bims-lycede Biomed News
on Lysosome-dependent cell death
Issue of 2024‒06‒09
four papers selected by
Sofía Peralta, Universidad Nacional de Cuyo

  1. J Environ Sci (China). 2024 Nov;pii: S1001-0742(23)00443-6. [Epub ahead of print]145 117-127
      Atmospheric particulate matter (PM) exacerbates the risk factor for Alzheimer's and Parkinson's diseases (PD) by promoting the alpha-synuclein (α-syn) pathology in the brain. However, the molecular mechanisms of astrocytes involvement in α-syn pathology underlying the process remain unclear. This study investigated PM with particle size <200 nm (PM0.2) exposure-induced α-syn pathology in ICR mice and primary astrocytes, then assessed the effects of mammalian target of rapamycin inhibitor (PP242) in vitro studies. We observed the α-syn pathology in the brains of exposed mice. Meanwhile, PM0.2-exposed mice also exhibited the activation of glial cell and the inhibition of autophagy. In vitro study, PM0.2 (3, 10 and 30 µg/mL) induced inflammatory response and the disorders of α-syn degradation in primary astrocytes, and lysosomal-associated membrane protein 2 (LAMP2)-mediated autophagy underlies α-syn pathology. The abnormal function of autophagy-lysosome was specifically manifested as the expression of microtubule-associated protein light chain 3 (LC3II), cathepsin B (CTSB) and lysosomal abundance increased first and then decreased, which might both be a compensatory mechanism to toxic α-syn accumulation induced by PM0.2. Moreover, with the transcription factor EB (TFEB) subcellular localization and the increase in LC3II, LAMP2, CTSB, and cathepsin D proteins were identified, leading to the restoration of the degradation of α-syn after the intervention of PP242. Our results identified that PM0.2 exposure could promote the α-syn pathological dysregulation in astrocytes, providing mechanistic insights into how PM0.2 increases the risk of developing PD and highlighting TFEB/LAMP2 as a promising therapeutic target for antagonizing PM0.2 toxicity.
    Keywords:  Astrocytes; Autophagy-lysosome; PM(0.2); α-Synuclein
  2. Trends Cell Biol. 2024 Jun 06. pii: S0962-8924(24)00111-9. [Epub ahead of print]
      The cyclic GMP-AMP (cGAMP) synthase (cGAS)-stimulator of interferon genes (STING) pathway has a crucial role in combating pathogen infection. However, its aberrant activation is involved in several human disorders. Lysosomes are emerging as key negative regulators of cGAS-STING signaling. Here, we discuss the lysosomal control of cGAS-STING signaling and its implication in human disorders.
    Keywords:  STING; autophagy; cGAS; human disorders; innate immunity; lysosome
  3. Heliyon. 2024 Jun 15. 10(11): e31925
      Background: Breast cancer is a major global cancer, for which radiation and chemotherapy are the main treatments. Natural remedies are being studied to reduce the side effects. Etoposide (ETO), a chemo-drug, and quercetin (QC), a phytochemical, are considered potential factors for adaptation to conventional treatments.Objectives: The anticancer effect of the synergy between ETO and Quercetin-loaded solid lipid nanoparticles (QC-SLNs), was investigated in MDA-MB-231 cells.
    Methods: We developed QC-SLNs for efficient cellular delivery, characterizing their morphology, particle size, and zeta potential. We assessed the cytotoxicity of QC-SLNs and ETO on breast cancer cells via the MTT assay. Effects on apoptosis intensity in MDA-MB-231 cells have been detected utilizing annexin V-FITC, PI, and caspase activities. Real-time PCR assessed Bax gene and Bcl-2 gene fold change expression, while Western blot analysis determined p53 and p21 protein levels.
    Results: Spherical, negatively charged QC-SLNs, when combined with ETO, significantly enhanced inhibition of MDA-MB-231 cell proliferation compared to ETO or QC-SLNs alone. The combined treatment also notably increased the apoptosis pathway. QC-SLNs + ETO increased the Bax/Bcl-2 gene ratio, elevated p53 and p21 proteins, and activated caspase 3 and 9 enzymes. These results indicate the potential for QC-SLNs + ETO as a strategy for breast cancer treatment, potentially overcoming ETO-resistant breast cancer chemoresistance.
    Conclusion: These results suggest that QC-SLN has the potential to have a substantial impact on the breast cancer cure by improving the efficacy of ETO. This enhancement could potentially help overcome chemoresistance observed in ETO-resistant breast cancer.
    Keywords:  Apoptosis; Etoposide (ETO); MDA-MB-231; Quercetin (QC); Solid lipid nanoparticles (SLN)
  4. Front Cell Dev Biol. 2024 ;12 1384047
      Autophagy is an evolutionarily conserved cellular recycling process that maintains cellular homeostasis. Despite extensive research in endocrine contexts, the role of autophagy in ovarian and testicular steroidogenesis remains elusive. The significant role of autophagy in testosterone production suggests potential treatments for conditions like oligospermia and azoospermia. Further, influence of autophagy in folliculogenesis, ovulation, and luteal development emphasizes its importance for improved fertility and reproductive health. Thus, investigating autophagy in gonadal cells is clinically significant. Understanding these processes could transform treatments for endocrine disorders, enhancing reproductive health and longevity. Herein, we provide the functional role of autophagy in testicular and ovarian steroidogenesis to date, highlighting its modulation in testicular steroidogenesis and its impact on hormone synthesis, follicle development, and fertility therapies.
    Keywords:  autophagy; ovarian steroidogenesis; progesterone; testicular steroidogenesis; testosterone