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Frontotemporal dementia (FTD), characterized by neurodegeneration mainly in the frontal and temporal lobes, accounts for ca. 10-15% of all dementias. In 1892 the Czech-German neuropsychiatrist Arnold Pick reported the fi rst case of FTD in a 71-year-old patient suffering from progressive dementia, memory disturbances, and aphasia associated with frontal and temporal lobe atrophy and the presence of neuronal inclusions. Later the inclusions were named Pick bodies.The neuropathological hallmark of FTD is very differentiated. In contrast to Alzheimer's disease(AD), there are neither senile plaques nor neurofibrillary tangles in the brains of FTD patients.Frontotemporal dementias are tauopathies, a group of disorders caused by aberrant metabolism of tau protein, a family of proteins associated with microtubules (MAPT: macro-tubule-associated tau protein). In the nervous system the protein stabilizes microtubules in neuronal axons and is thus responsible for crucial processes in neuron metabolism, such as signal transduction, plasticity,and intracellular transport. In the human brain, six isoforms are produced from the MAPT gene (chromosome 17 q21.2) by alternative mRNA splicing. The isoforms differ in the number of amino acids in the protein chain, the presence of three (3R tau type) or four (4R tau type) domains responsible for binding to microtubules, and one or two inserts containing from 29 to 58 amino acids. The isoforms are modified posttranslationally by hyperphosphorylation, glycation,or oxidation, which can change the protein's properties and disturb its normal function. Altered metabolism of tau protein changes its interactions with tubulin, leading to destabilization of the microtubule structure and initiating the generation of toxic tau aggregates. The fi rst mutations in the MAPT gene responsible for frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) were found in 1998. So far over 40 mutations in the MAPT gene have been identified, mainly in families with autosomal dominant FTDP-17 but also in sporadic families with Pick's disease and AD. The known DNA changes have been classified according to their molecular effects into at least two groups: mutations that change the biochemical properties of tau protein and mutations that alter the alternative splicing of mRNA and lead very often to the overproduction of the 4R tau isoform. The imbalance in the ratio of the synthesized 3R and 4R tau isoforms stimulates protein aggregation and initiates neurodegeneration, leading to the development of dementia.

Human survivin is a member of the IAP (Inhibitor of Apoptosis) family. It was reported that survivin expression is associated with drug resistance, cancer progression and low patient survival rate in many cancers. Survivin is implicated in both: inhibition of apoptosis and regulation of cell division. As a member of Chromosomal Passenger Complex (CPC) it is involved in sister chromatids segregation during mitosis. On the other hand, survivin plays an important role in the surveillance mechanism called mitotic spindle assembly checkpoint (MSAC) which regulates metaphase to anaphase transition during mitosis. Additionally, survivin is necessary for cytokinesis progression. The present review is a summary of survivin's functions, focused on its role in cell division in normal and cancer cells, as well as introduction to discussion about anticancer therapies based on survivin depletion.

Lamins belong to type V intermediate filaments superfamily. They are the main structural constituencies of the nuclear lamina but they also influence on chromatin structure, regulation of gene expression, localization and probably protein degradation. Because lamins play many different roles within the cell, mutations in their genes can results in variety of pathological phenotypes. Mutations in LMNA gene are the cause of many different diseases, called laminopathies. Among laminopathies are muscle tissue diseases, adipose tissue diseases and also progerias, the premature aging syndromes. One of the progerias, which results from mutation in LMNA gene, is Hutchinson-Gilford progeria syndrome (HGPS). It seems that the same molecular mechanisms which are responsible for premature aging of cells of HGPS patients, are involved in physiological aging.

The 14-3-3 proteins are a family of highly conserved proteins found in all eukaryotes - from the yeasts to mammals. They regulate several cellular processes recognizing unique conservative, mostly phosphorylated motif of partner proteins. Binding of the 14-3-3 proteins regulates their partners through a variety of mechanisms, such as altering their catalytic activity, subcellular localization, stability or altering their interactions with other protein molecules. The native 14-3-3 proteins are present in form of homo- and hetero-dimers. The most structurally variable N-and C-termini are responsible for isoform specific protein-protein interactions, and cellular localization. In plant cell, 14-3-3 proteins appear to play an important role in regulation of key enzymes of carbon and nitrogen metabolism, modulation ion pumps and channels. They are also involved in signal transduction pathways and even in gene expression.

In normal sperm, the 135 kD isoform of protein 4.1 is replaced by the 80 kD variant. Transcript for protein 4.1 loses the 'upstream' initiation codon by a stage-dependent alternative splicing and in mature sperm only 'downstream' initiation codon is active. A mutation in the 'downstream' initiation codon may be a reason for sperm differentiation arrest (azoospermia) or can be associated with the presence of amorphous spermatozoa in ejaculate (teratozoospermia). The aim of the study was the molecular analysis of gene coding for the protein 4.1, carrying a 'downstream' translation initiation codon. We have screened DNA samples obtained from azoospermic (blood) and teratozoospermic (spermatozoa) patients using PCR amplification of gene fragment, AUG containing exon with subsequent digestion (NlaIII) of CATG sequence. The absence of a cleavage site for this restriction enzyme would suggest the presence of mutation in the AUG codon. Analysis of DNA samples obtained from both azoospermic and teratozoospermic patients did not reveal any changes in the 'downstream' translation initiation codon. We concluded therefore that observed by others a defective expression of protein 4.1 in amorphous sperm cells is probably due to the other factor(s) than mutation in the 'downstream' translation initiation codon.