Distribution, nature, and origin of CXCL14-immunoreactive fibers in rat parotid gland

The Chemokine CXCL14-like Immunoreactivity Co-exists with Somatostatin, but not NPY in the Rat Dorsal Horn and Has Intimate Association with GABAergic Neurons in the Lateral Spinal Nucleus

Recent studies have proposed that the chemokine CXCL14 not only has a chemotactic activity, but also functions as a neuromodulator and/or neurotransmitter. In this study, we investigated the distribution of CXCL14 immunoreactive structures in the rat spinal cord and clarified the association of these structures with somatostatin, glutamic acid decarboxylase (GAD; a marker for GABAergic neurons), and neuropeptide Y (NPY). CXCL14 immunoreactive fibers and puncta were observed in lamina II, which modulates somatosensation including nociception, and the lateral spinal nucleus of the spinal dorsal horn at cervical, thoracic, and lumber spinal cord levels. These CXCL14 immunoreactive structures were also immuno-positive for somatostatin, but were immuno-negative for GAD and NPY. In the cervical lateral spinal nucleus, CXCL14 immunoreactive puncta, which were also immuno-positive for somatostatin, existed along the proximal dendrites of some of GABAergic neurons. Together, these results suggest that CXCL14 contributes to the modulation of somatosensation in concert with somatostatin. Neurons targeted by the CXCL14 fiber system include GABAergic neurons located in the lateral spinal nucleus suggesting that CXCL14 with somatostatin can influence the GABAergic neuron function.

Chemokine CXCL14-like immunoreactivity in the αMSH-producing cells and PRL-producing cells of the flat-tailed house gecko pituitary

The distribution pattern of chemokine CXCL14-immunoreactive cells was examined by immunohistochemistry in the pituitary of the gecko Hemidactylus platyurus. Immunoreactive cells were observed in the pars intermedia and pars distalis of the pituitary, but not in the pars nervosa. All α-melanocyte-stimulating hormone (αMSH)-producing cells were immunoreactive for CXCL14 in the pars intermedia. The CXCL14-immunoreactive cells corresponded to prolactin (PRL)-producing cells but not to other adenohypophyseal-hormone-producing cells in the pars distalis. CXCL14 secreted from αMSH-producing cells and PRL-producing cells may regulate insulin release from β cells in the pancreatic islets as well as glucose uptake in the muscle cells together with αMSH and/or PRL. In addition, secreted CXCL14 with αMSH and/or PRL may act as a bioactive factor regulating hormone release in the adenohypophyseal cells of the reptilian pars distalis.