bims-lycede 2024-07-07 papers

bims-lycede

Biomed News

on Lysosome-dependent cell death

Issue of 2024‒07‒07
five papers selected by
Sofía Peralta, Universidad Nacional de Cuyo

Two-Step Enrichment Facilitates Background Reduction for Proteomic Analysis of Lysosomes.
A Dual-Labeling Molecule for Efficient Drug Discovery of Mitochondrial-Lysosomal Interactions.
Dehydroandrographolide ameliorates doxorubicin-mediated cardiotoxicity by regulating autophagy through the mTOR-TFEB pathway.
Britannin suppresses MCF-7 breast cancer cell growth by inducing apoptosis and inhibiting autophagy.
Functional combination of resveratrol and tamoxifen to overcome tamoxifen-resistance in breast cancer cells.

J Proteome Res. 2024 Jul 05.

Two-Step Enrichment Facilitates Background Reduction for Proteomic Analysis of Lysosomes.

Sara Bonini, Dominic Winter.

  Lysosomes constitute the main degradative compartment of most mammalian cells and are involved in various cellular functions. Most of them are catalyzed by lysosomal proteins, which typically are low abundant, complicating their analysis by mass spectrometry-based proteomics. To increase analytical performance and to enable profiling of lysosomal content, lysosomes are often enriched. Two approaches have gained popularity in recent years, namely, superparamagnetic iron oxide nanoparticles (SPIONs) and immunoprecipitation from cells overexpressing a 3xHA-tagged version of TMEM192 (TMEM-IP). The effect of these approaches on the lysosomal proteome has not been investigated to date. We addressed this topic through a combination of both techniques and proteomic analysis of lysosome-enriched fractions. For SPIONs treatment, we identified altered cellular iron homeostasis and moderate changes of the lysosomal proteome. For overexpression of TMEM192, we observed more pronounced effects in lysosomal protein expression, especially for lysosomal membrane proteins and those involved in protein trafficking. Furthermore, we established a combined strategy based on the sequential enrichment of lysosomes with SPIONs and TMEM-IP. This enabled increased purity of lysosome-enriched fractions and, through TMEM-IP-based lysosome enrichment from SPIONs flow-through and eluate fractions, additional insights into the properties of individual approaches. All data are available via ProteomeXchange with PXD048696.

Keywords:  HEK 293; TMEM192; lysosome enrichment; lysosomes; mass spectrometry; organelles; proteomics; superparamagnetic iron oxide nanoparticles (SPIONs)

DOI:  https://doi.org/10.1021/acs.jproteome.4c00053
Mol Cell Probes. 2024 Jul 01. pii: S0890-8508(24)00020-3. [Epub ahead of print] 101968

A Dual-Labeling Molecule for Efficient Drug Discovery of Mitochondrial-Lysosomal Interactions.

Jinfang Wu, Xiaolei Wang, Xiang Li, Zixuan Zhu, Zhongcheng Cui, Tao Zhang, Weiwei Zou, Guanying Han.

  The close association between organelle interactions, such as mitochondrial-lysosomal interactions, and various diseases, including tumors, remains a challenge for drug discovering and identification. Conventional evaluation methods are often complex and multistep labeling procedures often generate false positives, such as cell damage. To overcome these limitations, we employed a single dual-color reporting molecule called Coupa, which labels mitochondria and lysosomes as blue and red, respectively. This facilitates the evaluation and discovering of drugs targeting mitochondria-lysosome contact (MLC). Using Coupa, we validated the effectiveness of various known antitumor drugs in intervening MLC by assessing their effect on key aspects, such as status, localization, and quantity. This provides evidence for the accuracy and applicability of our dual-color reporting molecule. Notably, we observed that several structural isomers of drugs, including Urolithin (A/B/C), exhibited distinct effects on MLC. In addition, Verteporfin and TEAD were found to induce anti-tumor effects by controlling MLC at the organelle level, suggesting a potential new mechanism of action. Collectively, Coupa offers a novel scientific tool for discovering drugs that target mitochondrial-lysosomal interactions. It not only distinguished the differential effects of structurally similar drugs on the same target, but also reveals new mechanisms underlying the reported antitumor properties of existing drugs. Ultimately, our findings contribute to the advancement of drug discovery and provide valuable insights into the complex interactions between organelles in a disease context.

Keywords:  drug discovering; lysosome; mitochondria; mitochondrial-lysosomal interaction; sensor

DOI:  https://doi.org/10.1016/j.mcp.2024.101968
Chem Biol Interact. 2024 Jul 02. pii: S0009-2797(24)00278-3. [Epub ahead of print] 111132

Dehydroandrographolide ameliorates doxorubicin-mediated cardiotoxicity by regulating autophagy through the mTOR-TFEB pathway.

Yongzhen Duan, Peixian Huang, Lu Sun, Panxia Wang, Yi Cai, Tingting Shi, Yuliang Li, Yuhua Zhou, Shanshan Yu.

  The clinical application of doxorubicin (DOX) was limited by the serious cardiotoxicity. The traditional Chinese medicine Andrographis paniculata and its principal active component (Dehydroandrographolide, DA) have been well known for their diverse cardiovascular protective effects. However, the effects of DA on Dox-induced cardiotoxicity (DIC) were still unknown. In this study, we evaluated the effects and revealed the potential mechanisms of DA on DIC both in vivo and in vitro. The effects of DA on DIC were systematically assessed by echocardiography and histological assays. Western blot and flow cytometry were used to measure apoptosis of cardiomyocytes. TEM and immunofluorescence were further used to assay autophagic flux. Our results showed that DA administration significantly improved cardiac function and attenuated DOX-induced cardiomyocyte apoptosis. Mechanically, DA restored autophagic flux and lysosome function via inhibiting Dox-induced mTOR signal pathway activation and increasing the translocation of TFEB to the nucleus. However, activation of mTOR or knockdown of TFEB significantly inhibited the protective effects of DA against DIC by impacting lysosomal functions and autophagic flux. In conclusion, our results revealed that DA might be a potential cardioprotective agent against DIC.

Keywords:  Autophagy; Cardiotoxicity; Dehydroandrographolide; Doxorubicin; TFEB; mTOR

DOI:  https://doi.org/10.1016/j.cbi.2024.111132
Avicenna J Phytomed. 2024 Jan-Feb;14(1):14(1): 90-99

Britannin suppresses MCF-7 breast cancer cell growth by inducing apoptosis and inhibiting autophagy.

Sadegh Rajabi, Mahboubeh Irani, Marzieh Moeinifard, Maryam Hamzeloo-Moghadam.

  Objective: Breast cancer is the main reason for cancer-related death in women. Britannin is a sesquiterpene lactone compound derived from Inula aucheriana with anti-tumor properties. We aimed to explore the impacts of britannin on apoptosis and autophagy in MCF-7 breast cancer cell line.Materials and Methods: The cytotoxic influences of britannin on MCF-7 cells were estimated by the MTT method. The expression levels of apoptosis-associated genes such as CASP3, BCL2, BCL2L1, STAT3, and JAK2 and transcripts of autophagy markers including ATG1, ATG4, ATG5, ATG7, ATG12, BECN1, and MAP1LC3A were quantified using quantitative real time-PCR (qRT-PCR). Western blotting method was used to evaluate the amount of caspase 3, phosphorylated JAK2, phosphorylated STAT3, ATG1, ATG4, ATG5, Beclin1, and LC-III.
Results: Treatment of MCF-7 cells with various concentrations of britannin remarkably hindered the viability of these cells compared to the controls. This compound significantly elevated the expression of pro-apoptotic caspase-3 but did not influence the levels of anti-apoptotic BCL2 and BCL2L1. Britannin decreased the levels of phosphorylated forms of JAK2 and STAT3 proteins causing the blockage of the JAK/STAT pathway. Four autophagy factors expressions, including ATG4, ATG5, Beclin1, and LCIII, were reduced due to the effect of britannin on MCF-7 cells.
Conclusion: Britannin triggered apoptosis in MCF-7 cells by a mechanism that led to the blockade of the JAK/STAT pathway. Moreover, britannin prohibited autophagy in these cancer cells. This may suggest britannin as an agent for the suppression of breast tumors or as an adjutant for the enhancement of anti-breast cancer drugs effect.

Keywords:  Apoptosis; Autophagy; Breast cancer; Britannin; JAK2; STAT3

DOI:  https://doi.org/10.22038/AJP.2023.22995
Arch Pharm (Weinheim). 2024 Jun 29. e2400261

Functional combination of resveratrol and tamoxifen to overcome tamoxifen-resistance in breast cancer cells.

Aliaa M Radwan, Hamed A Abosharaf, Marwa Sharaky, Rehab Abdelmonem, Heba Effat.

  Researchers are encountering challenges in addressing the issue of cancer cells becoming unresponsive to various chemotherapy treatments due to drug resistance. This study was designed to study the influence of antioxidant resveratrol (RSV) to sensitize resistant breast cancer (BC) cells toward tamoxifen (TAM). The cytotoxic effects of RSV and TAM against TAM-resistant LCC2 cells and their parental michigan cancer foundation-7 BC cells were determined by sulphorhodamine B assay. Further, the expression levels of multidrug resistance (MDR) genes including ABCB1, ABCC2, ABCG2, and MRP1 using quantitative polymerase chain reaction, apoptosis induction, and reactive oxygen species (ROS) content using flow cytometry were evaluated in either LCC2 cells treated with RSV, TAM, or their combination. The obtained results showed that resistant cells have a magnificent level of MDR genes. This elevated expression dramatically lowered upon receiving the combined therapy of RSV and TAM. Additionally, our work assessed the possible role of RSV in modulating the expression of MDR genes by controlling the expression of certain microRNAs (miRNAs) that target ATP-binding cassette (ABC) transporters. According to the obtained data, the TAM and RSV combination increased the expression of tumor inhibitor miRNAs such miR-10b-3p, miR-195-3p, and miR-223-3p, which made LCC2 cells more sensitive to TAM. Furthermore, this combination showed an elevation in apoptotic levels and total ROS content. The combination between RSV and TAM could be a functional therapy in the fight against TAM-resistant BC cells via modulating miRNA and ABC transporters.

Keywords:  LCC2 cells; miRNA; multidrug resistance genes; resveratrol; tamoxifen

DOI:  https://doi.org/10.1002/ardp.202400261