PROFILE OF CD150 EXPRESSION IN BONE MARROW CELLS OF PATIENTS WITH ACUTE MYELOID LEUKEMIA

BACKGROUND

Acute myeloid leukemia (AML) is a highly heterogeneous disease accompanied by the arrest of myeloid cell lineage differenti-ation due to accumulation of genetic abnormalities and clonal proliferation of myeloid blasts. Finding the differentially expressed molecules and studying their function within AML subgroups may help to improve diagnosis and prognosis with the aim of developing selected therapies for AML subsets. The aim of this study was to reveal the profile of CD150 cell surface expression on bone marrow (BM) cells of AML patients.

MATERIALS AND METHODS

The study was performed on samples of BM aspirates from 55 patients with primarily diagnosed AML. Flow cytometry analysis was applied for the evaluation of immunophenotype profile and CD150 cell surface expression on BM cells from AML patients.

RESULTS

Four AML subtypes (M1, M2, M3 and M5) were identified. The CD150 expression was found in 14 (25.5%) cases predominantly of AML M3 subtype. CD150 expression was detected on 43.2-83.8% of leukemia cells in AML M3. The frequency of CD150 positive cases of non-M3 AML subtypes was low: all AML M1 cases were CD150-negative, while only 1 (10.0%) of 10 patients with AML M2 and 6 (19.4%) of 31 patients with AML M5 were CD150 positive. The median percentage of CD150 positive leukemia cells and the index of mean fluorescence intensity in AML M3 cases were significantly higher than in non-M3 AML cases (p < 0.05). The CD150 expression was significantly associated with CD11c, CD11b, CD14, CD34, CD36, CD56 and HLA-DR negative expression and CD33, CD38, CD117 positive expression among the examined cohort of patients with AML M3.

CONCLUSIONS

High level of CD150 expression is a unique feature of AML M3 subtype and may serve as additional phenotype marker for the identification of blast cells with impaired maturation at the promyelocyte stage and the development of AML M3. At the same time, the revealed negative association of CD150 expression with poor prognostic factor CD56 in AML M3 subtype also allows us to suggest potential prognostic value of CD150 examination in AML patients.

Effect of methylmercury on fetal neurobehavioral development: an overview of the possible mechanisms of toxicity and the neuroprotective effect of phytochemicals

Methylmercury (MeHg) is a global environmental pollutant with neurotoxic effects. Exposure to MeHg via consumption of seafood and fish can severely impact fetal neurobehavioral development even when MeHg levels in maternal blood are as low as about 5 μg/L, which the mother tolerates well. Persistent motor dysfunctions and cognitive deficits may result from trans-placental exposure. The present review summarizes current knowledge on the mechanisms of MeHg toxicity during the period of nervous system development. Although cerebellar Purkinje cells are MeHg targets, the actions of MeHg on thiol components in the neuronal cytoskeleton as well as on mitochondrial enzymes and induction of disturbances of glutamate signaling can impair extra-cerebellar functions, also at levels well tolerated by adult individuals. Numerous herbal substances possess neuroprotective effects, predominantly represented by natural polyphenolic molecules that might be utilized to develop natural drugs to alleviate neurotoxicity symptoms caused by MeHg or other Hg compounds.

Ellagic Acid: A Review on Its Natural Sources, Chemical Stability, and Therapeutic Potential

Ellagic acid (EA) is a bioactive polyphenolic compound naturally occurring as secondary metabolite in many plant taxa. EA content is considerable in pomegranate (Punica granatum L.) and in wood and bark of some tree species. Structurally, EA is a dilactone of hexahydroxydiphenic acid (HHDP), a dimeric gallic acid derivative, produced mainly by hydrolysis of ellagitannins, a widely distributed group of secondary metabolites. EA is attracting attention due to its antioxidant, anti-inflammatory, antimutagenic, and antiproliferative properties. EA displayed pharmacological effects in various in vitro and in vivo model systems. Furthermore, EA has also been well documented for its antiallergic, antiatherosclerotic, cardioprotective, hepatoprotective, nephroprotective, and neuroprotective properties. This review reports on the health-promoting effects of EA, along with possible mechanisms of its action in maintaining the health status, by summarizing the literature related to the therapeutic potential of this polyphenolic in the treatment of several human diseases.

M1 and M2 mAChRs activate PDK1 and regulate PKC βI and ε and the exocytotic apparatus at the NMJ

Neuromuscular junctions (NMJ) regulate cholinergic exocytosis through the M₁ and M₂ muscarinic acetylcholine autoreceptors (mAChR), involving the crosstalk between receptors and downstream pathways. Protein kinase C (PKC) regulates neurotransmission but how it associates with the mAChRs remains unknown. Here, we investigate whether mAChRs recruit the classical PKCβI and the novel PKCε isoforms and modulate their priming by PDK1, translocation and activity on neurosecretion targets. We show that each M₁ and M₂ mAChR activates the master kinase PDK1 and promotes a particular priming of the presynaptic PKCβI and ε isoforms. M₁ recruits both primed-PKCs to the membrane and promotes Munc18-1, SNAP-25, and MARCKS phosphorylation. In contrast, M₂ downregulates PKCε through a PKA-dependent pathway, which inhibits Munc18-1 synthesis and PKC phosphorylation. In summary, our results discover a co-dependent balance between muscarinic autoreceptors which orchestrates the presynaptic PKC and their action on ACh release SNARE-SM mechanism. Altogether, this molecular signaling explains previous functional studies at the NMJ and guide toward potential therapeutic targets.

Passive Q-switching of an Er, Yb:glass laser with Co:Mg(Al,Ga)2O4-based glass-ceramics

Transparent glass-ceramics (GCs) containing Co:Mg(Al,Ga)₂O₄ nanocrystals (mean diameter of 7-9 nm) are synthesized by heat treatments at 850-950°C from magnesium aluminosilicate glass nucleated by TiO₂ and doped with Ga₂O₃ and CoO. The GCs exhibit a broadband A₂4(F4)→T₁4(F4) absorption due to the Co²⁺ ions, low saturation fluence (∼0.5  J/cm²), fast recovery time of initial absorption (∼300  ns), and high laser damage threshold (∼20  J/cm²). They are used for passive Q-switching of a diode side-pumped Er,Yb:glass laser generating 3.1 mJ/20 ns pulses (peak power, 155 kW) at 1535 nm with a TEM₀₀ output mode. The Q-switching performance of the Co:Mg(Al,Ga)₂O₄-based GCs is compared with that for various Co²⁺-doped GCs and Co:MgAl₂O₄ single crystal. The prepared GCs are promising for further applications in passively Q-switched Er:YAG and other Er crystalline (or ceramic) lasers.