In vitro effects of polyamines on polymorphonuclear cell apoptosis and implications in the pathogenesis of periodontal disease

Apoptosis provides a mechanism for clearance of unwanted cells in a variety of situations in which programmed or physiological cell death occurs; but the premature death of defensive cells could promote infection, inflammation and concomitant diseases. Polymorphonuclear cells (PMN) of gingival sulcus play an important role in host defense against periodontal tissue-invading bacteria, but their phagocytic activity is conditioned by several virulence factors released by oral pathogens. Polyamines derived from oral bacteria frequently occur at concentrations approaching 1 mM in gingival fluid at diseased periodontal sites. Brief exposure of PMN to polyamines shortened the lag culture time required to observe microscopical or DNA fragmentation traces. Increase of Fas/Apo-1 expression and caspase-8 and caspase-3 activation focused two typical steps in the pathway of the pro-apoptotic mechanism exhibited by polyamines, even if to a different extent: spermine > spermidine > putrescine. The possible role played by polyamines in the pathogenesis of periodontal disease by dysregulating apoptosis of gingival PMN is discussed

Dysfunctional CFTR Alters the Bactericidal Activity of Human Macrophages against Pseudomonas aeruginosa

Chronic inflammation of the lung, as a consequence of persistent bacterial infections by several opportunistic pathogens represents the main cause of mortality and morbidity in cystic fibrosis (CF) patients. Mechanisms leading to increased susceptibility to bacterial infections in CF are not completely known, although the involvement of cystic fibrosis transmembrane conductance regulator (CFTR) in microbicidal functions of macrophages is emerging. Tissue macrophages differentiate in situ from infiltrating monocytes, additionally, mature macrophages from different tissues, although having a number of common activities, exhibit variation in some molecular and cellular functions. In order to highlight possible intrinsic macrophage defects due to CFTR dysfunction, we have focused our attention on in vitro differentiated macrophages from human peripheral blood monocytes. Here we report on the contribution of CFTR in the bactericidal activity against Pseudomonas aeruginosa of monocyte derived human macrophages. At first, by real time PCR, immunofluorescence and patch clamp recordings we demonstrated that CFTR is expressed and is mainly localized to surface plasma membranes of human monocyte derived macrophages (MDM) where it acts as a cAMP-dependent chloride channel. Next, we evaluated the bactericidal activity of P. aeruginosa infected macrophages from healthy donors and CF patients by antibiotic protection assays. Our results demonstrate that control and CF macrophages do not differ in the phagocytic activity when infected with P. aeruginosa. Rather, although a reduction of intracellular live bacteria was detected in both non-CF and CF cells, the percentage of surviving bacteria was significantly higher in CF cells. These findings further support the role of CFTR in the fundamental functions of innate immune cells including eradication of bacterial infections by macrophages

Dopaminergic receptor gene polymorphisms in children affected by ADHD/ASD overlapping.

Background: Several  studies  have  shown  a  genetic  role  in  the  pathogenesis  of   many  childhood  psychiatric  disorders.  The  most  common  childhood  psychiatric   disorder  is  the  attention  deficit  hyperactivity  disorder  (ADHD)  and  some  reports   showed  the  co-­occurance  in  ADHD  children  and  Autism  Spectrum  Disorders  (ASD).   Many  investigators  focused  their  attention  on  polymorphisms  affecting  gene  regions   coding  for  dopamine  receptors.  In  this  study  we  evaluate  the  association  of  three   single-­nucleotide  polymorphisms  (SNPs)  with  clinically  significant  level  of  autistic   symptoms  among  children  with  ADHD. Methods: We  enrolled  150  children  who   were  divided  into  four  groups:  children  with  ADHD,  children  with  ASD,  children  with   co-­occurance  of  ADHD/ASD,  and  control  subjects.  We  investigated  rs265975  C/T   (174862195C>T)  for  dopamine  receptor  D1  gene,  rs1076560  C/A  (113283688C>A)   and  rs1079597  G/A  (113296286C>T)  for  dopamine  receptor  D2  gene  utilizing   previous  DNA  extraction  and  amplification,  restriction  enzymes  that  recognized  one   of  two  allelic  variants. Results: Our  results  demonstrated  that  homozygosis  T/T  for   rs265975  had  a  lower  frequency  in  ADHD  patients  compared  to  other  groups,whereas  small  differences  were  seen  in  heterozygosis  C/T.  Both  heterozygosis  C/A   for  rs1076560  and  heterozygosis  G/A  for  rs1079597  showed  higher  frequency  in   ASD  group  with  respect  to  control  children  and  ADHD  patients,  whereas  in   ADHD/ASD  group  a  ratio  3:1  vs  unaffected  people  was  seen.  The  same  trend,  but   with  slight  differences,  was  observed  in  homozygosis  A/A  for  rs1076560  and   rs1079597. Conclusions: These  preliminary  data  pointing  to  differences  between   ADHD/ASD  and  other  groups  must  be  confirmed  and  encourage  us  to  enlarge  our   study  populations