Related Experiment Video

Updated: Sep 5, 2025

Measuring Single-Cell Mitochondrial DNA Copy Number and Heteroplasmy Using Digital Droplet Polymerase Chain Reaction
09:15

Measuring Single-Cell Mitochondrial DNA Copy Number and Heteroplasmy Using Digital Droplet Polymerase Chain Reaction

Published on: July 12, 2022

4.8K

Decrease of MtDNA copy number affects mitochondrial function and involves in the pathological consequences of

Zhaojing Zhang1, Dongzhi Yang2, Baixue Zhou1

  • 1Department of Medical Genetics & Cell Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China.

Journal of Cellular and Molecular Medicine
|July 6, 2022
PubMed

Insights

Mitochondrial DNA (mtDNA) copy number reduction, linked to D-loop mutations and TFAM gene dysfunction, impairs nerve cell mitochondrial function and metabolism, contributing to ischemic stroke (IS) pathology.

Area of Science:

  • Mitochondrial biology
  • Neuroscience
  • Genetics

Background:

  • Mitochondrial DNA (mtDNA) copy number influences mitochondrial function and disease development.
  • The mechanisms underlying mtDNA copy number variation and its role in ischemic stroke (IS) are poorly understood.
  • Investigating mtDNA copy number variation is crucial for understanding IS pathogenesis.

Purpose of the Study:

  • To investigate the relationship between mtDNA copy number and ischemic stroke (IS).
  • To explore the impact of D-loop variations and TFAM gene on mtDNA copy number in IS.
  • To elucidate the effect of mtDNA copy number variation on mitochondrial function in nerve cells.

Main Methods:

  • Quantitative real-time PCR (qRT-PCR) to measure mtDNA copy number in 101 IS patients and 101 controls.
  • Construction of a TFAM gene knockdown-overexpression (KD-OE) PC12 cell model.
  • Transfection of HEK 293T cells with TFAM gene knockdown (Sh-TFAM) and over-expression (OE-TFAM) plasmids.

Main Results:

  • IS patients exhibited significantly lower mtDNA copy numbers compared to normal controls.
  • TFAM gene mRNA expression was significantly reduced in oxygen-glucose deprivation/reperfusion (OGD/R) treated cells.
  • TFAM knockdown decreased mtDNA copy number and ATP production, while TFAM overexpression increased them.

Conclusions:

  • Mitochondrial D-loop mutations and TFAM gene dysfunction contribute to decreased mtDNA copy number in IS.
  • Reduced mtDNA copy number negatively affects mitochondrial metabolism and nerve cell function.
  • These alterations play a role in the pathological mechanisms underlying ischemic stroke (IS).
Keywords:
TFAMischaemic strokemitochondrial functionmtDNA

More Related Videos

Use of Bisection to Reduce Mitochondrial DNA in the Bovine Oocyte06:15

Use of Bisection to Reduce Mitochondrial DNA in the Bovine Oocyte

Published on: July 6, 2022

2.2K
Author Spotlight: Decoding Mitochondrial Aging08:48

Author Spotlight: Decoding Mitochondrial Aging

Published on: June 30, 2023

4.2K

Related Concept Videos

Animal Mitochondrial Genetics02:59

Animal Mitochondrial Genetics

Among all the organelles in an animal cell, only mitochondria have their own independent genomes. Animal mitochondrial DNA is a double-stranded, closed-circular molecule with around 20,000 base pairs. Mitochondrial DNA is unique in that one of its two strands, the heavy, or H, -strand is guanine rich, whereas the complementary strand is cytosine rich and called the light, or L, -strand. Compared to nuclear DNA, mitochondrial DNA has a very low percentage of non-coding regions and is marked by...
8.0K
Electron Transport Chain: Complex I and II01:46

Electron Transport Chain: Complex I and II

The mitochondrial electron transport chain (ETC) is the main energy generation system in the eukaryotic cells. However, mitochondria also produce cytotoxic reactive oxygen species (ROS) due to the large electron flow during oxidative phosphorylation. While Complex I is one of the primary sources of superoxide radicals, ROS production by Complex II is uncommon and may only be observed in cancer cells with mutated complexes.
ROS generation is regulated and maintained at moderate levels necessary...
14.9K
ATP Synthase: Mechanism01:48

ATP Synthase: Mechanism

In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased...
15.1K
Myocarditis I: Introduction01:21

Myocarditis I: Introduction

Myocarditis is inflammation of the myocardium, which is the muscular layer of the heart.EtiologyMyocarditis has a diverse etiology, including a wide range of infectious and non-infectious causes:Infectious CausesViral: Common viruses include Coxsackie A and B, adenovirus, parvovirus B19, enteroviruses, and influenza A.Bacterial: Examples include infections caused by Streptococcus, Staphylococcus, and Mycoplasma species.Rickettsial: Infections like Rocky Mountain spotted fever can result in...
28
Mitochondria01:37

Mitochondria

Mitochondria are eukaryotic cellular organelles that are known to produce energy through a process called oxidative phosphorylation. Besides their primary function, mitochondria are involved in various cellular processes, including cell growth, differentiation, signaling, metabolism, and senescence. Age-related changes cause a decline in mitochondrial quality and integrity due to increased mitochondrial mutations and oxidative damage. Thus, aging can severely impact mitochondrial functions,...
14.6K
Mitochondrial Membranes01:45

Mitochondrial Membranes

A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...
12.0K