Minocycline Promotes Neurite Outgrowth of PC12 Cells Exposed to Oxygen-Glucose Deprivation and Reoxygenation Through Regulation of MLCP/MLC Signaling Pathways

Abstract

Minocycline, a semi-synthetic second-generation derivative of tetracycline, has been reported to exert neuroprotective effects both in animal models and in clinic trials of neurological diseases. In the present study, we first investigated the protective effects of minocycline on oxygen-glucose deprivation and reoxygenation-induced impairment of neurite outgrowth and its potential mechanism in the neuronal cell line, PC12 cells. We found that minocycline significantly increased cell viability, promoted neurite outgrowth and enhanced the expression of growth-associated protein-43 (GAP-43) in PC12 cells exposed to oxygen-glucose deprivation/reoxygenation injury. In addition, immunoblots revealed that minocycline reversed the overexpression of phosphorylated myosin light chain (MLC) and the suppression of activated extracellular signal-regulated kinase 1/2 (ERK1/2) caused by oxygen-glucose deprivation/reoxygenation injury. Moreover, the minocycline-induced neurite outgrowth was significantly blocked by Calyculin A (1 nM), an inhibitor of myosin light chain phosphatase (MLCP), but not by an ERK1/2 inhibitor (U0126; 10 μM). These findings suggested that minocycline activated the MLCP/MLC signaling pathway in PC12 cells after oxygen-glucose deprivation/reoxygenation injury, which resulted in the promotion of neurite outgrowth.

SH2B1 protects against OGD/R‑induced apoptosis in PC12 cells via activation of the JAK2/STAT3 signaling pathway

“…For viral transfection, PC12 cells (1×10 5 cells per 24-well plate) were incubated with Ad-SH2B1 or Ad-GFP for 4 h at 37°C, prior to glucose deprivation as described below, at different multiplicities of infections as calculated via: Viral titer × viral volume/cell number (0, 10, 20, 40 and 80 MOI), and finally, 20 MOI was selected for the following experiments due to ~95% transfection efficiency with no significant effects on cell viability as determined by flow cytometry described below. After 4 h of incubation at 37°C, medium was removed, and PC12 cells were further incubated at 37°C with complete medium (DMEM+FBS) for 48 h prior to OGD/R treatment ( 17 ). Each experiment was repeated in triplicate.…”

“…To further detect the underlying mechanisms of the anti-OGD/R effects conferred by SH2B1 in PC12 cells, an additional experiment was conducted in which Ad-SH2B1 or Ad-GFP was transduced into PC12 cells as aforementioned in the absence or presence of a JAK2 inhibitor (AG490, 10 µM, Sigma-Aldrich; Merck KGaA, Darmstadt, Germany). These cells were then subjected to OGD/R treatment as described ( 17 ). The inhibitor was added into the medium 30 min at 37°C prior to the OGD procedure ( 17 ).…”

“…These cells were then subjected to OGD/R treatment as described ( 17 ). The inhibitor was added into the medium 30 min at 37°C prior to the OGD procedure ( 17 ).…”

Age and neuroinflammation are important components of the mechanism of cognitive and neurobehavioral deficits in sickle cell disease

“…Minocycline is a drug (antibiotic) that is capable of crossing the blood brain barrier and that is beneficial to hippocampal integrity 76,77 . Minocycline has been implicated in the reversal of neuronal cell death and the promotion of neurite outgrowth 39,43 , reduction of inflammation 78,79 and the restoration of cognitive function 42,80 .…”

“…Studies also suggest that minocycline influences neuroplasticity by promoting dendritic spine development and maturation, 42 and neurite outgrowth. 43 All rodent neurobehavioral testing was performed using standard protocols by the Emory University Rodent Behavioral Core (RBC). The rodent behavioral core was blinded to the disposition and genotype of the mice.…”