Cytarabine prevents neuronal damage by enhancing AMPK to stimulate PINK1 / Parkin-involved mitophagy in Parkinson's disease model.

Parkinson's disease (PD) is a common age-related neurodegenerative disorder, which may be largely due to the mitochondrial dysfunction and impaired mitophagy. Thus, it is of great importance to seek novel therapeutic strategies for PD targeting mitochondrial function and mitophagy. Cytarabine is a marine-derived antimetabolite used in the treatment of acute leukemia, which is also used in the study of the nervous system. In this study, we found that cytarabine pretreatment significantly inhibited the apoptosis and necrosis in the ROT-induced SH-SY5Y cell PD model and reduced the oxidative stress, as evidenced by the reduced MDA levels and the increased levels of SOD, GSH, and total antioxidant capacity. Cytarabine can also enhance mitochondrial vitality, improve mitochondrial respiratory function, and preserve mitochondrial morphology. Cytarabine also enhanced the expression of the mitophagy-related proteins PINK1, Parkin, VDAC1, and DJ-1, and its actions can be reversed by treatment with AMPK inhibitor - Compound C (CC), suggesting that AMPK activation may be involved in cytarabine-enhanced mitophagy. Furthermore, cytarabine can also ameliorate the motor symptoms in the MPTP-induced PD-like mice model, and attenuate the neuropathy in the substantia nigra (SN) of PD mice, while Compound C antagonized cytarabine's beneficial effects. In summary, marine-derived compound cytarabine could resist neurological damage both in vitro and in vivo by activating AMPK to increase PINK1/Parkin-induced mitophagy, serving as a promising disease modulator for treating neurodegenerative disease.

Neuroprotective effects of polyphyllin VI against rotenone-induced toxicity in SH-SY5Y cells.

BACKGROUND: A substantial body of evidence is drawing connections between Parkinson's disease (PD) and the phenomena of oxidative stress and mitochondrial dysfunction. Polyphyllin VI (PPVI), an active compound found in Rhizoma Paridis-commonly known as Chonglou (CL) in China, has been identified for its various pharmacological properties, including anti-tumor and anti-inflammatory effects. OBJECTIVE: In the present study, an in vitro model of PD was established by treating SH-SY5Y cells with rotenone (ROT), to evaluate the potential neuroprotective effects of polyphyllin VI and its underlying mechanism. METHODS: SH-SY5Y cells were treated with ROT to establish an in vitro model of PD. The effects of polyphyllin VI on cell viability were assessed using the resazurin assay. Cell morphology was examined using a microscope. The YO-PRO-1/PI was used to detect apoptosis. Mito-Tracker Red CMXRos, Mito-Tracker Green, and JC-1 were used to detect the effects of polyphyllin Ⅵ on mitochondrial viability, morphology, and function. Oxidative stress-related marker detection kits were used to identify the effects of polyphyllin VI on oxidative stress. Western blot analysis was employed to investigate the signaling pathways associated with neuroprotection. RESULTS: PPVI increased ROT-induced SH-SY5Y cell viability and improved ROT-induced cellular morphological changes. PPVI ameliorated ROT-induced oxidative stress status, and attenuated mitochondrial function and morphological changes. PPVI may exert neuroprotective effects through FOXO3α/CREB1/DJ-1-related signaling pathways. CONCLUSION: These preliminary findings suggested that PPVI possesses neuroprotective attributes in vitro, and it may be a potential candidate for PD treatment. However, extensive research is necessary to fully understand the mechanisms of PPVI and its effectiveness both in vitro and in vivo.

SIRT1-dependent mitochondrial biogenesis supports therapeutic effects of vidarabine against rotenone-induced neural cell injury.

Parkinson's disease (PD) is the second most common neurodegenerative disease in the world, which is distinguished by the loss of dopaminergic (DA) neurons in the substantia nigra and the formation of intraneuronal. Numerous studies showed that the damage and dysfunction of mitochondria may play key roles in DA neuronal loss. Thus, it is necessary to seek therapeutic measures for PD targeting mitochondrial function and biogenesis. In this study, through screening the purchased compound library, we found that marine derived vidarabine had significant neuroprotective effects against rotenone (ROT) induced SH-SY5Y cell injury. Further studies indicated that vidarabine pretreatment significantly protected ROT-treated SH-SY5Y cells from toxicity by preserving mitochondrial morphology, improving mitochondrial function, and reducing cell apoptosis. Vidarabine also reduced the oxidative stress and increased the expression levels of PGC-1α, NRF1, and TFAM proteins, which was accompanied by the increased mitochondrial biogenesis. However, the neuroprotective effects of vidarabine were counteracted in the presence of SIRT1-specific inhibitor Ex-527. Besides, vidarabine treatment attenuated the weight loss, alleviated the motor deficits and inhibited the neuronal injury in the MPTP induced mouse model. Thus, vidarabine may exert neuroprotective effects via a mechanism involving specific connections between the SIRT1-dependent mitochondrial biogenesis and its antioxidant capacity, suggesting that vidarabine has potential to be developed into a novel therapeutic agent for PD.

HOXA13, Negatively Regulated by miR-139-5p, Decreases the Sensitivity of Gastric Cancer to 5-Fluorouracil Possibly by Targeting ABCC4.

PURPOSE: Chemoresistance remains a major challenge in the therapy of gastric cancer (GC). The homeobox (HOX) gene family has gained attention in carcinogenesis and chemoresistance. Here, this study aimed to explore the mechanism of HOXA13 in GC chemoresistance. METHODS: Quantitative real-time PCR (qRT-PCR) and Western blot were used to evaluate the expression of HOXA13 in GC tissues. The Kaplan-Meier plotter database was mined for prognosis analysis of GC patients with different HOXA13 expression receiving 5-Fluorouracil (5-FU) therapy. The effects of HOXA13 on sensitivity of GC cells to 5-FU were investigated by Cell Counting Kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU) incorporation, flow cytometry and experiment in vivo. RNA-Sequencing analysis was performed to explore the underlying mechanism of HOXA13-mediated 5-FU resistance in GC. Chromatin immunoprecipitation (ChIP) and rescue experiments were applied to determine the relationship between HOXA13 and ABCC4. Luciferase reporter assay was performed to assess interaction of miR-139-5p and HOXA13. RESULTS: HOXA13 was upregulated in GC and its high expression was associated with poor prognosis of GC patients with 5-FU treatment. Overexpression of HOXA13 impaired the inhibitory effects of 5-FU on GC cells proliferation in vitro and vivo, and knockdown of HOXA13 exacerbated 5-FU-induced GC cells apoptosis. Mechanistically, HOXA13, directly targeted by miR-139-5p in GC, might upregulate ABCC4 expression, thereby accentuating 5-FU resistance of GC cells. CONCLUSION: Our study suggests that HOXA13 attenuates 5-FU sensitivity of GC possibly by upregulating ABCC4. Thus, targeting HOXA13 would provide a novel prospective into the potential therapeutic strategy for reversing chemoresistance.

TDO2 Promotes the EMT of Hepatocellular Carcinoma Through Kyn-AhR Pathway.

Tryptophan 2,3-dioxygenase (TDO2), an enzyme involved in tryptophan (Trp) metabolism has been linked with some malignant traits of various cancers. Kyn, the main product of Trp metabolism pathway catalyzed by TDO2 and indoleamine 2,3-dioxygenase (IDO) in tumor cells, was also demonstrated to activate aryl hydrocarbon receptor (AhR), which may regulate cancer growth and invasion in some malignancies. However, whether TDO2 participates in the metastasis and invasion of HCC has not been explored before. The underlying mechanism played by TDO2 in this process still requires further investigation. Here, we demonstrated that overexpression of TDO2 correlates with advanced stage or malignant traits in HCC patients. Knockdown or inhibition of TDO2 suppressed the migration and invasion of HCC cells in vitro and in vivo. Epithelial to mesenchymal transition (EMT) is an essential program happened in the initial phase of cancer metastasis. We found that in HCC cells, TDO2 promoted the EMT process evidenced by altered levels of biomarkers for EMT. Mechanically, TDO2 regulated the Kyn production in HCC cell via activated aryl hydrocarbon receptor (AhR). Together, these results indicate that TDO2 promotes the EMT of hepatocellular carcinoma through activating Kyn-AhR pathway, thereby participating in the metastasis and invasion of HCC.

HOXA10 induces BCL2 expression, inhibits apoptosis, and promotes cell proliferation in gastric cancer.

Homeobox A10 (HOXA10) has been implicated critical for the promotion of carcinogenesis, but the underlying mechanism between HOXA10 and malignant gastric cancer (GC) phenotype remains elusive. In the present study, we analyzed and validated that HOXA10 and BCL2 expressions were elevated both at the mRNA and protein levels in GC tissues. Upregulated HOXA10 promoted GC cell proliferation with reduced apoptosis in vitro and accelerated GC tumor growth in vivo. Bioinformatics analysis and quantitative real-time polymerase chain reaction (qRT-PCR) experiment inferred that HOXA10 might upregulate the expression of BCL2. By performing western blot, chromatin immunoprecipitation and quantitative PCR (ChIP-qPCR), and rescue experiment, we found that HOXA10 might bind to BCL2 promoter region, induce its expression, and thus inhibit intrinsic apoptosis pathway. Moreover, higher expression of HOXA10 and BCL2 predicted poor overall survival (OS) in GC patients. In summary, our study indicated that HOXA10 was upregulated in GC, and that HOXA10 might promote cell proliferation by elevating BCL2 expression and inhibiting apoptosis.

Elevated HOXA13 expression promotes the proliferation and metastasis of gastric cancer partly via activating Erk1/2.

PURPOSE: HOXA13 is a transcription factor of the Homeobox (HOX) gene family, which is highly evolutionarily conserved. HOXA13 is upregulated and associated with oncogenic properties in some cancers. Here, we studied the potential mechanism of HOXA13-mediated proliferation and metastasis in gastric cancer (GC). METHODS: Quantitative real-time PCR, Western blot, and immunohistochemistry were used to detect HOXA13 expression levels in GC. In vitro and in vivo assays were performed to investigate the function of HOXA13 in GC cell proliferation, migration, and invasion. RNA-Seq transcriptome analysis was performed to study the underlying mechanism of HOXA13-mediated aggressiveness in GC. RESULTS: HOXA13 mRNA and protein expression levels were upregulated in GC tissues. According to Cell Counting Kit-8 and colony formation assays, we found that HOXA13 over-expression promoted proliferation. Flow cytometry analysis showed that HOXA13 overexpression or knockdown led to G1-S phase transition or G1 phase arrest, respectively. Western blot analysis results showed that HOXA13 overexpression increased cyclin D1 expression, while knockdown decreased its expression. Wound healing and transwell assay results demonstrated that HOXA13 overexpression promoted the migration and invasion of GC cells. Western blot analysis results also showed that HOXA13 overexpression upregulated N-cadherin and vimentin and downregulated E-cadherin, while HOXA13 knockdown led to the opposite results, indicating that HOXA13 might participate in epithelial to mesenchymal transition. These results were verified in vivo by tumor xenograft and metastasis assays. Mechanistically, using RNA-Seq transcriptome analysis, we found that Erk1/2 activation played an important role in HOXA13-induced GC progression. CONCLUSION: Our results show that HOXA13 plays an important role in GC development. HOXA13 overexpression promotes proliferation and metastasis partly via activation of Erk1/2 in GC. Thus, HOXA13, together with Erk1/2, may be promising targets for novel anticancer strategies.

New rubrolides from the marine-derived fungus Aspergillus terreus OUCMDZ-1925.

Two new rubrolides, rubrolides R (1) and S (2), were isolated from the fermentation broth of the marine-derived fungus Aspergillus terreus OUCMDZ-1925. Their structures were elucidated on the basis of spectroscopic analysis and X-ray single crystal diffraction. Compound 1 showed comparable or superior antioxidation against 2,2'-azino-di(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radicals to those of trolox and ascorbic acid with an IC50 value of 1.33 mM. Compound 2 showed comparable or superior anti-influenza A (H1N1) virus activity to that of ribavirin with an IC50 value of 87.1 µM. Both compounds 1 and 2 showed weak cytotoxicity against the K562 cell line with IC50 values of 12.8 and 10.9 µM, respectively.