You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["AnatomicalEntity"].

Please return the output as a JSON object of the format: {"AnatomicalEntity": ["tumor cells", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

[Decreased stimulation of glycosaminoglycan synthesis by human skin fibroblasts by interleukin 6 within the scope of in vitro aging].
Addition of human recombinant interleukin 6 (IL-6) to culture medium (supplemented MEM without or with 10% fetal calf serum (FCS)) of human skin fibroblasts exerted a stimulating effect in a dose-dependent manner on glycosaminoglycan (GAG) synthesis, including hyaluronic acid (hyaluronan) synthesis, of young (phase-II) skin fibroblasts in concentrations of 1 ng/ml and 10 ng/ml. Stimulation was mainly due to an increase in extracellular GAGs (secreted into culture medium), and to a lesser extent to an increase in peri- and intracellular GAGs. Stimulation with 1 ng/ml and 10 ng/ml IL-6 led to an increase in hyaluronic acid from 48% to 61% (-FCS) and from 77% to 90% (+10% FCS), respectively. Maximum stimulation, with and without FCS, was achieved by 10 ng/ml IL-6. Compared to young (phase-II) cells, senescent (phase-III) cells, showed no significant stimulation of total GAG (including hyaluronic acid) synthesis by IL-6. The diminished response of GAG- and hyaluronic acid synthesis during aging of these in vitro cultured fibroblasts should motivate further research if similar processes occur during aging in an organism.
{"AnatomicalEntity": ["intracellular", "peri", "FCS", "fibroblasts", "cells", "fetal calf serum", "skin fibroblasts", "extracellular"]}