Tento přehled si klade za cíl seznámit klinické a laboratorní pracovníky s nejdůležitějšími preanalytickými a analytickými aspekty stanovení lehkých řetězců neurofilament (NfL) v biologických tekutinách. NfL představují perspektivní nespecifický biomarker poškození neuronů a axonů, k němuž dochází u celé řady neurologických onemocnění. Před zavedením vyšetřování NfL do širší klinické praxe je nutné charakterizovat preanalytické a analytické stránky stanovení, které mohou významným způsobem ovlivnit správnost výsledku analýzy. Při hodnocení koncentrací NfL je zapotřebí brát v úvahu věk pacienta a vliv může mít i body mass index. Výhodou NfL je jejich dlouhodobá stabilita při různých teplotách skladování i odolnost vůči opakovaným cyklům zmrazování a rozmrazování. Koncentrace NfL v klinických studiích se stanovují především imunoanalytickými metodami, které se liší citlivostí. Pro stanovení NfL existuje několik imunoanalytických přístupů vhodných pro spolehlivé vyšetření v mozkomíšním moku (MMM) i v séru/plazmě. Volba optimálního analytického přístupu závisí mimo jiné na koncentracích NfL v biologických tekutinách. Pro stanovení NfL v MMM lze využít metod ELISA, které vykazují dostačující citlivost pro vyšší koncentrace NfL vyskytující se v této biologické tekutině. Postupně zaváděné nové technologie charakterizované výrazně vyšší citlivostí ve srovnání s metodou ELISA umožnily spolehlivé vyšetřování NfL i v séru či plazmě. Podrobněji jsou zmiňovány principy metod postavené na technologii Simoa®, SimplePlexTM a imunomagnetické redukce.
The aim of this review is to inform clinical and laboratory workers about the most important pre-analytical and analytical aspects of neurofilament light chain (NfL) determination in biological fluids. NfLs represent a promising nonspecific biomarker of neuronal and axonal damage that occurs in a variety of neurological diseases. Before introducing NfL determination into routine clinical practice, it is necessary to characterize the pre-analytical and analytical aspects of the assays, which can significantly affect the accuracy of the analysis results. When evaluating NfL concentrations, the patient‘s age should be taken into account and body mass index may also have an effect. The advantages of NfLs are their long-term storage stability at different temperatures as well as resistance to repeated freezing and thawing cycles. NfL concentrations in clinical trials are determined primarily by immunoassay methods that vary in sensitivity. There are several immunoassay technologies for the determination of NfL suitable for reliable determination in cerebrospinal fluid (CSF) and serum/plasma. The choice of the optimal analytical approach depends, among other things, on the concentration of NfL in biological fluids. ELISA methods can be used to determine NfL in CSF, which show sufficient sensitivity for higher concentrations of NfL occurring in this biological fluid. Newly introduced technologies characterized by significantly higher sensitivity in comparison with the ELISA methods enabled reliable examination of NfL also in serum/plasma. The principles of methods based on Simoa® technology, SimplePlexTM, and immunomagnetic reduction are mentioned in more detail.
- MeSH
- biologické markery analýza chemie MeSH
- intermediární filamenta * chemie MeSH
- lidé MeSH
- mozkomíšní mok chemie MeSH
- preanalytická fáze metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
Given the role of intermediate filaments (IFs) in normal cell physiology and scores of IF-linked diseases, the importance of understanding their molecular structure is beyond doubt. Research into the IF structure was initiated more than 30 years ago, and some important advances have been made. Using crystallography and other methods, the central coiled-coil domain of the elementary dimer and also the structural basis of the soluble tetramer formation have been studied to atomic precision. However, the molecular interactions driving later stages of the filament assembly are still not fully understood. For cytoplasmic IFs, much of the currently available insight is due to chemical cross-linking experiments that date back to the 1990s. This technique has since been radically improved, and several groups have utilized it recently to obtain data on lamin filament assembly. Here, we will summarize these findings and reflect on the remaining open questions and challenges of IF structure. We argue that, in addition to X-ray crystallography, chemical cross-linking and cryoelectron microscopy are the techniques that should enable major new advances in the field in the near future.
- MeSH
- cytoskelet chemie metabolismus MeSH
- fyziologie buňky * MeSH
- intermediární filamenta chemie metabolismus MeSH
- lidé MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Macrofibrils, the main structural features within the cortical cells of mammalian hair shafts, are long composite bundles of keratin intermediate filaments (KIFs) embedded in a matrix of keratin-associated proteins. The KIFs can be helically arranged around the macrofibril central axis, making a cylinder within which KIF helical angle relative to macrofibril axis increases approximately linearly from macrofibril centre to edge. Mesophase-based self-assembly has been implicated in the early formation of macrofibrils, which first appear as liquid-crystal tactoids in the bulb of hair follicles. Formation appears to be driven initially by interactions between pre-keratinized KIFs. Differences in the nature of these KIF-KIF interactions could result in all macrofibrils being internally twisted in a single handedness, or a 50:50 mixture of handedness within each cortical cell. We data-mined 41 electron tomograms containing three-dimensional macrofibril data from previously published studies of hair and wool. In all 644 macrofibrils examined we found that within each tomogram all macrofibrils had the same handedness. We concluded that earlier reports of left- and right-handed macrofibrils were due to artefacts of imaging or data processing. A handedness marker was used to confirm (using re-imaged sections from earlier studies) that, in both human and sheep, all macrofibrils are left-handed around the macrofibril axis. We conclude that this state is universal within mammalian hair. This also supports the conclusion that the origin of macrofibril twist is the expression of chiral twisting forces between adjacent KIFs, rather than mesophase splay and bending forces relaxing to twisting forces acting within a confined space.
- MeSH
- cytoskelet chemie ultrastruktura MeSH
- intermediární filamenta chemie ultrastruktura MeSH
- keratiny chemie ultrastruktura MeSH
- lidé MeSH
- ovce genetika MeSH
- tomografie elektronová MeSH
- vlasy, chlupy chemie ultrastruktura MeSH
- vlna chemie ultrastruktura MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The collapse of vimentin caused by some xenobiotics correlates with the loss of structural integrity of the seminiferous epithelium. In this study, we investigated the effect of busulphan (an anticancer drug with toxic effects on dividing germ cells) on vimentin filament distribution in rat seminiferous epithelium and compared it with changes found in testes of unilaterally cryptorchid rats. In the seminiferous epithelium, the vimentin labelling was observed only in the Sertoli cells, showing a stage-specific arrangement of the filaments. Both busulphan treatment and cryptorchism caused altered distribution of vimentin filaments in the Sertoli cells. In both models, the apical vimentin filaments collapsed towards the nuclei and were disorganized in the basal region of the Sertoli cells while the germ cells were diminished in the epithelium. After the busulphan effect subsided (4 weeks after administration), spermatogenesis began to restore and vimentin filaments began to organize in basal and perinuclear regions of Sertoli cells among the spermatogonia and spermatocytes. Vimentin labelling of the sloughed material in the lumen of cryptorchid testes (but not in busulphan treated animals) was observed. We conclude that the Sertoli cell vimentin filaments play an important role in the maintenance of spermatogenesis, their damage is associated with the seminiferous epithelium disintegration and their restoration with a recovery of spermatogenesis after the unfavourable conditions subside.
- MeSH
- busulfan farmakologie MeSH
- časové faktory MeSH
- financování organizované MeSH
- imunohistochemie MeSH
- intermediární filamenta chemie metabolismus ultrastruktura MeSH
- krysa rodu rattus MeSH
- potkani Wistar MeSH
- semenný epitel metabolismus ultrastruktura MeSH
- spermatogeneze fyziologie genetika účinky léků MeSH
- testis metabolismus ultrastruktura MeSH
- velikost orgánu MeSH
- vimentin biosyntéza metabolismus účinky léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- MeSH
- buněčné linie MeSH
- genetická heterogenita MeSH
- gliom genetika chemie patologie MeSH
- imunohistochemie MeSH
- intermediární filamenta genetika chemie MeSH
- keratiny genetika chemie MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- techniky in vitro MeSH
