Loss of TFB1M results in mitochondrial dysfunction that leads to impaired insulin secretion and diabetes. / Sharoyko, Vladimir V.; Abels, Mia; Sun, Jiangming; Nicholas, Lisa M.; Mollet, Ines Guerra; Stamenkovic, Jelena A.; Göhring, Isabel; Malmgren, Siri; Storm, Petter; Fadista, Joaõ; Spégel, Peter; Metodiev, Metodi D.; Larsson, Nils Göran5; Eliasson, Lena; Wierup, Nils; Mulder, Hindrik.
In: Human Molecular Genetics, Vol. 23, No. 21, 01.11.2014, p. 5733-5749.Research output: Contribution to journal › Article › peer-review
}
TY - JOUR
T1 - Loss of TFB1M results in mitochondrial dysfunction that leads to impaired insulin secretion and diabetes
AU - Sharoyko, Vladimir V.
AU - Abels, Mia
AU - Sun, Jiangming
AU - Nicholas, Lisa M.
AU - Mollet, Ines Guerra
AU - Stamenkovic, Jelena A.
AU - Göhring, Isabel
AU - Malmgren, Siri
AU - Storm, Petter
AU - Fadista, Joaõ
AU - Spégel, Peter
AU - Metodiev, Metodi D.
AU - Larsson, Nils Göran5
AU - Eliasson, Lena
AU - Wierup, Nils
AU - Mulder, Hindrik
PY - 2014/11/1
Y1 - 2014/11/1
N2 - Wehave previously identifiedtranscription factorB1mitochondrial (TFB1M)as a type 2 diabetes (T2D) risk gene, using human and mouse genetics. To further understand the function of TFB1M and how it is associated with T2D, we created a b-cell-specific knockout of Tfb1m, which gradually developed diabetes. Prior to the onset of diabetes, b-Tfb1m2/2 mice exhibited retarded glucose clearance owing to impaired insulin secretion. b-Tfb1m2/2 islets released less insulin in response to fuels, contained less insulin and secretory granules and displayed reduced b-cell mass. Moreover, mitochondria in Tfb1m-deficient b-cells were more abundant with disrupted architecture. TFB1M is known to control mitochondrial protein translation by adenine dimethylation of 12S ribosomalRNA(rRNA). Here,wefound that the levels ofTFB1Mand mitochondrial-encoded proteins, mitochondrial 12S rRNA methylation, ATP production and oxygen consumption were reduced in b-Tfb1m2/2 islets. Furthermore, the levels of reactive oxygen species (ROS) in response to cellular stress were increased whereas induction of defense mechanisms was attenuated. We also show increased apoptosis and necrosis as well as infiltration of macrophages and CD41 cells in the islets. Taken together, our findings demonstrate that Tfb1m-deficiency in b-cells caused mitochondrial dysfunction and subsequently diabetes owing to combined loss of b-cell function and mass. These observations reflect pathogenetic processes in human islets: using RNA sequencing, we found that the TFB1M risk variant exhibited a negative gene-dosage effect on islet TFB1M mRNA levels, as well as insulin secretion. Our findings highlight the role of mitochondrial dysfunction in impairments of b-cell function and mass, the hallmarks of T2D.
AB - Wehave previously identifiedtranscription factorB1mitochondrial (TFB1M)as a type 2 diabetes (T2D) risk gene, using human and mouse genetics. To further understand the function of TFB1M and how it is associated with T2D, we created a b-cell-specific knockout of Tfb1m, which gradually developed diabetes. Prior to the onset of diabetes, b-Tfb1m2/2 mice exhibited retarded glucose clearance owing to impaired insulin secretion. b-Tfb1m2/2 islets released less insulin in response to fuels, contained less insulin and secretory granules and displayed reduced b-cell mass. Moreover, mitochondria in Tfb1m-deficient b-cells were more abundant with disrupted architecture. TFB1M is known to control mitochondrial protein translation by adenine dimethylation of 12S ribosomalRNA(rRNA). Here,wefound that the levels ofTFB1Mand mitochondrial-encoded proteins, mitochondrial 12S rRNA methylation, ATP production and oxygen consumption were reduced in b-Tfb1m2/2 islets. Furthermore, the levels of reactive oxygen species (ROS) in response to cellular stress were increased whereas induction of defense mechanisms was attenuated. We also show increased apoptosis and necrosis as well as infiltration of macrophages and CD41 cells in the islets. Taken together, our findings demonstrate that Tfb1m-deficiency in b-cells caused mitochondrial dysfunction and subsequently diabetes owing to combined loss of b-cell function and mass. These observations reflect pathogenetic processes in human islets: using RNA sequencing, we found that the TFB1M risk variant exhibited a negative gene-dosage effect on islet TFB1M mRNA levels, as well as insulin secretion. Our findings highlight the role of mitochondrial dysfunction in impairments of b-cell function and mass, the hallmarks of T2D.
UR - http://www.scopus.com/inward/record.url?scp=84911361474&partnerID=8YFLogxK
U2 - 10.1093/hmg/ddu288
DO - 10.1093/hmg/ddu288
M3 - Article
C2 - 24916378
VL - 23
SP - 5733
EP - 5749
JO - Human Molecular Genetics
JF - Human Molecular Genetics
SN - 0964-6906
IS - 21
ER -
ID: 5715990