Bone tissue specific delivery of dietary metabolite phenolic acids using Clostridial collagenase collagen binding domain

Authors: CAVINESS, PERRY - Arkansas Children'S Nutrition Research Center (ACNC); LAZARENKO, OXANA - Arkansas Children'S Nutrition Research Center (ACNC); BLACKBURN, MICHAEL - Arkansas Children'S Nutrition Research Center (ACNC); CHEN, JIN-RAN - Arkansas Children'S Nutrition Research Center (ACNC)

Submitted to: American Society for Bone and Mineral Research
Publication Type: Abstract Only
Publication Acceptance Date: 7/2/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Previous research has found that dietary metabolite phenolic acids hippuric acid (HA) and 3-(3-hydroxyphenyl) propionic acid (3-3-PPA) promote bone formation, suppress bone resorption and have potential as novel anti-bone resorption therapeutics. To deliver HA and 3-3-PPA specifically to bone tissue and avoid degradation, metabolites were cross-linked to Arg side chains in Clostridial collagenase collagen binding (CBD) and the ability of cross-linked HA or 3-3-PPA (HA-CBD or 3-3-PPA-CBD) to specifically target bone was investigated in pregnant mouse models. In addition, HA-CBD and 3-3-PPA-CBD activities on both dam and fetal bone tissue epigenetics and gene expression were investigated. Prior to injection HA-CBD and 3-3-PPA CBD were shown to be as effective at suppression osteoclastogenesis when compared to free HA and 3-3-PPA (both Raw 264.7 and mouse primary bone marrow cell lines used). 4 hr. post injection HA-CBD and 3-3-PPA-CBD were shown to localize in dam’s tibia and fetal calvaria. Bone marrow plasma collected from dams revealed a significant increase in HA following HA-CBD injection when compared to control mice (Control mice: 685 +/- 61 µmole/µg, HA-CBD mice: 1358 +/- 306 µmole/µg). Preliminary results from our group have shown that both HA and 3-3-PPA promote DNA hypomethylation. Using ELISA, fetal bone tissue DNA methylation levels (%5-mC) were significantly lowered for HA-CBD and 3-3-PPA-CBD injected mice but dam bone tissue DNA methylation levels were unchanged. Fetal DNA hypomethylation may be due to either upregulation of Nicotinamide N-methyltransferase (leading to SAM depletion) or suppression of NADPH levels (inhibiting both folate and methionine cycles). In both dams and fetus, osteoclastic and osteogenic promoting genes expression levels were analyzed using real-time PCR. mRNA levels for osteogenic promoters BMP2 and ALP were significantly upregulated for fetal bone tissue. For dam’s bone tissue, BMP2 and Osteocalcin mRNA levels were also significantly upregulated. Findings from this study suggest that HA-CBD and 3-3-PPA-CBD’s ability to cross the placental barrier and promote increased gene expression of key osteogenic promoters make them prime candidates for alleviating poor maternal diet induced fetal bone development. Supported in part by USDA-ARS Project 6026-51000-010-05S; and NIH R01 project R37 AA18282 sub-awarded to JRC.