Anti-cancer activity of 5-O-alkyl 1,4-imino-1,4-dideoxyribitols

New derivatives of 1,4-dideoxy-1,4-imino-d-ribitol have been prepared and evaluated for their cytotoxicity on solid and haematological malignancies. 1,4-Dideoxy-5-O-[(9Z)-octadec-9-en-1-yl]-1,4-imino-d-ribitol (13, IC₅₀ ∼2 μM) and its C₁₈-analogues (IC₅₀ <10 μM) are cytotoxic toward SKBR3 (breast cancer) cells. 13 also inhibits (IC₅₀ ∼8 μM) growth of JURKAT cells.     

Lower limb entheseal morphology in the Neandertal Krapina population (Croatia, 130,000 BP)

Although the Neandertal locomotor system has been shown to differ from Homo sapiens, characteristics of Neandertal entheses, the skeletal attachments for muscles, tendons, ligaments and joint capsules, have never been specifically investigated. Here, we analyse lower limb entheses of the Krapina Neandertal bones (Croatia, 130,000 BP) with the aim of determining how they compare with modern humans, using a standard developed by our research group for describing modern human entheseal variability. The entheses examined are those of the gluteus maximus, iliopsoas and vastus medialis on the femur, the quadriceps tendon on the patella, and soleus on the tibia. For the entheses showing a different morphological pattern from H. sapiens, we discuss the possibility of recognising genetic versus environmental causes. Our results indicate that only the gluteus maximus enthesis (the gluteal tuberosity), falls out of the modern human range of variation. It displays morphological features that could imply histological differences from modern humans, in particular the presence of fibrocartilage. In both H. sapiens and the Krapina Neandertals, the morphological pattern of this enthesis is the same in adult and immature femurs. These results can be interpreted in light of genetic differences between the two hominins. The possibility of functional adaptations to higher levels of mechanical load during life in the Neandertals seems less likely. The particular morphology and large dimensions of the Krapina enthesis, and perhaps its fibrocartilaginous nature, could have been selected for in association with other pelvic and lower limb characteristics, even if genetic drift cannot be ruled out.     

Diblock glycopolymers promote colloidal stability of polyplexes and effective pDNA and siRNA delivery under physiological salt and serum conditions

A series of glycopolymers composed of 2-deoxy-2-methacrylamido glucopyranose (MAG) and the primary amine-containing N-(2-aminoethyl) methacrylamide (AEMA) were synthesized via aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization. The colloidal stability of the polyplexes formed with three diblock glycopolymers and pDNA was assessed using dynamic light scattering, and the polyplexes were found to be stable against aggregation in the presence of salt and serum over the 4 h time period studied. Delivery experiments were performed in vitro to examine the cellular uptake, transfection efficiency, and cytotoxicity of the glycopolymer/pDNA polyplexes in cultured HeLa cells and the diblock copolymer with the shortest AEMA block was found to be the most effective. Additionally, the ability of the diblock glycopolymers to deliver siRNA to U-87 (glioblastoma) cells was screened, and the diblock copolymer with the longest AEMA block was found to have gene knockdown efficacy similar to Lipofectamine 2000.     

Muscular laminopathies: role of prelamin A in early steps of muscle differentiation

Lamin A is a nuclear envelope constituent involved in a group of human disorders, collectively referred to as laminopathies, which include Emery-Dreifuss muscular dystrophy. Because increasing evidence suggests a role of lamin A precursor in nuclear functions, we investigated the processing of prelamin A along muscle differentiation. Both protein levels and cellular localization of prelamin A appears to be modulated during C2C12 mouse myoblasts activation. Similar changes also occur in the expression of two lamin A-binding proteins: emerin and LAP2α. Furthermore prelamin A forms a complex with LAP2α in differentiating myoblasts. Prelamin A accumulation in cycling myoblasts by expressing unprocessable mutants affects LAP2α and PCNA amount and increases caveolin 3 mRNA and protein levels, whilst accumulation of prelamin A in differentiated muscle cells following treatment with a farnesyl transferase inhibitor inhibits caveolin 3 expression. These data provide evidence for a critical role of lamin A precursor in the early steps of muscle cell differentiation. In fact the post-translational processing of prelamin A affects caveolin 3 expression and influences the myoblast differentiation process. Thus, altered lamin A processing could affect myoblast differentiation and/or muscle regeneration and might contribute to the myopathic phenotype.     

A combined morphological and molecular phylogeny of the genus Chironius Fitzinger, 1826 (Serpentes: Colubridae)

Chironius is one of the most speciose genera of the South American colubrid snakes. Although the genus represents a well‐known radiation of diurnal racers, its monophyly, affinities with other Neotropical colubrid genera, and intrageneric relationships are open questions. Here, we present a phylogenetic analysis of Chironius based on a data matrix that combines one nuclear (c‐mos) and two mitochondrial (12S and 16S rRNA) genes with 37 morphological characters derived from scutellation, skull, and hemipenial features. Phylogenetic relationships were inferred using maximum parsimony (MP) and maximum likelihood (ML). Our combined morphological and molecular analyses strongly support the monophyly of the genus Chironius and its sister‐group relationship with a clade formed by the genera Dendrophidion and Drymobius. Phylogenetic relationships within the genus Chironius is still controversial, although five clades are retrieved with medium to strong support. © 2014 The Linnean Society of London     

Histamine Transmission Modulates the Phenotype of Murine Narcolepsy Caused by Orexin Neuron Deficiency

Narcolepsy type 1 is associated with loss of orexin neurons, sleep-wake derangements, cataplexy, and a wide spectrum of alterations in other physiological functions, including energy balance, cardiovascular, and respiratory control. It is unclear which narcolepsy signs are directly related to the lack of orexin neurons or are instead modulated by dysfunction of other neurotransmitter systems physiologically controlled by orexin neurons, such as the histamine system. To address this question, we tested whether some of narcolepsy signs would be detected in mice lacking histamine signaling (HDC-KO). Moreover, we studied double-mutant mice lacking both histamine signaling and orexin neurons (DM) to evaluate whether the absence of histamine signaling would modulate narcolepsy symptoms produced by orexin deficiency. Mice were instrumented with electrodes for recording the electroencephalogram and electromyogram and a telemetric arterial pressure transducer. Sleep attacks fragmenting wakefulness, cataplexy, excess rapid-eye-movement sleep (R) during the activity period, and enhanced increase of arterial pressure during R, which are hallmarks of narcolepsy in mice, did not occur in HDC-KO, whereas they were observed in DM mice. Thus, these narcolepsy signs are neither caused nor abrogated by the absence of histamine. Conversely, the lack of histamine produced obesity in HDC-KO and to a greater extent also in DM. Moreover, the regularity of breath duration during R was significantly increased in either HDC-KO or DM relative to that in congenic wild-type mice. Defects of histamine transmission may thus modulate the metabolic and respiratory phenotype of murine narcolepsy.     

Autocrine abscisic acid mediates the UV-B-induced inflammatory response in human granulocytes and keratinocytes

UV-B is an abiotic environmental stress in both plants and animals. Abscisic acid (ABA) is a phytohormone regulating fundamental physiological functions in plants, including response to abiotic stress. We previously demonstrated that ABA is an endogenous stress hormone also in animal cells. Here, we investigated whether autocrine ABA regulates the response to UV-B of human granulocytes and keratinocytes, the cells involved in UV-triggered skin inflammation. The intracellular ABA concentration increased in UV-B-exposed granulocytes and keratinocytes and ABA was released into the supernatant. The UV-B-induced production of NO and of reactive oxygen species (ROS), phagocytosis, and cell migration were strongly inhibited in granulocytes irradiated in the presence of a monoclonal antibody against ABA. Moreover, presence of the same antibody strongly inhibited release of NO, prostaglandin E2 (PGE(2)), and tumor necrosis factor-α (TNF-α) by UV-B irradiated keratinocytes. Lanthionine synthetase C-like protein 2 (LANCL2) is required for the activation of the ABA signaling pathway in human granulocytes. Silencing of LANCL2 in human keratinocytes by siRNA was accompanied by abrogation of the UV-B-triggered release of PGE(2), TNF-α, and NO and ROS production. These results indicate that UV-B irradiation induces ABA release from human granulocytes and keratinocytes and that autocrine ABA stimulates cell functions involved in skin inflammation.     

Effects of Coxiella burnetii on MAPKinases phosphorylation

Q fever is a disease caused by Coxiella burnetii, an obligate intracellular bacterium. Acute Q fever is characterized by efficient immune response, whereas chronic Q fever is characterized by dysregulated immune response as demonstrated by the lack of granulomas, the failure of C. burnetii to induce lymphoproliferation, and interferon-γ production. The mitogen-activated protein kinase (MAPK) signaling pathway plays crucial roles in innate immune responses and control of bacterial infections. However, its role in Q fever has not been addressed. First, we investigated the activation of MAPKs p38, c-jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) 1/2 in murine macrophages stimulated with C. burnetii. Coxiella burnetii NM phase I (virulent) and NM phase II (avirulent) induced the activation of JNK and ERK1/2. Avirulent C. burnetii activate p38, whereas C. burnetii did not induce the phosphorylation of p38. Second, the level of p38 activation was studied in Q fever patients. We found that p38 was activated in monocyte-derived macrophages from healthy donors and patients with acute Q fever in response to a potent agonist such as lipopolysaccharide. Interestingly, p38 was not activated in patients with active chronic Q fever and was activated in patients with cured chronic Q fever. These results suggest that the determination of p38 activation may serve as a tool for measuring Q fever activity.     

Homogentisic acid induces morphological and mechanical aberration of ochronotic cartilage in alkaptonuria

Alkaptonuria (AKU) is a disease caused by a deficient homogentisate 1,2-dioxygenase activity leading to systemic accumulation of homogentisic acid (HGA), that forms a melanin-like polymer that progressively deposits onto connective tissues causing a pigmentation called “ochronosis” and tissue degeneration. The effects of AKU and ochronotic pigment on the biomechanical properties of articular cartilage need further investigation. To this aim, AKU cartilage was studied using thermal (thermogravimetry and differential scanning calorimetry) and rheological analysis. We found that AKU cartilage had a doubled mesopore radius compared to healthy cartilage. Since the mesoporous structure is the main responsible for maintaining a correct hydrostatic pressure and tissue homoeostasis, drastic changes of thermal and rheological parameters were found in AKU. In particular, AKU tissue lost its capability to enhance chondrocytes metabolism (decreased heat capacity) and hence the production of proteoglycans. A drastic increase in stiffness and decrease in dissipative and lubricant role ensued in AKU cartilage. Multiphoton and scanning electron microscopies revealed destruction of cell–matrix microstructure and disruption of the superficial layer. Such observations on AKU specimens were confirmed in HGA-treated healthy cartilage, indicating that HGA is the toxic responsible of morphological and mechanical alterations of cartilage in AKU.