Interleukin-1ß-Treated Mesenchymal Stem Cells Inhibit Inflammation in Hippocampal Astrocytes Through Exosome-Activated Nrf-2 Signaling.

BACKGROUND: Interleukin-1ß (IL-1)-treated mesenchymal stem cells (MSCs) and IL-1-MSCs-conditioned medium (CM) exert anti-inflammatory roles. Astrocytes are essential for the modulation of synaptic activity and neuronal homeostasis in the brain. Exosomes are the critical mediators in intercellular communication. However, the mechanism underlying the anti-inflammatory effect of IL-1-treated MSCs remains unknown. METHODS: In this study, exosomes (IL-1-Exo) were isolated from IL-1-treated MSCs. In addition, lipopolysaccharide (LPS)-treated hippocampal astrocytes and status epilepticus (SE) mice were treated with IL-1-Exo. Inflammatory activity, astrogliosis, and cognitive performance were measured to determine the effect of IL-1-Exo on inflammation. RESULTS: The results revealed that IL-1-Exo significantly inhibited LPS-induced astrogliosis and inflammatory responses of astrocytes. Also, IL-1-Exo reversed the LPS-induced effect on calcium signaling. The Nrf2 signaling pathway was associated with the effect of IL-1-Exo in LPS-treated astrocytes. Furthermore, IL-1-Exo reduced the inflammatory response and improved the cognitive performance of SE mice. CONCLUSION: The results suggest that IL-1-Exo inhibited LPS-induced inflammatory responses in astrocytes and SE mice and that the effect of IL-1-Exo was primarily mediated through the Nrf-2 signaling pathway. This study provides a new understanding of the molecular mechanism of inflammation-associated brain diseases and an avenue to develop nanotherapeutic agents for the treatment of inflammatory conditions in the brain.

[Safety research on treatment of cough reflex disorder after cerebral hemorrhage with crossing nape electroacupuncture in guinea pig].

OBJECTIVE: To observe the effect of crossing nape electroacupuncture(EA) on cough count (CCnt), cough incubation period and blood routine, liver function, renal function, myocardial enzymology, and heart, liver and kidney pathological structure in guinea pig with cough reflex disorder after cerebral hemorrhage, so as to evaluate the efficacy and safety of crossing nape EA in the treatment of cough reflex disorder after cerebral hemorrhage. METHODS: A total of 160 male pure white guinea pigs were randomly divided into normal group, model group, acupuncture group, crossing nape EA group and nape EA group (n=32 in each group). These 5 groups were further divided into 1, 3, 7 and 14 d subgroups(n=8 in each subgroup). The model of cough reflex disorder after cerebral hemorrhage was established by injection of the guinea pigs' autoblood (50 µL) into the basal ganglia region confirmed by Longa's neurologic examination grading system(0-4 points). Acupuncture was applied to bilateral "Fengchi" (GB20) and "Yifeng" (SJ17) in the acupuncture group. In the crossing nape EA group, the positive pole of the needle is connected to SJ17, while the negative pole is connected to the opposite side of GB20(2 Hz, 0.5 mA). In the nape EA group, the positive pole of the needle is connected to SJ17, while the negative pole is connected to the same side of GB20(2 Hz, 0.5 mA). All treatments were applied 20 min each time, once a day. The changes of CCnt and cough incubation period were recorded by Buxco device. The changes of blood routine, liver function, kidney function, myocardial enzyme and other laboratory indexes were monitored by automatic analyzer instrument. The pathological changes of heart, liver and kidney of guinea pigs were observed by transmission electron microscopy. RESULTS: Compared with the normal group, the guinea pigs' neurological deficit scores in the model group were significantly increased at each time point (P<0.01). Compared with the model group, the neurological deficit scores of the acupuncture group, crossing nape EA group and nape EA group at 3 d, 7 d and 14 d all decreased (P<0.01, P<0.05). Following modeling, the CCnt at each time point in the model group was significantly reduced (P<0.01), and the cough latency was significantly prolonged (P<0.01). After interventions, the CCnts were increased and the incubation periods of cough were shortened (P<0.05, P<0.01) at 7 d and 14 d in the 3 intervention groups, and were superior in the crossing nape EA group than those of acupuncture group and nape EA group (P<0.05, P<0.01). The improvement degrees of these 2 indexes in the nape EA group at 14 d were better than those of the acupuncture group (P<0.05). There were no significant differences among the 3 groups in red blood cells counting, hemoglobin, myocardial enzymes, liver and kidney function (P>0.05). Compared with the normal group, the WBC counts in all the time points (except 1 d after operation) were significantly increased(P<0.01) in the model group. In comparison with the model group, the WBC counts at 3 d in crossing nape EA group, and at 7 d and 14 d in the 3 intervention groups decreased (P<0.01, P<0.05). Meanwhile, the WBC counts were lower in the crossing nape EA group at 7 d and 14 d than those of acupuncture group and nape EA group (P<0.05). The results of transmission electron microscopy showed that the histopathological structure of heart, liver and kidney of guinea pigs in each group had no significant changes. CONCLUSION: Crossing nape EA is safe and effective in the treatment of cough reflex disorder after cerebral hemorrhage in guinea pigs. In addition, guinea pigs will have an inflammatory response after cerebral hemorrhage, and crossing nape EA may have a certain anti-inflammatory effect.

Cross electro-nape-acupuncture ameliorates cerebral hemorrhage-induced brain damage by inhibiting necroptosis.

BACKGROUND: Receptor interacting protein kinase 1 (RIPK1)-mediated cell death, including apoptosis and necroptosis, belongs to programmed cell death. It has been reported that RIPK1-mediated necroptosis exists in lesions of cerebral hemorrhage (CH). Electroacupuncture, a treatment derived from traditional Chinese medicine, could improve neurological impairment in patients with brain injury. AIM: To investigate the protective role of cross electro-nape acupuncture (CENA) in CH, and clarify the potential mechanism. METHODS: CH rat models were established, and CENA was applied to the experimental rats. Neurological functions and encephaledema were then measured. Necrotic cells in the brain of rats with CH were evaluated by propidium iodide staining. Necroptosis was assessed by immunofluorescence. Activation of the necroptosis-related pathway was detected by western blot. Extraction of brain tissue, cerebrospinal fluid and serum samples was conducted to measure the expression and secretion of inflammatory cytokines by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. RESULTS: The necroptotic marker p-MLKL was detectable in the brains of rats with CH. Next, we found that CENA could ameliorate neurological functions in rat models of CH. Moreover, the upregulation of RIPK1-mediated necroptosis-related molecules in the brains of rats with CH were inhibited by CENA. Further investigation revealed that CENA partially blocked the interaction between RIPK1 and RIPK3. Finally, in vivo assays showed that CENA decreased the expression of the inflammatory cytokines tumor necrosis factor-α, interleukin-6 and interleukin-8 in CH rat models. CONCLUSION: These findings revealed that CENA exerts a protective role in CH models by inhibiting RIPK1-mediated necroptosis.