Project description:RNAseq analysis of gene expression in Liver of Control and JNK deficient mice fed a control or a High fat diet Contro(Albcre+)l and mice with liver-specific defiency of JNK (Alb Cre+ Jnk1flox/flox, Jnk2flox/flox or Jnk1flox/floxJnk2flox/flox) were fed a control or a high fat diet for 16 weeks. Gene expression analysis in liver was analyzed by RNAseq
Project description:Endothelial cell (EC) injury is a major contributing factor to vascular surgical failure. As such, understanding the mechanisms of endothelial healing is essential to the development of vascular therapeutics and procedures. Gap junctions formed by connexin 43 (Cx43) are implicated in regulating skin wound healing, but their role in endothelial healing is unknown. Secondary analysis of RNAseq data from in vivo injured mouse aortas (GEO: GSE115618), identified significant Cx43 upregulation in EC post-injury. We developed a novel in vivo model of EC injury using mouse carotid artery ligation to test the role of Cx43. We identified that EC immediately adjacent to the wound edge upregulate Cx43 protein expression, predominantly at cell-cell junctions. We show significantly delayed EC healing in a mouse model of inducible EC-specific Cx43 deletion (EC-Cx43 KO) at 24 hr post ligation. Single cell RNAseq analysis of 10,829 cells from 18 hr injured EC-WT and EC-Cx43 KO carotids revealed a Cx43-associated reduction in enrichment of EC pathways associated with migration, proliferation, and ERK/MAPK signaling pathways. Finally, the importance of Cx43 phosphorylation on EC healing was tested in mice with single-point alanine mutations (phospho-null) in known phosphorylation sites that alter Cx43 channel assembly and opening. Mice containing alanine mutations at ERK phosphorylated Cx43 serines (Cx43S255/262/279/282A) reduces healing rates similar to EC-Cx43 KO. These data suggest that EC injury-induced Cx43 upregulation, and subsequent Cx43 gap junction-mediated cell-to-cell communication are required for normal EC migration during wound healing after vascular injury.
Project description:Infertility observed in adult Sertoli cell (SC)-specific Connexin 43 Knockout-mice rather seems to be an effect of the disturbed SC-Germ cell (GC) crosstalk than a direct consequence of the loss of Cx43 protein in SC with important GC specific genes being mostly affected by this deletion. Identification of differentially expressed genes in testis of cx43 KO-mice at developmental stage 8 days post partum when compared with testis of WT-mice
Project description:Hematopoietic stem cells (HSCs) exhibit a distinctive antioxidant profile during steady-state and stress hematopoiesis. HSCs and multipotential progenitors (MPPs) are metabolically coupled to bone marrow mesenchymal stromal cells through mitochondrial transfer, a process dependent on hematopoietic connexin 43 (Cx43) and low adenosine monophosphate–activated protein kinase (AMPK) activity. However, the mechanism by which Cx43 preserves mitochondrial functionality in HSCs remains elusive. Here, through integrated transcriptomic, proteomic, metabolomic, phenotypic, and functional analyses of HSCs and their isolated mitochondria, we identified that Cx43 is present on the inner and outer mitochondrial membranes of HSCs/MPPs, in which it primarily regulates mitochondrial metabolism and adenosine triphosphate synthesis by preserving the mitochondrial cristae and activating mitochondrial AMPK and 2-oxoglutarate dehydrogenase, a rate-liming enzyme in tricarboxylic acid cycle and electron transfer chain. During replicative stress, Cx43-deficient HSCs/MPPs fail to adapt metabolically and accumulate mitochondrial Ca2+, leading to increased mitochondrial AMPK activity, mitochondrial fission, mitophagy, and production of reactive oxygen species, thereby limiting HSC/MPP regeneration potential. Disruption of hyperfragmentation of mitochondrial and mitophagy by Drp1 dominant-negative mutant (Drp1K38A) or restoration of mitochondrial function through ex vivo heteroplasmy prevents the harmful effects of Cx43 deficiency on mitochondrial metabolism and restore HSC activity in serial transplantation experiments. Re-expression analysis of Cx43 structure-function mutants indicates that Cx43 hemichannels are sufficient to reset HSC mitochondrial metabolism, dynamics, Ca2+ levels, and regeneration capacity. This report defines the cell-autonomous mechanism of action behind the role of Cx43 in HSC activity and opens a venue to translational applications in transplantation.
Project description:The gap junction protein connexin 43 (Cx43) has been implicated in the development of cardiac fibrosis. We found that Cx43 dephosphorylation at serine 282 (S282) is related to cardiomyocyte apoptosis and arrhythmias in hearts damaged by ischemia/reperfusion. Here, we investigated the effect of Cx43 S282 phosphorylation on fibrosis. We found a decrease in Cx43 S282 phosphorylation in transforming growth factor beta-1 (TGF-β)-induced fibrosis in fibroblasts and an angiotensin II-induced rat model. We transferred a lentivirus with S282A (alanine) into cardiac fibroblasts and an adenovirus with S282A into the hearts of rats. We found that the Cx43 S282A mutation caused fibrosis in cardiac fibroblasts and in the hearts of rats, which suggested that the phosphorylation of Cx43 S282 is important in the development of fibrosis. Furthermore, mRNA sequencing showed that Cx43 dephosphorylation at S282 increased the expression of Dchs1, and Dchs1 inhibited Yes-associated protein (YAP) phosphorylation, subsequently activating the YAP/TEAD signaling pathway and increasing the development of fibrosis. This study suggests that the phosphorylation of Cx43 S282 could be an effective antifibrotic target in cardiac fibroblasts, indicating a novel mechanism and a molecular target that might be promising for the treatment of cardiac fibrosis.
Project description:Objective: We previously reported that white matter connexin43 (Cx43) may related to the severity of the multiple sclerosis (MS), whereas the role of gray matter Cx43 in demyelinating disease is unknown. It was considered MS lesions were only exist in white matter, but recent studies revealed that demyelinating lesions are also exist in the cerebral cortex. This fact suggest the possibility that gray matter is somewhat related to the pathophysiology of MS. In this study, we aimed to clarify the role of gray matter Cx43 in a mouse model of MS (experimental autoimmune encephalomyelitis [EAE]). Methods: We developed Cx43F/F;Glutamate aspartate transporter (GLAST)-CreER(T2)KI/+ mice as gray matter specific Cx43 conditional knock-out (Cx43cKO) mice. We induced MOG-EAE 10 days after tamoxifen injection, and analyze its clinical course and pathology. We used Cx43F/F mice as controls. Results: EAE was significantly milder in gray matter astrocyte-specific Cx43cKO mice from acute phase to chronic phase, as compared with control mice. Pathology demonstrated less demyelinating lesions and infiltrating cells. Infiltrating immune cells did not express Cx43 in the active demyelinating lesions of the lumbar cord in both groups. The expression level of Cx43 was similar between these two groups in the spleen and the inguinal lymph nodes. Interpretation: Acute KO of gray matter specific Cx43 before induction of EAE reduce its aggressiveness. This finding may suggest the possibility that gray matter Cx43 modify the MS pathophysiology.
Project description:Objective: We previously reported that white matter connexin43 (Cx43) may related to the severity of the multiple sclerosis (MS), whereas the role of gray matter Cx43 in demyelinating disease is unknown. It was considered MS lesions were only exist in white matter, but recent studies revealed that demyelinating lesions are also exist in the cerebral cortex. This fact suggest the possibility that gray matter is somewhat related to the pathophysiology of MS. In this study, we aimed to clarify the role of gray matter Cx43 in a mouse model of MS (experimental autoimmune encephalomyelitis [EAE]). Methods: We developed Cx43F/F;Glutamate aspartate transporter (GLAST)-CreER(T2)KI/+ mice as gray matter specific Cx43 conditional knock-out (Cx43cKO) mice. We induced MOG-EAE 10 days after tamoxifen injection, and analyze its clinical course and pathology. We used Cx43F/F mice as controls. Results: EAE was significantly milder in gray matter astrocyte-specific Cx43cKO mice from acute phase to chronic phase, as compared with control mice. Pathology demonstrated less demyelinating lesions and infiltrating cells. Infiltrating immune cells did not express Cx43 in the active demyelinating lesions of the lumbar cord in both groups. The expression level of Cx43 was similar between these two groups in the spleen and the inguinal lymph nodes. Interpretation: Acute KO of gray matter specific Cx43 before induction of EAE reduce its aggressiveness. This finding may suggest the possibility that gray matter Cx43 modify the MS pathophysiology.
Project description:Microarray analysis of WT (Pten2fl/fl:Shp2fl/fl:Alb-Cre-), SKO (Shp2hep-/-, or Shp2fl/fl:Alb-Cre+), PKO (Ptenhep-/-, or Pten2fl/fl:Alb-Cre+) and DKO (Ptenfl/fl:Shp2fl/fl:Alb-Cre+) liver samples to gain global molecular insights how shp2 and pten is involved in liver tumorigenesis.
Project description:BAC array purification of hippocampus astroglial ribosome-bound transcriptome in astrocytes from Aldh1l1:Rpl10a eGFP/ Cx43 KO and Aldh1l1:Rpl10a eGFP/ Cx43FL mice
Project description:Connexin 43 (Cx43) plays a crucial role in maintaining synchronous contraction in the heart. However, it remains unclear whether Cx43 directly influences the contractile force and synchrony of entire cardiac tissues. Previously, we successfully developed human-induced pluripotent stem cell (hiPSC)-derived cardiac tissues capable of directly measuring both the contractile force of the entire tissue and cellular synchrony within it. This study aimed to evaluate whether regulating GJA1, the gene encoding Cx43, could enhance contractility and synchrony in these tissues. Using adeno-associated virus (AAV), we mediated GJA1 overexpression (OE) or knockdown (shGJA1) in bioengineered hiPSC-derived cardiac tissues. Under electrical stimulation at 60 ppm, there were no significant differences in contractile force between the AAV-GJA1-OE and control tissues (0.78 ± 0.39 vs. 0.98 ± 0.43 mN, p = 0.32). Synchrony levels were also similar between these groups (p = 0.20). In contrast, shGJA1 tissues demonstrated significantly higher contractile force compared to scramble controls (1.55 ± 0.38 vs. 1.20 ± 0.15 mN, p = 0.039), although the difference in synchrony was not statistically significant (p = 0.08). RNA sequencing data revealed that a total of 37,199 genes were detected, comparing AAV6-GFP control and GJA1-OE treated hiPSC-CMs, as well as AAV6-shRNA scramble and shGJA1 treated hiPSC-CMs. We highlighted several candidate genes potentially contributing to the enhanced contractile force observed in the shGJA1 group. Furthermore, nineteen common genes were identified between the upregulation of shGJA1 compared to scramble and downregulation of GJA1-OE compared to control, which were associated with cell proliferation, transcription, contraction, and BMP signaling pathways. In conclusion, Cx43-OE did not appear to influence contractility and synchrony, meanwhile, Cx43 suppression may effectively improve contractility without impairing the synchrony in the entire cardiac tissues. Cx43 expression beyond a certain threshold may be sufficient to maintain synchronous contraction in the tissues.