Saturday, December 21, 2024 12/21/2024

The stage-specific regulation of ameloblastin and enamelin by the distinct nuclear factors

Award Number: R01DE027076
ORGANIZATION: NATIONAL INSTITUTE OF DENTAL AND CRANIOFACIAL RESEARCH
OPDIV: NIH
AWARD CLASS: DISCRETIONARY
AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)

Group Awards By:

View Award Abstract

Project Summary/Abstract Cell identity is largely determined by specific epigenetic landscapes and transcriptional networks. Ameloblast is the only epithelial cell that can generate calcified tissue during development, where preameloblasts (PABs) first differentiate to the secretory ameloblasts (SABs) that synthesize and deposit enamel matrix proteins (EMPs) to scaffold organic matrix, and then to the maturation ameloblasts (MABs) that hydrolyze, endocytose EMPs, and transport ions to mineralize enamel. To bioengineer enamel, a nonregenerative tissue, we must understand the transcriptional regulation of ameloblasts that has been limited due to a loss of ameloblasts after the tooth eruption and a lack of cell line fully recapitulating the characteristics of ameloblasts. Previous fundings allow us to establish a novel and comprehensive list of genes significant to each developmental stage of ameloblasts across species and to explore the functions of chromatin organizer SATB1, and enamel matrix modeling regulators -peptidase KLK4 and the major calcium transporter NCKX4- in the context of ameloblast differentiation. These efforts resulted in a discovery that SATB1, KLK4, and NCKX4 all contribute to the transcriptional regulation of ameloblastin (Ambn) and enamelin (Enam), encoding the major EMPs co- upregulated in SABs and then co-downregulated in MABs. We found that ablation of SATB1, highly expressed in PABs, repressed Ambn & Enam transcription and H3K27ac level. Our organ culture showed that elevated histone acetylation upregulated Ambn & Enam. An enhancer and base unpairing region (BUR, selective SATB1 DNA binding site) have been predicted in the vicinity of Ambn & Enam. These data suggest that SATB1 organizes chromatin conformation and poises a transcriptional complex to upregulate Ambn & Enam to advance PABs to SABs. In the case of mice lacking Klk4 and Nckx4—the causative genes for amelogenesis imperfecta—we found a retention of proline/glutamine (P/G)-rich EMPs resulting from defective hydrolysis. These Nckx4-/- and Klk4-/- MABs had upregulated Ambn & Enam and downregulated Hif1a. In vitro studies showed that P/G-rich peptides downregulated Ambn & Enam and upregulated Hif1a. Our RNA-seq analyses revealed that HIF1A, a transcription factor regulating cell responses to oxidative stress, had a 6-fold upregulation in MABs vs SABs, reflecting MAB’s robust anti-oxidative capacity to continuously provide energy for ion transport and protein degradation. These data suggest that retake of P/G-rich peptides upregulate Hif1a, which in turn downregulate Ambn & Enam. Our in vivo and in vitro studies allow us to hypothesize that the dynamic expression of Ambn & Enam in the two major functional stages of ameloblasts is coordinately regulated by distinct factors chromatin organizer SATB1 and transcription factor HIF1A. This hypothesis will be addressed by specific aim 1: To determine the roles of SATB1 as a pioneer factor in PABs to poise the enhancer establishment for activating the transcription of Ambn & Enam gene in SABs; and specific aim 2: To determine the regulatory roles of HIF1A on Ambn & Enam expression and enamel formation.


Issue Date FY	Funding FY	Legal Entity Name	Legal Entity Address	Legal Entity City	Legal Entity State	Legal Entity Zip Code	Legal Entity COUNTY	Legal Entity COUNTRY	Assistance Listing	Award Code	Budget Year	Action Date	Action Type	Action Amount

Issue Date FY: 2025 ( Subtotal = $69,982 )
2025	2025	REGENTS OF THE UNIVERSITY OF CALIFORNIA, SAN FRANCISCO, THE	1855 FOLSOM ST STE 425	SAN FRANCISCO	CA	94103	SAN FRANCISCO	USA	Oral Diseases and Disorders Research	000	7	12/19/2024	SUPPLEMENT FOR EXPANSION	$69,982
														Subtotal = $69,982

Issue Date FY: 2024 ( Subtotal = $599,626 )
2024	2024	REGENTS OF THE UNIVERSITY OF CALIFORNIA, SAN FRANCISCO, THE	1855 FOLSOM ST STE 425	SAN FRANCISCO	CA	94103	SAN FRANCISCO	USA	Oral Diseases and Disorders Research	002	7	8/27/2024	NON-COMPETING CONTINUATION	$502,968
2024	2023	REGENTS OF THE UNIVERSITY OF CALIFORNIA, SAN FRANCISCO, THE	1855 FOLSOM ST STE 425	SAN FRANCISCO	CA	94103	SAN FRANCISCO	USA	Oral Diseases and Disorders Research	001	6	3/13/2024	COMPETING CONTINUATION	$282,855
2024	2021	REGENTS OF THE UNIVERSITY OF CALIFORNIA, SAN FRANCISCO, THE	1855 FOLSOM ST STE 425	SAN FRANCISCO	CA	94103	SAN FRANCISCO	USA	Oral Diseases and Disorders Research	000	5	11/8/2023	NON-COMPETING CONTINUATION	-$186,197
														Subtotal = $599,626

Issue Date FY: 2023 ( Subtotal = $479,957 )
2023	2023	REGENTS OF THE UNIVERSITY OF CALIFORNIA, SAN FRANCISCO, THE	1855 FOLSOM ST STE 425	SAN FRANCISCO	CA	94143	SAN FRANCISCO	USA	Oral Diseases and Disorders Research	000	6	9/6/2023	COMPETING CONTINUATION	$479,957
														Subtotal = $479,957

Issue Date FY: 2021 ( Subtotal = $376,438 )
2021	2021	REGENTS OF THE UNIVERSITY OF CALIFORNIA, SAN FRANCISCO, THE	1855 FOLSOM ST STE 425	SAN FRANCISCO	CA	94143	SAN FRANCISCO	USA	Oral Diseases and Disorders Research	000	5	6/24/2021	NON-COMPETING CONTINUATION	$376,438
														Subtotal = $376,438

Issue Date FY: 2020 ( Subtotal = $376,438 )
2020	2020	REGENTS OF THE UNIVERSITY OF CALIFORNIA, SAN FRANCISCO, THE	1855 FOLSOM ST STE 425	SAN FRANCISCO	CA	94143	SAN FRANCISCO	USA	Oral Diseases and Disorders Research	000	4	6/15/2020	NON-COMPETING CONTINUATION	$376,438
														Subtotal = $376,438

Issue Date FY: 2019 ( Subtotal = $376,438 )
2019	2019	REGENTS OF THE UNIVERSITY OF CALIFORNIA, SAN FRANCISCO, THE	1855 FOLSOM ST STE 425	SAN FRANCISCO	CA	94143	SAN FRANCISCO	USA	Oral Diseases and Disorders Research	000	3	6/12/2019	NON-COMPETING CONTINUATION	$376,438
														Subtotal = $376,438

Issue Date FY: 2018 ( Subtotal = $376,438 )
2018	2018	REGENTS OF THE UNIVERSITY OF CALIFORNIA, SAN FRANCISCO, THE	1855 FOLSOM ST STE 420	SAN FRANCISCO	CA	94103	SAN FRANCISCO	USA	Oral Diseases and Disorders Research	000	2	6/6/2018	NON-COMPETING CONTINUATION	$376,438
														Subtotal = $376,438

Issue Date FY: 2017 ( Subtotal = $376,438 )
2017	2017	UNIVERSITY OF CALIFORNIA, SAN FRANCISCO	1855 FOLSOM ST STE 425	SAN FRANCISCO	CA	94103	SAN FRANCISCO	USA	Oral Diseases and Disorders Research	000	1	6/21/2017	NEW	$376,438
														Subtotal = $376,438

Grand Total All Awards = $3,031,755

Top

All Categories

About

Search

Reports

Data Submission

Award Information

The stage-specific regulation of ameloblastin and enamelin by the distinct nuclear factors

Award Number: R01DE027076

ORGANIZATION: NATIONAL INSTITUTE OF DENTAL AND CRANIOFACIAL RESEARCH

OPDIV: NIH

AWARD CLASS: DISCRETIONARY

AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)

Federal Websites

Department of Health & Human Services

HHS Operating Divisions

HHS Staff Divisions

Download A Document Viewer