scholarly journals Mitochondrial Regulation Is Essential for Erythroid Nuclear Clearance

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 843-843
Author(s):  
Raymond Liang ◽  
Vijay Menon ◽  
Miao Lin ◽  
Roberta Nowak ◽  
Velia M. Fowler ◽  
...  
Keyword(s):  
Conflicts Of Interest ◽  
Fetal Liver ◽  
Mitochondrial Metabolism ◽  
Mitochondrial Activity ◽  
Mouse Bone Marrow ◽  
In Vitro Production ◽  
Nuclear Condensation ◽  
Human Cd34 ◽  
Vitro Production

Abstract The terminal steps of red blood cell (RBC) generation involve an extensive cellular remodeling. This encompasses alterations of cellular content through five erythroblast stages that result in the expulsion of the nucleus (enucleation) followed by loss of mitochondria and all other organelles, and a transition to anaerobic glycolysis. Whether there is any link between the erythroid removal of the nucleus and the function of any other organelle including mitochondria remains unknown. Here we show that mitochondria are essential for nuclear clearance. We first demonstrate through high-throughput single-cell imaging and confocal microscopy that as mouse bone marrow erythroblasts mature (Gate 3: TER119+,CD44low, FSClow), mitochondria migrate to one end of the cell, aggregate and trail behind the nucleus as it extrudes from the cell, a prerequisite for enucleation to complete. We further show that mitochondrial localization behind the nucleus has similar kinetics as nuclear polarization. This process is also conserved in mouse fetal liver erythroid cells as well as in primary human CD34+-derived erythroblasts in culture. Notably, kinesin inhibition disrupts mitochondrial motility and localization and reduces significantly erythroblast enucleation rate in the absence of any impact on dynein or tubulin. These results suggest that mitochondria function as necessary chaperones during erythroblast enucleation. Furthermore, mitochondrial activity distinguishes erythroblasts on the verge of enucleation from others at the same erythroblast stage (Gate 3). We show that active mitochondrial respiration facilitates nuclear condensation and is required for nuclear extrusion. To our surprise however, metabolite profiling revealed that late-stage erythroblasts sustain mitochondrial metabolism and subsequent enucleation primarily through extracellular pyruvate but independently of glucose oxidation or anapleorotic reactions of amino acids. 13C-labeled metabolite tracing also confirmed pyruvate incorporation into mitochondria while glycolysis was minimal in orthochromatic erythroblasts. Thus, we provide evidence for the first time of a link between erythroid enucleation and mitochondrial metabolism. The process described establishes a model of mitochondrial compartmentalization within the cell for providing essential metabolites in a precise spatial and temporal manner. These findings are likely to improve the in vitro production of RBC and might be relevant to anemias of congenital mitochondrial disorders and aging. Disclosures No relevant conflicts of interest to declare.

scholarly journals Mitochondrial localization and moderated activity are key to murine erythroid enucleation

2021 ◽  
Vol 5 (10) ◽  
pp. 2490-2504
Author(s):  
Raymond Liang ◽  
Vijay Menon ◽  
Jiajing Qiu ◽  
Tasleem Arif ◽  
Santosh Renuse ◽  
...  
Keyword(s):  
Nuclear Polarization ◽  
Cell Imaging ◽  
Mitochondrial Activity ◽  
Open Chromatin ◽  
Mitochondrial Localization ◽  
In Vitro Production ◽  
Single Cell Imaging ◽  
Vitro Production

Abstract Mammalian red blood cells (RBCs), which primarily contain hemoglobin, exemplify an elaborate maturation process, with the terminal steps of RBC generation involving extensive cellular remodeling. This encompasses alterations of cellular content through distinct stages of erythroblast maturation that result in the expulsion of the nucleus (enucleation) followed by the loss of mitochondria and all other organelles and a transition to anaerobic glycolysis. Whether there is any link between erythroid removal of the nucleus and the function of any other organelle, including mitochondria, remains unknown. Here we demonstrate that mitochondria are key to nuclear clearance. Using live and confocal microscopy and high-throughput single-cell imaging, we show that before nuclear polarization, mitochondria progressively move toward one side of maturing erythroblasts and aggregate near the nucleus as it extrudes from the cell, a prerequisite for enucleation to proceed. Although we found active mitochondrial respiration is required for nuclear expulsion, levels of mitochondrial activity identify distinct functional subpopulations, because terminally maturing erythroblasts with low relative to high mitochondrial membrane potential are at a later stage of maturation, contain greatly condensed nuclei with reduced open chromatin–associated acetylation histone marks, and exhibit higher enucleation rates. Lastly, to our surprise, we found that late-stage erythroblasts sustain mitochondrial metabolism and subsequent enucleation, primarily through pyruvate but independent of in situ glycolysis. These findings demonstrate the critical but unanticipated functions of mitochondria during the erythroblast enucleation process. They are also relevant to the in vitro production of RBCs as well as to disorders of the erythroid lineage.

scholarly journals In vitro production of erythropoietin by mouse fetal liver

Blood ◽  
1975 ◽  
Vol 46 (1) ◽  
pp. 85-90 ◽  
Author(s):  
JR Zucali ◽  
V Stevens ◽  
EA Mirand
Keyword(s):  
Dose Response ◽  
Active Substance ◽  
Liver Tissue ◽  
Culture Medium ◽  
Fetal Liver ◽  
Response Relationship ◽  
In Vitro Production ◽  
Dose Response Relationship ◽  
Vitro Production

Abstract Mouse fetal liver tissue has been cultured and shown to produce and release into the culture medium an erythropoietically active substance for up to 30 days of culture. Since this substance can be completely neutralized by an antiserum to erythropoietin and shows a dose-- response relationship in the plethoric mouse assay, it is suggested that the culture medium contains erythropoietin, a hormone important in the regulation of erythropoiesis. Using this procedure, we have obtained the equivalent of about 20.7 unites of erythropoietin from five T-flasks (75 sq cm) over the 30-day culture period.

scholarly journals In vitro production of erythropoietin by mouse fetal liver

Blood ◽  
1975 ◽  
Vol 46 (1) ◽  
pp. 85-90
Author(s):  
JR Zucali ◽  
V Stevens ◽  
EA Mirand
Keyword(s):  
Dose Response ◽  
Active Substance ◽  
Liver Tissue ◽  
Culture Medium ◽  
Fetal Liver ◽  
Response Relationship ◽  
In Vitro Production ◽  
Dose Response Relationship ◽  
Vitro Production

Mouse fetal liver tissue has been cultured and shown to produce and release into the culture medium an erythropoietically active substance for up to 30 days of culture. Since this substance can be completely neutralized by an antiserum to erythropoietin and shows a dose-- response relationship in the plethoric mouse assay, it is suggested that the culture medium contains erythropoietin, a hormone important in the regulation of erythropoiesis. Using this procedure, we have obtained the equivalent of about 20.7 unites of erythropoietin from five T-flasks (75 sq cm) over the 30-day culture period.

THE IN VITRO PRODUCTION OF ANDROGENS BY FOLLICULAR TISSUE OF RABBITS

1964 ◽  
Vol 47 (2) ◽  
pp. 306-313 ◽  
Author(s):  
Denis Gospodarowicz
Keyword(s):  
In Vitro Production ◽  
Vitro Production

ABSTRACT Incubation in vitro of rabbit follicles in separate experiments with dehydroepiandrosterone-14C (DHEA-14C), progesterone-14C and pregnenolone-3H in the presence of FSH gave the following results: 39 % of the radioactivity of DHEA-14C is converted to androstenedione and testosterone, while only 3 % of the radioactivity of either progesterone-14C or pregnenolone-3H is found in the androgen fraction. From the ratio of testosterone to androstenedione formed from the three precursors, the results are interpreted to mean that DHEA and pregnenolone, and not progesterone, are precursors of androgens in the follicle.

Oxygenation of 18-hydroxycorticosterone as the final reaction for aldosterone biosynthesis

1984 ◽  
Vol 107 (3) ◽  
pp. 395-400 ◽  
Author(s):  
Itaru Kojima ◽  
Etsuro Ogata ◽  
Hiroshi Inano ◽  
Bun-ichi Tamaoki
Keyword(s):  
Carbon Monoxide ◽  
Hydroxysteroid Dehydrogenase ◽  
Dependent Manner ◽  
In Vitro Production ◽  
Mitochondrial Preparation ◽  
Final Reaction ◽  
Vitro Production ◽  
Dose Dependent ◽  
Cytochrome P 450

Abstract. Incubation of 18-hydroxycorticosterone with the sonicated mitochondrial preparation of bovine adrenal glomerulosa tissue leads to the production of aldosterone, as measured by radioimmunoassay. The in vitro production of aldosterone from 18-hydroxycorticosterone requires both molecular oxygen and NADPH, and is inhibited by carbon monoxide. Cytochrome P-450 inhibitors such as metyrapone, SU 8000. SU 10603, SKF 525A, amphenone B and spironolactone decrease the biosynthesis of aldosterone from 18-hydroxycorticosterone. These results support the conclusion that the final reaction in aldosterone synthesis from 18-hydroxycorticosterone is catalyzed by an oxygenase, but not by 18-hydroxysteroid dehydrogenase. By the same preparation, the production of [3H]aldosterone but not [3H]18-hydroxycorticosterone from [1,2-3H ]corticosterone is decreased in a dose-dependent manner by addition of non-radioactive 18-hydroxycorticosterone.

scholarly journals Nano-Elicitation as an Effective and Emerging Strategy for In Vitro Production of Industrially Important Flavonoids

2021 ◽  
Vol 11 (4) ◽  
pp. 1694
Author(s):  
Amna Komal Khan ◽  
Sidra Kousar ◽  
Duangjai Tungmunnithum ◽  
Christophe Hano ◽  
Bilal Haider Abbasi ◽  
...  
Keyword(s):  
World Market ◽  
Culture Technique ◽  
In Vitro Cultures ◽  
Defense System ◽  
In Vitro Production ◽  
Metallic Oxide ◽  
Global Demand ◽  
Over Exploitation ◽  
Vitro Production

Flavonoids represent a popular class of industrially important bioactive compounds. They possess valuable health-benefiting and disease preventing properties, and therefore they are an important component of the pharmaceutical, nutraceutical, cosmetical and medicinal industries. Moreover, flavonoids possess significant antiallergic, antihepatotoxic, anti-inflammatory, antioxidant, antitumor, antiviral, and antibacterial as well as cardio-protective activities. Due to these properties, there is a rise in global demand for flavonoids, forming a significant part of the world market. However, obtaining flavonoids directly from plants has some limitations, such as low quantity, poor extraction, over-exploitation, time consuming process and loss of flora. Henceforth, there is a shift towards the in vitro production of flavonoids using the plant tissue culture technique to achieve better yields in less time. In order to achieve the productivity of flavonoids at an industrially competitive level, elicitation is a useful tool. The elicitation of in vitro cultures induces stressful conditions to plants, activates the plant defense system and enhances the accumulation of secondary metabolites in higher quantities. In this regard, nanoparticles (NPs) have emerged as novel and effective elicitors for enhancing the in vitro production of industrially important flavonoids. Different classes of NPs, including metallic NPs (silver and copper), metallic oxide NPs (copper oxide, iron oxide, zinc oxide, silicon dioxide) and carbon nanotubes, are widely reported as nano-elicitors of flavonoids discussed herein. Lastly, the mechanisms of NPs as well as knowledge gaps in the area of the nano-elicitation of flavonoids have been highlighted in this review.

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