Ulcerative colitis (UC) is a chronic and non-specific inflammatory bowel disease (IBD). Huanglian Ganjiang decoction (HGD), derived from ancient book Beiji Qianjin Yao Fang, has demonstrated efficacy in treating UC patients traditionally. Previous research established that the compatibility of cold herb Coptidis Rhizoma + Phellodendri Chinensis Cortex (CP) and hot herb Angelicae Sinensis Radix + Zingiberis Rhizoma (AZ) in HGD synergistically improved colitis mice. This study investigated the compatibility mechanisms through which CP and AZ regulated inflammatory balance in colitis mice. The experimental colitis model was established by administering 3% dextran sulphate sodium (DSS) to mice for 7 days, followed by CP, AZ and CPAZ treatment for an additional 7 days. M1/M2 macrophage polarization levels, glucose metabolites levels and pyruvate dehydrogenase kinase 4 (PDK4) expression were analyzed using flow cytometry, Western blot, immunofluorescence and targeted glucose metabolomics. The findings indicated that CP inhibited M1 macrophage polarization, decreased inflammatory metabolites associated with tricarboxylic acid (TCA) cycle, and suppressed PDK4 expression and pyruvate dehydrogenase (PDH) (Ser-293) phosphorylation level. AZ enhanced M2 macrophage polarization, increased lactate axis metabolite lactate levels, and upregulated PDK4 expression and PDH (Ser-293) phosphorylation level. TCA cycle blocker AG-221 and adeno-associated virus (AAV)-PDK4 partially negated CP's inhibition of M1 macrophage polarization. Lactate axis antagonist oxamate and PDK4 inhibitor dichloroacetate (DCA) partially reduced AZ's activation of M2 macrophage polarization. In conclusion, the compatibility of CP and AZ synergistically alleviated colitis in mice through M1/M2 macrophage polarization balance via PDK4-mediated glucose metabolism reprogramming. Specifically, CP reduced M1 macrophage polarization by restoration of TCA cycle via PDK4 inhibition, while AZ increased M2 macrophage polarization through activation of PDK4/lactate axis.
Animals ; Drugs, Chinese Herbal/chemistry* ; Mice ; Macrophages/immunology* ; Glucose/metabolism* ; Pyruvate Dehydrogenase Acetyl-Transferring Kinase/genetics* ; Male ; Mice, Inbred C57BL ; Humans ; Colitis/drug therapy* ; Disease Models, Animal ; Colitis, Ulcerative/drug therapy* ; Metabolic Reprogramming

The protein kinase A/protein kinase G/protein kinase C-family (AGC kinase family) of eukaryotes is involved in regulating numerous biological processes. The 3-phosphoinositide- dependent protein kinase 1 (PDK1), is a conserved serine/threonine kinase in eukaryotes. To understand the roles of PDK1 homologous genes in cell death and immunity in tetraploid Nicotiana tabacum, the previuosly generated transgenic CRISPR/Cas9 lines, in which 5-7 alleles of the 4 homologous PDK1 genes (NtPDK1a/1b/1c/1d homologs) simultaneously knocked out, were used in this study. Our results showed that the hypersensitive response (HR) triggered by transient overexpression of active Pto (Pto^Y207D) or soybean GmMEKK1 was significantly delayed, whereas the resistance to Pseudomonas syrangae pv. tomato DC3000 (Pst DC3000) and tobacco mosaic virus (TMV) was significantly elevated in these partial knockout lines. The elevated resistance to Pst DC3000 and TMV was correlated with the elevated activation of NtMPK6, NtMPK3, and NtMPK4. Taken together, our results indicated that NtPDK1s play a positive role in cell death but a positive role in disease resistance, likely through negative regulation of the MAPK signaling cascade.
Nicotiana/virology* ; Disease Resistance/genetics* ; Plant Diseases/immunology* ; Plants, Genetically Modified/genetics* ; Gene Knockout Techniques ; Plant Proteins/genetics* ; CRISPR-Cas Systems ; Protein Serine-Threonine Kinases/genetics* ; 3-Phosphoinositide-Dependent Protein Kinases/genetics* ; Pyruvate Dehydrogenase Acetyl-Transferring Kinase ; Tobacco Mosaic Virus/pathogenicity*