Tanshinone IIA Alleviates CCL2-Induced Leaning memory and Cognition Impairment in Rats: A Potential Therapeutic Approach for HIV-Associated Neurocognitive Disorder

Spotlight on pro-inflammatory chemokines: regulators of cellular communication in cognitive impairment

Cognitive impairment is a decline in people's ability to think, learn, and remember, and so forth. Cognitive impairment is a global health challenge that affects the quality of life of thousands of people. The condition covers a wide range from mild cognitive impairment to severe dementia, which includes Alzheimer's disease (AD) and Parkinson's disease (PD), among others. While the etiology of cognitive impairment is diverse, the role of chemokines is increasingly evident, especially in the presence of chronic inflammation and neuroinflammation. Although inflammatory chemokines have been linked to cognitive impairment, cognitive impairment is usually multifactorial. Researchers are exploring the role of chemokines and other inflammatory mediators in cognitive dysfunction and trying to develop therapeutic strategies to mitigate their effects. The pathogenesis of cognitive disorders is very complex, their underlying causative mechanisms have not been clarified, and their treatment is always one of the challenges in the field of medicine. Therefore, exploring its pathogenesis and treatment has important socioeconomic value. Chemokines are a growing family of structurally and functionally related small (8-10 kDa) proteins, and there is growing evidence that pro-inflammatory chemokines are associated with many neurobiological processes that may be relevant to neurological disorders beyond their classical chemotactic function and play a crucial role in the pathogenesis and progression of cognitive disorders. In this paper, we review the roles and regulatory mechanisms of pro-inflammatory chemokines (CCL2, CCL3, CCL4, CCL5, CCL11, CCL20, and CXCL8) in cognitive impairment. We also discuss the intrinsic relationship between the two, hoping to provide some valuable references for the treatment of cognitive impairment.

Activation of CNR1/PI3K/AKT Pathway by Tanshinone IIA Protects Hippocampal Neurons and Ameliorates Sleep Deprivation-Induced Cognitive Dysfunction in Rats

Sleep deprivation is commonplace in modern society, Short periods of continuous sleep deprivation (SD) may negatively affect brain and behavioral function and may lead to vehicle accidents and medical errors. Tanshinone IIA (Tan IIA) is an important lipid-soluble component of Salvia miltiorrhiza, which could exert neuroprotective effects. The aim of this study was to investigate the mechanism of neuroprotective effect of Tan IIA on acute sleep deprivation-induced cognitive dysfunction in rats. Tan IIA ameliorated behavioral abnormalities in sleep deprived rats, enhanced behavioral performance in WMW and NOR experiments, increased hippocampal dendritic spine density, and attenuated atrophic loss of hippocampal neurons. Tan IIA enhanced the expression of CB1, PI3K, AKT, STAT3 in rat hippocampus and down-regulated the expression ratio of Bax to Bcl-2. These effects were inhibited by cannabinoid receptor 1 antagonist (AM251). In conclusion, Tan IIA can play a neuroprotective role by activating the CNR1/PI3K/AKT signaling pathway to antagonize apoptosis in the hippocampus and improve sleep deprivation-induced spatial recognition and learning memory dysfunction in rats. Our study suggests that Tan IIA may be a candidate for the prevention of sleep deprivation-induced dysfunction in spatial recognition and learning memory.

Recent Research Progress (2015-2021) and Perspectives on the Pharmacological Effects and Mechanisms of Tanshinone IIA

Tanshinone IIA (Tan IIA) is an important characteristic component and active ingredient in Salvia miltiorrhiza, and its various aspects of research are constantly being updated to explore its potential application. In this paper, we review the recent progress on pharmacological activities and the therapeutic mechanisms of Tan IIA according to literature during the years 2015-2021. Tan IIA shows multiple pharmacological effects, including anticarcinogenic, cardiovascular, nervous, respiratory, urinary, digestive, and motor systems activities. Tan IIA modulates multi-targets referring to Nrf2, AMPK, GSK-3β, EGFR, CD36, HO-1, NOX4, Beclin-1, TLR4, TNF-α, STAT3, Caspase-3, and bcl-2 proteins and multi-pathways including NF-κB, SIRT1/PGC1α, MAPK, SREBP-2/Pcsk9, Wnt, PI3K/Akt/mTOR pathways, TGF-β/Smad and Hippo/YAP pathways, etc., which directly or indirectly influence disease course. Further, with the reported targets, the potential effects and possible mechanisms of Tan IIA against diseases were predicted by bioinformatic analysis. This paper provides new insights into the therapeutic effects and mechanisms of Tan IIA against diseases.

Corrigendum to "Tanshinone IIA Alleviates CCL2-Induced Leaning memory and Cognition Impairment in Rats: A Potential Therapeutic Approach for HIV-Associated Neurocognitive Disorder"

[This corrects the article DOI: 10.1155/2020/2702175.].

Chemokine CCL2 impairs spatial memory and cognition in rats via influencing inflammation, glutamate metabolism and apoptosis-associated genes expression- a potential mechanism for HIV-associated neurocognitive disorder

AIMS

To explore the role of chemokine CC motif ligand 2 (CCL2) in spatial memory and cognition impairment, and the underlying mechanisms focused on inflammatory, glutamate metabolistic and apoptotic- associated mRNA expression.

MATERIALS AND METHODS

Stereotaxic surgery was performed here to establish a rat model by bilateral intra-hippocampal injection of CCL2. Morris water maze (MWM) and Novel object recognition test (NORT) were used to assess the learning, memory and cognitive ability respectively. RT-PCR was used to detect the relative mRNA expression of inflammatory, glutamate metabolistic and apoptotic- associated indexes. Nissl and TUNEL staining were performed to observe the morphological changes of hippocampal CA1 zone and quantified the apoptosis of hippocampal neurons of CA1 zones respectively.

KEY FINDINGS

We found CCL2 injured cognitive function in rats. Six days after CCL2 injection, we revealed the following obvious mRNA expression changes: (1) increasing of the neuroinflammatory cytokines IL-1β, CXCL-10, IL-6; (2) decreasing of the glutamate transporters GLT-1 and GLAST and increasing of PAG; (3) increasing of the apoptotic genes caspase-8, caspase-3 and Bax, while decreasing the anti-apoptotic gene Bcl-2. Further, Nissl staining and TUNEL confirmed the injury of the structure of hippocampal CA1 zones and the apoptosis of hippocampal neurons.

SIGNIFICANCE

Our results indicated that CCL2 impaired spatial memory and cognition, the involving mechanisms may link to the up-regulation of mRNA expression of the three major pathological events: inflammation, excitotoxicity and neuronal apoptosis, which were involved in HIV-associated neurocognitive disorder (HAND). Taken together, these findings suggest a potential therapeutic strategy against CCL2.