Magic™ Anti-TSH monoclonal antibody, clone C2658N

Background: Chromogranin A (CgA) is a general marker of gut endocrine cells, which are part of the "gut-brain axis" in Parkinson's disease (PD). Objective: We analyzed CgA as a marker of synaptic dysfunction to assess its role in the differential diagnosis across different Lewy body disorders. Methods: We analyzed the CgA levels in the cerebrospinal fluid (CSF) and serum from 54 patients covering the spectrum of Lewy body disorders [13 Parkinson's disease (PD), 17 Parkinson's disease dementia (PDD), 24 dementia with Lewy bodies (DLB)] and 14 controls using an ELISA. Results: A positive correlation was noted between CSF and serum CgA levels (rho = 0.47, 95% CI: 0.24 to 0.65, p < 0.0001). The highest values of CgA in CSF and in serum were measured in DLB and there was a significant difference between DLB and PDD (p = 0.03 and p = 0.004). The serum levels of CgA in controls achieved lower values compared to DLB (p = 0.006). There was a gradual increase in serum levels from PD to PDD and DLB. An inverse correlation was seen between the CSF level of CgA and A beta(42) (rho = -0.296, 95% CI: -0.51 to - 0.04, p = 0.02). Conclusion: The incorporation of CgA analysis as an additional biomarker may be useful in the diagnostic work-up of Lewy body dementia. CgA analysis may be relevant in distinguishing DLB from PDD patients and presumably early stages of PD. Our data on altered serum levels in DLB pave the way to the development of blood-based parameters for the differential diagnosis, which however needs to be confirmed in a prospective study.

APC mutations drive human colorectal cancer (CRC) development. A major contributing factor is colonic stem cell (SC) overpopulation. But, the mechanism has not been fully identified. A possible mechanism is the dysregulation of neuroendocrine cell (NEC) maturation by APC mutations because SCs and NECs both reside together in the colonic crypt SC niche where SCs mature into NECs. So, we hypothesized that sequential inactivation of APC alleles in human colonic crypts leads to progressively delayed maturation of SCs into NECs and overpopulation of SCs. Accordingly, we used quantitative immunohistochemical mapping to measure indices and proportions of SCs and NECs in human colon tissues (normal, adenomatous, malignant), which have different APC-zygosity states. In normal crypts, many cells staining for the colonic SC marker ALDH1 co-stained for chromogranin-A (CGA) and other NEC markers. In contrast, in APC-mutant tissues from familial adenomatous polyposis (FAP) patients, the proportion of ALDH+ SCs progressively increased while NECs markedly decreased. To explain how these cell populations change in FAP tissues, we used mathematical modelling to identify kinetic mechanisms. Computational analyses indicated that APC mutations lead to: 1) decreased maturation of ALDH+ SCs into progenitor NECs (not progenitor NECs into mature NECs); 2) diminished feedback signaling by mature NECs. Biological experiments using human CRC cell lines to test model predictions showed that mature GLP-2R+ and SSTR1+ NECs produce, via their signaling peptides, opposing effects on rates of NEC maturation via feedback regulation of progenitor NECs. However, decrease in this feedback signaling wouldn't explain the delayed maturation because both progenitor and mature NECs are depleted in CRCs. So the mechanism for delayed maturation must explain how APC mutation causes the ALDH+ SCs to remain immature. Given that ALDH is a key component of the retinoic acid (RA) signaling pathway, that other components of the RA pathway are selectively expressed in ALDH+ SCs, and that exogenous RA ligands can induce ALDH+ cancer SCs to mature into NECs, RA signaling must be attenuated in ALDH+ SCs in CRC. Thus, attenuation of RA signaling explains why ALDH+ SCs remain immature in APC mutant tissues. Since APC mutation causes increased WNT signaling in FAP and we found that sequential inactivation of APC in FAP patient tissues leads to progressively delayed maturation of colonic ALDH+ SCs, the hypothesis is developed that human CRC evolves due to an imbalance between WNT and RA signaling.