Triptolide mediates Wnt/β-catenin signalling pathway to reduce cerebral ischemia-reperfusion injury in rats

Neuroprotective effect of triptolide on neuronal inflammation in rats with mild brain injury

Concussions sustained while playing sports are a prominent cause of mild traumatic brain injury (mTBI), which is prevalent among teenagers. The early and intermediate stages of mild traumatic brain injury (mTBI) can be characterized by inflammation, neurodegeneration, and brain tissue edema, which can lead to permanent brain damage. The present study investigated the therapeutic effects of triptolide in mTBI and brain damage recovery. After building mTBI model in male rat, triptolide administrated daily for 1 week in the treated group. On day 3 and day 7 of administration, hippocampus tissues were collected to evaluate inflammation and autophagy in the brain. The expressions of inflammatory factors interleukin (IL)-1β and tumor necrosis factor-alpha in serum were downregulated, while IL-10 expression was upregulated when compared with the mTBI group on day 3 and day 7. The expression of IL-10 on day 7 was higher than on day 3. Quantitative polymerase chain reaction (qPCR) analysis of inflammatory-related factors (i.e., Il-1β and nuclear factor-κB (Nf-κb), and western blot as well as immunofluorescence staining of autophagy-related proteins (i.e., LC3B) and aquaporin (AQP 4) showed lower expression on day 3 and day 7 in the triptolide-treated group. Moreover, NeuN immunostaining, and hematoxylin and eosin (HE) staining for hippocampus region revealed that the triptolide-treated group showed a decrease in damaged cells. Our findings emphasize the effectiveness of triptolide therapy after mild traumatic brain injury via modulating autophagy, attenuating inflammation and reduces edema by decreasing AQP 4 expression.

Molecular mechanism of triptolide in myocardial fibrosis through the Wnt/β-catenin signaling pathway

Objective. Myocardial fibrosis (MF) is a common manifestation of end-stage cardiovascular diseases. Triptolide (TP) provides protection against cardiovascular diseases. This study was to explore the functional mechanism of TP in MF rats via the Wnt/β-catenin pathway. Methods. The MF rat model was established via subcutaneous injection of isoproterenol (ISO) and treated with low/medium/high doses of TP (L-TP/M-TP/H-TP) or Wnt agonist BML-284. Cardiac function was examined by echocardiography. Pathological changes of myocardial tissues were observed by HE and Masson staining. Col-I/Col-III/Vimentin/α-SMA levels were detected by immunohistochemistry, RT-qPCR, and Western blot. Collagen volume fraction content was measured. Expression levels of the Wnt/β-catenin pathway-related proteins (β-catenin/c-myc/Cyclin D1) were detected by Western blot. Rat cardiac fibroblasts were utilized for in vitro validation experiments. Results. MF rats had enlarged left ventricle, decreased systolic and diastolic function and cardiac dysfunction, elevated collagen fiber distribution, collagen volume fraction and hydroxyproline content. Levels of Col-I/Col-III/Vimentin/α-SMA, and protein levels of β-catenin/c-myc/Cyclin D1 were increased in MF rats. The Wnt/β-catenin pathway was activated in the myocardial tissues of MF rats. TP treatment alleviated impairments of cardiac function and myocardial tissuepathological injury, decreased collagen fibers, collagen volume fraction, Col-I, Col-III, α-SMA and Vimentin levels, HYP content, inhibited Wnt/β-catenin pathway, with H-TP showing the most significant effects. Wnt agonist BML-284 antagonized the inhibitive effect of TP on MF. TP inhibited the Wnt/β-catenin pathway to repress the proliferation and differentiation of mouse cardiac fibroblasts in vitro. Conclusions. TP was found to ameliorate ISO-induced MF in rats by inhibiting the Wnt/β-catenin pathway.

Triptolide alleviates cerebral ischemia/reperfusion injury via regulating the Fractalkine/CX3CR1 signaling pathway

PURPOSE

To evaluate the potential efficacy of Triptolide (TP) on cerebral ischemia/reperfusion injury (CIRI) and to uncover the underlying mechanism through which TP regulates CIRI.

METHODS

We constructed a middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model to simulate CIRI, and established a lipopolysaccharide (LPS)-stimulated BV-2 cell model to mimic the inflammatory state during CIRI. The neurological deficits score (NS) of mice were measured for assessment of neurologic functions. Both the severity of cerebral infarction and the apoptosis level in mouse brain tissues or cells were respectively evaluated using corresponding techniques. The expression levels of Ionized calcium binding adapter molecule 1 (IBA-1), Inductible Nitric Oxide Synthase (iNOS), Arginase 1 (Arg-1), Tumor necrosis factor-α (TNF-α), Interleukin 1β (IL-1β), Cysteine histoproteinase S (CTSS), Fractalkine, chemokine C-X3-C motif receptor 1 (CX3CR1), BCL-2-associated X protein (BAX), and antiapoptotic proteins (Bcl-2) were detected using immunofluorescence, qRT-PCR as well as Western blot, respectively.

RESULTS

Relative to the Sham group, treatment with TP attenuated the increased NS, infarct area and apoptosis levels observed in MCAO/R mice. Upregulated expression levels of IBA-1, iNOS, Arg-1, TNF-α and IL-1β were found in MCAO/R mice, while TP suppressed iNOS, TNF-α and IL-1β expression, and enhanced Arg-1 expression in both MCAO/R mice and LPS-stimulated BV-2 cells. Besides, TP inhibited the CTSS/Fractalkine/CX3CR1 pathway activation in both MCAO/R mice and LPS-induced BV-2 cells, while overexpression of CTSS reversed such effect. Co-culturing HT-22 cells with TP+LPS-treated BV-2 cells led to enhanced cell viability and decreased apoptosis levels. However, overexpression of CTSS further aggravated HT-22 cell injury.

CONCLUSION

TP inhibits not only microglia polarization towards the M1 phenotype by suppressing the CTSS/Fractalkine/CX3CR1 pathway activation, but also HT-22 apoptosis by crosstalk with BV-2 cells, thereby ameliorating CIRI. These findings reveal a novel mechanism of TP in improving CIRI, and offer potential implications for addressing the preventive and therapeutic strategies of CIRI.

Antitumor mechanisms and future clinical applications of the natural product triptolide

Triptolide (TPL) is a compound sourced from Tripterygium wilfordii Hook. F., a traditional Chinese medicinal herb recognized for its impressive anti-inflammatory, anti-angiogenic, immunosuppressive, and antitumor qualities. Notwithstanding its favorable attributes, the precise mechanism through which TPL influences tumor cells remains enigmatic. Its toxicity and limited water solubility significantly impede the clinical application of TPL. We offer a comprehensive overview of recent research endeavors aimed at unraveling the antitumor mechanism of TPL in this review. Additionally, we briefly discuss current strategies to effectively manage the challenges associated with TPL in future clinical applications. By compiling this information, we aim to enhance the understanding of the underlying mechanisms involved in TPL and identify potential avenues for further advancement in antitumor therapy.

Friend or foe? The dual role of triptolide in the liver, kidney, and heart

Triptolide, a controversial natural compound due to its significant pharmacological activities and multiorgan toxicity, has gained much attention since it was isolated from the traditional Chinese herb Tripterygium wilfordii Hook F. However, in addition to its severe toxicity, triptolide also presents powerful therapeutic potency in the same organs, such as the liver, kidney, and heart, which corresponds to the Chinese medicine theory of You Gu Wu Yun (anti-fire with fire) and deeply interested us. To determine the possible mechanisms involved in the dual role of triptolide, we reviewed related articles about the application of triptolide in both physiological and pathological conditions. Inflammation and oxidative stress are the two main ways triptolide exerts different roles, and the cross-talk between NF-κB and Nrf2 may be one of the mechanisms responsible for the dual role of triptolide and may represent the scientific connotation of You Gu Wu Yun. For the first time, we present a review of the dual role of triptolide in the same organ and propose the possible scientific connotation of the Chinese medicine theory of You Gu Wu Yun, hoping to promote the safe and efficient use of triptolide and other controversial medicines.

Pro-fibrotic and apoptotic activities of circARAP1 in myocardial ischemia-reperfusion injury

Reperfusion modality can cause damage to cardiomyocytes, known as myocardial ischemia-reperfusion injury (MI/RI). Circular RNAs (circRNAs) are fundamental regulators associated with many cardiac diseases, including MI/RI. However, their functional impact on cardiomyocyte fibrosis and apoptosis remains elusive. Therefore, this study aimed to explore possible molecular mechanisms of circARPA1 in animal models and in hypoxia/reoxygenation (H/R)-treated cardiomyocytes. GEO dataset analysis showed that has_circ_0023461 (circARPA1) was differentially expressed in myocardial infarction samples. Real-time quantitative PCR further supported that circARPA1 was expressed at high levels in animal models and in H/R-triggered cardiomyocytes. Then, loss-of-function assays were performed to show that circARAP1 suppression effectively ameliorated cardiomyocyte fibrosis and apoptosis in MI/RI mice. Mechanistic experiments showed that miR-379-5p, KLF9 and Wnt signaling pathways were associated with circARPA1. circARPA1 can sponge miR-379-5p to regulate KLF9 expression, thereby activating the wnt/β-catenin pathway. Finally, gain-of-function assays revealed that circARAP1 aggravated MI/RI in mice and H/R-induced cardiomyocyte injury by regulating the miR-379-5p/KLF9 axis to activate Wnt/β-catenin signaling.

The therapeutic potential of triptolide and celastrol in neurological diseases

Neurological diseases are complex diseases affecting the brain and spinal cord, with numerous etiologies and pathogenesis not yet fully elucidated. Tripterygium wilfordii Hook. F. (TWHF) is a traditional Chinese medicine with a long history of medicinal use in China and is widely used to treat autoimmune and inflammatory diseases such as systemic lupus erythematosus and rheumatoid arthritis. With the rapid development of modern technology, the two main bioactive components of TWHF, triptolide and celastrol, have been found to have anti-inflammatory, immunosuppressive and anti-tumor effects and can be used in the treatment of a variety of diseases, including neurological diseases. In this paper, we summarize the preclinical studies of triptolide and celastrol in neurological diseases such as neurodegenerative diseases, brain and spinal cord injury, and epilepsy. In addition, we review the mechanisms of action of triptolide and celastrol in neurological diseases, their toxicity, related derivatives, and nanotechnology-based carrier system.

Scalp Electroacupuncture Promotes Angiogenesis after Stroke in Rats by Activation of Wnt/β-Catenin Signal Pathway

Background

Scalp acupuncture is a contemporary acupuncture method based on the fundamental theories of traditional acupuncture, which has been widely used in patients with stroke in China. However, the effectiveness is controversial due to lack of solid experimental evidence.

Methods

In this study, a rat model of cerebral ischemia-reperfusion injury (CIRI) was established by the middle cerebral artery occlusion/recirculation. The efficacy of scalp acupuncture against CIRI was evaluated by the mNSS scores, TTC staining for brain slices, and laser Doppler perfusion imaging. Immunohistochemical staining for angiogenetic factors indicated the vascularization after CIRI, including VEGF, Ang2, and bFGF. Activation of the Wnt/β-catenin signaling pathway and p-GSK3β (ser9)/VEGF pathway in the injured brain tissues was assessed by western blotting and qRT-PCR.

Results

On the 7, 14, and 21 days after CIRI, scalp acupuncture could reduce the mNSS scores, decrease the cerebral infarction area, and accelerate the recirculation of ischemic brain tissues. VEGF, FLK1, bFGF, and Ang2 were upregulated on both the mRNA and protein levels in the ischemic brain tissues of the AC group, suggesting that the recirculation might result from angiogenesis, which was also confirmed with the IHC staining in the angiogenetic markers of VEGF, Ang2, and bFGF. Moreover, Wnt3a, β-catenin, and cyclin D1 were also upregulated on both the mRNA and protein levels in the ischemic brain tissues of the AC group on day 7, 14, and 21, indicating that the Wnt/β-catenin signaling pathway was activated after the treatment of scalp acupuncture. In contrast, dikkoppf-1 (DKK1) pretreatment, a specific inhibitor for the Wnt/β-catenin signaling pathway, inactivated the Wnt3a/β-catenin signaling pathway and exacerbated the infarct size induced by the cerebral IR injury on day 7.

Conclusion

Together, our findings demonstrated a mechanism whereby scalp acupuncture led to the activation of Wnt/β-catenin signaling pathway, promoting angiogenetic factor expression and restoring blood perfusion in the ischemic zone.

Chemical composition and protective effect of cerebrospinal fluid of Dan-Deng-Tong-Nao capsules on brain microvascular endothelial cells injured by OGD/R

ETHNOPHARMACOLOGICAL RELEVANCE

Dan-Deng-Tong-Nao Capsules (DDTNC) is a Chinese patent medicine and has been used in treating cerebral ischemic stroke (IS) for a long time in China, protection of brain microvascular endothelial cells (BMECs) is the main treatment strategy. But the holistic chemical information and potential bioactive components of DDTNC on protecting BMECs and its underlying mechanism is still unclear.

AIM OF THE STUDY

To identify the active ingredients of DDTNC and to explore the protective effects of DDTNC on BMECs associated with Wnt/β-catenin pathway.

MATERIALS AND METHODS

The components of DDTNC and cerebrospinal fluid containing composition of DDTNC (DDTNC-CSF) were detected by High performance liquid chromatography combined with Diode array detector (HPLC-DAD) and Ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS), respectively. The experiment rat model was established with middle cerebral artery occlusion (MCAO), the therapeutic effects of DDTNC were assessed by Longa assay and TTC staining. The cerebral micro vessel density was determined by immunofluorescence staining. The injured BMECs caused by oxygen-glucose deprivation and reperfusion (OGD/R) was used to evaluate the protective effect of cerebrospinal fluid containing composition of DDTNC (DDTNC-CSF). The cell survival rate was detected by the method of CCK-8, the intracellular Ca²⁺ and reactive oxygen species (ROS) was estimated by Fluo-3. Moreover, the proteins of Bax, Bcl-2, Wnt, β-catenin, GSK-3β was determined by Western blotting.

RESULTS

The RSD values of all methodological studies were less than 3.0%. A total of 20 compounds were detected under the optimized HPLC-DAD chromatographic condition. In the UPLC-Q-TOF-MS negative mode, peak 1 and peak 2 were detecteted in DDTNC-CSF and was identified as Danshensu and Puerarin, respectively. In the UPLC-Q-TOF-MS positive mode, peak 1 and peak 3 were detecteted in DDTNC-CSF and was identified as Danshensu and Scutellarin, respectively. DDTNC significantly decreased the Longa values and infarct volume and significantly increased the cerebral microvessel density of the MCAO rats. The accumulation of intracellular Ca²⁺ and ROS in BMECs injured by OGD/R decreased significantly in DDTNC-CSF group. The expression of Bcl-2, β-catenin, wnt-1 was upregulated by DDTNC-CSF and the level of Bax and GSK3β could be downregulated by DDTNC-CSF.

CONCLUSION

The present study provided a scientific basis for revealing the mechanism of DDTNC in the treatment of IS and DDTNC is expected to be an effective drug for the treatment of IS.

Luteolin alleviates ischemia/reperfusion injury-induced no-reflow by regulating Wnt/β-catenin signaling in rats

The no-reflow phenomenon induced by ischemia-reperfusion (I/R) injury seriously limits the therapeutic value of coronary recanalization and leads to a poor prognosis. Previous studies have shown that luteolin (LUT) is a vasoprotective factor. However, whether LUT can be used to prevent the no-reflow phenomenon remains unknown. Positron emission tomography perfusion imaging, performed to detect the effects of LUT on the no-reflow phenomenon in vivo, revealed that LUT treatment was able to reduce the no-reflow area in rat I/R models. In vitro, LUT was shown to reduce the hypoxia-reoxygenation injury-induced endothelial permeability and apoptosis. The levels of malondialdehyde, reactive oxygen species and NADPH were also measured and the results indicated that LUT could inhibit the oxidative stress. Western blot analysis revealed that LUT protected endothelial cells from I/R injury by regulating the Wnt/β-catenin pathway. Overall, we concluded that the use of LUT to minimize I/R induced microvascular damage is a feasible strategy to prevent the no-reflow phenomenon.

Dendrobium officinale polysaccharide-induced neuron-like cells from bone marrow mesenchymal stem cells improve neuronal function a rat stroke model

Various methods have been used to induce the neuronal differentiation of marrow mesenchymal stem cells (MSCs). However, the limited induction efficiency of cells in vitro has restricted their use. Therefore, identifying a simple and efficient treatment method is necessary. Dendrobium officinale is an important traditional Chinese medicine, and its main component, polysaccharides, has many pharmacological activities. However, the effects of D. officinale polysaccharide (DOP) on the neuronal differentiation of bone marrow mesenchymal stem cells (BMSCs) and treatment of ischaemic stroke remain unknown. We found that DOP promoted the neuronal differentiation of BMSCs by increasing the expression levels of neural markers, and the optimal concentration of DOP was 25 μg/mL. Additionally, the Notch signalling pathway was inhibited during the neuronal differentiation of BMSCs induced by DOP, and this effect was strengthened using an inhibitor of this pathway. The Wnt signalling pathway was activated during the differentiation of BMSCs, and inhibition of the Wnt signalling pathway downregulated the expression of neuronal genes. Furthermore, the transplantation of neuron-like cells induced by DOP improved neuronal recovery, as the brain infarct volume, neurologic severity scores and levels of inflammatory factors were all significantly reduced in vivo. In conclusion, DOP is an effective inducer of the neuronal differentiation of BMSCs and treatment option for ischaemic stroke.