The lurcher gene induces apoptotic death in cerebellar Purkinje cells

Development ◽  
1995 ◽  
Vol 121 (4) ◽  
pp. 1183-1193 ◽  
Author(s):  
D.J. Norman ◽  
L. Feng ◽  
S.S. Cheng ◽  
J. Gubbay ◽  
E. Chan ◽  
...  
Keyword(s):  
Purkinje Cells ◽  
Nuclear Dna ◽  
Neuronal Loss ◽  
Terminal Phase ◽  
Nuclear Condensation ◽  
Electron Microscopic ◽  
Apoptotic Death ◽  
Microscopic Studies ◽  
Cerebellar Purkinje Cells

In the neurologically mutant mouse strain lurcher (Lc), heterozygous animals display cell autonomous degeneration of cerebellar Purkinje cells beginning in the second postnatal week. During the course of our studies to identify the genetic lesion responsible for this disease (Norman et al., 1991), we have formulated an hypothesis suggesting that in Lc Purkinje cells homeostasis is sufficiently perturbed to lead to the activation of programmed cell death, thus resulting in neuronal loss and the consequent neurologic disease (Heintz, 1993). To address this possibility, we have examined the properties of Lc Purkinje cells as they die during the second postnatal week. Our light and electron microscopic studies demonstrate that dying Lc Purkinje cells exhibit the characteristic morphologic features of apoptosis, including nuclear condensation, axon beading and membrane blebbing. Using an in situ end-labeling method, we have also detected nicked nuclear DNA in these cells. Furthermore, we have examined the expression of the sulfated glycoprotein 2 (SGP2), whose mRNA is induced in both T-cells and prostate epithelial cells undergoing apoptotic death. We show by in situ hybridization that SGP2 is not expressed at detectable levels in normal Purkinje cells, but that its mRNA is present in Lc Purkinje cells prior to their death. Also expression of the Kv3.3b potassium channel, which marks the terminal phase of Purkinje cell differentiation, is evident in Lc Purkinje cells prior to their death. These data demonstrate that the Lc mutation induces apoptosis in cerebellar Purkinje cells following their maturation in postnatal cerebellum. Isolation of the Lc mutation and further analysis of its action in eliciting apoptosis can provide an important opportunity for understanding the etiology of neurodegenerative disease.

Polarized pigment granule transport occurs in the absence of microtubules in squirrelfish erythrophores: studies of the effects of estramustine

1987 ◽  
Vol 87 (4) ◽  
pp. 565-580
Author(s):  
M.E. Stearns ◽  
M. Wang
Keyword(s):  
Pigment Granule ◽  
Electron Microscopic ◽  
Microtubule Associated Proteins ◽  
Voltage Electron ◽  
Associated Proteins ◽  
Drug Inhibition ◽  
Microscopic Studies ◽  
10 Nm Filaments ◽  
Inhibition Studies

We have re-examined the involvement of microtubules in the process of pigment granule transport in squirrelfish erythrophores in situ (i.e. on scales). Light-microscopic studies revealed that following exposure to 5 microM-nocodazole for 1 h at 4 degrees C erythrophores retained an ability to aggregate and disperse their pigment uniformly, though at reduced rates. Serial thick-section stereo high-voltage electron-microscopic studies showed that the entire microtubule population was removed by drug treatment and that the microtubules were not reassembled as a result of pigment translocation processes in the presence of reduced levels of nocodazole (0.4 microM). Immunofluorescence microscopic studies confirmed that nocodazole (0.5-1 microM) produced rapid disassembly of the microtubules. Whole-mount electron-microscopic studies showed that the pigment granules were suspended in a cross-linking network of 3–10 nm filaments, which appeared to support ordered pigment transport in situ in the absence of microtubules. Drug inhibition studies showed that micromolar levels of estramustine, a novel anti-MAPs (microtubule-associated proteins) drug, reversibly inhibited pigment transport. The results suggest that an estramustine-sensitive cytomatrix component might produce polarized pigment transport in intact erythrophores.

scholarly journals Expression of the yes proto-oncogene in cerebellar Purkinje cells.

1989 ◽  
Vol 9 (10) ◽  
pp. 4545-4549 ◽  
Author(s):  
M Sudol ◽  
C F Kuo ◽  
L Shigemitsu ◽  
A Alvarez-Buylla
Keyword(s):  
In Situ Hybridization ◽  
Purkinje Cell ◽  
Gene Product ◽  
Purkinje Cells ◽  
Immunofluorescent Staining ◽  
Cell Degeneration ◽  
Functional Studies ◽  
Cerebellar Purkinje Cells ◽  
The Brain

To identify the kinds of cells in the brain that express the yes proto-oncogene, we examined chicken brains by using immunofluorescent staining and in situ hybridization. Both approaches showed that the highest level of the yes gene product was in cerebellar Purkinje cells. In addition, we analyzed Purkinje cell degeneration (pcd) mutant mice. The level of yes mRNA in cerebella of pcd mutants was four times lower than that found in cerebella of normal littermates. Our studies point to Purkinje cells as an attractive model for functional studies of the yes protein.

scholarly journals Visualizing a Convergence of Three Mitochondrial Molecule mRNAs for Drp1/Mfn2/Ucp4 on Soma of Cerebellar Purkinje Cells by RNAscope

2021 ◽  
Author(s):  
Hui Liu ◽  
Tingting Luo ◽  
Feifei Wu ◽  
Baolin Guo ◽  
Kunlong Zhang ◽  
...  
Keyword(s):  
Purkinje Cells ◽  
Drug Targets ◽  
Mitochondrial Dynamics ◽  
Structural Basis ◽  
Preclinical Development ◽  
Mitofusin 2 ◽  
Set Up ◽  
Cerebellar Purkinje Cells ◽  
Potential Drug Targets

Abstract We know little about how mitochondrial dynamics regulates in the Purkinje cells. To explore it, we first set up the Gad2-cre:ZsGreen-tdTomatofl/fl mice where Purkinje cells expressed tdTomato in the cerebellum. Secondly, double stainings verified tdTomato cells were Calbinin (CB)-positive Purkinje cells, but colocalized neither with astrocyte marker GFAP nor with microglia marker Iba1. Thirdly, application of RNAscope in situ hybridization with the identification of mRNAs of mitofusin 2 (Mfn2), calcium transporter (Mcu and Nclx) and uncoupling proteins (Ucp2 and Ucp4) were used onto Purkinje cells for specific spatial analysis. Our findings demonstrated that Mfn2 mRNAs expression was evident in Purkinje cells. And few expressions of Ucp4 mRNAs were presented in dendritic shafts of Purkinje cells. It should be noted that Mcu, Nclx, and Ucp2 mRNAs expression were only scattered on both soma and dendrites in Purkinje cells. The double RNAscope profiling of mitochondrial molecules showed Mfn1 mRNAs are presented only in the soma of the Purkinje cells. Double RNAscope showed none of Drp1 mRNAs were co-localized with Mcu mRNAs, as well as almost none of Ucp2 mRNAs were co-localized with Mfn2 mRNAs. All of these results showed the mitochondrial Drp1/Mfn2/Ucp4 convergence on the Purkinje cells. Finally, present research focuses on developing new and more specific molecules tuning the activity of the Purkinje cells activate or inactivate and opening therapeutic windows for Purkinje cells-related diseases. The molecular identification of potential drug targets, mechanism of action, and structural basis of their activity will crucially enable preclinical development.

In Situ Nitride Growth Studies by Low Energy Electron Microscopy (LEEM) and Low Energy Electron Diffraction (LEED)

1997 ◽  
Vol 3 (S2) ◽  
pp. 611-612
Author(s):  
E. Bauer ◽  
A. Pavlovska ◽  
I.S.T. Tsong
Keyword(s):  
Low Energy ◽  
Energy Electron ◽  
Ex Situ ◽  
Electron Microscopic ◽  
Insulating Layer ◽  
Light Emitting ◽  
Surface Sensitivity ◽  
Microscopic Studies ◽  
Low Energy Electron

Nitride films play an increasing role in modern electronics, for example silicon nitride as insulating layer in Si-based devices or GaN in blue light emitting diodes and lasers. For this reason they have been the subject of many ex situ electron microscopic studies. A much deeper understanding of the growth of these important materials can be obtained by in situ studies. Although these could be done by SEM, LEEM combined with LEED is much better suited because of its excellent surface sensitivity and diffraction contrast. We have in the past studied the high temperture nitridation of Si(l11) by ammonia (NH3)and the growth of GaN and A1N films on Si(l11) and 6H-SiC(0001) by depositing Ga and Al in the presence of NH3 and will report some of the results of this work for comparison with more recent work using atomic nitrogen instead of NH3.

Surface morphology of Purkinje cells and myocardial cells following chemical digestion

1990 ◽  
Vol 48 (3) ◽  
pp. 420-421
Author(s):  
Tetsuo Morita ◽  
Tatsuo Shimada
Keyword(s):  
Aqueous Solution ◽  
Purkinje Cells ◽  
Morphological Characteristics ◽  
Tween 20 ◽  
Myocardial Cells ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Moderator Band ◽  
Microscopic Studies ◽  
Endocardial Endothelium

From light and transmission electron microscopic studies, it has been long known that Purkinje cells of mammalian hearts have morphological characteristics different from ordinary myocardial cells. In the present study, not only Purkinje cells and myocardial cells but also connective tissue sheaths surrounding these cells were investigated by combined scanning electron microscopy(SEM) and chemical digestion.The moderator band of adult sheep heart was used because it possessed both Purkinje cells and myocardial cells (Fig.1). Tissue blocks were immersed in Karnovsky’s fixative for 3hr or longer. Some fixed tissues were inrrtersed in a 3-5% aqueous solution of NaClO for 1 min to digest the endocardial endothelium, and then were treated with 8N HCl for 30 min at 60°C to remove connection tissue elements. The others were iirmersed in a 2N NaOH or KOH solution for 7 days at room temperature to digest cellular elements. After freeze-cracking in a 40% dimethyl sulfoxide solution, the tissues were washed throughout in a saline solution containing tween 20, placed in a 1% aqueous solution of tannic acid for 2hr and conductive-stained with 1% OsO4 for 2hr.

LIGHT AND ELECTRON MICROSCOPIC STUDIES OF THYROTROPHIN RELEASING HORMONE-INDUCED GROWTH HORMONE AND PROLACTIN RELEASE IN HYPOPHYSECTOMIZED RATS BEARING AN ECTOPIC PITUITARY GLAND

1977 ◽  
Vol 72 (3) ◽  
pp. 313-319 ◽  
Author(s):  
G. L. ROSSI ◽  
DOROTHEA PROBST ◽  
A. E. PANERAI ◽  
IRIT GIL-AD ◽  
DANIELA COCCHI ◽  
...  
Keyword(s):  
Prolactin Cells ◽  
Electron Microscopic ◽  
Time Intervals ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
Highly Active ◽  
Microscopic Studies ◽  
Pituitary Glands ◽  
Hypophysectomized Rats

SUMMARY A light microscopic and ultrastructural study of anterior pituitary glands transplanted under the kidney capsule of hypophysectomized rats was performed, in basal conditions and after stimulation with thyrotrophin releasing hormone, at various intervals (24 h–2 months) after transplantation. Confirming previous biochemical findings, the results suggest that with time, somatotrophs acquire sensitivity to thyrotrophin releasing hormone and respond with increased exocytosis at doses that were found ineffective in pituitary glands in situ. Thryotrophin releasing hormone stimulation did not seem to influence the morphology of prolactin cells, which were already highly active under basal conditions at all time intervals.

Progressive polyuria without vasopressin neuron loss in a mouse model for familial neurohypophysial diabetes insipidus

2009 ◽  
Vol 296 (5) ◽  
pp. R1641-R1649 ◽  
Author(s):  
Masayuki Hayashi ◽  
Hiroshi Arima ◽  
Noriyuki Ozaki ◽  
Yoshiaki Morishita ◽  
Maiko Hiroi ◽  
...  
Keyword(s):  
Diabetes Insipidus ◽  
Inclusion Bodies ◽  
Urine Volume ◽  
Neuronal Loss ◽  
Wild Type ◽  
Autosomal Dominant Disorder ◽  
Electron Microscopic ◽  
Vasopressin Neuron ◽  
Immunohistochemical Analyses

Familial neurohypophysial diabetes insipidus (FNDI), an autosomal dominant disorder, is mostly caused by mutations in the gene of neurophysin II (NPII), the carrier protein of arginine vasopressin (AVP). Previous studies suggest that loss of AVP neurons might be the cause of polyuria in FNDI. Here we analyzed knockin mice expressing mutant NPII that causes FNDI in humans. The heterozygous mice manifested progressive polyuria as do patients with FNDI. Immunohistochemical analyses revealed that inclusion bodies that were not immunostained with antibodies for mutant NPII, normal NPII, or AVP were present in the AVP cells in the supraoptic nucleus (SON), and that the size of inclusion bodies gradually increased in parallel with the increases in urine volume. Electron microscopic analyses showed that aggregates existed in the endoplasmic reticulum (ER) as well as in the nucleus of AVP neurons in 1-mo-old heterozygous mice. At 12 mo, dilated ER filled with aggregates occupied the cytoplasm of AVP cells, while few aggregates were found in the nucleus. Analyses with in situ hybridization revealed that expression of AVP mRNA was significantly decreased in the SON in the heterozygous mice compared with that in wild-type mice. Counting cells expressing AVP mRNA in the SON indicated that polyuria had progressed substantially in the absence of neuronal loss. These data suggest that cell death is not the primary cause of polyuria in FNDI, and that the aggregates accumulated in the ER might be involved in the dysfunction of AVP neurons that lead to the progressive polyuria.

NOVEL IN SITU SILICA/POLYDIMETHYLSILOXANE NANOCOMPOSITES: FACILE ONE-POT SYNTHESIS AND CHARACTERIZATION

2012 ◽  
Vol 85 (1) ◽  
pp. 92-107 ◽  
Author(s):  
Nabarun Roy ◽  
Anil K. Bhowmick
Keyword(s):  
Storage Modulus ◽  
Polymorphic Modification ◽  
Structure Property ◽  
Electron Microscopic ◽  
One Pot ◽  
Simultaneous Generation ◽  
In Situ Silica ◽  
Transmission Electron ◽  
Microscopic Studies

Abstract Synthesis of in situ silica/polydimethylsiloxane (PDMS) nanocomposites by using tetraethylorthosilicate (TEOS) as the precursor for silica and octamethylcyclotetrasiloxane for the polymer in presence of base was undertaken. Simultaneous generation of silica and polymer and dispersion of the nanofiller in the polymer have been reported for the first time. Fourier transform infrared spectroscopy was used as a tool to monitor the reaction conditions. The structure–property relationship of in situ silica/PDMS nanocomposites has been highlighted. Transmission electron microscopic studies reveal finest extent of dispersion of the in situ generated nanosilica, which is found to undergo polymorphic modification determined from wide-angle X-ray diffraction. Nanocomposites exhibit huge improvement in mechanical properties (>150% improvement in tensile strength for just 2 phr TEOS-filled sample) and room temperature storage modulus (>460% improvement in storage modulus for 8 phr TEOS-loaded sample). Polymer–filler interaction significantly improves oxidative thermal stability of the nanocomposites.

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