Miroslava Čedíková

Mitochondria in White, Brown, and Beige Adipocytes.

Mitochondria play a key role in energy metabolism in many tissues, including cardiac and skeletal muscle, brain, liver, and adipose tissue. Three types of adipose depots can be identified in mammals, commonly classified according to their colour appearance: the white (WAT), the brown (BAT), and the beige/brite/brown-like (bAT) adipose tissues. WAT is mainly involved in the storage and mobilization of energy and BAT is predominantly responsible for nonshivering thermogenesis. Recent data suggest that adipocyte mitochondria might play an important role in the development of obesity through defects in mitochondrial lipogenesis and lipolysis, regulation of adipocyte differentiation, apoptosis, production of oxygen radicals, efficiency of oxidative phosphorylation, and regulation of conversion of white adipocytes into brown-like adipocytes. This review summarizes the main characteristics of each adipose tissue subtype and describes morphological and functional modifications focusing on mitochondria and their activity in healthy and unhealthy adipocytes.

Immunohistochemical Detection of Cancer Stem Cell Related Markers CD44 and CD133 in Metastatic Colorectal Cancer Patients

Aim. The goal of this study was to semiquantitatively detect presence of cancer stem cells markers CD44 and CD133 in immunohistochemically stained paired samples of colorectal cancer (CRC) and colorectal liver metastases (CLM). Level of staining intensity was compared to clinical and pathological characteristics of tumors with the aim to identify impact of CD44 or CD133 expression on tumor behavior. Patients and Methods. Formalin fixed paraffin embedded samples from 94 patients with colorectal tumor and liver metastases were collected at Sikls Department of Pathology. Samples were stained by antibodies against CD44 and CD133. Presence and intensity of staining was assessed semiquantitatively by three trained researchers. Results. Patients with higher level of CD133 staining in CRC had longer disease free interval (Cox-Mantel P = 0.0244), whereas we found no relation between CD44 expression and overall survival or disease free interval. CD133 expression in CRC and CLM differed based on CRC grading; in case of CD44 we found differences in staining intensity in individual stages of tumor lymph node invasion. Conclusion. Effect of cancer stem cell markers on prognosis of colorectal cancer can vary depending on pathological classification of tumor, and we have shown that CD133, generally considered to be a negative marker, can bear also clinically positive prognostic information in group of patients with colorectal liver metastases.

Intracerebellar application of P19-derived neuroprogenitor and naive stem cells to Lurcher mutant and wild type B6CBA mice

Summary Background Neurotransplantation has great potential for future treatments of various neurodegenerative disorders. Preclinically, the Lurcher mutant mouse represents an appropriate model of genetically-determined olivocerebellar degeneration. The aim of the present study was to assess survival of naïve and neurally differentiated P19 carcinoma stem cells following transplantation into the cerebellum of Lurcher mice and wild type littermates. Material/Methods Adult normal wild type (n=51) and Lurcher mutant mice (n=87) of the B6CBA strain were used. The mean age of the animals at the time of transplantation was 261.5 days. Suspension of naive and neurally differentiated P19 carcinoma stem cells was injected into the cerebellum of the mice. In the Lurcher mutants, 2 depths of graft injection were used. Three weeks after implantation the brains of experimental animals were examined histologically. Results Survival of neuroprogenitor grafts at a depth of 1.6 mm was significantly higher in wild type vs. Lurcher mutant mice. In wild type mice, the typical graft localization was in the middle of the cerebellum, whereas in Lurcher mice the graft was never found inside the degenerated cerebellum and was primarily localized in the mesencephalon. Conclusions We conclude that the appearance and low survival rate of cerebellar P19 carcinoma stem cell grafts in the Lurcher mutant mice weigh against the therapeutic value of this cell line in preclinical studies of neurodegeneration.

Effects of the Czech Propolis on Sperm Mitochondrial Function

Propolis is a natural product that honeybees collect from various plants. It is known for its beneficial pharmacological effects. The aim of our study was to evaluate the impact of propolis on human sperm motility, mitochondrial respiratory activity, and membrane potential. Semen samples from 10 normozoospermic donors were processed according to the World Health Organization criteria. Propolis effects on the sperm motility and mitochondrial activity parameters were tested in the fresh ejaculate and purified spermatozoa. Propolis preserved progressive motility of spermatozoa in the native semen samples. Oxygen consumption determined in purified permeabilized spermatozoa by high-resolution respirometry in the presence of adenosine diphosphate and substrates of complex I and complex II (state OXPHOSI+II) was significantly increased in the propolis-treated samples. Propolis also increased uncoupled respiration in the presence of rotenone (state ETSII) and complex IV activity, but it did not influence state LEAK induced by oligomycin. Mitochondrial membrane potential was not affected by propolis. This study demonstrates that propolis maintains sperm motility in the native ejaculates and increases activities of mitochondrial respiratory complexes II and IV without affecting mitochondrial membrane potential. The data suggest that propolis improves the total mitochondrial respiratory efficiency in the human spermatozoa in vitro thereby having potential to improve sperm motility.

Trends in gene expression changes during adipogenesis in human adipose derived mesenchymal stem cells under dichlorodiphenyldichloroethylene exposure

BackgroundsExposure to lipophilic environmental pollutants has been explored as a risk factor of development of diabetes mellitus in obese. Adipose tissue is a reservoir of bioaccumulative lipophilic contaminants including p,pʹ-dichlorodiphenyldichloroethylene (DDE). Our aim was to analyze the effect of DDE (in concentrations 0.1 μM, 1 μM, and 10 μM) on adipocyte differentiation and insulin signalling pathway on in vitro adipogenic model of human adipose derived mesenchymal stem cells (hADMSC).MethodsThe effect of DDE was monitored by analysis of expression (RT qPCR, Western blotting) of genes involved in adipocyte differentiation and insulin signalling pathway including lipid metabolism on days 0, 4, 10, 21, 28 of differentiation.ResultsThe main observation was significant increase of INSR, LIPE, FASN, SREBP1, OCT4 and AKT2 expression under influence of DDE. We did not record any increase of the active form of Akt.ConclusionOur findings suggest that DDE exposure changes the differentiation of adipocytes, enhances the lipid metabolism and so may play a role in the development of obesity and metabolic diseases by affecting the insulin signalling pathway. The influence of DDE seems to be similar to the effect of insulin itself. However, further studies to elucidate the mechanism of action of DDE are necessary.