Phthalic anhydride-induced skin inflammation is augmented in KLF10-deficient mice

A network pharmacology-based study on key pharmacological pathways and targets of Qi Fu Yin acting on Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a central nervous system (CNS) disease characterized by progressive cognitive dysfunction and memory loss. Qi Fu Yin is mainly used to treat dementia, particularly AD, in the clinic, but its comprehensive mechanisms are not known.

OBJECTIVE

In this research, we aimed to investigate the mechanisms of Qi Fu Yin in AD by network pharmacology and molecular docking.

METHODS

First, the chemical constituents in Qi Fu Yin were obtained from five databases and classified according to their structure. Targets of chemical constituents and AD-related targets were also collected from the databases. Then, overlapping genes between Qi Fu Yin and AD were identified by intersection analysis. MetaCore was used to gather enrichment information. Combination synergy analysis was performed by Cytoscape. After ligand-receptor docking, the binding affinity was verified by ADP-Glo™ kinase assay and fluorescence resonance energy transfer (FRET) assay.

RESULTS

We found 12 classes with 977 components in Qi Fu Yin. A total of 511 compounds and 577 potential target proteins in Qi Fu Yin were found to be related to AD. The pathways of Qi Fu Yin in AD included oxidative stress and immune response. There was the best binding affinity between 11 pairs of genes and compounds. Furthermore, CDK5 was inhibited by nepetin with an IC₅₀ of 3.172 μM and kaempferol with an IC₅₀ of 2.659 μM. Ceanothic acid and 18 beta-glycyrrhetinic acid inhibited GSK3β, and the IC₅₀ values were 8.732 μM and 8.06 μM, respectively.

CONCLUSION

Qi Fu Yin might alleviate Tau hyperphosphorylation by nepetin, kaempferol, ceanothic acid and 18 beta-glycyrrhetinic acid.

The basal transcriptional activity of the murine Klf10 gene is regulated by the transcriptional factor JunB

BACKGROUND

Krüppel-like factor 10 (KLF10) belongs to the Sp1-like transcription factor family, which plays an important role in many directions, e.g., cell proliferation, apoptosis, and differentiation. Its 5' upstream regions are conserved across mammalian species. However, the regulatory mechanism has not been elucidated yet.

OBJECTIVE

Nonetheless the basal transcriptional regulation mechanisms of these regions are unknown. Here, we characterized it which is indispensable for the basal transcription of the Klf10 gene.

METHODS

Seven deletions of 5' upstream DNA fragments from the 10 kb mKlf10 genomic DNA were produced by PCR and cloned into the upstream of the luciferase (Luc) reporter gene in the pGL3 basic plasmid.

RESULT

The luciferase reporter assay showed that the DNA sequence at positions from -101 to +68 was required for a principle activity in the promoter of mKlf10 gene, in which transcriptional factor binding motifs, one JunB and two Sp1 sites, are included. Mutations at the sequence of JunB motif, but not at the two Sp1, abrogated the promoter activity completely, suggesting the indispensable role of JunB site for basal transcription of mKlf10 gene. Moreover, electrophoretic mobility and supershift assays (EMSA) uncovered that JunB protein bound to this region specifically.

CONCLUSION

Taken together, our study revealed that the JunB but not Sp1 at mKlf10 promoter functions as a positive basic factor for the transcriptional activity of the gene.

Impaired epidermal Langerhans cell maturation in TGFβ-inducible early gene 1 (TIEG1) knockout mice

TGF-β-inducible early gene 1 (TIEG1), also known as Krüppel-like factor 10 (Klf10), represents a major downstream transcription factor of transforming growth factor-β1 (TGF-β1) signaling. Epidermal Langerhans cells (LCs), a unique subpopulation of dendritic cells (DC), essentially mediates immune surveillance and tolerance. TGF-β1 plays a pivotal role in LC maintenance and function after birth, although the underpinning mechanisms remain elusive. Here, we hypothesized that TIEG1 might be involved in TGF-β1-mediated LC homeostasis and function. Utilizing TIEG1 null mice, we discovered that TIEG1 deficiency did not alter LC homeostasis at the steady state and LC repopulation at inflamed-state, as well as their antigen-uptake capacity, but significantly impaired their maturation ability, which was opposite to the fact that loss of TGF-β1 induced spontaneous LC maturation. Moreover, the ablation of TIEG1 enhanced skin contact hypersensitivity response. Our results suggested that TIEG1 is not a key molecule involved in TGF-β1-mediated homeostasis, while TIEG1-related signaling pathways regulate LC maturation and their function.