Protein and lysozyme content of adult human nucleus pulposus

A radiologically normal human nucleus pulposus was extracted with 4 M guanidinium chloride and the non-collagenous proteins separated from the proteoglycans by dissociative density gradient centrifugation. Lysozyme was identified as a matrix constituent of the normal, mature human nucleus pulposus.     

Description of neurons immunoreactive to anti-beta-endorphin immune serum present in the infundibular nucleus in man]

Neurons containing peptide (s) immunologically related to beta-endorphin have been detected by immunochemistry in human adult and fetal hypothalami. Their perikarya are located in the infundibular nucleus. Some fibres terminate close to vessels in the median eminence, others form pericellular baskets around perikarya of non-immunoreactive neurons of the infundibular nucleus. These results suggest that the central nervous system elaborates beta-endorphin or immunologically related peptides.     

Impaired nuclear translocation of glucocorticoid receptors: novel findings from psoriatic epidermal keratinocytes

Psoriasis is a chronic proliferative skin disease and is usually treated with topical glucocorticoids, which act through the glucocorticoid receptor (GR), a component of the physiological systems essential for immune responses, differentiation, and homeostasis. To investigate the possible role of GR in the pathogenesis of psoriasis, normal and psoriatic lesional skin were recruited. Firstly, the immunolocalization of GR in the skin and cultured epidermal keratinocytes were determined by immunofluorescence. In normal skin and cultured human epidermal keratinocytes, intracellular GR is localized in the nuclei, while in psoriatic skin and cultured keratinocytes, GR is in the cytoplasm. Next, we investigated possible factors associated with the cytoplasmic distribution. We found that VEGF and IFN-γ led to impaired nuclear translocation of GR through p53 and microtubule-inhibitor, vincristine, and inhibited nuclear uptake of GR in normal keratinocytes. In addition to dexamethasone, interleukin (IL)-13 was also able to transfer GR into nuclei of psoriatic keratinocytes. Furthermore, discontinuation of dexamethasone induced cytoplasmic retention of GR in normal keratinocytes. In contrast, energy depletion of normal epidermal keratinocytes did not change the nuclear distribution of GR. To confirm our findings in vivo, an imiquimod-induced psoriasis-like skin mouse model was included. IL-13 ameliorated (but vincristine exacerbated) the skin lesions on the mouse. Taken together, our findings define that impaired nuclear translocation of GR is associated with VEGF, IFN-γ, p53, and microtubule. Therapeutic strategies designed to accumulate GR in the nucleus, such as IL-13, may be beneficial for the therapy of psoriasis.     

Cellular maintenance of nuclear protein homeostasis

The accumulation and aggregation of misfolded proteins is the primary hallmark for more than 45 human degenerative diseases. These devastating disorders include Alzheimer’s, Parkinson’s, Huntington’s, and amyotrophic lateral sclerosis. Over 15 degenerative diseases are associated with the aggregation of misfolded proteins specifically in the nucleus of cells. However, how the cell safeguards the nucleus from misfolded proteins is not entirely clear. In this review, we discuss what is currently known about the cellular mechanisms that maintain protein homeostasis in the nucleus and protect the nucleus from misfolded protein accumulation and aggregation. In particular, we focus on the chaperones found to localize to the nucleus during stress, the ubiquitin–proteasome components enriched in the nucleus, the signaling systems that might be present in the nucleus to coordinate folding and degradation, and the sites of misfolded protein deposition associated with the nucleus.     

Gold nanoparticles induce nuclear damage in breast cancer cells,which is further amplified by hyperthermia

Gold nanoparticles have emerged as promising tools for cancer research and therapy, where they can promote thermal killing. The molecular mechanisms underlying these events are not fully understood. The geometry and size of gold nanoparticles can determine the severity of cellular damage. Therefore, small and big gold nanospheres as well as gold nanoflowers were evaluated side-by-side. To obtain quantitative data at the subcellular and molecular level, we assessed how gold nanoparticles, either alone or in combination with mild hyperthermia, altered the physiology of cultured human breast cancer cells. Our analyses focused on the nucleus, because this organelle is essential for cell survival. We showed that all the examined gold nanoparticles associated with nuclei. However, their biological effects were quantitatively different. Thus, depending on the shape and size, gold nanoparticles changed multiple nuclear parameters. They redistributed stress-sensitive regulators of nuclear biology, altered the nuclear morphology, reorganized nuclear laminae and envelopes, and inhibited nucleolar functions. In particular, gold nanoparticles reduced the de novo biosynthesis of RNA in nucleoli, the subnuclear compartments that produce ribosomes. While small gold nanospheres and nanoflowers, but not big gold nanospheres, damaged the nucleus at normal growth temperature, several of these defects were further exacerbated by mild hyperthermia. Taken together, the toxicity of gold nanoparticles correlated with changes in nuclear organization and function. These results emphasize that the cell nucleus is a prominent target for gold nanoparticles of different morphologies. Moreover, we demonstrated that RNA synthesis in nucleoli provides quantitative information on nuclear damage and cancer cell survival.     

Sumoylation regulates diverse biological processes

Ten years after its discovery, the small ubiquitin-like protein modifier (SUMO) has emerged as a key regulator of proteins. While early studies indicated that sumoylation takes place mainly in the nucleus, an increasing number of non-nuclear substrates have recently been identified, suggesting a wider stage for sumoylation in the cell. Unlike ubiquitylation, which primarily targets a substrate for degradation, sumoylation regulates a substrate’s functions mainly by altering the intracellular localization, protein-protein interactions or other types of post-translational modifications. These changes in turn affect gene expression, genomic and chromosomal stability and integrity, and signal transduction. Sumoylation is counter-balanced by desumoylation, and well-balanced sumoylation is essential for normal cellular behaviors. Loss of the balance has been associated with a number of diseases. This paper reviews recent progress in the study of SUMO pathways, substrates, and cellular functions and highlights important findings that have accelerated advances in this study field and link sumoylation to human diseases. Received 19 March 2007; received after version 16 July 2007; accepted 1 August 2007     

Correlation between lactate levels and pH in discs of patients with lumbar rhizopathies

Zusammenfassung An 10 Patienten wurde das während der Operation im Discus gemessene pH mit dem Laktatspiegel des in derselben Zeit entfernten Nucleus pulposus in Korrelation gebracht. Mit absteigenden pH-Werten war der Laktatspiegel höher. Es wird dem erhöhten Laktatspiegel der lumbaren Bandscheiben eine mögliche Rolle in der Pathologie einiger lumbarer Rhizopathien zugeschrieben.     

Identification of GABA accumulating neurons in the dorsal raphe nucleus]

A possible GABAergic innervation of the nucleus raphe dorsalis (NRD) was investigated by measuring glutamate decarboxylase activity in the NRD after lesioning the afferents of this nucleus. The slight decrease found in the enzymatic activity suggests that these afferents have a minor participation in the GABA innervation of the NRD and implies the existence of an intrinsic GABAergic system in this nucleus. This local innervation was demonstrated by radio-autography and shows fibers, axonal varicosities and cell bodies which accumulate 3H GABA in the caudal part of this nucleus.     

<Emphasis Type="Italic">XPF</Emphasis> knockout via CRISPR/Cas9 reveals that ERCC1 is retained in the cytoplasm without its heterodimer partner XPF

The XPF/ERCC1 heterodimeric complex is essentially involved in nucleotide excision repair (NER), interstrand crosslink (ICL), and double-strand break repair. Defects in XPF lead to severe diseases like xeroderma pigmentosum (XP). Up until now, XP-F patient cells have been utilized for functional analyses. Due to the multiple roles of the XPF/ERCC1 complex, these patient cells retain at least one full-length allele and residual repair capabilities. Despite the essential function of the XPF/ERCC1 complex for the human organism, we successfully generated a viable immortalised human XPF knockout cell line with complete loss of XPF using the CRISPR/Cas9 technique in fetal lung fibroblasts (MRC5Vi cells). These cells showed a markedly increased sensitivity to UVC, cisplatin, and psoralen activated by UVA as well as reduced repair capabilities for NER and ICL repair as assessed by reporter gene assays. Using the newly generated knockout cells, we could show that human XPF is markedly involved in homologous recombination repair (HRR) but dispensable for non-homologous end-joining (NHEJ). Notably, ERCC1 was not detectable in the nucleus of the XPF knockout cells indicating the necessity of a functional XPF/ERCC1 heterodimer to allow ERCC1 to enter the nucleus. Overexpression of wild-type XPF could reverse this effect as well as the repair deficiencies.     

Immunohistochemical demonstration of an SRIF-like system in the brain of the reptile: Lacerta muralis Laur

Summary The distribution of an SRIF-like substance in the brain of normal lizards (Lacerta muralis Laur.) has been determined. SRIF is shown to be present in neural cell bodies in the hypothalamic paraventricular nucleus, the hypothalamo-hypophysial tractus and the median eminence.Contrat INSERM, No. 74.1.444.35.     

Demonstration of tissue-specific antigens shared by normal pancreas and pancreatic neoplasms

Summary Xenoantiserum raised against extracts of normal hamster pancreas, after absorption with normal tissues, reacted specifically with normal hamster and human pancreas by immunodiffusion. Absorbed antiserum also reacted with hamster and human pancreatic carcinoma but not with other neoplasms. Immunization of hamsters with normal pancreas extracts prevented growth of transplantable pancreatic carcinomas.     

Demonstration of tissue-specific antigens shared by normal pancreas and pancreatic neoplasms

Xenoantiserum raised against extracts of normal hamster pancreas, after absorption with normal tissues, reacted specifically with normal hamster and human pancreas by immunodiffusion. Absorbed antiserum also reacted with hamster and human pancreatic carcinoma but not with other neoplasms. Immunization of hamsters with normal pancreas extracts prevented growth of transplantable pancreatic carcinomas.     

Demonstration of antigen associated with human breast cancers]

The insoluble pellet of human mammary carcinomas was solubilized by an acid buffer. Antiserum prepared with this acidosoluble fraction, after suitable absorption gave one precipitin line with the immunizing extracts: this line is different from those given by the tumor associated antigens actually known. The same antiserum reacted only with sections of human mammary carcinomas by immunofluorescence . It did not stain sections of normal mammary glands or benign mammary diseases. Reactivity with cancers of other organs was absent or doubtful. Hence it is likely that an antigen associated to human mammary carcinomas was characterized.     

L'effet de la basse température sur l'incorporation de précurseurs des acides nucléiques et des protéines dans les cellules du méristème radiculaire deVicia faba

Summary The uptake of labelled RNA and protein precursors inVicia faba root meristems into nuclei at 4°C is less depressed than in the cytoplasm. Reversion of the normal pattern of incorporation would seem to indicate an inhibition of the RNA transfer from nucleus to cytoplasm.     

Common antigenicity between a human thymic epithelial cell product and a thymus-dependent serum factor

Summary Specific immunofluorescence of human thymic epithelial cytoplasm was obtained with antibodies to supernatant of thymic epithelial cultures, and with anti-prealbumin antibodies. These antibodies also reacted with normal serum but not with serum from Di George patients. The data indicates that thymic epithelium and a component of the prealbumin fraction of normal serum share a common antigen believed to be thymic hormone.Acknowledgment. The authors wish to thank Mrs Francine Rivard and Claire Prévost for technical assistance and Dr A.R.C. Dobell for human thymic material. This work was supported by the National Cancer Institute of Canada and the Medical Research Council of Canada.     

Harmaline tremor: activity of the interposito-rubral system and of the bulbo-ponto-reticular formation

The effects of tremogenic doses of harmaline have been studied by extracellular unit recordings and 14C 2-deoxyglucose marking in two groups of cats. Harmaline sensitive neurons were found in the lateral reticular nucleus and the nucleus reticularis tegmenti pontis. The nucleus interpositus as well as the red nucleus were also found to be discharging at the tremor frequency, indicating that the cerebello-interposito-rubral system participates in harmaline tremor. In cats with unilateral sections of the inferior cerebellar peduncle, 14C 2-deoxyglucose marking demonstrated that the increased activity previously observed in those structures was a consequence of harmaline acting on the inferior olive.     

Reciprocal connections between substantia nigra and medullary reticular formation in the rat

Summary Electrophysiological analysis shows reciprocal connections between substantia nigra and medullary reticular formation (nucleus reticularis giganto celullaris). The nigro-reticular connection appears to be monosynaptic, as shown by antidromic activation, and comprises an ipsi and a contralateral component. Its effect is mainly inhibitory. The reticulonigral component produces mainly excitatory effects and includes fibres from nucleus giganto celullaris and nucleus parvocelullaris in the medullary reticular formation.This work was aided by a grant from CONICIT (projecto 31.26.S1-0412).     

Immunocytochemical location of the centrosphere of human cancer cells using natural rabbit antibodies]

Sera of 40 normal nonimmunized rabbits were eprouved by immunoperoxidase on cultural human cells. Four sera contain centrosphere-reactive antibodies and for the strongest serum the centrospheres were still stained with the 1/600 dilution. This last serum visualized the centrospheres within the height human cell lines eprouved, whatever the phase of the mitotic cycle. The staining was not inhibited after serum absorption by tubulin.