Ulinastatin attenuates isoflurane-induced cognitive dysfunction in aged rats by inhibiting neuroinflammation and β-amyloid peptide expression in the brain

FGF19 improves sevoflurane-induced cognitive dysfunction in rats through the PGC-1α/BDNF/FNDC5 pathway

Postoperative cognitive dysfunction (POCD) is a serious central nervous system complication characterized by impaired memory, reduced information processing ability, and anxiety. Recently, the role of FGF19 in neurological diseases has been reported. However, the effect and mechanisms of FGF19 in improving symptoms of POCD remain unknown. This study aimed to identify the role and exploring the underlying mechanisms of FGF19 in POCD. Here, rats were separated into four different groups, including control, sevoflurane (sev), sev + AAV-empty, and sev + AAV-FGF19 group. Then, the Morris water maze (MWM) test was applied to identify the effect of FGF19 on POCD rats. The result proved that FGF19 improved sevoflurane induced cognitive dysfunction in rats. Subsequently, the expressions of TNF-α, IL-6, IL-1β, and IL-10 were detected to verify the anti-neuroinflammatory effects of FGF19 in POCD rats. Furthermore, DHE fluorescent staining assay showed that FGF19 could inhibit sevoflurane-induced oxidative stress in POCD rats. Besides, NISSL staining and TUNEL assay were applied to reveal that FGF19 could alleviate hippocampal neuron injury induced by sevoflurane in rats. Moreover, mechanistic studies confirmed that FGF19 improved symptoms of POCD by mediated PGC-1α/BDNF/FNDC5 pathway. Together, these results suggested that FGF19 improves sevoflurane-induced POCD in rats through the PGC-1α/BDNF/FNDC5 pathway.

ANGPTL2 Deletion Attenuates Neuroinflammation and Cognitive Dysfunction Induced by Isoflurane in Aged Mice through Modulating MAPK Pathway

Postoperative cognitive dysfunction (POCD) is a well-known complication after surgery with cognitive impairments. Angiopoietin-like protein 2 (ANGPTL2) has been found to be associated with inflammation. However, the role of ANGPTL2 in inflammation of POCD is unclear. Here, mice were subjected into isoflurane anesthesia. It was demonstrated that isoflurane increased ANGPTL2 expression and promoted pathological change in brain tissues. However, downregulation of ANGPTL2 alleviated the pathological change and elevated learning and memory abilities, improving isoflurane-induced cognitive dysfunction in mice. In addition, isoflurane-induced cell apoptosis and inflammation were repressed via ANGPTL2 knockdown in mice. Downregulation of ANGPTL2 was also verified to suppress isoflurane-induced microglial activation, evidenced by a decrease of Iba1 and CD86 expressions and an increase of CD206 expression. Further, the isoflurane-induced MAPK signaling pathway was repressed through downregulation of ANGPTL2 in mice. In conclusion, this study proved that downregulation of ANGPTL2 attenuated isoflurane-induced neuroinflammation and cognitive dysfunction in mice via modulating the MAPK pathway, which provided a new therapeutic target for POCD.

Ulinastatin Alleviates Repetitive Ketamine Exposure-Evoked Cognitive Impairment in Adolescent Mice

Ketamine (KET) is widely used for induction and maintenance of anesthesia, and long-term use is required for treatment of depression patients. Repeated use of KET is associated with mood and memory disorders. Ulinastatin (UTI), a urinary trypsin inhibitor, has been widely undertaken as an anti-inflammatory drug and proved to have neuroprotective effects. The aim of this work was to determine whether prophylactic use of UTI could attenuate KET-induced cognitive impairment. It was found that repetitive KET anesthesia cause cognitive and emotional disorders in adolescent mice in WMZ and OFT test, while UTI pretreatment reversed the poor performance compared to the AK group, and the platform finding time and center crossing time were obviously short in the CK+UTI group (P < 0.05). Our ELISA experiment results discovered that UTI pretreatment reduced the expression levels of IL-1β and IL-6 induced by CK anesthesia compared to AK (P < 0.05). In addition, UTI pretreatment protected the cognitive function by restraining the expression levels of Tau protein, Tau phospho-396 protein, and Aβ protein in the CK group compared to the AK group in Western blotting (P < 0.05). The results suggested that UTI could act as a new strategy to prevent the neurotoxicity of KET, revealing a significant neuroprotective effect of UTI.

Targeting neuroinflammation as a preventive and therapeutic approach for perioperative neurocognitive disorders

Perioperative neurocognitive disorders (PND) is a common postoperative complication associated with regional or general anesthesia and surgery. Growing evidence in both patient and animal models of PND suggested that neuroinflammation plays a critical role in the development and progression of this problem, therefore, mounting efforts have been made to develop novel therapeutic approaches for PND by targeting specific factors or steps alongside the neuroinflammation. Multiple studies have shown that perioperative anti-neuroinflammatory strategies via administering pharmacologic agents or performing nonpharmacologic approaches exert benefits in the prevention and management of PND, although more clinical evidence is urgently needed to testify or confirm these results. Furthermore, long-term effects and outcomes with respect to cognitive functions and side effects are needed to be observed. In this review, we discuss recent preclinical and clinical studies published within a decade as potential preventive and therapeutic approaches targeting neuroinflammation for PND.

Protective effects of chlorogenic acid on isoflurane-induced cognitive impairment of aged mice

Postoperative cognitive dysfunction (POCD) is characterized by impairment in cognitive functions in patients following anesthesia and surgery. Chlorogenic acid (CGA) is a plant-derived compound possessing numerous bioactive properties. The aim of this study was to investigate the therapeutic potential of CGA in isoflurane (ISO)-induced cognitive dysfunction of aged mice, and further identify the mechanisms involved in the protective effects of CGA. A total of 80 male C57BL/6 mice, 20-month-old, were randomly divided into control group, isoflurane group (ISO), and ISO + 30 mg/kg CGA group and ISO + 60 mg/kg CGA. CGA was given orally once daily for 7 days to the mice and they were exposed to ISO (1.5%; 4 h). The open-field and Morris water maze tests were used to investigate the cognitive function of mice. Pretreatment with CGA significantly attenuated ISO-induced cognitive impairment. The levels of IL-1β, TNF-α, IL-6, nuclear p65 NF-kB, cleaved caspase-3, and Bax were significantly increased, while the levels of IkBα and Bcl-2 were decreased in the hippocampus 24 h after the ISO anesthesia. All the mentioned effects induced by ISO were reversed by CGA pretreatment. Furthermore, ISO exposure induced marked downregulation of SOD, CAT, HO-1, and NQO-1 and elevation of MDA and nuclear translocation of Nrf2 in the hippocampus tissue. All these parameters were reversed by CGA treatment. Importantly, the higher dose of CGA (60 mg/kg) showed a greater neuroprotective effect. In conclusion, these findings suggest that CGA attenuates the ISO-induced cognitive impairment via its anti-inflammatory, anti-oxidative, and anti-apoptotic properties in aged mice.

Sevoflurane-Induced Neurotoxicity in the Developing Hippocampus via HIPK2/AKT/mTOR Signaling

Sevoflurane (Sev) is a widely used inhalational anesthetic for general anesthesia in children. Previous studies have confirmed that multiple exposures to inhaled anesthetic can induce long-term neurotoxicity in newborn mice. However, the underlying mechanisms remain elusive. In this study, we investigated the role of homeodomain interacting protein kinase 2 (HIPK2), a stress activating kinase involved in neural survival and synaptic plasticity, and its underlying mechanism in sevoflurane-induced neurotoxicity. Empirical study showed that neuronal apoptosis was elevated after exposure to sevoflurane. Meanwhile, up-regulation of HIPK2 and AKT/mTOR signaling was observed in primary hippocampal neurons and hippocampus in mice upon anesthetic exposure. A64, antagonist of HIPK2, could significantly reduce increased apoptosis and activation of AKT/mTOR induced by sevoflurane. AKT antagonist MK2206 partially alleviated neuronal apoptosis without affecting the expression of HIPK2. Experimental results demonstrated a crucial role of HIPK2/AKT/mTOR signaling in neurotoxicity of sevoflurane. Thus, HIPK2/AKT/mTOR signaling can serve as a potential target for the protection of inhalation anesthesia-induced cytotoxicity in the future.

Salubrious effects of ulinastatin and quercetin alone or in combination in endothelial dysfunction and vascular dementia

BACKGROUND

Vascular dementia is the second most prevalent form of dementia. Hypertension is the leading risk factor for endothelial dysfunction and the progression of dementia that is of vascular origin. This study investigates the role of ulinastatin (UTI) and quercetin alone as well as in combination in hypertension-induced endothelial dysfunction and vascular dementia (VaD).

METHOD

Two-kidney one-clip (2K1C) renovascular model was set up to induce hypertension in the Albino Wistar rats (males). Rats were assessed for mean arterial blood pressure, behavioral function (Morris water maze, attention set-shifting tests), vascular endothelial function, and biochemical levels (aortic superoxide anion and serum nitrite/nitrate), as well as brains' thiobarbituric acid reactive species-TBARS, reduced glutathione-GSH, interleukin-6, 10, tumor necrosis factor-TNF-α and acetylcholinesterase-AChE). UTI (10,000 U/kg, ip) and quercetin (60 mg/kg) were used alone and in combination for treatment. Donepezil (0.5 mg/kg) was used as a positive control.

RESULTS

2K1C rats showed impairment in learning, memory, executive functioning, and reversal learning. These rats further showed endothelial dysfunction as well as an increase in mean arterial blood pressure, brains' oxidative stress, inflammation, and AChE-activity. Treatment with UTI and quercetin alone as well in combination significantly attenuated the 2K1C model induced impairments in the behavioural, biochemical, and endothelial parameters.

CONCLUSION

2K1C renovascular hypertension-induced impairment in behavioural, biochemical, and endothelial parameters were attenuated by the treatment with UTI and quercetin alone as well as in combination. Therefore, the utility of these agents might be studied further to understand their full potential in hypertension-induced VaD.

Neuroprotective effect of AGGF1 against isoflurane-induced cognitive dysfunction in aged rats through activating the PI3K/AKT signaling pathways

PURPOSE

This study aimed to evaluate and identify the value and explore the mechanisms of Angiogenic Factor with G-patch and FHA domains 1 (AGGF1) in postoperative cognitive dysfunction (POCD).

METHODS

Rats were separated into four different groups, namely sham, isoflurane, isoflurane + recombinant human Aggf1 (rh-Aggf1) (5 μg kg-1), and isoflurane + rh-Aggf1 (10 μg kg-1). qPCR and western blot assays were applied to detect the correlation between the expression of AGGF1 and isoflurane administration. Then, the Morris water maze (MWM) test was applied to evaluate the effect of AGGF1 on improving the POCD rats. Subsequently, TUNEL assay was applied and the cell apoptosis-related proteins were tested to reveal the anti-apoptotic effect of AGGF1 in POCD rats. Furthermore, the mRNA and protein levels of TNF-α, IL-6, and IL-1β were also detected by qPCR and ELISA to verify the anti-inflammatory effects of AGGF1 on POCD rats. Besides, the protein expression levels of PI3K, Akt, and NF-κB in each group were examined by western blot.

RESULTS

In this study, the results revealed that isoflurane induced a decrease in AGGF1 expression in the hippocampus of aged rats. In addition, exogenous AGGF1 attenuated POCD in aged rats. Meanwhile, exogenous AGGF1 had anti-apoptotic and anti-inflammatory effects in POCD rats. Further research indicated that AGGF1 activated the PI3K/Akt pathway.

CONCLUSION

AGGF1 has neuroprotective effect against isoflurane-induced cognitive dysfunction in aged rats via activating the PI3K/AKT signaling pathways.

Effect of Ulinastatin Combined with Xingnaojing Injection on Severe Traumatic Craniocerebral Injury and Its Influence on Oxidative Stress Response and Inflammatory Response

Objective

This study is aimed at exploring the effect of ulinastatin combined with Xingnaojing injection on severe traumatic craniocerebral injury and its influence on oxidative stress response and inflammatory response in patients.

Methods

A total of 100 patients with severe traumatic craniocerebral injury admitted to our hospital from January 2018 to January 2020 were selected and equally assigned into a study group (50 cases) and a control group (50 cases) according to a random sampling method. Patients in study group received treatment of ulinastatin combined with Xingnaojing injection, while those in control group were treated with ulinastatin only. The study compared the two groups on the oxidative stress response, inflammatory response, the therapeutic effect, and the incidence rate of adverse reactions.

Results

It is observed that patients in study group obtained lower levels of free cortisol (FC) and norepinephrine (NE) in the serum and higher level of total thyroxine (TT4) after treatment compared with those in control group with significant difference (P < 0.05); in the meantime, they were examined to have significantly fewer oxidative stress response products, lower serum inflammatory factor level, and serum indicator levels of craniocerebral injury as opposed to those in control group, suggesting significant differences (P < 0.05); study group demonstrated higher treatment response rate and lower incidence rate of adverse reactions compared with control group with a significant difference (P < 0.05).

Conclusion

The study found that ulinastatin combined with Xingnaojing infection has a significant effect in the treatment of severe traumatic craniocerebral injury, which can reduce the degree of craniocerebral injury and the level of inflammatory factors in the serum of patients. It is worthy of being promoted and applied clinically.

Overexpression of miR-133b protects against isoflurane-induced learning and memory impairment

A number of microRNAs (miRs) have been identified as being involved in the regulation of anesthesia-induced cognitive impairment. The aim of the present study was to investigated the role and potential mechanism of miR-133b in isoflurane-induced learning and memory impairment. An animal model of isoflurane exposure was established using neonatal Sprague-Dawley rats. The rats were trained for Morris water maze (MWM) testing to assess their spatial learning and memory ability. Reverse transcription-quantitative polymerase chain reaction was used for the measurement of miR-133b expression in hippocampal tissues and primary hippocampal neuron cultures. Cell viability was assessed using a Cell Counting Kit-8 assay, and flow cytometric analysis was used to determine the rate of apoptosis. The MWM test results indicated that during the training period, the time required to locate the platform was significantly increased for rats exposed to isoflurane, and this increased time was reduced by the overexpression of miR-133b. The results of a probe trial indicated that isoflurane exposure increased escape latency and decreased the time spent in the platform area for isoflurane-treated rats; however, these effects were reversed by the injection of miR-133b agomir. The in vitro experiments demonstrated that the overexpression of miR-133b attenuated the reduction of neuronal cell viability induced by isoflurane, and inhibited the isoflurane-induced apoptosis of hippocampal neurons. In conclusion, the present study revealed that the overexpression of miR-133b attenuated isoflurane-induced learning and memory impairment in rats. Furthermore, miR-133b overexpression promoted the viability of hippocampal neurons and their resistance to apoptosis when exposed to isoflurane.

Efficacy of Ulinastatin and Sulforaphane Alone or in Combination in Rat Model of Streptozotocin Diabetes Induced Vascular Dementia

Objective

Vascular Dementia (VaD), is associated with metabolic conditions. Diabetes is a major risk factor for the development of VaD. This study investigates the efficacy of ulinastatin (UTI) and sulforaphane (SUL) in streptozotocin (STZ)-diabetes induced vascular endothelium dysfunction and related dementia.

Methods

Single dose STZ (50 mg/kg i.p.) was administered to Albino Wistar rats (male, 200−250 g). Morris water maze and attentional set shifting tests were used to assess the spatial learning, memory, reversal learning, and executive functioning in animals. Body weight, serum glucose, serum nitrite/nitrate, vascular endothelial function, aortic superoxide anion, brains’ oxidative markers (thiobarbituric acid reactive species-TBARS, reduced glutathione-GSH, superoxide dismutase-SOD, and catalase-CAT), inflammatory markers (IL-6, IL-10, TNF-a, and myeloperoxidase-MPO), acetylcholinesterase activity-AChE, blood brain barrier (BBB) permeability and histopathological changes were also assessed. UTI (10,000 U/kg) and SUL (25 mg/kg) were used alone as well as in combination, as the treatment drugs. Donepezil (0.5 mg/kg) was used as a positive control.

Results

STZ-administered rats showed reduction in body weight, learning, memory, reversal learning, executive functioning, impairment in endothelial function, BBB permeability, increase in serum glucose, brains’ oxidative stress, inflammation, AChE-activity, BBB permeability and histopathological changes. Administration of UTI and SUL alone as well as in combination, significantly and dose dependently attenuated the STZ-diabetes-induced impairments in the behavioral, endothelial, and biochemical parameters.

Conclusion

STZ administration caused diabetes and VaD which was attenuated by the administration of UTI and SUL. Therefore, these agents may be studied further for the assessment of their full potential in diabetes induced VaD.

Intranasal levosimendan prevents cognitive dysfunction and apoptotic response induced by repeated isoflurane exposure in newborn rats

Anesthetic-induced toxicity in early life may lead to risk of cognitive decline at later ages. Notably, multiple exposures to isoflurane (ISO) cause acute apoptotic cell death in the developing brain and long-term cognitive dysfunction. This study is the first to investigate whether levosimendan (LVS), known for its protective myocardial properties, can prevent anesthesia-induced apoptotic response in brain cells and learning and memory impairment. Postnatal day (P)7 Wistar albino pups were randomly assigned to groups consisting of an equal number of males and females in this laboratory investigation. We treated rats with LVS (0.8 mg/kg/day) intranasally 30 min before each ISO exposure (1.5%, 3 h) at P7+9+11. We selected DMSO as the drug vehicle. Also, the control group at P7+9+11 received 50% O2 for 3 h instead of ISO. Neuroprotective activity of LVS against ISO-induced cognitive dysfunction was evaluated by Morris water maze. Expression of apoptotic-related proteins was detected in the whole brain using western blot. LVS pretreatment significantly prevented anesthesia-induced deficit in spatial learning (at P28-32) and memory (at P33, P60, and P90). No sex-dependent difference occurred on any day of the training and probe trial. Intranasal LVS was also found to significantly prevent the ISO-induced apoptosis by reducing Bax and cleaved caspase-3, and by increasing Bcl-2 and Bcl-xL. Our findings support pretreatment with intranasal LVS application as a simple strategy in daily clinical practice in pediatric anesthesia to protect infants and children from the risk of general anesthesia-induced cell death and cognitive declines.

Tetramethylpyrazine ameliorates isoflurane-induced cognitive dysfunction by inhibiting neuroinflammation via miR-150 in rats

Tetramethylpyrazine (TMP) has neuroprotective effects in the pathogenesis of some human diseases, such as Parkinson's disease. The present study aimed to investigate the role of TMP in isoflurane-induced cognitive dysfunction in rats, and further identify the mechanisms involved in the protective effects of TMP. The Morris water maze test was used to evaluate the cognitive function of rats exposed to isoflurane or treated with TMP. ELISA was conducted to evaluate the effects of isoflurane or TMP on neuroinflammation. The expression of microRNA-150 (miR-150) was measured using reverse transcription-quantitative PCR, and the potential target genes of miR-150 were predicted and verified. The impaired cognitive function induced by isoflurane in the rats was significantly ameliorated by treatment with TMP. In addition, TMP treatment in rats attenuated neuroinflammation caused by isoflurane. The expression of miR-150 was inhibited by isoflurane exposure, but was enhanced by TMP treatment in rats. Furthermore, the overexpression of miR-150 alleviated the isoflurane-induced cognitive dysfunction and neuroinflammation, while the neuroprotective effects of TMP were significantly abrogated by the knockdown of miR-150. AKT3 was a direct target of miR-150, and its mRNA expression was significantly decreased by the overexpression of miR-150 in isoflurane- and TMP-treated rats. These results demonstrated the protective effects of TMP against isoflurane-induced cognitive dysfunction, which were achieved by attenuating neuroinflammation via the regulation of the miR-150/AKT3 pathway. In addition, miR-150 may serve as a novel therapeutic target for the alleviation of cognitive dysfunction induced by anesthetics.