Partial persistence of exercise-induced myocardial angiogenesis following 4-week detraining in the rat

Enhanced angiogenesis, or capillary growth, has a prominent role among the various beneficial effects of exercise training on the myocardium. The aim of the present study is to assess if training-induced increases in capillarity and vascularization persist after 4 weeks of detraining. Adult male rats were trained to run on a treadmill for 10 weeks at approximately 60% VO(2max), which did not induce cardiac hypertrophy, but increased (P < 0.05) the soleus/body weight ratio, left ventricle capillarity and von Willebrand-positive cell density (n = 6). In another group of animals (n = 6) subjected to training followed by 4-week detraining, the soleus/body weight ratio returned to normal, with only partial reversal of left ventricle capillarity and von Willebrand-positive cell density. Markers of angiogenesis (VEGF, KDR/VEGF-R2 and HIF-1alpha mRNA, studied by real-time RT-PCR) were upregulated at the end of training, and returned to baseline value after detraining. Electron microscopy highlighted some morphological features in trained hearts (endothelial cell sprouting and bridges and pericyte detachment), suggestive of endothelial cell proliferation and capillary growth that were absent in untrained and detrained hearts. We conclude that the training-induced increase in cardiac capillarity and vascularization are retained for some time upon cessation of the training program even in the absence of angiogenic stimuli

Therapeutic Potential and Challenges of Targeting Receptor Tyrosine Kinase ROR1 with Monoclonal Antibodies in B-Cell Malignancies

Based on its selective cell surface expression in chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), receptor tyrosine kinase ROR1 has recently emerged as a promising target for therapeutic monoclonal antibodies (mAbs). To further assess the suitability of ROR1 for targeted therapy of CLL and MCL, a panel of mAbs was generated and its therapeutic utility was investigated.A chimeric rabbit/human Fab library was generated from immunized rabbits and selected by phage display. Chimeric rabbit/human Fab and IgG1 were investigated for their capability to bind to human and mouse ROR1, to mediate antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and internalization, and to agonize or antagonize apoptosis using primary CLL cells from untreated patients as well as MCL cell lines. A panel of mAbs demonstrated high affinity and specificity for a diverse set of epitopes that involve all three extracellular domains of ROR1, are accessible on the cell surface, and mediate internalization. The mAb with the highest affinity and slowest rate of internalization was found to be the only mAb that mediated significant, albeit weak, ADCC. None of the mAbs mediated CDC. Alone, they did not enhance or inhibit apoptosis.Owing to its relatively low cell surface density, ROR1 may be a preferred target for armed rather than naked mAbs. Provided is a panel of fully sequenced and thoroughly characterized anti-ROR1 mAbs suitable for conversion to antibody-drug conjugates, immunotoxins, chimeric antigen receptors, and other armed mAb entities for preclinical and clinical studies

Gene expression in medium- and long term-denervated rat tibialis anterior

Traumatic injuries, neurodegenerative diseases or aging may determine skeletal muscle denervation and induce an atrophy-dependent loss of fibers and a number of morphological, biochemical and physiological modifications. Upregulation of mRNAs encoding for myogenic transcriprtional factors and for the protein degradation machineryis well documented after medium-term denervation. We decided to evaluate by Real Time RT-PCR a number of mRNAs from rat skeletal muscles after medium- (2-3 months) or long- (9 months) term denervation, in order to extend the observations reported in literature to a longer time interval, and to include a number of previously undescribed mRNAs. Rat tibialis anterior muscles from the hind limbs were surgically denervated in aseptic conditions. Rats rapidly recovered and were stabulated in standard conditions before sacrifice. The muscles were removed from age-matched control rats and from rats that had undergone denervation. RNA was extracted by Tryzol\ua9 and quality controlled, then retrotrascribed and evaluated by Real Time PCR using Sybr Green dye. MCK RNA, a housekeeping gene, was used for standardization purposes. The folllowing mRNAs were evaluated: Myogenin, MyoD, Mrf4, PGC1-a, embryonal Myosin Chain 3 (Myh3), metalloproteinase-2, calsequestrin-2, HSP70, VEGF, VEGF-R2 (KDR). Main results can be summarised as follows: I) all examined mRNAs were found to be upregulated after 2-3 month denervation in respect to controls; ii) the amount of expression widely varied amoing different mRNAs, with muscle-specific transcription factors and Myh3 mRNAs being the higher expressed; for such genes, as well as for HSP70, VEGF and KDR, upragulation was maintained also aftrer long-term denervation. This observation may be of clinical interest in humans, were rehabilitation care is supplied months and even years from denervation

MHC variability in an isolated wolf population in Italy.

Small, isolated populations may experience increased extinction risk due to reduced genetic variability at important functional genes, thus decreasing the population's adaptive potential. The major histocompatibility complex (MHC), a key immunological gene cluster, usually shows high variability maintained by positive or balancing selection in response to challenges by pathogens. Here we investigated for the first time, the variability of 3 MHC class II genes (DRB1, DQA1, and DQB1) in 94 samples collected from Italian wolves. The Italian wolf population has been long isolated south of the Alps and is presently recovering from a recent bottleneck that decreased the population to less than 100 individuals. Despite the bottleneck, Italian wolves show remarkable MHC variability with 6-9 alleles per locus, including 2 recently described alleles at DRB1. MHC sequences show signatures of historical selective pressures (high d N/d S ratio, ω > 1.74) but no evidence of ongoing selection. Variation at the MHC genes and 12 background microsatellite loci were not apparently affected by the recent bottleneck. Although MHC alleles of domestic dog origin were detected in 8 genetically admixed individuals, these alleles were rare or absent in nonadmixed wolves. Thus, despite known hybridization events between domestic dogs and Italian wolves, the Italian wolf population does not appear affected by deep introgression of domestic dog MHC alleles