurological disorder Alzheimer's disease. However, little is known about the expression pattern of TNFAIP1 under physiological conditions and its function during embryonic development. In this study, we used zebrafish as a model to illustrate the early developmental expression pattern of tnfaip1 and its role in early development. First, we examined the expression pattern of tnfaip1 during early zebrafish development using quantitative real-time PCR and whole mount in situ hybridization and found that tnfaip1 was highly expressed in early embryonic development and, subsequently, expression became localized to anterior embryonic structures. To investigate the function of tnfaip1 during early development, we constructed a model of a stably inherited tnfaip1 mutant using the CRISPR/Cas9 system. Tnfaip1 mutant embryos showed significant developmental delays as well as microcephaly and microphthalmia. At the same time, we found decreased expression of the neuronal marker genes tuba1b, neurod1, and ccnd1 in tnfaip1 mutants. Analysis of transcriptome sequencing data revealed altered expression of the embryonic development related genes dhx40, hspa13, tnfrsf19, nppa, lrp2b, hspb9, clul1, zbtb47a, cryba1a, and adgrg4a in the tnfaip1 mutants. These findings suggest an important role for tnfaip1 in the early development of zebrafish.

New Insights into lncRNAs in Aβ Cascade Hypothesis of Alzheimer's Disease

Alzheimer's disease (AD) is the most common type of dementia, but its pathogenesis is not fully understood, and effective drugs to treat or reverse the progression of the disease are lacking. Long noncoding RNAs (lncRNAs) are abnormally expressed and deregulated in AD and are closely related to the occurrence and development of AD. In addition, the high tissue specificity and spatiotemporal specificity make lncRNAs particularly attractive as diagnostic biomarkers and specific therapeutic targets. Therefore, an in-depth understanding of the regulatory mechanisms of lncRNAs in AD is essential for developing new treatment strategies. In this review, we discuss the unique regulatory functions of lncRNAs in AD, ranging from Aβ production to clearance, with a focus on their interaction with critical molecules. Additionally, we highlight the advantages and challenges of using lncRNAs as biomarkers for diagnosis or therapeutic targets in AD and present future perspectives in clinical practice.

Downregulation of TNFAIP1 alleviates OGD/R‑induced neuronal damage by suppressing Nrf2/GPX4‑mediated ferroptosis

TNFα-induced protein 1 (TNFAIP1) serve a role in neurovascular disease. However, the potential role and molecular mechanism of TNFAIP1 in cerebral ischemia-reperfusion (I/R) remains elusive. In the present study, reverse transcription-quantitative PCR and western blotting were used to assess TNFAIP1 mRNA and protein expression levels in PC12 cells. Furthermore, using Cell Counting Kit-8, flow cytometry and western blotting, cell viability and apoptosis were evaluated. Oxidative stress was evaluated using DCFH-DA staining and ELISA was used for assessment of inflammatory factors. Expression of components in the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway and ferroptosis were assessed using western blotting analysis and an iron assay kit. TNFAIP1 expression was significantly upregulated in oxygen glucose deprivation and reperfusion (OGD/R)-injured PC12 cells. However, knocking down TNFAIP1 expression restored PC12 cell viability and decreased apoptosis following OGD/R-challenge. Furthermore, TNFAIP1 silencing significantly suppressed OGD/R-induced oxidative stress and inflammatory damage in PC12 cells. TNFAIP1 knockdown inhibited ferroptosis via activation of the Nrf2 signaling pathway in OGD/R-injured PC12 cells. Erastin treatment reversed the beneficial effects of TNFAIP1 knockdown on PC12 cell viability, apoptosis alleviation, oxidative stress and inflammation following OGD/R treatment. These results suggested that TNFAIP1 knockdown could alleviate OGD/R-induced neuronal cell damage by suppressing Nrf2-mediated ferroptosis, which might lay the foundation for the investigation of targeted-therapy for cerebral I/R injury in clinic.

MicroRNA-223 Attenuates Stretch-Injury-Induced Apoptosis in Brain Microvascular Endothelial Cells by Regulating RhoB Expression

MiR-223 is a miRNA with important functions in apoptosis, carcinogenesis, and inflammation, and it was demonstrated to be over-expressed in brain tissue after traumatic brain injury (TBI). However, few studies have focused on its role in protecting brain microvascular endothelial cells (BMECs). This study evaluated the protective effect of miR-223 on BMECs after stretch injury (SI). bEnd.3 cells (BMECs of mouse) were transfected with overexpressing and blocking lentivirus of miR-223, then were subjected to SI. After immunofluorescence assay, it was demonstrated that miR-223 overexpression significantly rescued the SI-induced loss of ZO-1 (Zonula Occludens 1, tight junction protein) (p < 0.01), while miR-223 blocking exacerbated the loss of ZO-1 (p < 0.05). Flow cytometry confirmed a significant increase in the proportion of apoptotic bEnd.3 cells after SI, and miR-223 overexpression reduced this proportion (p < 0.001). The result of Western blot revealed that miR-223 overexpression significantly reduced the expression of cleaved caspase-3 (cl-caspase 3) (p < 0.05) and RhoB (p < 0.01), while miR-223 blocking increased the expression of these proteins (p < 0.05, p < 0.001). Additionally, knockdown of RhoB significantly reduced the expression of cl-caspase 3 (p < 0.001). These findings suggested that miR-223 can alleviate SI-induced apoptosis of BMECs, and this anti-apoptotic effect is at least partially achieved by inhibiting the expression of RhoB. Moreover, miR-223 may play a role in maintaining the integrity of BBB during TBI.

Formononetin attenuates Aβ25-35-induced adhesion molecules in HBMECs via Nrf2 activation

Brain vascular inflammation plays a crucial role in the pathogenesis of Alzheimer's disease (AD). As a central pathogenic factor in AD, the extracellular buildup of amyloid-β (Aβ) induces brain microvascular endothelial cells activation, impairs endothelial structure and function. Formononetin (FMN) has been reported to protect against Alzheimer's disease (AD) and attenuates vascular inflammation in atherosclerosis. However, its involvement in regulating vascular inflammation of AD has not been investigated. In the study, we found that FMN significantly attenuates Aβ_25-35-induced expression of adhesion molecules, including intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the human brain microvascular endothelial cells (HBMECs), suggesting that FMN inhibits Aβ_25-35-induced brain endothelial cells inflammatory response. Moreover, we observed that FMN attenuates Aβ_25-35-induced translocation of NFκB (p65) into the nucleus of HBMECs, and found that FMN treatment induces Nrf2 expression and attenuates Nrf2-Keap1 association in a dose-dependent manner in HBMECs. Furthermore, we demonstrated that Nrf2 silencing significantly attenuates FMN-reduced NFκB (p65) activation and nuclear translocation. Lastly, our results showed that FMN treatment attenuates Aβ_25-35-induced adhesion of THP-1 cell to endothelial cell monolayer. Collectively, these findings suggest that FMN attenuates Aβ_25-35-induced activation in human brain microvascular endothelial cells, which at least in part was mediated through Nrf2 pathways.

Epigenetic axis of SNHG19/miR-137/TNFAIP1 modulates amyloid beta peptide 25-35-induced SH-SY5Y cytotoxicity

Aims: In this study, the authors hypothesized that, in an in vitro Alzheimer's disease model, the epigenetic axis of SNHG19/hsa-miR-137 functionally regulates amyloid beta peptide 25-35 (Aβ_25-35)-induced SH-SY5Y cytotoxicity. Methods: Dual luciferase activity assay demonstrated that SNHG19 could directly bind hsa-miR-137. In Aβ_25-35-treated SH-SY5Y cells, SNHG19 was upregulated and hsa-miR-137 downregulated. Results: SNHG19 knockdown ameliorated Aβ_25-35-induced SH-SY5Y cytotoxicity, then reversed by secondary hsa-miR-137 downregulation. TNFAIP1 was dynamically regulated by Aβ_25-35 and gene modifications in SH-SY5Y cells. Finally, upregulation of TNFAIP1 reversed the protective effect of SNHG19 knockdown on Aβ_25-35-induced cytotoxicity. Conclusions: The authors concluded that the epigenetic axis of SNHG19/hsa-miR-137/TNFAIP1 may functionally regulate Aβ_25-35-induced SH-SY5Y cytotoxicity, thus making it a potential molecular target for Alzheimer's disease treatment.