Gallic Acid Induces Neural Stem Cell Differentiation into Neurons and Proliferation through the MAPK/ERK Pathway

Mild hypothermia promotes neuronal differentiation of human neural stem cells via RBM3-SOX11 signaling pathway

Both therapeutic hypothermia and neural stem cells (NSCs) transplantation have shown promise in neuroprotection and neural repair after brain injury. However, the effects of therapeutic hypothermia on neuronal differentiation of NSCs are not elucidated. In this study, we aimed to investigate whether mild hypothermia promoted neuronal differentiation in cultured and transplanted human NSCs (hNSCs). A significant increase in neuronal differentiation rate of hNSCs was found when exposed to 35°C, from 33% to 45% in vitro and from 7% to 15% in vivo. Additionally, single-cell RNA sequencing identified upregulation of RNA-binding motif protein 3 (RBM3) in neuroblast at 35°C, which stabilized the SRY-box transcription factor 11 (SOX11) mRNA and increased its protein expression, leading to an increase in neuronal differentiation of hNSCs. In conclusion, our study highlights that mild hypothermia at 35°C enhances hNSCs-induced neurogenesis through the novel RBM3-SOX11 signaling pathway, and provides a potential treatment strategy in brain disorders.

Neurotrophic Natural Products

Neurotrophins (NGF, BDNF, NT3, NT4) can decrease cell death, induce differentiation, as well as sustain the structure and function of neurons, which make them promising therapeutic agents for the treatment of neurodegenerative disorders. However, neurotrophins have not been very effective in clinical trials mostly because they cannot pass through the blood-brain barrier owing to being high-molecular-weight proteins. Thus, neurotrophin-mimic small molecules, which stimulate the synthesis of endogenous neurotrophins or enhance neurotrophic actions, may serve as promising alternatives to neurotrophins. Small-molecular-weight natural products, which have been used in dietary functional foods or in traditional medicines over the course of human history, have a great potential for the development of new therapeutic agents against neurodegenerative diseases such as Alzheimer's disease. In this contribution, a variety of natural products possessing neurotrophic properties such as neurogenesis, neurite outgrowth promotion (neuritogenesis), and neuroprotection are described, and a focus is made on the chemistry and biology of several neurotrophic natural products.

Gallic acid ameliorates behavioral dysfunction, oxidative damage, and neuronal loss in the prefrontal cortex and hippocampus in stressed rats

Gallic acid (GA) is known to be a natural phenolic compound with antioxidant and neuroprotective effects. This study aims to investigate the impact of GA against restraint stress-induced oxidative damage, anxiety-like behavior, neuronal loss, and spatial learning and memory impairment in male Wistar rats. The animals were divided into four groups (n = 8) and subjected to restraint stress for 4 h per day for 14 consecutive days or left undisturbed (control without inducing stress). In the treatment group, the animals were treated with 2 mL normal saline plus 100 mg/kg GA per day for 14 consecutive days (STR + GA group). The animals received the drug or normal saline by gavage 2 h before inducing restraint stress. ELISA assay measured oxidative stress factors. Elevated-plus maze and Morris water maze tests assessed anxiety-like behavior and spatial learning and memory, respectively. Also, neuronal density was determined using Nissl staining. Restraint stress significantly increased MDA and reduced the activities of GPX and SOD in the stressed rats, which were reserved by treatment with 100 mg/kg GA. Restraint stress markedly enhanced the anxiety-like behavior and spatial learning and memory impairment that were reserved by GA. In addition, treatment with GA reduced the neuronal loss in the stressed rats in the hippocampus and prefrontal cortex (PFC) regions. Taken together, our findings suggest that GA has the potential to be used as a good candidate to attenuate neurobehavioral disorders as well as neuronal loss in the hippocampus and PFC induced by restraint stress via reducing oxidative damage.

TRPA1 is involved in the inhibitory effect of Ke-teng-zi on allergic contact dermatitis via MAPK and JAK/STAT3 signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

The seeds of Entada phaseoloides (Linn.) Merr. commonly named "Ke-teng-zi" is a traditional Chinese folk medicine and reported to treat dermatitis, spasm, and headache. However, the exact effect and the mechanism of Ke-teng-zi on the treatment of dermatitis is unclear.

AIM OF THE STUDY

To elucidate the antipruritic effect and molecular mechanisms of Ke-teng-zi on the treatment of allergic contact dermatitis (ACD).

MATERIALS AND METHODS

The main components of the n-butanol fraction of 70% ethanol extract from Ke-teng-zi (abbreviated as KB) were analyzed by HPLC. The chloroquine (CQ)-induced acute itch and squaraine dibutyl ester (SADBE)-induced ACD chronic itch in mice was established, and the TNF-α/IFN-γ stimulated Human keratinocytes (HaCaT) were used to evaluate the antipruritic and anti-inflammatory effects of KB. Behavioral tests, lesion scoring, and histology were also examined. The expression levels of molecules in MAPK and JAK/STAT3 pathways, the mRNA levels of chemokines and cytokines in both the skin of ACD mice and the HaCaT cells were detected by western blot and qPCR. Furthermore, whole-cell patch-clamp recordings in TRPA1-tranfected HEK293T cells were used to elucidate the effect of KB on TRPA1 channels. TRPA1 siRNA was used to evaluate the role of TRPA1 in the anti-inflammatory effect of KB in keratinocytes.

RESULTS

The main compounds in KB could bind to the active sites of TRPA1 mainly through hydrogen bond and hydrophobic bond interactions. KB could inhibit the scratching behavior in CQ-induced acute itch, and the inhibitory effect of KB was blocked by TRPA1 inhibitor HC-030031. In addition, KB significantly decreased the scratching bouts of ACD mice, reduced the skin lesion scores, mast cells degranulation, and epidermal thickening, inhibited the production of inflammatory chemokines/cytokines and CGRP, and down-regulated the levels of p-ERK1/2, p-p38, and p-STAT3, compared to the ACD mice. Moreover, continuous application of KB induced the desensitization of TRPA1 channels. Also, KB inhibited the expression of p-ERK1/2, p-p38, and p-STAT3, and down-regulated the expression of inflammatory chemokines and cytokines in vitro, which were reversed by the TRPA1 siRNA.

CONCLUSIONS

KB alleviated the pruritus and skin inflammation in ACD mice through TRPA1 channels desensitization and down-regulation of intracellular MAPK and JAK/STAT3 signaling pathways. Our results suggested that Ke-teng-zi is a potential drug for the treatment of inflammatory skin diseases such as ACD.

A Simplified and Effective Approach for the Isolation of Small Pluripotent Stem Cells Derived from Human Peripheral Blood

Pluripotent stem cells are key players in regenerative medicine. Embryonic pluripotent stem cells, despite their significant advantages, are associated with limitations such as their inadequate availability and the ethical dilemmas in their isolation and clinical use. The discovery of very small embryonic-like (VSEL) stem cells addressed the aforementioned limitations, but their isolation technique remains a challenge due to their small cell size and their efficiency in isolation. Here, we report a simplified and effective approach for the isolation of small pluripotent stem cells derived from human peripheral blood. Our approach results in a high yield of small blood stem cell (SBSC) population, which expresses pluripotent embryonic markers (e.g., Nanog, SSEA-3) and the Yamanaka factors. Further, a fraction of SBSCs also co-express hematopoietic markers (e.g., CD45 and CD90) and/or mesenchymal markers (e.g., CD29, CD105 and PTH1R), suggesting a mixed stem cell population. Finally, quantitative proteomic profiling reveals that SBSCs contain various stem cell markers (CD9, ITGA6, MAPK1, MTHFD1, STAT3, HSPB1, HSPA4), and Transcription reg complex factors (e.g., STAT5B, PDLIM1, ANXA2, ATF6, CAMK1). In conclusion, we present a novel, simplified and effective isolating process that yields an abundant population of small-sized cells with characteristics of pluripotency from human peripheral blood.

Tibetan medicine Si-Wei-Qiang-Wei Powder ameliorates cholecystitis via inhibiting the production of pro-inflammatory cytokines and regulating the MAPK signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Si-Wei-Qiang-Wei Powder (SWQ) is a formulated traditional Tibetan medicine preparation that has been used clinically to treat liver and gallbladder diseases for centuries. Previous work has confirmed its clinical effectiveness, however, the specific mechanism of SWQ is still unknown.

AIM OF THE STUDY

This study aims to explore the anti-inflammatory effect of SWQ on cholecystitis and its possible mechanism.

MATERIALS AND METHODS

The main chemical components of SWQ were analyzed by HPLC. The network pharmacology database was used to screen and construct the network of the main components and molecular targets of SWQ, and to predict the molecular pathways of its core targets. Cholecystitis guinea pig model and LPS stimulated cultured human gallbladder epithelial cells (HGBEC) were used, as in vivo and in vitro methods respectively, to study the anti-cholecystitis activity of SWQ. Specifically, gallbladder wall thickness, hematoxylin-eosin (H&E) staining, and liver function indexes were used to evaluate the anti-inflammatory activities of SWQ in cholecystitis; qRT-PCR and ELISA were used to detect the changes of the production of inflammatory cytokines; Western blot analysis was used to analyze the effects of SWQ on phosphorylation of P38, ERK1/2, JNK and AKT.

RESULTS

SWQ decreased the indexes of ALT, AST, TBA, CHOL, DBIL in serum and TBIL, TC and Ca²⁺ in bile, and alleviated the wall thickness of gallbladder and hepatobiliary fibrosis in LCA-induced guinea pigs. In addition, SWQ attenuated the expression and production of TNF-α, IL-6, IL-1β, COX-2 both in liver and gallbladder. Moreover, SWQ reversed the up-regulation of p-P38, p-ERK1/2, and p-JNK in animals with cholecystitis and LPS-induced HGBEC. Furthermore, mechanistic studies indicated that SWQ inhibited the activation of ERK1/2, thereby decreasing the expression of TNF-α, IL-6, IL-1β and phosphorylation P38 and JNK.

CONCLUSION

In summary, our research showed that SWQ relieves gallbladder inflammation by inhibiting the MAPK pathway.

Kaempferia parviflora Extracts Protect Neural Stem Cells from Amyloid Peptide-Mediated Inflammation in Co-Culture Model with Microglia

The existence of neuroinflammation and oxidative stress surrounding amyloid beta (Aβ) plaques, a hallmark of Alzheimer's disease (AD), has been demonstrated and may result in the activation of neuronal death and inhibition of neurogenesis. Therefore, dysregulation of neuroinflammation and oxidative stress is one possible therapeutic target for AD. Kaempferia parviflora Wall. ex Baker (KP), a member of the Zingiberaceae family, possesses health-promoting benefits including anti-oxidative stress and anti-inflammation in vitro and in vivo with a high level of safety; however, the role of KP in suppressing Aβ-mediated neuroinflammation and neuronal differentiation has not yet been investigated. The neuroprotective effects of KP extract against Aβ₄₂ have been examined in both monoculture and co-culture systems of mouse neuroectodermal (NE-4C) stem cells and BV-2 microglia cells. Our results showed that fractions of KP extract containing 5,7-dimethoxyflavone, 5,7,4'-trimethoxyflavone, and 3,5,7,3',4'-pentamethoxyflavone protected neural stem cells (both undifferentiated and differentiated) and microglia activation from Aβ₄₂-induced neuroinflammation and oxidative stress in both monoculture and co-culture system of microglia and neuronal stem cells. Interestingly, KP extracts also prevented Aβ₄₂-suppressed neurogenesis, possibly due to the contained methoxyflavone derivatives. Our data indicated the promising role of KP in treating AD through the suppression of neuroinflammation and oxidative stress induced by Aβ peptides.

Construction of double network hydrogels using agarose and gallic acid with antibacterial and anti-inflammatory properties for wound healing

Gallic acid (GA) has attracted extensive attention due to its excellent health benefits. Our recent work demonstrated that GA could be self-assembled into hydrogels. However, the poor mechanical properties and rapid degradation of GA hydrogels presented challenges for further applications. In this study, agarose (AG), a water-soluble polysaccharide, was used with GA to develop a double network hydrogel (GA-AG). Physical and chemical tests demonstrated that the GA-AG hydrogel at ratio of 4:5 had the highest cross-linked structure, along with excellent porosity, good water retention and a swelling ratio of 9.72 %. In addition, the cross-linked network structure enabled the GA-AG hydrogel to have good mechanical properties and better viscosity than the pure GA hydrogel. The glass transition temperature of the GA-AG hydrogel increased from 59.49 °C to 65.54 °C, while its disintegration rate decreased from 99.07 % to 64.37 % within 48 h. In vitro tests showed that the GA-AG hydrogel had excellent antibacterial activity and biocompatibility. Meanwhile, we demonstrated that this double network hydrogel significantly reduced inflammation and accelerated wound healing in vivo. From the results of our study, we expect that this stable GA-AG double network hydrogel has potential applications in wound healing.