scholarly journals Autocrine Positive Feedback Regulation of Prolactin Release From Tilapia Prolactin Cells and Its Modulation by Extracellular Osmolality

Endocrinology ◽  
2016 ◽  
Vol 157 (9) ◽  
pp. 3505-3516 ◽  
Author(s):  
Yoko Yamaguchi ◽  
Shunsuke Moriyama ◽  
Darren T. Lerner ◽  
E. Gordon Grau ◽  
Andre P. Seale
Keyword(s):  
Teleost Fish ◽  
Cell Function ◽  
Critical Role ◽  
Feedback Regulation ◽  
Prolactin Cells ◽  
Prolactin Release ◽  
Autocrine Regulation ◽  
Euryhaline Teleost ◽  
Regulatory Complexity ◽  
Osmotic Stimuli

Prolactin (PRL) is a vertebrate hormone with diverse actions in osmoregulation, metabolism, reproduction, and in growth and development. Osmoregulation is fundamental to maintaining the functional structure of the macromolecules that conduct the business of life. In teleost fish, PRL plays a critical role in osmoregulation in fresh water. Appropriately, PRL cells of the tilapia are directly osmosensitive, with PRL secretion increasing as extracellular osmolality falls. Using a model system that employs dispersed PRL cells from the euryhaline teleost fish, Oreochromis mossambicus, we investigated the autocrine regulation of PRL cell function. Unknown was whether these PRL cells might also be sensitive to autocrine feedback and whether possible autocrine regulation might interact with the well-established regulation by physiologically relevant changes in extracellular osmolality. In the cell-perfusion system, ovine PRL and two isoforms of tilapia PRL (tPRL), tPRL177 and tPRL188, stimulated the release of tPRLs from the dispersed PRL cells. These effects were significant within 5–10 minutes and lasted the entire course of exposure, ceasing within 5–10 minutes of removal of tested PRLs from the perifusion medium. The magnitude of response varied between tPRL177 and tPRL188 and was modulated by extracellular osmolality. On the other hand, the gene expression of tPRLs was mainly unchanged or suppressed by static incubations of PRL cells with added PRLs. By demonstrating the regulatory complexity driven by positive autocrine feedback and its interaction with osmotic stimuli, these findings expand upon the knowledge that pituitary PRL cells are regulated complexly through multiple factors and interactions.

scholarly journals Empowering Muscle Stem Cells for the Treatment of Duchenne Muscular Dystrophy

2021 ◽  
pp. 1-14
Author(s):  
Romina L. Filippelli ◽  
Natasha C. Chang
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Cell Function ◽  
Critical Role ◽  
Membrane Integrity ◽  
Muscle Membrane ◽  
Muscle Stem Cell ◽  
Muscle Stem Cells

Duchenne muscular dystrophy (DMD) is a devastating and debilitating muscle degenerative disease affecting 1 in every 3,500 male births worldwide. DMD is progressive and fatal; accumulated weakening of the muscle tissue leads to an inability to walk and eventual loss of life due to respiratory and cardiac failure. Importantly, there remains no effective cure for DMD. DMD is caused by defective expression of the <i>DMD</i> gene, which encodes for dystrophin, a component of the dystrophin glycoprotein complex. In muscle fibers, this protein complex plays a critical role in maintaining muscle membrane integrity. Emerging studies have shown that muscle stem cells, which are adult stem cells responsible for muscle repair, are also affected in DMD. DMD muscle stem cells do not function as healthy muscle stem cells, and their impairment contributes to disease progression. Deficiencies in muscle stem cell function include impaired establishment of cell polarity leading to defective asymmetric stem cell division, reduced myogenic commitment, impaired differentiation, altered metabolism, and enhanced entry into senescence. Altogether, these findings indicate that DMD muscle stem cells are dysfunctional and have impaired regenerative potential. Although recent advances in adeno-associated vector and antisense oligonucleotide-mediated mechanisms for gene therapy have shown clinical promise, the current therapeutic strategies for muscular dystrophy do not effectively target muscle stem cells and do not address the deficiencies in muscle stem cell function. Here, we discuss the merits of restoring endogenous muscle stem cell function in degenerating muscle as a viable regenerative medicine strategy to mitigate DMD.

scholarly journals CD4+ regulatory T cells require CTLA-4 for the maintenance of systemic tolerance

2009 ◽  
Vol 206 (2) ◽  
pp. 421-434 ◽  
Author(s):  
Randall H. Friedline ◽  
David S. Brown ◽  
Hai Nguyen ◽  
Hardy Kornfeld ◽  
JinHee Lee ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Cell Function ◽  
Cytotoxic T Lymphocyte ◽  
Critical Role ◽  
Lymphoproliferative Disease ◽  
In Trans ◽  
And Function

Cytotoxic T lymphocyte antigen-4 (CTLA-4) plays a critical role in negatively regulating T cell responses and has also been implicated in the development and function of natural FOXP3+ regulatory T cells. CTLA-4–deficient mice develop fatal, early onset lymphoproliferative disease. However, chimeric mice containing both CTLA-4–deficient and –sufficient bone marrow (BM)–derived cells do not develop disease, indicating that CTLA-4 can act in trans to maintain T cell self-tolerance. Using genetically mixed blastocyst and BM chimaeras as well as in vivo T cell transfer systems, we demonstrate that in vivo regulation of Ctla4−/− T cells in trans by CTLA-4–sufficient T cells is a reversible process that requires the persistent presence of FOXP3+ regulatory T cells with a diverse TCR repertoire. Based on gene expression studies, the regulatory T cells do not appear to act directly on T cells, suggesting they may instead modulate the stimulatory activities of antigen-presenting cells. These results demonstrate that CTLA-4 is absolutely required for FOXP3+ regulatory T cell function in vivo.

scholarly journals Host genetics play a critical role in controlling CD8 T cell function and lethal immunopathology during chronic viral infection

2017 ◽  
Vol 13 (7) ◽  
pp. e1006498 ◽  
Author(s):  
Allison F. Christiaansen ◽  
Megan E. Schmidt ◽  
Stacey M. Hartwig ◽  
Steven M. Varga
Keyword(s):  
T Cell ◽  
Viral Infection ◽  
Cell Function ◽  
Critical Role ◽  
Cd8 T Cell ◽  
Chronic Viral Infection ◽  
Host Genetics ◽  
T Cell Function

scholarly journals T-cell lineage commitment and cytokine responses of thymic progenitors

Blood ◽  
1995 ◽  
Vol 86 (5) ◽  
pp. 1850-1860 ◽  
Author(s):  
TA Moore ◽  
A Zlotnik
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Cultured Cells ◽  
Critical Role ◽  
Cell Lineage ◽  
Lineage Commitment ◽  
Organ Cultures ◽  
Cell Commitment

The earliest steps of intrathymic differentiation recently have been elucidated. It has been reported that both CD4lo (CD44+ CD25- c-kit+ CD3- CD4lo CD8-) and pro-T cells (CD44+ CD25+ c-kit+ CD3- CD4- CD8-, representing the next step in maturation) exhibit germline T-cell receptor beta and gamma loci, suggesting that neither population is exclusively committed to the T-cell lineage. Several groups have shown that CD4lo cells retain the capacity to generate multiple lymphoid lineages in vivo; however, the lineage commitment status of pro-T cells is unknown. To determine when T-cell lineage commitment occurs, we examined the ability of sorted CD4lo and pro-T cells to generate lymphoid lineage cells in vivo or in fetal thymic organ cultures (FTOCs). When intravenously injected into scid mice, CD4lo cells generated both T and B cells, whereas the progeny of pro-T cells contained T cells exclusively. Fetal thymic organ cultures repopulated with CD4lo cells contained both T and natural killer (NK) cells, whereas cultures repopulated with pro-T cells contained T cells almost exclusively. These observations strongly suggest that T-cell lineage commitment occurs during the transition of CD4lo to pro-T cells. Because it is likely that the thymic microenvironment plays a critical role in T-cell commitment, we compared the responses of CD4lo and pro-T cells to various cytokine combinations in vitro, as well as the ability of the cultured cells to repopulate organ cultures. Cytokine combinations that maintained T-cell repopulation potential for both CD4lo and pro-T cells were found. CD4lo cells proliferated best in response to the combination containing interleukin-1 (IL-1), IL-3, IL- 6, IL-7, and stem cell factor (SCF). Unlike CD4lo cells, pro-T cells were much more dependent upon IL-7 for proliferation and FTOC repopulation. However, combinations of cytokines lacking IL-7 were found that maintained the T-cell repopulating potential of pro-T cells, suggesting that, whereas this cytokine is clearly very important for normal pro-T cell function, it is not an absolute necessity during early T-cell expansion and differentiation.

scholarly journals Mast cell function in prostate inflammation, fibrosis, and smooth muscle cell dysfunction

2021 ◽  
Author(s):  
Goutham Pattabiraman ◽  
Ashlee J Bell-Cohn ◽  
Stephen F. Murphy ◽  
Daniel J Mazur ◽  
Anthony J Schaeffer ◽  
...  
Keyword(s):  
Mast Cell ◽  
Smooth Muscle ◽  
Mast Cells ◽  
Cell Activation ◽  
Cell Function ◽  
Critical Role ◽  
Smooth Muscle Contraction ◽  
Urinary Dysfunction ◽  
Mast Cell Activation ◽  
Prostate Inflammation

Intraurethral inoculation of mice with uropathogenic E. coli (CP1) results in prostate inflammation, fibrosis, and urinary dysfunction, recapitulating some but not all of the pathognomonic clinical features associated with benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). In both patients with LUTS and in CP1-infected mice, we observed increased numbers and activation of mast cells and elevated levels of prostate fibrosis. Therapeutic inhibition of mast cells using a combination of mast cell stabilizer (MCS), cromolyn sodium, and the histamine 1 receptor antagonist (H1RA), cetirizine di-hydrochloride, in the mouse model resulted in reduced mast cell activation in the prostate and significant alleviation of urinary dysfunction. Treated mice showed reduced prostate fibrosis, less infiltration of immune cells, and decreased inflammation. In addition, as opposed to symptomatic CP1-infected mice, treated mice showed reduced myosin light chain (MLC)-2 phosphorylation, a marker of prostate smooth muscle contraction. These results show that mast cells play a critical role in the pathophysiology of urinary dysfunction and may be an important therapeutic target for men with BPH/LUTS.

scholarly journals Dynamics of TCR repertoire and T cell function in COVID-19 convalescent individuals

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Lingjie Luo ◽  
Wenhua Liang ◽  
Jianfeng Pang ◽  
Gang Xu ◽  
Yingying Chen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Critical Role ◽  
World Health ◽  
Cell Repertoire ◽  
Metabolic Functions ◽  
Tcr Repertoire ◽  
Discharged Patients ◽  
Health Organization

AbstractSARS-CoV-2 outbreak has been declared by World Health Organization as a worldwide pandemic. However, there are many unknowns about the antigen-specific T-cell-mediated immune responses to SARS-CoV-2 infection. Here, we present both single-cell TCR-seq and RNA-seq to analyze the dynamics of TCR repertoire and immune metabolic functions of blood T cells collected from recently discharged COVID-19 patients. We found that while the diversity of TCR repertoire was increased in discharged patients, it returned to basal level ~1 week after becoming virus-free. The dynamics of T cell repertoire correlated with a profound shift of gene signatures from antiviral response to metabolism adaptation. We also demonstrated that the top expanded T cell clones (~10% of total T cells) display the key anti-viral features in CD8+ T cells, confirming a critical role of antigen-specific T cells in fighting against SARS-CoV-2. Our work provides a basis for further analysis of adaptive immunity in COVID-19 patients, and also has implications in developing a T-cell-based vaccine for SARS-CoV-2.

scholarly journals NKX6.1 transcription factor: a crucial regulator of pancreatic β cell development, identity, and proliferation

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Idil I. Aigha ◽  
Essam M. Abdelalim
Keyword(s):  
Transcription Factor ◽  
Cell Function ◽  
Disease Modeling ◽  
Critical Role ◽  
Cell Mass ◽  
Cell Development ◽  
Pancreatic Β Cell ◽  
Β Cells ◽  
Β Cell ◽  
Β Cell Function

Abstract Understanding the biology underlying the mechanisms and pathways regulating pancreatic β cell development is necessary to understand the pathology of diabetes mellitus (DM), which is characterized by the progressive reduction in insulin-producing β cell mass. Pluripotent stem cells (PSCs) can potentially offer an unlimited supply of functional β cells for cellular therapy and disease modeling of DM. Homeobox protein NKX6.1 is a transcription factor (TF) that plays a critical role in pancreatic β cell function and proliferation. In human pancreatic islet, NKX6.1 expression is exclusive to β cells and is undetectable in other islet cells. Several reports showed that activation of NKX6.1 in PSC-derived pancreatic progenitors (MPCs), expressing PDX1 (PDX1+/NKX6.1+), warrants their future commitment to monohormonal β cells. However, further differentiation of MPCs lacking NKX6.1 expression (PDX1+/NKX6.1−) results in an undesirable generation of non-functional polyhormonal β cells. The importance of NKX6.1 as a crucial regulator in MPC specification into functional β cells directs attentions to further investigating its mechanism and enhancing NKX6.1 expression as a means to increase β cell function and mass. Here, we shed light on the role of NKX6.1 during pancreatic β cell development and in directing the MPCs to functional monohormonal lineage. Furthermore, we address the transcriptional mechanisms and targets of NKX6.1 as well as its association with diabetes.

Tumor necrosis factor-alpha and interferon-gamma reduce prolactin release in vitro

1990 ◽  
Vol 259 (5) ◽  
pp. E672-E676
Author(s):  
P. E. Walton ◽  
M. J. Cronin
Keyword(s):  
Anterior Pituitary ◽  
Tumor Necrosis ◽  
Cell Function ◽  
Tnf Alpha ◽  
Pituitary Cells ◽  
Prolactin Release ◽  
Necrosis Factor Alpha ◽  
Ifn Gamma ◽  
Factor Alpha ◽  
Necrosis Factor

Prolactin binds to lymphocytes and monocytes and can modulate immune cell function. It was postulated that proteins released from activated macrophages and lymphocytes could directly influence prolactin release and thus form an endocrine control loop during infection, tumor invasion, or inflammation. This hypothesis was tested by exposing cultured rat anterior pituitary cells to murine tumor necrosis factor-alpha (TNF-alpha) and/or interferon-gamma (IFN-gamma) for 24 h before a 4-h test of cell function. Overall prolactin accumulation during this first 24 h was inhibited by TNF-alpha and markedly reduced by TNF-alpha plus IFN-gamma. In contrast, thyroid-stimulating hormone levels were unchanged in these same media. During the subsequent 4-h challenge, both cytokines reduced thyrotropin-releasing hormone-stimulated prolactin release but had no effect on inhibited prolactin release mediated by dopamine and somatostatin receptors. Cellular viability (assessed by trypan blue and chromium release assays) and prolactin cell content were unchanged after TNF-alpha or IFN-gamma treatment. We conclude that both TNF-alpha and IFN-gamma have the potential to act directly on anterior pituitary cells to slow the rate of prolactin release.

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