Related Experiment Video
Updated: Feb 3, 2026
07:13
Application of Retinoic Acid to Obtain Osteocytes Cultures from Primary Mouse Osteoblasts
Published on: May 13, 2014
13.9K
Nephronectin Expression is Inhibited by Inorganic Phosphate in Osteoblasts
Tadashi Kato1,2, Atsushi Yamada3, Kiyohito Sasa1
1Department of Biochemistry, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa, 142-8555, Japan.
Calcified Tissue International
|October 21, 2018
Summary
Elevated phosphate levels inhibit nephronectin (Npnt) expression in bone cells, requiring calcium. This process involves sodium-dependent phosphate transporters and fibroblast growth factor receptors, revealing a novel regulatory pathway.
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Nephronectin (Npnt) is an extracellular matrix protein and a ligand for integrin α8β1.
- Npnt plays crucial roles in the development and function of various organs.
Purpose of the Study:
- To investigate the effect of extracellular inorganic phosphate (Pi) on Npnt gene expression in MC3T3-E1 cells.
- To elucidate the role of calcium (Ca) in Pi-induced regulation of Npnt.
- To identify the molecular mechanisms, including transporters and receptors, involved in this regulation.
Main Methods:
- Treatment of MC3T3-E1 cells with varying concentrations of inorganic phosphate (Pi) and calcium (Ca).
- Analysis of Npnt gene expression.
- Inhibition studies using specific inhibitors for sodium-dependent Pi transporters (Pit) and fibroblast growth factor receptors (Fgfrs).
Main Results:
- Elevated extracellular Pi significantly inhibited Npnt expression in MC3T3-E1 cells.
- Extracellular calcium (Ca) was essential for the inhibitory effect of Pi on Npnt expression.
- Inhibition of Npnt gene expression by Pi was reversed by inhibitors of Pit and Fgfrs.
Conclusions:
- Extracellular inorganic phosphate (Pi) negatively regulates nephronectin (Npnt) gene expression in osteoblast precursor cells.
- The presence of extracellular calcium is indispensable for Pi-mediated inhibition of Npnt.
- Npnt gene expression is regulated by extracellular Pi through the involvement of sodium-dependent Pi transporters (Pit) and fibroblast growth factor receptors (Fgfrs).
Related Concept Videos
00:46Feedback Inhibition
57.1K
Biochemical reactions are occurring constantly in cells, converting starting substances to different products, usually with the help of enzymes that speed the reactions. Without enzymes, it would take far too long for most reactions to occur to be useful to the cell!
57.1K
01:22Phosphate Buffer
5.2K
The phosphate buffer system is a critical biological mechanism for maintaining pH stability in the body. This system operates primarily through two components: sodium dihydrogen phosphate (NaH2PO4), which acts as a weak acid, and sodium hydrogen phosphate (Na2HPO4), which serves as a weak base.
Sodium dihydrogen phosphate does not fully dissociate in neutral or acidic solutions. When a strong base, such as sodium hydroxide (NaOH), is introduced into the solution, sodium dihydrogen phosphate...
Sodium dihydrogen phosphate does not fully dissociate in neutral or acidic solutions. When a strong base, such as sodium hydroxide (NaOH), is introduced into the solution, sodium dihydrogen phosphate...
5.2K
00:49Gravimetry: Inorganic And Organic Precipitating Agents
7.1K
In gravimetry, the precipitant is chosen carefully to obtain a pure solid that can be easily filtered. Common inorganic precipitants can be used to determine several cations and anions. In some cases, the formation of the same precipitate can be used to determine the cation and the anion. For example, the reaction of barium and chromate ions to give barium chromate is used to determine both barium and chromate. However, precipitates such as hydroxides, oxalates, and metal ammonium phosphates...
7.1K
01:22Inorganic Nitrogen Assimilation
529
Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme...
529
01:42What is Gene Expression?
196.7K
Overview
Gene expression is the process in which DNA directs the synthesis of functional products, that is, proteins. Cells can regulate gene expression at various stages. It allows organisms to generate different cell types and enables cells to adapt to internal and external factors.
Genetic Information Flows from DNA to RNA to Protein
A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is made up of nucleotides and proteins consist of amino...
Gene expression is the process in which DNA directs the synthesis of functional products, that is, proteins. Cells can regulate gene expression at various stages. It allows organisms to generate different cell types and enables cells to adapt to internal and external factors.
Genetic Information Flows from DNA to RNA to Protein
A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is made up of nucleotides and proteins consist of amino...
196.7K
01:27Roles of Electrolytes: Calcium and Phosphate
1.2K
Calcium and phosphate are essential electrolytes in the human body, with calcium being the most abundant mineral. Around 99% of the body's calcium is stored in the skeleton and teeth, forming a crystal lattice of mineral salts in combination with phosphates. Calcium plays crucial roles in various bodily functions such as blood clotting, neurotransmitter release, muscle tone maintenance, and nervous and muscle tissue excitability.
The calcium concentration in blood plasma is primarily...
The calcium concentration in blood plasma is primarily...
1.2K