Lycium Barbarum polysaccharide protects HaCaT cells from PM2.5-induced apoptosis via inhibiting oxidative stress, ER stress and autophagy

ABSTRACT

Objectives: Lycium barbarum polysaccharide (LBP) is a natural polysaccharide extracted from Lycium barbarum that has anti-inflammatory, anti-apoptotic and anti-aging effects, and plays a role in the prevention and treatment of various diseases. In this study, we investigated the therapeutic effect of LBP on particulate matter 2.5 (PM2.5)-induced skin damage.

Methods: Cell viability was analyzed by MTT and LDH assays. Apoptosis was analyzed by Annexin V-FITC/PI staining. Oxidative stress/damage were assessed by intracellular ROS levels, MDA content and SOD activity. The intracellular protein expression was analyzed by Western blot. Mitochondrial damage was assayed by mitochondrial membrane potential with JC-1 probe. LC3-GFP adenovirus was transfected into HaCaT cells to analyze intracellular autophagosome levels.

Results: In PM2.5-treated HaCaT cells, LBP pretreatment reduced PM2.5-induced cytotoxicity, ameliorated cell morphology and reduced cell apoptosis. LBP also inhibited the expression levels of GRP78 and CHOP, reduced the conversion of LC3I to LC3II, inhibited Bax protein and activated Bcl-2 protein. Furthermore, LBP inhibited PM2.5-induced mitochondrial autophagy (mitophagy) and mitochondrial damage. PM2.5-induced autophagy was regulated by endoplasmic reticulum (ER) stress.

Conclusion: LBP protects skin cells from PM2.5-induced cytotoxicity by regulating the oxidative stress-ER stress-autophagy-apoptosis signaling axis, revealing that LBP has a great potential for the skin protection.

GRAPHICAL ABSTRACT

KEYWORDS:

• PM2.5
• Lycium barbarum polysaccharide (LBP)
• antioxidant
• oxidative damage
• endoplasmic reticulum (ER) stress
• autophagy
• apoptosis
• mitochondrial damage

Acknowledgements

The authors are grateful to the Core Facility of School of Life Sciences, Lanzhou University. This work is supported partly by the LZU-IMPCAS cooperation (Grant No. (20)0920).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Submission declaration

We declare that its publication has been approved by all the authors.

Data availability

The data used to support the findings of this study are available from the corresponding author upon request.

Additional information

Funding

This work is supported partly by the LZU-IMPCAS cooperation.