SIRT1, miR-132 and miR-212 link human longevity to Alzheimer's Disease

Alzheimer's Disease (AD) is the most common cause of dementia in the elderly. Centenarians - reaching the age of >100 years while maintaining good cognitive skills - seemingly have unique biological features allowing healthy aging and protection from dementia. Here, we studied the expression of SIRT1 along with miR-132 and miR-212, two microRNAs known to regulate SIRT1, in lymphoblastoid cell lines (LCLs) from 45 healthy donors aged 21 to 105 years and 24 AD patients, and in postmortem olfactory bulb and hippocampus tissues from 14 AD patients and 20 age-matched non-demented individuals. We observed 4.0-fold (P = 0.001) lower expression of SIRT1, and correspondingly higher expression of miR-132 (1.7-fold; P = 0.014) and miR-212 (2.1-fold; P = 0.036), in LCLs from AD patients compared with age-matched healthy controls. Additionally, SIRT1 expression was 2.2-fold (P = 0.001) higher in centenarian LCLs compared with LCLs from individuals aged 56-82 years; while centenarian LCLs miR-132 and miR-212 indicated 7.6-fold and 4.1-fold lower expression, respectively. Correlations of SIRT1, miR-132 and miR-212 expression with cognitive scores were observed for AD patient-derived LCLs and postmortem AD olfactory bulb and hippocampus tissues, suggesting that higher SIRT1 expression, possibly mediated by lower miR-132 and miR-212, may protect aged individuals from dementia and is reflected in their peripheral tissues.

RGS2 expression predicts amyloid-β sensitivity, MCI and Alzheimer's disease: genome-wide transcriptomic profiling and bioinformatics data mining

Alzheimer's disease (AD) is the most frequent cause of dementia. Misfolded protein pathological hallmarks of AD are brain deposits of amyloid-β (Aβ) plaques and phosphorylated tau neurofibrillary tangles. However, doubts about the role of Aβ in AD pathology have been raised as Aβ is a common component of extracellular brain deposits found, also by in vivo imaging, in non-demented aged individuals. It has been suggested that some individuals are more prone to Aβ neurotoxicity and hence more likely to develop AD when aging brains start accumulating Aβ plaques. Here, we applied genome-wide transcriptomic profiling of lymphoblastoid cells lines (LCLs) from healthy individuals and AD patients for identifying genes that predict sensitivity to Aβ. Real-time PCR validation identified 3.78-fold lower expression of RGS2 (regulator of G-protein signaling 2; P=0.0085) in LCLs from healthy individuals exhibiting high vs low Aβ sensitivity. Furthermore, RGS2 showed 3.3-fold lower expression (P=0.0008) in AD LCLs compared with controls. Notably, RGS2 expression in AD LCLs correlated with the patients' cognitive function. Lower RGS2 expression levels were also discovered in published expression data sets from postmortem AD brain tissues as well as in mild cognitive impairment and AD blood samples compared with controls. In conclusion, Aβ sensitivity phenotyping followed by transcriptomic profiling and published patient data mining identified reduced peripheral and brain expression levels of RGS2, a key regulator of G-protein-coupled receptor signaling and neuronal plasticity. RGS2 is suggested as a novel AD biomarker (alongside other genes) toward early AD detection and future disease modifying therapeutics.

Improvement of functional bloating by an enterovaccine: a preliminary study

BACKGROUND

Bloating is a fastidious symptom reported by many patients who also have other gastrointestinal functional disorders. Bloating is more common in women, and it is often associated with meals and improves or disappears overnight. No specific treatments are to date available for this disturbing symptom.

AIMS

to evaluate the effects of an oral enterovaccine (Colifagina) on bloating and other abdominal symptoms in patients with prevalent complaints of functional bloating.

PATIENTS AND METHODS

One hundred and forty-eight patients with functional bloating according to Rome III criteria were recruited. Questionnaires and a VAS scale on their symptoms were administered at baseline and after four weeks of therapy with Colifagina.

RESULTS

After treatment, a significant amelioration of bloating (p < 0.0001), abdominal pain (p < 0.0001) and flatus (p < 0.0001) was observed; nausea and vomiting scores were not significantly different at the end of the treatment. Subjective wellbeing was also generally improved (p < 0.001) in treated patients.

CONCLUSION

Treatment with an enterovaccine may help improve symptoms in patients with functional bloating.

Water load test before and after PPI therapy in patients with gastro-oesophageal reflux disease

BACKGROUND

Patients with gastro-oesophageal reflux disease may complain of epigastric pain, bloating, early satiety, epigastric fullness, epigastric burning, nausea and vomiting.

AIMS

To evaluate the symptoms in response to gastric distension and its relationship to a therapeutic course in patients with gastro-oesophageal reflux disease using the water load test, compared to healthy controls.

METHODS

Thirty gastro-oesophageal reflux disease patients with grade A oesophagitis (studied before and after 4 weeks of therapy with esomeprazole, 40 mg per day) and 15 patients with reflux-related symptoms demonstrated at wireless pH monitoring (non-erosive reflux disease) were compared to 30 healthy volunteers.

RESULTS

Patients with grade A oesophagitis and with reflux-related symptoms ingested significantly lower water volumes than did controls, before onset of fullness, without statistically significant difference between erosive or non-erosive gastro-oesophageal reflux disease; this variable improved in patients after treatment. Nausea scores were higher basally in patients, pre- and post-therapy, and improved after therapy. Thirty-minute fullness and bloating scores improved after therapy in all gastro-oesophageal reflux disease patients compared to controls and pre-therapy. In all pre-treatment patients, a significant correlation was found only with epigastric fullness; after treatment, there was no significant relationship between the water load and the symptom scores.

CONCLUSIONS

In patients with reflux-related symptoms, with or without grade A oesophagitis, the water load test is frequently abnormal, suggesting an altered gastric function. This could explain the incomplete resolution of symptoms after treatment in some patients, and should lead to additional studies aimed at exploring gastric function in gastro-oesophageal reflux disease patients.