The role of prolactin in central nervous system inflammation

Abstract

Prolactin has been shown to favor both the activation and suppression of the microglia and astrocytes, as well as the release of inflammatory and anti-inflammatory cytokines. Prolactin has also been associated with neuronal damage in diseases such as multiple sclerosis, epilepsy, and in experimental models of these diseases. However, studies show that prolactin has neuroprotective effects in conditions of neuronal damage and inflammation and may be used as neuroprotector factor. In this review, we first discuss general information about prolactin, then we summarize recent findings of prolactin function in inflammatory and anti-inflammatory processes and factors involved in the possible dual role of prolactin are described. Finally, we review the function of prolactin specifically in the central nervous system and how it promotes a neuroprotective effect, or that of neuronal damage, particularly in experimental autoimmune encephalomyelitis and during excitotoxicity. The overall studies indicated that prolactin may be a promising molecule for the treatment of some neurological diseases.

The clinical pharmacology and potential therapeutic applications of 5‐methoxy‐N,N‐dimethyltryptamine (5‐MeO‐DMT)

“…Moreover, recent findings have shown that PRL has a direct inhibitory effect on key factors and pathways involved in inflammation, such as nuclear factor kappa-B (NF-κB) signaling, and on the secretion of inflammatory cytokines, for example, interleukin-1β (IL-1β), IL-6, tumor necrosis factor-alpha (TNFα)(Olmos-Ortiz et al, 2019). Furthermore, it also exerts anti-inflammatory effects in the central nervous system by regulating microglial functions and has been described as a neuroprotective and neuroplasticitypromoting factor(Ramos-Martinez et al, 2021). Since 5-MeO-DMT strongly modulates the circulating levels of PRL, it may have antiinflammatory and immune regulatory properties at both systemic and intracellular levels, for example, via the indirect inhibition of NF-κB signaling and pro-inflammatory cytokine production (Figure3).Because of its biphasic effect on PRL secretion in vivo, the immunemodulatory potential of 5-MeO-DMT is expected to be stronger in early acute scenarios (0-4 h after administration) and is graduallyF I G U R E 3The putative physiological effects of 5-MeO-DMT administration on the neuroendocrine and immune systems.…”

Prolactin and Its Altered Action in Alzheimer’s Disease and Parkinson’s Disease

“…Specifically, low levels of PRL (10–30 ng/mL) may activate the JAK2/STAT5-mediated signaling pathway in CD4+ T cells. High levels of PRL (100 ng/mL) may activate the signaling pathway via SOCS1 and 3, resulting in suppression of T-bet activation [101, 102]. Furthermore, accumulating evidence indicates that PRL is functionally active in the CNS, mediates inflammatory processes, and has anti-inflammatory and protective functions [103] (Table 1).…”

Associations between Prolactin, Diabetes, and Cognitive Impairment: A Literature Review

“…On the other hand, PRL increases the expression of the T-box transcription factor TBX21 (T-bet) via JAK2/STAT5 in T cells [24]. Low concentrations of PRL (10–30 ng/mL) may stimulate the JAK2/STAT5-mediated signaling pathway in CD4 + T cells, whereas high concentrations of PRL (100 ng/mL) may stimulate the SOCS1 and 3 signaling pathways, resulting in T-bet suppression [24, 25].…”

“…Fourth, neuroinflammation plays an important role in the pathogenesis of cognitive impairment [126]. In the CNS, PRL mediates both pro- and anti-inflammatory properties [7, 25]. As mentioned above, high concentrations of PRL may activate the signaling pathway via SOCS1 and 3, suppressing T-bet activation [24].…”