Klotho is a longevity-associated protein found in membrane-bound and secreted forms, with the latter detectable in blood and cerebrospinal fluid (CSF). Circulating Klotho mainly originates from the ki Show more
Klotho is a longevity-associated protein found in membrane-bound and secreted forms, with the latter detectable in blood and cerebrospinal fluid (CSF). Circulating Klotho mainly originates from the kidney, while the choroid plexus (CP) secretes it into the CSF. CP dysfunction is associated with reduced Klotho expression and neurodegeneration and may result in CP enlargement on magnetic resonance imaging (MRI). In this preliminary study, we investigated Klotho levels in neurodegenerative patients and their association with CP enlargement. We retrospectively analyzed 40 patients from the IRCCS Ca' Granda Ospedale Policlinico, Milan, including 32 neurodegenerative patients (Deg) and 8 cognitively normal controls (NonDeg). CSF and serum Klotho levels were measured using an ELISA kit. KL-VS and apolipoprotein E (APOE) genotyping were performed. CP volumes were segmented using ITK-SNAP and normalized to total intracranial volume (TIV), resulting in a measure known as the CP volume fraction (CPVF). A multivariate linear regression analysis was conducted, adjusting for diagnostic group, age, sex, APOEε4, CPVF, and gray matter volume fraction (GMVF). CSF Klotho levels were significantly lower in Deg patients (mean = 729 pg./mL, SD = 364) compared to NonDeg individuals (mean = 1,077 pg./mL, SD = 220) ( In this preliminary study, we observed a strong association between CSF Klotho levels and CP enlargement. Reduced CSF Klotho levels, due to CP dysfunction, may contribute to neurodegeneration. If confirmed in larger cohorts, this association suggests that CSF Klotho may serve as a biomarker for CP enlargement, possibly reflecting its underlying dysfunction. Show less
HER2-overexpression promotes malignancy by modulating signalling molecules, which include PTPs/DSPs (protein tyrosine and dual-specificity phosphatases). Our aim was to identify PTPs/DSPs displaying H Show more
HER2-overexpression promotes malignancy by modulating signalling molecules, which include PTPs/DSPs (protein tyrosine and dual-specificity phosphatases). Our aim was to identify PTPs/DSPs displaying HER2-associated expression alterations. HER2 activity was modulated in MDA-MB-453 cells and PTPs/DSPs expression was analysed with a DNA oligoarray, by RT-PCR and immunoblotting. Two public breast tumor datasets were analysed to identify PTPs/DSPs differentially expressed in HER2-positive tumors. In cells (1) HER2-inhibition up-regulated 4 PTPs (PTPRA, PTPRK, PTPN11, PTPN18) and 11 DSPs (7 MKPs [MAP Kinase Phosphatases], 2 PTP4, 2 MTMRs [Myotubularin related phosphatases]) and down-regulated 7 DSPs (2 MKPs, 2 MTMRs, CDKN3, PTEN, CDC25C); (2) HER2-activation with EGF affected 10 DSPs (5 MKPs, 2 MTMRs, PTP4A1, CDKN3, CDC25B) and PTPN13; 8 DSPs were found in both groups. Furthermore, 7 PTPs/DSPs displayed also altered protein level. Analysis of 2 breast cancer datasets identified 6 differentially expressed DSPs: DUSP6, strongly up-regulated in both datasets; DUSP10 and CDC25B, up-regulated; PTP4A2, CDC14A and MTMR11 down-regulated in one dataset. Several DSPs, mainly MKPs and, unexpectedly, MTMRs, were altered following HER2-modulation in cells and 3 DSPs (DUSP6, CDC25B and MTMR11) were altered in both cells and tumors. Among these, DUSP6, strongly up-regulated in HER2-positive tumors, would deserve further investigation as tumor marker or potential therapy target. Show less