Epigenetics #PulmonaryArterialHypertension

JMJD1C a histone demethylase
⏫p-STAT3->
#Glycolysis HK2/PGK1/LDHA->
⏫PA #SmoothMuscleCell Proliferation

Serum Lactate⏬by AAV2-shJMJD1C in🐭#Hypoxia-PAH
Local effect on #EndMT?

Dr H Zhao lab Cell Death Discovery 2023
https://www.nature.com/articles/s41420-023-01390-5

JMJD1C promotes smooth muscle cell proliferation by activating glycolysis in pulmonary arterial hypertension - Cell Death Discovery

Pulmonary arterial hypertension (PAH) is a chronic disorder characterized by hyperproliferation of pulmonary arterial smooth muscle cells (PASMCs). JMJD1C, a member of the Jumonji domain containing C (JMJC) histone demethylase family, contributes to cardiovascular dysfunction. However, the role of JMJD1C in PAH remains unknown. Mice were exposed to hypoxia to mimic several features associated with PAH clinically. We found that JMJD1C was highly expressed in the lungs of mice after hypoxia exposure. JMJD1C knockdown ameliorated hypoxia-induced right ventricular remodeling and thickening of the pulmonary arterial wall. PASMC hyperproliferation and resistance to apoptosis in mice exposed to hypoxia were suppressed by JMJD1C inhibition. We demonstrated that JMJD1C silencing reduced glycolytic enzymes (HK2, PGK1 and LDHA) and lactate overaccumulation in the lungs of mice exposed to hypoxia. In vitro, hypoxia-induced hyperproliferation and activated glycolytic processes in mouse PASMCs were impaired by JMJD1C knockdown. In addition, the activation of STAT3 signaling by hypoxia was suppressed by JMJD1C silencing both in vivo and in vitro. The overexpression of STAT3 reversed the inhibitory effect of JMJD1C depletion on proliferation and glycolysis in PASMCs under hypoxia. Thus, JMJD1C induces glycolytic processes by activating STAT3 signaling to promote PASMC proliferation and pulmonary vascular remodeling, suggesting the potential role of JMJD1C in regulating the metabolic program and vascular remodeling in PAH.

Nature

#ArterioVenousFistula #EndMT

Low #OscillatoryShearStress->
⏫Osteopontin-CD44 in #EndothelialCell->
⏫EndMT->
⏫24% of neointimal cells at rat aortocaval junction

A cascade independent of #HyaluronicAcid🤓

Dr. Yung-Hsin Yeh lab Kidney Int 2023
https://www.kidney-international.org/article/S0085-2538(23)00011-X/fulltext

Partial #EndMT,⏫by #Hypoxia-induced CD45, as a major cellular source for neointima formation

50% ECs in ligated artery are CD45+

CD45 is required to maintain this Partial status
Amazing!🤩

Dr. Yoshito Yamashiro & Yoshito Yamashiro lab #CardiovascRes 2022
https://academic.oup.com/cardiovascres/advance-article/doi/10.1093/cvr/cvac190/6942105

How CD45 titrates the extent of mesenchymalization of #EndothelialCell?

CD45 stabilizes VE-cad junction via fortifying integrin α11-SHARPIN complex

Very interesting data on Biomechanics of #EndMT 😋

What (beyond CD45) control partial-to-complete EndMT transition?🤓

Induced #EndothelialCell KLF4 KO in adult🐭->
Lung Inflammation+Fibrosis within 1 month😎

KLF4-KO EC has⏫KLF2 & #EndMT simultaneously!
Perturbed shear-sensing?
Link b/w⏫KLF2 & #EndMT?
EC secretome? So interesteing😆

Dr. Kishore Wary lab @FrontCellDevBio 2022 @KishoreWary
https://www.frontiersin.org/articles/10.3389/fcell.2022.1003028/full

A requirement for Krüppel Like Factor‐4 in the maintenance of endothelial cell quiescence

Rationale and Goal: Endothelial cells (ECs) are quiescent and critical for maintaining homeostatic functions of the mature vascular system, while disruption of quiescence is at the heart of endothelial to mesenchymal transition (EndMT) and tumor angiogenesis. Here, we addressed the hypothesis that KLF4 maintains the EC quiescence.Methods and Results: In ECs, KLF4 bound to KLF2, and the KLF4-transctivation domain (TAD) interacted directly with KLF2. KLF4-depletion increased KLF2 expression, accompanied by phosphorylation of SMAD3, increased expression of alpha-smooth muscle actin (αSMA), VCAM-1, TGF-β1, and ACE2, but decreased VE-cadherin expression. In the absence of Klf4, Klf2 bound to the Klf2-promoter/enhancer region and autoregulated its own expression. Loss of EC-Klf4 in RosamT/mG::Klf4fl/fl::Cdh5CreERT2 engineered mice, increased Klf2 levels and these cells underwent EndMT. Importantly, these mice harboring EndMT was also accompanied by lung inflammation, disruption of lung alveolar architecture, and pulmonary fibrosis.Conclusion: In quiescent ECs, KLF2 and KLF4 partnered to regulate a combinatorial mechanism. The loss of KLF4 disrupted this combinatorial mechanism, thereby upregulating KLF2 as an adaptive response. However, increased KLF2 expression overdrives for the loss of KLF4, giving rise to an EndMT phenotype.

Frontiers

Evidence on #EndMT in human #MultipleSclerosis

Inflammation-induced endothelial to mesenchymal transition promotes brain endothelial cell dysfunction & occurs during multiple sclerosis pathophysiology

Dr. Helga de Vries lab Cell Death Dis 2019
https://www.nature.com/articles/s41419-018-1294-2

Inflammation-induced endothelial to mesenchymal transition promotes brain endothelial cell dysfunction and occurs during multiple sclerosis pathophysiology - Cell Death & Disease

The blood-brain barrier (BBB) has a major role in maintaining brain homeostasis through the specialized function of brain endothelial cells (BECs). Inflammation of the BECs and loss of their neuroprotective properties is associated with several neurological disorders, including the chronic neuro-inflammatory disorder multiple sclerosis (MS). Yet, the underlying mechanisms of a defective BBB in MS remain largely unknown. Endothelial to mesenchymal transition (EndoMT) is a pathophysiological process in which endothelial cells lose their specialized function and de-differentiate into mesenchymal cells. This transition is characterized by an increase in EndoMT-related transcription factors (TFs), a downregulation of brain endothelial markers, and an upregulation of mesenchymal markers accompanied by morphological changes associated with cytoskeleton reorganization. Here, we postulate that EndoMT drives BEC de-differentiation, mediates inflammation-induced human BECs dysfunction, and may play a role in MS pathophysiology. We provide evidence that stimulation of human BECs with transforming growth factor (TGF)-β1 and interleukin (IL)-1β promotes EndoMT, a process in which the TF SNAI1, a master regulator of EndoMT, plays a crucial role. We demonstrate the involvement of TGF-β activated kinase 1 (TAK1) in EndoMT induction in BECs. Finally, immunohistochemical analysis revealed EndoMT-associated alterations in the brain vasculature of human post-mortem MS brain tissues. Taken together, our novel findings provide a better understanding of the molecular mechanisms underlying BECs dysfunction during MS pathology and can be used to develop new potential therapeutic strategies to restore BBB function.

Nature

#EndothelialCell ARF6 GTPase links IL-1β inflammation with TGFβ/BMP-SMAD1/5 #EndMT

EC Arf6 KO in🐭#EAE->
#BBB #BloodSpinalCordBarrier
⏬T cell infiltration & demyelination
w/o altering normal immunity

Dr. Shannon Odelberg, Weiquan Zhu labs Neuron 2022
https://www.sciencedirect.com/science/article/pii/S0896627322006602