scholarly journals The Oak Ridge Polycystic Kidney (orpk) disease gene is required for left-right axis determination

Development ◽  
2000 ◽  
Vol 127 (11) ◽  
pp. 2347-2355 ◽  
Author(s):  
N.S. Murcia ◽  
W.G. Richards ◽  
B.K. Yoder ◽  
M.L. Mucenski ◽  
J.R. Dunlap ◽  
...  
Keyword(s):  
Critical Role ◽  
Polycystic Kidney ◽  
Functional Feature ◽  
Knock Out ◽  
Oak Ridge ◽  
Hypomorphic Allele ◽  
Heart Looping ◽  
Left Right Asymmetry ◽  
Midline Development ◽  
Knockout Allele

Analysis of several mutations in the mouse is providing useful insights into the nature of the genes required for the establishment of the left-right axis during early development. Here we describe a new targeted allele of the mouse Tg737 gene, Tg737(Delta)2-3(beta)Gal), which causes defects in left-right asymmetry and other abnormalities during embryogenesis. The Tg737 gene was originally identified based on its association with the mouse Oak Ridge Polycystic Kidney (orpk) insertional mutation, which causes polycystic kidney disease and other defects. Complementation tests between the original orpk mutation and the new targeted knock-out mutation demonstrate that Tg737(Delta)2-3(beta)Gal) behaves as an allele of Tg737. The differences in the phenotype between the two mutations suggest that the orpk mutation is a hypomorphic allele of the Tg737 gene. Unlike the orpk allele, where all homozygotes survive to birth, embryos homozygous for the Tg737(Delta)2-3(beta)Gal) mutation arrest in development at mid-gestation and exhibit neural tube defects, enlargement of the pericardial sac and, most notably, left-right asymmetry defects. At mid-gestation the direction of heart looping is randomized, and at earlier stages in development lefty-2 and nodal, which are normally expressed asymmetrically, exhibit symmetrical expression in the mutant embryos. Additionally, we determined that the ventral node cells in mutant embryos fail to express the central cilium, which is a characteristic and potentially functional feature of these cells. The expression of both Shh and Hnf3(beta) is downregulated in the midline at E8.0, indicating that there are significant alterations in midline development in the Tg737(Delta)2-3(beta)Gal) homozygous embryos. We propose that the failure of ventral node cells to fully mature alters their ability to undergo differentiation as they migrate out of the node to contribute to the developing midline structures. Analysis of this new knockout allele allows us to define a critical role for the Tg737 gene during early embryogenesis. We have named the product of the Tg737 gene Polaris, which is based on the various polarity related defects associated with the different alleles of the Tg737 gene.

scholarly journals The p47phox mouse knock-out model of chronic granulomatous disease.

1995 ◽  
Vol 182 (3) ◽  
pp. 751-758 ◽  
Author(s):  
S H Jackson ◽  
J I Gallin ◽  
S M Holland
Keyword(s):  
Nadph Oxidase ◽  
Chronic Granulomatous Disease ◽  
Fungal Infections ◽  
Critical Role ◽  
Granulomatous Inflammation ◽  
Mammalian Host ◽  
Granulomatous Disease ◽  
Knock Out ◽  
Phagocyte Nadph Oxidase ◽  
Life Threatening

Chronic granulomatous disease (CGD) is caused by a congenital defect in phagocyte reduced nicotinamide dinucleotide phosphate (NADPH) oxidase production of superoxide and related species. It is characterized by recurrent life-threatening bacterial and fungal infections and tissue granuloma formation. We have created a mouse model of CGD by targeted disruption of p47phox, one of the genes in which mutations cause human CGD. Identical to the case in human CGD, leukocytes from p47phox-/- mice produced no superoxide and killed staphylococci ineffectively. p47phox-/- mice developed lethal infections and granulomatous inflammation similar to those encountered in human CGD patients. This model mirrors human CGD and confirms a critical role for the phagocyte NADPH oxidase in mammalian host defense.

scholarly journals Immune regulation of neuronal injury and repair by observing T cell activation

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Eric J. Regele ◽  
Elizabeth M. Runge ◽  
Felicia M. Kennedy ◽  
Virginia M. Sanders ◽  
Kathryn J. Jones
Keyword(s):  
T Cells ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Critical Role ◽  
Cd4 Cells ◽  
Knock Out ◽  
Facial Motoneuron ◽  
Injury And Repair ◽  
Antigen Presenting

Background and Hypothesis:  It is unknown how the immune system maintains the majority of facial motoneuron (FMN) survival after axotomy. IL-10 cytokine is necessary for FMN survival and CD4+ T cells are activated and play a critical role in survival, but do not produce IL-10. It was proposed that the source of IL-10 resides in the CNS; however, it is possible that antigen presenting cells (APC) produce IL-10 which activate CD4+ T cells to a neuroprotective phenotype. The regulation of IL-10 receptors (IL-10R) in immunodeficient compared to wild-type (WT) mice in the facial nucleus was studied in this experiment, as well as the possibility of the PNS producing IL-10.  Experimental Design or Project Methods:  To study APC’s role in motoneuron survival, we transferred WT whole splenocytes into global IL-10 knock out (KO) mice prior to axotomy. To study IL-10R gene expression, immunodeficient RAG-2 KO mice received WT or IL-10R-/- CD4+ T cells prior to axotomy.   Results:  qPCR revealed that WT mice upregulate IL-10R after axotomy, whereas RAG-2 KO mice had decreased expression comparatively. RAG-2 mice who received WT CD4+ T cells transfer restored IL-10R comparable to WT values.IL-10R was rescued in RAG-2 mice after the adoptive transfer of WT CD4+T cells. When IL-10R-/- CD4+ cells were transferred into RAG-2 mice, IL-10R values were restored; however, these T cells were unable to rescue FMN survival.   Conclusion and Potential Impact:  If WT whole splenocytes transferred into global IL-10 KO mice rescue FMN survival, it implies that APC play a role in producing IL-10. If they cannot mediate rescue, then peripheral IL-10 is unlikely sufficient for FMN survival. CD4+ T cells regulate central IL-10R response and must respond to IL-10 to mediate FMN survival. The transfer of whole splenocytes provides APCs capable of producing IL-10 and CD4+ T cells capable of responding to IL-10. 

scholarly journals N-Cadherin Is Critical for the Survival of Germ Cells, the Formation of Steroidogenic Cells, and the Architecture of Developing Mouse Gonads

Cells ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1610 ◽  
Author(s):  
Rafal P. Piprek ◽  
Michal Kolasa ◽  
Dagmara Podkowa ◽  
Malgorzata Kloc ◽  
Jacek Z. Kubiak
Keyword(s):  
Germ Cells ◽  
Hormonal Regulation ◽  
Critical Role ◽  
Somatic Cells ◽  
Gonad Development ◽  
Knock Out ◽  
Gonad Differentiation ◽  
Steroidogenic Cells ◽  
The Individual ◽  
And Function

Normal gonad development assures the fertility of the individual. The properly functioning gonads must contain a sufficient number of the viable germ cells, possess a correct architecture and tissue structure, and assure the proper hormonal regulation. This is achieved by the interplay between the germ cells and different types of somatic cells. N-cadherin coded by the Cdh2 gene plays a critical role in this interplay. To gain an insight into the role of N-cadherin in the development of mouse gonads, we used the Cre-loxP system to knock out N-cadherin separately in two cell lines: the SF1+ somatic cells and the OCT4+ germ cells. We observed that N-cadherin plays a key role in the survival of both female and male germ cells. However, the N-cadherin is not necessary for the differentiation of the Sertoli cells or the initiation of the formation of testis cords or ovigerous cords. In the later stages of gonad development, N-cadherin is important for the maintenance of testis cord structure and is required for the formation of steroidogenic cells. In the ovaries, N-cadherin is necessary for the formation of the ovarian follicles. These results indicate that N-cadherin plays a major role in gonad differentiation, structuralization, and function.

scholarly journals Histone deacetylase 6 inhibition reduces cysts by decreasing cAMP and Ca2+ in knock-out mouse models of polycystic kidney disease

2017 ◽  
Vol 292 (43) ◽  
pp. 17897-17908 ◽  
Author(s):  
Murali K. Yanda ◽  
Qiangni Liu ◽  
Valeriu Cebotaru ◽  
William B. Guggino ◽  
Liudmila Cebotaru
Keyword(s):  
Endoplasmic Reticulum ◽  
Kidney Disease ◽  
Histone Deacetylase ◽  
Polycystic Kidney Disease ◽  
Histone Deacetylase 6 ◽  
Polycystic Kidney ◽  
Knock Out ◽  
Intracellular Ca ◽  
Camp Levels ◽  
Cyst Growth

Autosomal dominant polycystic kidney disease (ADPKD) is associated with progressive enlargement of multiple renal cysts, often leading to renal failure that cannot be prevented by a current treatment. Two proteins encoded by two genes are associated with ADPKD: PC1 (pkd1), primarily a signaling molecule, and PC2 (pkd2), a Ca2+ channel. Dysregulation of cAMP signaling is central to ADPKD, but the molecular mechanism is unresolved. Here, we studied the role of histone deacetylase 6 (HDAC6) in regulating cyst growth to test the possibility that inhibiting HDAC6 might help manage ADPKD. Chemical inhibition of HDAC6 reduced cyst growth in PC1-knock-out mice. In proximal tubule–derived, PC1-knock-out cells, adenylyl cyclase 6 and 3 (AC6 and -3) are both expressed. AC6 protein expression was higher in cells lacking PC1, compared with control cells containing PC1. Intracellular Ca2+ was higher in PC1-knock-out cells than in control cells. HDAC inhibition caused a drop in intracellular Ca2+ and increased ATP-simulated Ca2+ release. HDAC6 inhibition reduced the release of Ca2+ from the endoplasmic reticulum induced by thapsigargin, an inhibitor of endoplasmic reticulum Ca2+-ATPase. HDAC6 inhibition and treatment of cells with the intracellular Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid tetrakis(acetoxymethyl ester) reduced cAMP levels in PC1-knock-out cells. Finally, the calmodulin inhibitors W-7 and W-13 reduced cAMP levels, and W-7 reduced cyst growth, suggesting that AC3 is involved in cyst growth regulated by HDAC6. We conclude that HDAC6 inhibition reduces cell growth primarily by reducing intracellular cAMP and Ca2+ levels. Our results provide potential therapeutic targets that may be useful as treatments for ADPKD.

scholarly journals Suppression of Insulin-Like3 Receptor Reveals the Role of β-Catenin and Notch Signaling in Gubernaculum Development

2011 ◽  
Vol 25 (1) ◽  
pp. 170-183 ◽  
Author(s):  
Elena M. Kaftanovskaya ◽  
Shu Feng ◽  
Zaohua Huang ◽  
Yingchun Tan ◽  
Agustin M. Barbara ◽  
...  
Keyword(s):  
Gene Expression ◽  
Myogenic Differentiation ◽  
Critical Role ◽  
Abnormal Development ◽  
Testicular Descent ◽  
Hypomorphic Allele ◽  
Conditional Suppression ◽  
Notch Pathways ◽  
Cellular Components

During male development, the testes move from a high intraabdominal position and descend into the scrotum. The gubernaculum, an inguinoscrotal ligament connecting the testis to the lower abdomen, is believed to play a critical role in this process. The first stage of testicular descent is controlled by insulin like3 hormone (INSL3), produced in testicular Leydig cells. Deletion of Insl3 or its receptor, Rxfp2, in mice causes cryptorchidism. We produced Cre/loxP regulated shRNA transgenic mice targeting RXFP2 expression. We have shown that the transgene was able to reduce Rxfp2 gene expression and thus behaved as a hypomorphic allele of Rxfp2. Variable degrees of uni- and bilateral cryptorchidism was detected in males with the activated shRNA transgene on an Rxfp2+/− background. Conditional suppression of Rxfp2 in the gubernaculum led to cryptorchidism. Gene expression analysis of a mutant cremasteric sac using Illumina microarrays indicated abnormal expression of a significant number of genes in Wnt/β-catenin and Notch pathways. We have demonstrated profound changes in the expression pattern of β-catenin, Notch1, desmin, and androgen receptor (AR), in Rxfp2−/− male embryos, indicating the role of INSL3 in proliferation, differentiation, and survival of specific cellular components of the gubernaculum. We have shown that INSL3/RXFP2 signaling is essential for myogenic differentiation and maintenance of AR-positive cells in the gubernaculum. Males with the deletion of β-catenin or Notch1 in the gubernacular ligament demonstrated abnormal development. Our data indicates that β-catenin and Notch pathways are potential targets of INSL3 signaling during gubernacular development.

scholarly journals Designer Nodal/BMP2 Chimeras Mimic Nodal Signaling, Promote Chondrogenesis, and Reveal a BMP2-like Structure

2013 ◽  
Vol 289 (3) ◽  
pp. 1788-1797 ◽  
Author(s):  
Luis Esquivies ◽  
Alissa Blackler ◽  
Macarena Peran ◽  
Concepcion Rodriguez-Esteban ◽  
Juan Carlos Izpisua Belmonte ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Chondrogenic Differentiation ◽  
Biochemical Study ◽  
Adipose Derived Stem Cells ◽  
Nodal Signaling ◽  
Induced Differentiation ◽  
Therapeutic Implications ◽  
Heart Looping ◽  
Cartilage Injuries ◽  
Left Right Asymmetry

Nodal, a member of the TGF-β superfamily, plays an important role in vertebrate and invertebrate early development. The biochemical study of Nodal and its signaling pathway has been a challenge, mainly because of difficulties in producing the protein in sufficient quantities. We have developed a library of stable, chemically refoldable Nodal/BMP2 chimeric ligands (NB2 library). Three chimeras, named NB250, NB260, and NB264, show Nodal-like signaling properties including dependence on the co-receptor Cripto and activation of the Smad2 pathway. NB250, like Nodal, alters heart looping during the establishment of embryonic left-right asymmetry, and both NB250 and NB260, as well as Nodal, induce chondrogenic differentiation of human adipose-derived stem cells. This Nodal-induced differentiation is shown to be more efficient than BPM2-induced differentiation. Interestingly, the crystal structure of NB250 shows a backbone scaffold similar to that of BMP2. Our results show that these chimeric ligands may have therapeutic implications in cartilage injuries.

scholarly journals Aberrant expression of laminin-332 promotes cell proliferation and cyst growth in ARPKD

2014 ◽  
Vol 306 (6) ◽  
pp. F640-F654 ◽  
Author(s):  
Soundarapandian Vijayakumar ◽  
Suparna Dang ◽  
M. Peter Marinkovich ◽  
Zelmira Lazarova ◽  
Bradley Yoder ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Basement Membrane ◽  
Polycystic Kidney ◽  
Primary Defect ◽  
Aberrant Expression ◽  
Altered Expression ◽  
Oak Ridge ◽  
Matrigel Culture ◽  
Laminin 332 ◽  
Cyst Growth

Basement membrane abnormalities have often been observed in kidney cysts of polycystic kidney disease (PKD) patients and animal models. There is an abnormal deposition of extracellular matrix molecules, including laminin-α3,β3,γ2 (laminin-332), in human autosomal dominant PKD (ADPKD). Knockdown of PKD1 paralogs in zebrafish leads to dysregulated synthesis of the extracellular matrix, suggesting that altered basement membrane assembly may be a primary defect in ADPKD. In this study, we demonstrate that laminin-332 is aberrantly expressed in cysts and precystic tubules of human autosomal recessive PKD (ARPKD) kidneys as well as in the kidneys of PCK rats, an orthologous ARPKD model. There was aberrant expression of laminin-γ2 as early as postnatal day 2 and elevated laminin-332 protein in postnatal day 30, coinciding with the formation and early growth of renal cysts in PCK rat kidneys. We also show that a kidney cell line derived from Oak Ridge polycystic kidney mice, another model of ARPKD, exhibited abnormal lumen-deficient and multilumen structures in Matrigel culture. These cells had increased proliferation rates and altered expression levels of laminin-332 compared with their rescued counterparts. A function-blocking polyclonal antibody to laminin-332 significantly inhibited their abnormal proliferation rates and rescued their aberrant phenotype in Matrigel culture. Furthermore, abnormal laminin-332 expression in cysts originating from collecting ducts and proximal tubules as well as in precystic tubules was observed in a human end-stage ADPKD kidney. Our results suggest that abnormal expression of laminin-332 contributes to the aberrant proliferation of cyst epithelial cells and cyst growth in genetic forms of PKD.

scholarly journals Deficiency of Arcuate Nucleus Kisspeptin Results in Post-Pubertal Central Hypogonadism

2021 ◽  
Author(s):  
Nimisha Nandankar ◽  
Ariel L. Negron ◽  
Andrew Wolfe ◽  
Jon E Levine ◽  
Sally Radovick
Keyword(s):  
Feedback Control ◽  
Arcuate Nucleus ◽  
Critical Role ◽  
Knock Out ◽  
Protein Levels ◽  
Reproductive Axis ◽  
Lh Pulsatility ◽  
Estrous Cyclicity ◽  
Lh Release ◽  
Kndy Neurons

Kisspeptin (encoded by Kiss1), a neuropeptide critically involved in neuroendocrine regulation of reproduction, is primarily synthesized in two hypothalamic nuclei: the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC). AVPV kisspeptin is thought to regulate the estrogen-induced positive feedback control of gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH), and the pre-ovulatory LH surge in females. In contrast, ARC kisspeptin neurons, which largely co-express neurokinin B and dynorphin A (collectively named KNDy neurons), are thought to mediate estrogen-induced negative feedback control of GnRH/LH and be the major regulators of pulsatile GnRH/LH release. However, definitive data to delineate the specific roles of AVPV versus ARC kisspeptin neurons in the control of GnRH/LH release is lacking. Therefore, we generated a novel mouse model targeting deletion of Kiss1 to the ARC nucleus (Pdyn-Cre/Kiss1fl/fl KO) to determine the functional differences between ARC and AVPV kisspeptin neurons on the reproductive axis. The efficacy of the knock-out was confirmed at both the mRNA and protein levels. Adult female Pdyn-Cre/Kiss1fl/fl KO mice exhibited persistent diestrus and significantly fewer LH pulses when compared to controls, resulting in arrested folliculogenesis, hypogonadism, and infertility. Pdyn-Cre/Kiss1fl/fl KO males also exhibited disrupted LH pulsatility, hypogonadism, and variable, defective spermatogenesis and subfertility. The timing of pubertal onset in males and females was equivalent to controls. These findings add to the current body of evidence for the critical role of kisspeptin in ARC KNDy neurons in GnRH/LH pulsatility in both sexes, while directly establishing ARC kisspeptin's role in regulating estrous cyclicity in female mice, and gametogenesis in both sexes, and culminating in disrupted fertility. The Pdyn-Cre/Kiss1fl/fl KO mice present a novel mammalian model of post-pubertal central hypogonadism.

Retinoic acid is required in the mouse embryo for left-right asymmetry determination and heart morphogenesis

Development ◽  
1999 ◽  
Vol 126 (12) ◽  
pp. 2589-2596 ◽  
Author(s):  
C. Chazaud ◽  
P. Chambon ◽  
P. Dolle
Keyword(s):  
Retinoic Acid ◽  
Vitamin A ◽  
Mouse Embryo ◽  
Time Course ◽  
Retinoic Acid Receptor ◽  
Mouse Embryos ◽  
Anteroposterior Patterning ◽  
Heart Looping ◽  
Left Right Asymmetry

Determination of the left-right position (situs) of visceral organs involves lefty, nodal and Pitx2 genes that are specifically expressed on the left side of the embryo. We demonstrate that the expression of these genes is prevented by the addition of a retinoic acid receptor pan-antagonist to cultured headfold stage mouse embryos, whereas addition of excess retinoic acid leads to their symmetrical expression. Interestingly, both treatments lead to randomization of heart looping and to defects in heart anteroposterior patterning. A time course analysis indicates that only the newly formed mesoderm at the headfold-presomite stage is competent for these retinoid effects. We conclude that retinoic acid, the active derivative of vitamin A, is essential for heart situs determination and morphogenesis.

Linkage of cardiac left-right asymmetry and dorsal-anterior development in Xenopus

Development ◽  
1995 ◽  
Vol 121 (5) ◽  
pp. 1467-1474 ◽  
Author(s):  
M.C. Danos ◽  
H.J. Yost
Keyword(s):  
Cell Cycle ◽  
Spatial Patterns ◽  
Organizer Region ◽  
Common Mechanism ◽  
Contrast Injection ◽  
Dorsal Midline ◽  
Heart Looping ◽  
Left Right Asymmetry ◽  
Midline Cells ◽  
Anterior Posterior

The left-right body axis is defined relative to the dorsal-ventral and anterior-posterior body axes. Since left-right asymmetries are not randomly oriented with respect to dorsal-ventral and anterior-posterior spatial patterns, it is possible that a common mechanism determines all three axes in a coordinate manner. Two approaches were undertaken to determine whether alteration in dorsal-anterior development perturbs the left-right orientation of heart looping. Treatments known to decrease dorsal-anterior development in Xenopus laevis, UV irradiation during the first cell cycle or Xwnt-8 DNA injections into dorsal blastomeres, caused an increase in cardiac left-right reversals. The frequency of left-right reversal was correlated with the severity of dorsal-anterior perturbation and with the extent of anterior notochord regression. Injection of Xwnt-8 DNA into dorsal midline cells resulted in decreased dorsal-anterior development and a correlated increase in cardiac left-right reversals. In contrast, injection of Xwnt-8 DNA into cardiac progenitor blastomeres did not result in left-right reversals, and dorsal-anterior development and notochord formation were normal. Disrupting development of dorsal-anterior cells, including cells that give rise to the Organizer region and the notochord, results in the randomization of cardiac left-right asymmetry. These results suggest dorsal-anterior development and the regulation of left-right orientation are linked.

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