Mitochondrial Medicine & Neurogenetics (MMN)


There has not been added a translated version of this content. You can either try searching or go to the "area" home page to see if you can find the information there


Congratulations! Dr. Kristina Xiao Liang has been honored with grant from PolG Fondation

Dr. Kristina Xiao Liang has been honored with a coveted grant from the PolG Foundation, marking a significant milestone in the quest to combat POLG diseases. The primary objective of this research project is to establish a cutting-edge human stem cell-based 2D neural system and 3D brain organoid platform. These platforms are poised to revolutionize drug discovery by facilitating the identification of mitochondria-targeting therapies that are not only effective but also readily adaptable for repurposing. This breakthrough research aims to accelerate the development of potential treatments, expediting their journey to clinical trials for POLG patients. See more information via the link: https://lnkd.in/d42Ag8r5

Dr. Kristina Xiao Liang
Dr. Kristina Xiao Liang

Warm Welcome to Our New Members: Shraboni Debnath and Nathnael Tezera Tuffa as They Begin Their Master's Project!

We are delighted to introduce Shraboni Debnath and Nathnael Tezera Tuffa from the Department of Global Health. They are embarking on their master's project focused on developing drug screening methods for treating POLG disease and neurodegeneration. A hearty welcome to both of you! We are confident that you will have a rewarding journey with our stem cell group.

Master Students
MMN New Master Students


Our group has just published a Method/Video paper in JoVE. This report details a novel flow cytometry-based approach to measure multiple mitochondrial parameters in different cell types, including human induced pluripotent stem cells (iPSCs) and iPSC-derived neural and glial cells.Our protocol provides the scientist with a powerful tool for marrying multiple micro parameters at single cell level from human IPS and their neuro and clear derivatives. This protocols allow the merriment of mitochondrial parameters, both at the total level and the specific level per mitochondrial volume, using flow cytometry. This technique can be applied to several cell types including those from other neurodegenerative diseases.

From JoVE

Welcome to our new Master's student starting from 2022

Great welcome to Bjørn Christian Lundberg, Sharika Marjan, and Tsering Yangzom to join our MMN group and work on different stem cell projects. We wish you a great achievement during your masters' study.


New master students in 2022-2023
From Tsering, Sharika and Bjørn

Congratulations - our research published on social media

- Stem cell research may offer new hope for people with severe epilepsy

Kristina Xiao Liang rekonstruerer mitokondriesykdom ved hjelp av stamceller. Foto: Kim E. Andreassen/ Universitetet i Bergen
Kristina Xiao Liang rekonstruerer mitokondriesykdom ved hjelp av stamceller. Foto: Kim E. Andreassen/ Universitetet i Bergen

With the help of stem cell research, researchers at the University of Bergen have succeeded in reconstructing the course of disease in mitochondrial failure. It could be a step towards the treatment of severe epilepsy and other brain disorders.

The mitochondria convert food into energy in our cells and move to the areas where the energy is needed. Failure of the mitochondria can lead to serious illness. The brain, which requires a lot of energy, is particularly vulnerable. Mitochondrial failure in the brain can lead to severe epilepsy, for which there is currently no treatment. Stem cells are a unique type of cells that are responsible for repairing damage and maintaining tissues in the body. Every day thousands of cells die, and the stem cells are responsible for producing new cells, thus repairing and maintaining our organs. It is these cells from which a human embryo develops, and they are found in all the body's organs and tissues. Scientists hope that the stem cells can be used to cure more and more diseases and to create new organs. And with the help of stem cell research, researchers at the University of Bergen have, as the first ever, managed to create cell tissue that is usually destroyed by the gene mutation in the mitochondria. The researchers have converted the patient's skin cells into stem cells, and then developed them into nerve cells. - Since we have now found a research method that reproduces the actual course of the disease, we can use it to test out different treatment methods, says researcher Kristina Xiao Liang, at Clinical Institute 1, at the University of Bergen. - This could be a promising step towards the treatment of mitochondrial diseases such as severe epilepsy.

Read the entire article on the website of the University of Bergen.



Our group has just published a major study in Frontiers in Cell and Developmental Biology. In this study, we reveal that impaired mitophagy is involved in the observed mitochondrial dysfunction caused by POLG mutations in astrocytes, potentially contributing to the phenotype in POLG-related diseases. This study also demonstrates the therapeutic potential of NR and metformin in these incurable mitochondrial diseases.

from MMN group


Kristin Nielsen Varhaug will present her dissertation for the Ph.D. degree with the thesis "Mitochondrial biomarkers and biomarkers of mitochondrial disease" on November 26th, 2021. The main supervisor for this thesis was Professor Laurence A. Bindoff and co-supervisor was Professor Christian A. Vedeler.

from MMN group



In this study, we established for the first time a direct link between an altered mitochondrial function and amyloid neurodegeneration. 

In this collaborative study, we described the first family with a (recessive) pathological mutation in the gene encoding PITRM1, the mitochondrial matrix metallopeptidase that digests mitochondrial targeting sequences after cleavage by the mitochondrial matrix peptidase. The PITRM1 mutation was associated with a slowly progressive neurodegenerative condition characterized by mild mental retardation, spinocerebellar ataxia with cerebellar atrophy, and psychosis.

We confirmed the pathogenicity of the mutation by investigating mutant and RNAi cells, and a yeast model (the yeast ortholog is CYM1). In vitro assays carried out on the recombinant protein expressed in E. coli, led us to conclude that the mutation causes severe protein instability mimicking a condition of haploinsufficiency. Investigations of a Pitrm1-/+ mouse model (the Pitrm1-/- individuals are embryonic lethal), also showed reduced Pitrm1 protein in different tissues and the animals developed a progressive neurological syndrome characterized by ataxia, behavioral impairment, and abnormal bioenergetics parameters in vivo.

Interestingly, neuropathological investigation of these animals revealed the accumulation of Amyloid Precursor Protein and amyloid-beta (Aβ) deposits, similar to the amyloid plaques seen in Alzheimer's disease brains (see figure). The accumulation of Aβ supports the hypothesis that PITRM1 is involved in the quantitative digestion of a fraction of Aβ and that this protein product is indeed contained within mitochondria. This observation has been controversial and our findings confirm this for the first time in a mammalian model.

This work was a collaboration between groups from Norway (Bergen - MMN & Center for Medical Genetics and Molecular Medicine; Førde), UK (MBU, Cambridge), Italy (Rome, Parma) and Sweden (Stockholm).


from Pubmed



Omar Hikmat presented his dissertation for the Ph.D. degree with the thesis "The phenotypic spectrum of polymerase gamma (POLG) disease from birth to late adulthood" on September 25th, 2020. The main supervisor for this thesis was Professor Laurence A. Bindoff and the co-supervisor was Professor Charalampos Tzoulis

Omar Hikmat
Omar Hikmat, photo is from UiB website.



Using stem cell technology, our group has managed to reconstruct disease progression in mitochondrial failure. This can be a step towards the treatment of severe epilepsy and other brain diseases. Our group has managed to reconstruct disease progression in mitochondrial failure. This can be a step towards the treatment of severe epilepsy and other brain diseases. The study is published in EMBO Molecular Medicine.  


NSC paper
from EMBO mol. med.



Our group has attended the 6th Bergen Stem cell Consortium (BSCC) annual meeting in Solstrand Hotel & Bad on 19-20, October 2019. , This is a networking event with basic and clinical research updates in the field of stem cells and regenerative medicine. Senior researcher Kristina Xiao Liang presented a talk on “Using induced pluripotent stem cells (iPSCs) to model mitochondrial disease, study tissue-specific manifestations and investigate treatments”. Postdoc. Yu Hong and Ph.D. fellows Cecilie, Sepideh, and Anbin gave a lightning talk in the meeting. 

6th annual meeting
Lightning talk section, photo is from Kristina Xiao Liang.


Our group has recently published a new paper on “A method for differentiating human induced pluripotent stem cells toward functional cardiomyocytes in 96-well microplates”. In this study, Novin Balafkan (first author) and Sepideh Mostafavi (co-first author) et al. developed a protocol for efficient differentiation towards cardiomyocytes from iPSCs using a defined, serum-free culture medium combined with small molecules. We believe that this technique will improve the applicability of these cells for use in developmental biology and mechanistic studies of disease. The study is published in Scientific Report. 

Novin paper
from Scientific Report



As one of the research groups in Bergen Stem Cell Consortium (BSCC). We have organized and attended the 5th BSCC annual meeting in Hotel Scandic Ørnen on 3-4, October 2019.

from UiB website