scholarly journals Generation of functional liver organoids on combining hepatocytes and cholangiocytes with hepatobiliary connections ex vivo

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Naoki Tanimizu ◽  
Norihisa Ichinohe ◽  
Yasushi Sasaki ◽  
Tohru Itoh ◽  
Ryo Sudo ◽  
...  
Keyword(s):  
Liver Tissue ◽  
Ex Vivo ◽  
Drainage System ◽  
Functional Connection ◽  
Functional Connections ◽  
Intrahepatic Bile Ducts ◽  
Metabolic Functions ◽  
Bile Drainage ◽  
Liver Organoids

AbstractIn the liver, the bile canaliculi of hepatocytes are connected to intrahepatic bile ducts lined with cholangiocytes, which remove cytotoxic bile from the liver tissue. Although liver organoids have been reported, it is not clear whether the functional connection between hepatocytes and cholangiocytes is recapitulated in those organoids. Here, we report the generation of a hepatobiliary tubular organoid (HBTO) using mouse hepatocyte progenitors and cholangiocytes. Hepatocytes form the bile canalicular network and secrete metabolites into the canaliculi, which are then transported into the biliary tubular structure. Hepatocytes in HBTO acquire and maintain metabolic functions including albumin secretion and cytochrome P450 activities, over the long term. In this study, we establish functional liver tissue incorporating a bile drainage system ex vivo. HBTO enable us to reproduce the transport of hepatocyte metabolites in liver tissue, and to investigate the way in which the two types of epithelial cells establish functional connections.

scholarly journals Generation of functional liver tissue by establishing hepatobiliary connections ex vivo

2020 ◽  
Author(s):  
Naoki Tanimizu ◽  
Norihisa Ichinohe ◽  
Yasushi Sasaki ◽  
Tohru Itoh ◽  
Ryo Sudo ◽  
...  
Keyword(s):  
Liver Tissue ◽  
Ex Vivo ◽  
Drainage System ◽  
Bile Canaliculi ◽  
Mouse Hepatocyte ◽  
Functional Connections ◽  
Intrahepatic Bile Ducts ◽  
Metabolic Functions ◽  
Bile Drainage

Abstract In the liver, the bile canaliculi of hepatocytes are connected to intrahepatic bile ducts lined with cholangiocytes, which remove cytotoxic bile from the liver tissue. We have developed a hepatobiliary organoid using mouse hepatocyte progenitors and cholangiocytes. Hepatocyte metabolites were secreted into the bile canaliculi, and then transported into the biliary structure. Hepatocytes in the organoid acquired and maintained metabolic functions including albumin secretion and cytochrome P450 activities, over the long term. In this study, we established functional liver tissue incorporating a bile drainage system ex vivo. This hepatobiliary organoid enabled us to reproduce the transport of hepatocyte metabolites in liver tissue, and to investigate the way in which the two types of epithelial cells establish functional connections.

scholarly journals Generation of mouse hepatobiliary organoids from hepatocyte progenitors and cholangiocytes isolated from healthy adult mouse liver

2021 ◽  
Author(s):  
Naoki Tanimizu ◽  
Norihisa Ichinohe ◽  
Yasushi Sasaki ◽  
Tohru Itoh ◽  
Ryo Sudo ◽  
...  
Keyword(s):  
Adult Mouse ◽  
Functional Connection ◽  
Report Generation ◽  
Mouse Hepatocyte ◽  
Functional Connections ◽  
Metabolic Functions ◽  
Small Hepatocytes ◽  
Liver Organoids ◽  
Adult Mouse Liver

Abstract Number of liver organoids have been reported, though it is not clearly shown whether the functional connection between hepatocytes and cholangiocytes is recapitulated in those organoids. Here, we report generation of a hepatobiliary tubular organoid (HBTO) using mouse hepatocyte progenitors called small hepatocytes (SHs) and cholangiocytes. SHs differentiate and form the bile canalicular network in HBTOs and secret metabolites into the canaliculi, which are then transported into the biliary structure. Hepatocytes in the organoid acquire and maintain metabolic functions including albumin secretion and cytochrome P450 activities, over the long term. We provide the step-by-step protocol for induction of HBTO including isolation of cholangiocytes and SHs and co-culture of these two types of cell to generate functional connections between hepatocytes and cholangiocytes.

P12 LONG-TERM MAINTENANCE OF HUMAN LIVER TISSUE BY EX-VIVO PERFUSION OF LIVER SECTIONS

2014 ◽  
Vol 60 (1) ◽  
pp. S70
Author(s):  
T. Schreiter ◽  
J.-P. Sowa ◽  
Z. Mathé ◽  
J. Treckmann ◽  
M. Bröcker-Preuß ◽  
...  
Keyword(s):  
Liver Tissue ◽  
Human Liver ◽  
Ex Vivo ◽  
Human Liver Tissue ◽  
Ex Vivo Perfusion ◽  
Term Maintenance

Long-term maintenance of human liver tissue by ex-vivo perfusion of liver sections

2014 ◽  
Vol 52 (01) ◽  
Author(s):  
T Schreiter ◽  
J Sowa ◽  
Z Mathe ◽  
J Treckmann ◽  
M Broecker-Preuß ◽  
...  
Keyword(s):  
Liver Tissue ◽  
Human Liver ◽  
Ex Vivo ◽  
Human Liver Tissue ◽  
Ex Vivo Perfusion ◽  
Term Maintenance

Differential Outcomes for Long Term ex vivo Lung Perfusion in a Porcine Model - With or without Red Cells?

2015 ◽  
Vol 63 (S 01) ◽  
Author(s):  
W. Sommer ◽  
M. Avsar ◽  
J. Salman ◽  
C. Kühn ◽  
I. Tudorache ◽  
...  
Keyword(s):  
Porcine Model ◽  
Ex Vivo ◽  
Lung Perfusion ◽  
Red Cells ◽  
Ex Vivo Lung Perfusion ◽  
Differential Outcomes

Strategies to Protect Hematopoietic Stem Cells from Culture-Induced Stress Conditions

2020 ◽  
Vol 15 ◽  
Author(s):  
Fatima Aerts-Kaya
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Ex Vivo ◽  
Stress Conditions ◽  
Stress Factors ◽  
Hematopoietic Stem ◽  
Induced Stress

: In contrast to their almost unlimited potential for expansion in vivo and despite years of dedicated research and optimization of expansion protocols, the expansion of Hematopoietic Stem Cells (HSCs) in vitro remains remarkably limited. Increased understanding of the mechanisms that are involved in maintenance, expansion and differentiation of HSCs will enable the development of better protocols for expansion of HSCs. This will allow procurement of HSCs with long-term engraftment potential and a better understanding of the effects of the external influences in and on the hematopoietic niche that may affect HSC function. During collection and culture of HSCs, the cells are exposed to suboptimal conditions that may induce different levels of stress and ultimately affect their self-renewal, differentiation and long-term engraftment potential. Some of these stress factors include normoxia, oxidative stress, extra-physiologic oxygen shock/stress (EPHOSS), endoplasmic reticulum (ER) stress, replicative stress, and stress related to DNA damage. Coping with these stress factors may help reduce the negative effects of cell culture on HSC potential, provide a better understanding of the true impact of certain treatments in the absence of confounding stress factors. This may facilitate the development of better ex vivo expansion protocols of HSCs with long-term engraftment potential without induction of stem cell exhaustion by cellular senescence or loss of cell viability. This review summarizes some of available strategies that may be used to protect HSCs from culture-induced stress conditions.

scholarly journals Protein recycling and limb muscle recovery after critical illness in slow- and fast-twitch limb muscle

2019 ◽  
Vol 316 (5) ◽  
pp. R584-R593 ◽  
Author(s):  
Sebastien Preau ◽  
Michael Ambler ◽  
Anna Sigurta ◽  
Anna Kleyman ◽  
Alex Dyson ◽  
...  
Keyword(s):  
Critical Illness ◽  
Functional Disability ◽  
Ex Vivo ◽  
Therapeutic Option ◽  
Limb Muscle ◽  
Fungal Cell ◽  
Hindlimb Muscles ◽  
Initial Reduction ◽  
Male Wistar Rats

An impaired capacity of muscle to regenerate after critical illness results in long-term functional disability. We previously described in a long-term rat peritonitis model that gastrocnemius displays near-normal histology whereas soleus demonstrates a necrotizing phenotype. We thus investigated the link between the necrotizing phenotype of critical illness myopathy and proteasome activity in these two limb muscles. We studied male Wistar rats that underwent an intraperitoneal injection of the fungal cell wall constituent zymosan or n-saline as a sham-treated control. Rats ( n = 74) were killed at 2, 7, and 14 days postintervention with gastrocnemius and soleus muscle removed and studied ex vivo. Zymosan-treated animals displayed an initial reduction of body weight but a persistent decrease in mass of both lower hindlimb muscles. Zymosan increased chymotrypsin- and trypsin-like proteasome activities in gastrocnemius at days 2 and 7 but in soleus at day 2 only. Activated caspases-3 and -9, polyubiquitin proteins, and 14-kDa fragments of myofibrillar actin (proteasome substrates) remained persistently increased from day 2 to day 14 in soleus but not in gastrocnemius. These results suggest that a relative proteasome deficiency in soleus is associated with a necrotizing phenotype during long-term critical illness. Rescuing proteasome clearance may offer a potential therapeutic option to prevent long-term functional disability in critically ill patients.

scholarly journals Aη-α and Aη-β peptides impair LTP ex vivo within the low nanomolar range and impact neuronal activity in vivo

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Maria Mensch ◽  
Jade Dunot ◽  
Sandy M. Yishan ◽  
Samuel S. Harris ◽  
Aline Blistein ◽  
...  
Keyword(s):  
Neuronal Activity ◽  
Ex Vivo ◽  
Long Term Potentiation ◽  
Network Activity ◽  
Strongly Correlated ◽  
App Processing ◽  
Term Potentiation ◽  
Hippocampal Network

Abstract Background Amyloid precursor protein (APP) processing is central to Alzheimer’s disease (AD) etiology. As early cognitive alterations in AD are strongly correlated to abnormal information processing due to increasing synaptic impairment, it is crucial to characterize how peptides generated through APP cleavage modulate synapse function. We previously described a novel APP processing pathway producing η-secretase-derived peptides (Aη) and revealed that Aη–α, the longest form of Aη produced by η-secretase and α-secretase cleavage, impaired hippocampal long-term potentiation (LTP) ex vivo and neuronal activity in vivo. Methods With the intention of going beyond this initial observation, we performed a comprehensive analysis to further characterize the effects of both Aη-α and the shorter Aη-β peptide on hippocampus function using ex vivo field electrophysiology, in vivo multiphoton calcium imaging, and in vivo electrophysiology. Results We demonstrate that both synthetic peptides acutely impair LTP at low nanomolar concentrations ex vivo and reveal the N-terminus to be a primary site of activity. We further show that Aη-β, like Aη–α, inhibits neuronal activity in vivo and provide confirmation of LTP impairment by Aη–α in vivo. Conclusions These results provide novel insights into the functional role of the recently discovered η-secretase-derived products and suggest that Aη peptides represent important, pathophysiologically relevant, modulators of hippocampal network activity, with profound implications for APP-targeting therapeutic strategies in AD.

scholarly journals Assessment of Electrospun Pellethane-Based Scaffolds for Vascular Tissue Engineering

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3678
Author(s):  
Vera Chernonosova ◽  
Alexandr Gostev ◽  
Ivan Murashov ◽  
Boris Chelobanov ◽  
Andrey Karpenko ◽  
...  
Keyword(s):  
Vascular Tissue ◽  
Ex Vivo ◽  
Vascular Grafts ◽  
Wistar Rat ◽  
Graft Occlusion ◽  
Suitable Candidate ◽  
Large Animals ◽  
Cell Adhesion And Proliferation

We examined the physicochemical properties and the biocompatibility and hemocompatibility of electrospun 3D matrices produced using polyurethane Pellethane 2363-80A (Pel-80A) blends Pel-80A with gelatin or/and bivalirudin. Two layers of vascular grafts of 1.8 mm in diameter were manufactured and studied for hemocompatibility ex vivo and functioning in the infrarenal position of Wistar rat abdominal aorta in vivo (n = 18). Expanded polytetrafluoroethylene (ePTFE) vascular grafts of similar diameter were implanted as a control (n = 18). Scaffolds produced from Pel-80A with Gel showed high stiffness with a long proportional limit and limited influence of wetting on mechanical characteristics. The electrospun matrices with gelatin have moderate capacity to support cell adhesion and proliferation (~30–47%), whereas vascular grafts with bivalirudin in the inner layer have good hemocompatibility ex vivo. The introduction of bivalirudin into grafts inhibited platelet adhesion and does not lead to a change hemolysis and D-dimers concentration. Study in vivo indicates the advantages of Pel-80A grafts over ePTFE in terms of graft occlusion, calcification level, and blood velocity after 6 months of implantation. The thickness of neointima in Pel-80A–based grafts stabilizes after three months (41.84 ± 20.21 µm) and does not increase until six months, demonstrating potential for long-term functioning without stenosis and as a suitable candidate for subsequent preclinical studies in large animals.

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