scholarly journals Gilgamesh (Gish)/CK1γ regulates tissue homeostasis and aging in adult Drosophila midgut

2020 ◽  
Vol 219 (4) ◽  
Author(s):  
Shuangxi Li ◽  
Aiguo Tian ◽  
Shuang Li ◽  
Yuhong Han ◽  
Bing Wang ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Activity ◽  
Adult Life ◽  
Small Gtpase ◽  
Tissue Homeostasis ◽  
Jnk Pathway ◽  
Pathway Activation ◽  
Stem Cell Activity ◽  
Resident Stem Cells ◽  
Jnk Activation

Adult tissues and organs rely on resident stem cells to generate new cells that replenish damaged cells. To maintain homeostasis, stem cell activity needs to be tightly controlled throughout the adult life. Here, we show that the membrane-associated kinase Gilgamesh (Gish)/CK1γ maintains Drosophila adult midgut homeostasis by restricting JNK pathway activity and that Gish is essential for intestinal stem cell (ISC) maintenance under stress conditions. Inactivation of Gish resulted in aberrant JNK pathway activation and excessive production of multiple cytokines and growth factors that drive ISC overproliferation. Mechanistically, Gish restricts JNK activation by phosphorylating and destabilizing a small GTPase, Rho1. Interestingly, we find that Gish expression is down-regulated in aging guts and that increasing Gish activity in aging guts can restore tissue homeostasis. Hence, our study identifies Gish/CK1γ as a novel regulator of Rho1 and gatekeeper of tissue homeostasis whose activity is compromised in aging guts.

scholarly journals A transit-amplifying population underpins the efficient regenerative capacity of the testis

2017 ◽  
Vol 214 (6) ◽  
pp. 1631-1641 ◽  
Author(s):  
Claudia Carrieri ◽  
Stefano Comazzetto ◽  
Amit Grover ◽  
Marcos Morgan ◽  
Andreas Buness ◽  
...  
Keyword(s):  
Stem Cell ◽  
Tissue Repair ◽  
Cell Activity ◽  
Adult Life ◽  
Spermatogonial Stem Cell ◽  
Mouse Testis ◽  
Regenerative Capacity ◽  
Cell Pool ◽  
Stem Cell Activity ◽  
Stem Cell Pool

The spermatogonial stem cell (SSC) that supports spermatogenesis throughout adult life resides within the GFRα1-expressing A type undifferentiated spermatogonia. The decision to commit to spermatogenic differentiation coincides with the loss of GFRα1 and reciprocal gain of Ngn3 (Neurog3) expression. Through the analysis of the piRNA factor Miwi2 (Piwil4), we identify a novel population of Ngn3-expressing spermatogonia that are essential for efficient testicular regeneration after injury. Depletion of Miwi2-expressing cells results in a transient impact on testicular homeostasis, with this population behaving strictly as transit amplifying cells under homeostatic conditions. However, upon injury, Miwi2-expressing cells are essential for the efficient regenerative capacity of the testis, and also display facultative stem activity in transplantation assays. In summary, the mouse testis has adopted a regenerative strategy to expand stem cell activity by incorporating a transit-amplifying population to the effective stem cell pool, thus ensuring rapid and efficient tissue repair.

scholarly journals mastermind regulates niche ageing independently of the Notch pathway in the Drosophila ovary

Open Biology ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 190127
Author(s):  
María Lobo-Pecellín ◽  
Miriam Marín-Menguiano ◽  
Acaimo González-Reyes
Keyword(s):  
Stem Cell ◽  
Cell Activity ◽  
Notch Pathway ◽  
Tissue Homeostasis ◽  
Germline Stem Cells ◽  
Proliferation And Differentiation ◽  
Stem Cell Activity ◽  
Stem Cell Populations ◽  
Drosophila Ovary ◽  
Systemic Signals

Proper stem cell activity in tissues ensures the correct balance between proliferation and differentiation, thus allowing tissue homeostasis and repair. The Drosophila ovary develops well-defined niches that contain on average 2–4 germline stem cells (GSCs), whose maintenance depends on systemic signals and local factors. A known player in the decline of tissue homeostasis is ageing, which correlates with the waning of resident stem cell populations. In Drosophila , ovaries from old females contain fewer GSCs than those from young flies. We isolated niche cells of aged ovaries, performed a transcriptomic analysis and identified mastermind (mam) as a factor for Drosophila ovarian niche functionality during ageing. We show that mam is upregulated in aged niche cells and that we can induce premature GSC loss by overexpressing mam in otherwise young niche cells. High mam levels in niche cells induce reduced Hedgehog amounts, a decrease in cadherin levels and a likely increase in reactive oxygen species, three scenarios known to provoke GSC loss. Mam is a canonical co-activator of the Notch pathway in many Drosophila tissues. However, we present evidence to support a Notch-independent role for mam in the ovarian germline niche.

scholarly journals Maintaining Tissue Homeostasis: Dynamic Control of Somatic Stem Cell Activity

2011 ◽  
Vol 9 (5) ◽  
pp. 402-411 ◽  
Author(s):  
Benoit Biteau ◽  
Christine E. Hochmuth ◽  
Heinrich Jasper
Keyword(s):  
Stem Cell ◽  
Dynamic Control ◽  
Cell Activity ◽  
Tissue Homeostasis ◽  
Somatic Stem Cell ◽  
Stem Cell Activity

scholarly journals Positional information specifies the site of organ regeneration and not tissue maintenance in planarians

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Eric M Hill ◽  
Christian P Petersen
Keyword(s):  
Stem Cell ◽  
Cell Activity ◽  
Positional Information ◽  
Tissue Homeostasis ◽  
Target Site ◽  
Maintenance And Repair ◽  
Organ Regeneration ◽  
Stem Cell Activity ◽  
Factor Expression

Most animals undergo homeostatic tissue maintenance, yet those capable of robust regeneration in adulthood use mechanisms significantly overlapping with homeostasis. Here we show in planarians that modulations to body-wide patterning systems shift the target site for eye regeneration while still enabling homeostasis of eyes outside this region. The uncoupling of homeostasis and regeneration, which can occur during normal positional rescaling after axis truncation, is not due to altered injury signaling or stem cell activity, nor specific to eye tissue. Rather, pre-existing tissues, which are misaligned with patterning factor expression domains, compete with properly located organs for incorporation of migratory progenitors. These observations suggest that patterning factors determine sites of organ regeneration but do not solely determine the location of tissue homeostasis. These properties provide candidate explanations for how regeneration integrates pre-existing tissues and how regenerative abilities could be lost in evolution or development without eliminating long-term tissue maintenance and repair.

scholarly journals Positional information specifies the site of organ regeneration and not tissue maintenance in planarians

2018 ◽  
Author(s):  
Eric M. Hill ◽  
Christian P. Petersen
Keyword(s):  
Stem Cell ◽  
Cell Activity ◽  
Positional Information ◽  
Tissue Homeostasis ◽  
Target Site ◽  
Maintenance And Repair ◽  
Organ Regeneration ◽  
Stem Cell Activity ◽  
Factor Expression

AbstractMost animals undergo homeostatic tissue maintenance, yet those capable of robust regeneration in adulthood use mechanisms significantly overlapping with homeostasis. Here we show in planarians that modulations to body-wide patterning systems shift the target site for eye regeneration while still enabling homeostasis of eyes outside this region. The uncoupling of homeostasis and regeneration, which can occur during normal positional rescaling after axis truncation, is not due to altered injury signaling or stem cell activity, nor specific to eye tissue. Rather, pre-existing tissues, which are misaligned with patterning factor expression domains, compete with properly located organs for incorporation of migratory progenitors. These observations suggest that patterning factors determine sites of organ regeneration but do not solely determine the location of tissue homeostasis. These properties provide candidate explanations for how regeneration integrates pre-existing tissues and how regenerative abilities could be lost in evolution or development without eliminating long-term tissue maintenance and repair.One Sentence SummaryHomeostatic tissue maintenance can occur independent of precise positional information in planarians.

scholarly journals Hair-follicle mesenchymal stem-cell activity during homeostasis and wound healing

2021 ◽  
Author(s):  
Emil Aamar ◽  
Efrat Avigad Laron ◽  
Wisal Asaad ◽  
Sarina Harshuk-Shabso ◽  
David Enshell-Seijffers
Keyword(s):  
Wound Healing ◽  
Stem Cell ◽  
Mesenchymal Stem Cell ◽  
Hair Follicle ◽  
Cell Activity ◽  
Stem Cell Activity
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