Unscheduled DNA synthesis in rat adult myenteric neurons: an immunohistochemical study

Abstract

Unscheduled DNA synthesis refers to DNA synthesis not followed by cell division. Previous studies have suggested that this phenomenon may occur in neurons from peripheral myenteric ganglia in conditions of functional hyperstimulation. In order to verify these observations, we have carried on an immunohistochemical study on myenteric neurons from the hypertrophic intestinal loops upstream from a partial obstruction (an experimental condition that induces a relevant increase of the neuronal workload) after labelling with two different markers: the proliferating cell nuclear antigen (PCNA), that is specifically expressed in cell nuclei during the S-phase, and the protein gene product 9.5 (PGP 9.5), a specific marker of nerve cells. While no myenteric neuron immunopositive for the anti-PCNA antibody was found in the control intestine, in the hypertrophic myenteric ganglia some neurons were positive for PCNA. These results provide an unequivocal evidence on the existence of unscheduled DNA synthesis in myenteric neurons from the hypertrophic intestine.

A 5-HT4-receptor activation-induced neural plasticity enhances in vivo reconstructs of enteric nerve circuit insult

“…Antibodies used in primary reaction and the working concentrations were as followed: anti‐tyrosine receptor kinase B (TrkB; clone H‐181, 1 μg mL −1 , Santa‐Cruz Biotechnology, Inc., Santa‐Cruz, CA, USA), anti‐NF (clone 2F11, reacting with 70, 160, and 200 kDa proteins, 0.5 μg mL −1 ; DAKO), 2 anti‐serotonin receptor 4 (anti‐SR4) (clone N‐16, the epitope is located at the N‐terminus of human SR‐4, 0.5 μg mL −1 ; Santa‐Cruz Biotechnology, Inc.) and anti‐distal less homeobox 2 (DLX2)(cat. ab18188, 0.5 μg mL −1 ; Abcam Co, Tokyo, Japan) 3,19 and anti‐p75 (intracellular domain, 0.5 μg mL −1 ; Upstate, Lake Placid, NY, USA) as enteric neural stem cell markers, 1 and anti‐proliferating cell nuclear antigen (PCNA) (clone PC10; DAKO Corp) as a cell proliferating marker that is specifically expressed in cell nuclei during the S‐phase 20 …”

A new possibility for repairing the anal dysfunction by promoting regeneration of the reflex pathways in the enteric nervous system

“…Antibodies used in primary reaction and the working concentrations were as followed: anti-tyrosine receptor kinase B (TrkB) (clone H-181, 1 g/ml, Santa Cruz Biotechnology) as a BDNF receptor (6,18); anti-NF (clone 2F11, reacting with 70-, 160-, and 200-kDa proteins, 0.5 g/ml, DAKO) (18), anti-distal-less homeobox 2 (DLX2) (Abcam, cat. ab18188, 0.5 g/ml, Tokyo, Japan) (24), and anti-p75 (intracellular domain, 0.5 g/ml, Upstate, Lake Placid, NY) as enteric neural stem cell markers (18); and anti-PCNA (clone PC10, DAKO) as a cell proliferating marker that is specifically expressed in cell nuclei during the S phase (1).…”

Recruitment of postmitotic neurons into the regenerating spinal cord of urodeles

“…Thus, at least some differentiated cells in the urodele can reverse their phenotypic decisions during regeneration. Furthermore, there are at least two accounts that suggest mammalian neurons maintained in culture can be stimulated to divide (Brewer, 1999; Jacobs and Miller, 2000), and adult rat myenteric neurons can be induced to express the cell proliferation antigen PCNA (but not divide) under conditions of hypertrophic stress in vivo (Corvetti et al, 2001). Given the remarkable regenerative potential of urodele spinal cord, this seemed a good system in which to examine the possibility that mature neurons close to the amputation plane could contribute to this process either by re‐entering the cell cycle or by migrating into the regenerating structure.…”