Upregulated Long Non-coding RNA ALMS1-IT1 Promotes Neuroinflammation by Activating NF-κB Signaling in Ischemic Cerebral Injury

Curr Pharm Des. 2021;27(41):4270-4277. doi: 10.2174/1381612827666210827104316.

Abstract

Background: ALMS1-IT1, a recently identified lncRNA, has been proven to play a crucial role in regulating tumor progression and predicting the survival time of tumor patients. Data analysis from the Human Body Map (HBM) revealed that ALMS1-IT1 is expressed mainly in brain tissues.

Methods: In this study, the role of ALMS1-IT in regulating neuro-inflammation and functional recovery was investigated after ischemic cerebral damage. To this end, the rat model of transient middle cerebral artery occlusion (tMCAO) was constructed, the cell model of oxygen-glucose deprivation (OGD) was established using BV2 microglial cells, and the aberrant expression of ALMS1-IT1 was assessed in brain tissues. After ALMS1- IT1 knockdown through intrathecal injection of Lv-shALMS1-IT1, neuro-inflammatory response and functional tests including a modified neurological severity score (mNSS) and a foot-fault test were assessed.

Results: The level of ALMS1-IT1 was promptly enhanced at 12 hours (h) following MCAO, peaking at 48 h, and remaining high at day 14 compared to the sham group. Pro-inflammatory cytokines (IL-1β, IL-6, and TNF- α) were increased after MCAO, whereas ALMS1-IT1 inhibition suppressed the expression of IL-1β, IL-6 and TNF-α in MCAO rats. The results from mNSS and foot-fault test showed that ALMS1-IT1 knockdown significantly improved spatial learning and sensorimotor function of MCAO rats. Mechanistically, ALMS1-IT1 knockdown suppressed the activation of NF-κB signaling in vitro and in vivo, as evidenced by decreased p65 expression and p65 nuclear translocation. ALMS1-IT1 overexpression facilitated pro-inflammatory cytokines expression in microglia, whereas the effect was blocked by treatment with JSH-23 (a specific NF-κB inhibitor).

Conclusion: These data demonstrated that ALMS1-IT1 inhibition improved neurological function of MCAO rats, at least in part by repressing NF-κB-dependent neuro-inflammation.

Keywords: ALMS1-IT1; Ischemic cerebral injury; MCAO; NF-κB; mNSS.; neuro-inflammation.

MeSH terms

  • Animals
  • Brain Ischemia* / metabolism
  • Cell Cycle Proteins / metabolism
  • Cell Cycle Proteins / pharmacology
  • Humans
  • Microglia / pathology
  • NF-kappa B / metabolism
  • Neuroinflammatory Diseases
  • RNA, Long Noncoding* / genetics
  • RNA, Long Noncoding* / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction

Substances

  • Cell Cycle Proteins
  • NF-kappa B
  • RNA, Long Noncoding