• Home
  • Search Results
  • Scutellarin regulates microglia-mediated TNC1 astrocytic reaction and astrogliosis in cerebral ischemia in the adult rats.

Scutellarin regulates microglia-mediated TNC1 astrocytic reaction and astrogliosis in cerebral ischemia in the adult rats.

BMC neuroscience (2015-11-27)
Ming Fang, Yun Yuan, Parakalan Rangarajan, Jia Lu, Yajun Wu, Huadong Wang, Chunyun Wu, Eng-Ang Ling
ABSTRACT

Scutellarin, an anti-inflammatory agent, effectively suppressed microglia activation in rats with middle cerebral artery occlusion (MCAO). Robust microglia activation, acute in onset, was followed by astrogliosis. This study was aimed to determine if scutellarin would also affect the reactive astrocytes that play an important role in tissue repair. Expression of GFAP and Notch-1 and its members: Notch receptor intracellular domain (NICD), and transcription factor hairy and enhancer of split-1 (HES-1), together with nestin and proinflammatory mediators was assessed by immunofluorescence staining in TNC1 astrocytes treated, respectively, with BV-2 conditioned medium (CM) and CM + lipopolysaccharide (LPS) (CM + L) serving as the controls, and conditioned medium derived from LPS-activated BV-2 cells pretreated with scutellarin (CM + SL). Study of the above biomarkers was then extended to reactive astrocytes in scutellarin injected MCAO rats. TNC1 astrocytes remained relatively unreactive in terms of expression of different biomarkers to direct scutellarin treatment when compared with the control cells. In comparison to cells in the control medium (CM, CM + L), they responded vigorously to CM + SL as evidenced by the enhanced protein expression of GFAP, Notch-1, NICD and HES-1 coupled with that of nestin, TNF-α, IL-1β, and iNOS by Western and immunofluorescence analysis. Electron microscopy showed marked hypertrophy and cell expansion of TNC1 astrocytes bearing many filamentous processes indicative of enhanced astrocyte reaction when treated with CM + SL. In MCAO rats, scutellarin also augmented the expression of the above markers in reactive astrocytes; moreover, astrocytes were evidently hypertrophic. The results suggest that scutellarin regulates astrogliosis; more importantly, it is microglia-mediated as demonstrated in vitro. Increased expression of Notch signaling in synchrony with nestin may be linked to proliferation and "de-differentiation" of reactive astrocytes; the significance of enhanced TNF-α, IL-1β and iNOS expression in reactive astrocytes by scutellarin may be neuroprotective but this remains speculative.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
DAPI, for nucleic acid staining
Sigma-Aldrich
Glutaraldehyde solution, Grade I, 25% in H2O, specially purified for use as an electron microscopy fixative
Sigma-Aldrich
Monoclonal Anti-β-Actin antibody produced in mouse, clone AC-15, ascites fluid
Sigma-Aldrich
Glutaraldehyde solution, Grade II, 25% in H2O
Sigma-Aldrich
Glutaraldehyde solution, 50 wt. % in H2O
Sigma-Aldrich
Osmium tetroxide, ReagentPlus®, 99.8%
Sigma-Aldrich
Glutaraldehyde solution, Grade I, 50% in H2O, specially purified for use as an electron microscopy fixative or other sophisticated use
Sigma-Aldrich
Glutaraldehyde solution, Grade I, 70% in H2O, specially purified for use as an electron microscopy fixative or other sophisticated use
Sigma-Aldrich
Osmium tetroxide, Sealed ampule.
Sigma-Aldrich
Glutaraldehyde solution, Grade I, 8% in H2O, specially purified for use as an electron microscopy fixative or other sophisticated use
Sigma-Aldrich
Osmium tetroxide solution, suitable for electron microscopy, 4% in H2O
Sigma-Aldrich
Osmium tetroxide solution, 4 wt. % in H2O
Sigma-Aldrich
Anti-Glial Fibrillary Acidic Protein Antibody, clone GA5, ascites fluid, clone GA5, Chemicon®
Sigma-Aldrich
Osmium tetroxide solution, 2.5 wt. % in tert-butanol
Sigma-Aldrich
Glutaric dialdehyde solution, 50 wt. % in H2O, FCC
Sigma-Aldrich
Osmium tetroxide solution, suitable for electron microscopy, 2% in H2O
Sigma-Aldrich
Glutaraldehyde solution, 50% in H2O, suitable for photographic applications
Sigma-Aldrich
Osmium tetroxide, ACS reagent, ≥98.0%
Sigma-Aldrich
Os EnCat® 40, extent of labeling: 0.3 mmol/g Os loading
Sigma-Aldrich
Anti-Notch 1 Antibody, NT, serum, from rabbit
Sigma-Aldrich
Anti-Tumor Necrosis Factor-α Antibody, Chemicon®, from rabbit
Sigma-Aldrich
Anti-Interleukin-1β Antibody, Chemicon®, from rabbit
Sigma-Aldrich
Anti-Nestin (C-terminal region) antibody produced in rabbit, ~1.5 mg/mL, affinity isolated antibody
Sigma-Aldrich
Anti-Tumor Necrosis Factor-α antibody produced in rabbit, IgG fraction of antiserum, buffered aqueous solution