GSK-3β Inhibitor Alsterpaullone Attenuates MPP+-Induced Cell Damage in a c-Myc-Dependent Manner in SH-SY5Y Cells

Periplaneta americana L. extract exerts neuroprotective effects by inhibiting endoplasmic reticulum stress via AKT-dependent pathway in experimental models of Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a chronic neurodegenerative disorder that currently has no curable strategies. More and more evidence suggests that endoplasmic reticulum (ER) stress plays an essential role in PD pathogenesis. Periplaneta americana L. (P. americana) is a traditional Chinese medicine with diverse therapeutic properties. This study aims to investigate the neuroprotective effect and underlying mechanism of P. americana in in vitro and in vivo PD models.

METHODS

The exposure of SH-SY5Y cells to 1-methyl-4-phenyl-pyridinium (MPP+) was used as the in vitro PD model. MTT assay, Hoechst staining, Calcein AM-PI staining and flow cytometry were performed to measure the cell viability and apoptosis. DCFH-DA and JC-1 assay were used to measure the intracellular ROS and mitochondrial membrane potential (Δψm), respectively. Western-blot and immunostaining were conducted to detect the expression of key molecules related with ER stress. For the in vivo PD model induced by 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydro-pyridine (MPTP), the motor function of mice was assessed by behavioral tests, the level of TH was examined by western-blot and immunostaining, the expression of key molecules related with ER stress was measured by western-blot.

RESULTS

Periplaneta americana ethanol extract (PAE) concentration-dependently inhibited MPP+-induced cell loss and increased cell viability. PAE also remarkably attenuated ROS accumulation, the decline of Δψm as well as the excessive ER stress. The neuroprotective effects of PAE could be blocked by ROS inducer trimethylamine N-Oxide or ER stress activator tunicaymycin, while the antioxidant N-Acetyl-L-cysteine or ER stress inhibitor sodium 4-phenylbutyrate mimicked the effects of PAE. Furthermore, we found that PAE could activate AKT/GSK3β/β-catenin pathway. The effect of PAE on ROS production, Δψm and ER stress was blocked by AKT inhibitor MK-2206. In in vivo model, PAE significantly improved motor function, prevented dopaminergic neuronal loss and attenuated ER stress in substantia nigra and striatum of MPTP-treated mice. Similarly, the effects of PAE on MPTP-treated mice were also abolished by MK-2206.

CONCLUSIONS

Our results suggest that P. americana exerts neuroprotective effects through inhibiting ER stress via AKT-dependent pathway. Periplaneta americana may represent a promising therapeutic agent for PD treatment and is worthy of further being exploited.

A Diagnostic Model for Parkinson's Disease Based on Anoikis-Related Genes

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease, and its pathological mechanisms are thought to be closely linked to apoptosis. Anoikis, a specific type of apoptosis, has recently been suggested to play a role in the progression of Parkinson's disease; however, the underlying mechanisms are not well understood. To explore the potential mechanisms involved in PD, we selected genes from the GSE28894 dataset and compared their expression in PD patients and healthy controls to identify differentially expressed genes (DEGs), and selected anoikis-related genes (ANRGs) from the DEGs. Furthermore, the least absolute shrinkage and selection operator (LASSO) regression approach and multivariate logistic regression highlighted five key genes-GSK3B, PCNA, CDC42, DAPK2, and SRC-as biomarker candidates. Subsequently, we developed a nomogram model incorporating these 5 genes along with age and sex to predict and diagnose PD. To evaluate the model's coherence, clinical applicability, and distinguishability, we utilized receiver operating characteristic (ROC) curves, the C-index, and calibration curves and validated it in both the GSE20295 dataset and our center's external clinical data. In addition, we confirmed the differential expression of the 5 model genes in human blood samples through qRT-PCR and Western blotting. Our constructed anoikis-related PD diagnostic model exhibits satisfactory predictive accuracy and offers novel insights into both diagnosis and treatment strategies for Parkinson's disease while facilitating its implementation in clinical practice.

Identification of 3-Aryl-1-benzotriazole-1-yl-acrylonitrile as a Microtubule-Targeting Agent (MTA) in Solid Tumors

Recently, a compound derived from recent scientific advances named 34 has emerged as the focus of this research, the aim of which is to explore its potential impact on solid tumor cell lines. Using a combination of bioinformatics and biological assays, this study conducted an in-depth investigation of the effects of 34. The results of this study have substantial implications for cancer research and treatment. 34 has shown remarkable efficacy in inhibiting the growth of several cancer cell lines, including those representing prostate carcinoma (PC3) and cervical carcinoma (HeLa). The high sensitivity of these cells, indicated by low IC50 values, underscores its potential as a promising chemotherapeutic agent. In addition, 34 has revealed the ability to induce cell cycle arrest, particularly in the G2/M phase, a phenomenon with critical implications for tumor initiation and growth. By interfering with DNA replication in cancer cells, 34 has shown the capacity to trigger cell death, offering a new avenue for cancer treatment. In addition, computational analyses have identified key genes affected by 34 treatment, suggesting potential therapeutic targets. These genes are involved in critical biological processes, including cell cycle regulation, DNA replication and microtubule dynamics, all of which are central to cancer development and progression. In conclusion, this study highlights the different mechanisms of 34 that inhibit cancer cell growth and alter the cell cycle. These promising results suggest the potential for more effective and less toxic anticancer therapies. Further in vivo validation and exploration of combination therapies are critical to improve cancer treatment outcomes.

Identification of antimycin A as a c-Myc degradation accelerator via high-throughput screening

c-Myc is a critical regulator of cell proliferation and growth. Elevated levels of c-Myc cause transcriptional amplification, leading to various types of cancers. Small molecules that specifically inhibit c-Myc-dependent regulation are potentially invaluable for anticancer therapy. Because c-Myc does not have enzymatic activity or targetable pockets, researchers have attempted to obtain small molecules that inhibit c-Myc cofactors, activate c-Myc repressors, or target epigenetic modifications to regulate the chromatin of c-Myc-addicted cancer without any clinical success. In this study, we screened for c-Myc inhibitors using a cell-dependent assay system in which the expression of c-Myc and its transcriptional activity can be inferred from monomeric Keima and enhanced GFP fluorescence, respectively. We identified one mitochondrial inhibitor, antimycin A, as a hit compound. The compound enhanced the c-Myc phosphorylation of threonine-58, consequently increasing the proteasome-mediated c-Myc degradation. The mechanistic analysis of antimycin A revealed that it enhanced the degradation of c-Myc protein through the activation of glycogen synthetic kinase 3 by reactive oxygen species (ROS) from damaged mitochondria. Furthermore, we found that the inhibition of cell growth by antimycin A was caused by both ROS-dependent and ROS-independent pathways. Interestingly, ROS-dependent growth inhibition occurred only in the presence of c-Myc, which may reflect the representative features of cancer cells. Consistently, the antimycin A sensitivity of cells was correlated to the endogenous c-Myc levels in various cancer cells. Overall, our study provides an effective strategy for identifying c-Myc inhibitors and proposes a novel concept for utilizing ROS inducers for cancer therapy.

Propionic acid induces alterations in mitochondrial morphology and dynamics in SH-SY5Y cells

Propionic acid (PPA) is used to study the role of mitochondrial dysfunction in neurodevelopmental conditions like autism spectrum disorders. PPA is known to disrupt mitochondrial biogenesis, metabolism, and turnover. However, the effect of PPA on mitochondrial dynamics, fission, and fusion remains challenging to study due to the complex temporal nature of these mechanisms. Here, we use complementary quantitative visualization techniques to examine how PPA influences mitochondrial ultrastructure, morphology, and dynamics in neuronal-like SH-SY5Y cells. PPA (5 mM) induced a significant decrease in mitochondrial area (p < 0.01), Feret's diameter and perimeter (p < 0.05), and in area2 (p < 0.01). Mitochondrial event localiser analysis demonstrated a significant increase in fission and fusion events (p < 0.05) that preserved mitochondrial network integrity under stress. Moreover, mRNA expression of cMYC (p < 0.0001), NRF1 (p < 0.01), TFAM (p < 0.05), STOML2 (p < 0.0001), and OPA1 (p < 0.01) was significantly decreased. This illustrates a remodeling of mitochondrial morphology, biogenesis, and dynamics to preserve function under stress. Our data provide new insights into the influence of PPA on mitochondrial dynamics and highlight the utility of visualization techniques to study the complex regulatory mechanisms involved in the mitochondrial stress response.

Genetic analysis of the LRP10 gene in Chinese patients with Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder characterized by resting tremor, bradykinesia, muscle rigidity, and abnormal gait. The low-density lipoprotein receptor-related protein 10 (LRP10) was recently shown to be a causal gene for PD, and different ethnic cohorts have distinct frequencies and spectrum of LRP10 variants.

METHODS

We sequenced the full coding regions and exon-intron boundaries of LRP10 in 129 patients with sporadic Chinese PD to further investigate the connection of LRP10 with PD in a sample of Chinese patients.

RESULTS

In this study, we identified four potentially pathogenic mutations, including one novel mutation of p.Gly328Asp and three known mutations of p.Cys165Tyr, p.Arg230Trp, and p.Arg661His in four of the 129 Chinese patients with PD.

CONCLUSION

According to our study, the LRP10 gene may attribute to PD pathogenesis.

Comparative proteomics study of mitochondrial electron transport system modulation in SH-SY5Y cells following MPP+ versus 6-OHDA-induced neurodegeneration

Parkinson’s disease (PD) is the second-most common neurodegenerative disease worldwide. Several studies have investigated PD for decades; however, the exact mechanism of disease development remains unknown. To study PD, SH-SY5Y cells are often treated with 6-hydroxydopamine (6-OHDA) or 1-methyl-4-phenylpyridinium (MPP+) to induce PD. To understand the mechanism of PD pathogenesis, we confirmed protein changes between 6-OHDA- and MPP+-treated SH-SY5Y cells via proteomics analysis using liquid chromatography coupled with tandem mass spectrometry. 6-OHDA-treated SH-SY5Y cells showed increased expression of electron transporter-related proteins compared to that in the control group, along with decreased expression in MPP+-treated SH-SY5Y cells. However, both down- and upregulation of electron transporter-related proteins increased mitochondrial dysfunction and apoptosis. These proteins were confirmed via protein–protein interaction network analysis using IPA and STRING to induce mitochondrial dysfunction and apoptosis. Cell-based experiments using flow cytometry verified that apoptosis and mitochondrial membrane potential were increased in both 6-OHDA- and MPP+-treated SH-SY5Y cells. Our results provide new insights into PD pathogenesis, thereby contributing to the understanding of the mechanisms of PD development.

LRP10 Mutations May Correlate with Sporadic Parkinson's Disease in China

LDL receptor-related protein (LRP) 10 was recently identified as a Parkinson's disease gene through genome-wide linkage and sequencing analysis, but its role in Parkinson's disease in various populations is still unclear. The aim of this study was to determine the frequency and spectrum of LRP10 mutations in a cohort of Parkinson's disease patients from mainland China. All LRP10 exons and their flanking intron regions were screened by direct sequencing in 567 unrelated Parkinson's disease patients and 600 unrelated controls. We detected 29 exonic or splicing variants in 79 patients with Parkinson's disease. Five variants (c.A181C:p.I61L, c.C652T:p.Q218X, c.C833T:p.T278I, c.T1592G:p.I531S, c.T1697C:p.L566P) were predicted to be disease-causing or damaging by multiple in silico tools. Our study provides genetic evidence that LRP10 defects may correlate with sporadic Parkinson's disease.

PGK1 inhibitor CBR-470-1 protects neuronal cells from MPP+

The neurotoxin MPP⁺ (1-methyl-4-phenylpyridinium ion) disrupts mitochondrial function leading to oxidative stress and neuronal death. Here we examine whether activation of the Keap1-Nrf2 cascade can protect SH-SY5Y neuroblastoma cells from MPP⁺-induced cytotoxicity. Treatment of SH-SY5Y cells with CBR-470-1, an inhibitor of the glycolytic enzyme phosphoglycerate kinase 1 (PGK1), leads to methylglyoxal modification of Keap1, Keap1-Nrf2 disassociation, and increased expression of Nrf2 responsive genes. Pretreatment with CBR-470-1 potently attenuated MPP⁺-induced oxidative injury and SH-SY5Y cell apoptosis. CBR-470-1 neuroprotection is dependent upon Nrf2, as Nrf2 shRNA or CRISPR/Cas9-mediated Nrf2 knockout, abolished CBR-470-1-induced SH-SY5Y cytoprotection against MPP⁺. Consistent with these findings, PGK1 depletion or knockout mimicked CBR-470-1-induced actions and rendered SH-SY5Y cells resistant to MPP⁺-induced cytotoxicity. Furthermore, activation of the Nrf2 cascade by CRISPR/Cas9-induced Keap1 knockout protected SH-SY5Y cells from MPP⁺. In Keap1 or PGK1 knockout SH-SY5Y cells,CBR-470-1 failed to offer further cytoprotection against MPP⁺. Collectively PGK1 inhibition by CBR-470-1 protects SH-SY5Y cells from MPP⁺ via activation of the Keap1-Nrf2 cascade.