OBJECTIVES: The neurotoxicity of carbon monoxide (CO) to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning (DEACMP). Our previous study found that retinoic acid (RA) can suppress the neurotoxic effects of CO. This study further explores, in vivo and in vitro, the molecular mechanisms by which RA alleviates CO-induced central nervous system damage. METHODS: A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO, and a DEACMP animal model was established in adult Kunming mice. Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Annexin V/propidium iodide (PI) double staining. The transcriptional and protein expression of each gene was detected using real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting. Long noncoding RNA (lncRNA) SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes. In DEACMP mice, SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression. RESULTS: RA at 10 and 20 μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes, downregulation of SNHG15 and LINGO-1, and upregulation of brain-derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (TrkB) (all P<0.05). Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity (all P<0.05). Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels (all P<0.05). Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP (all P<0.05). CONCLUSIONS RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes, thereby reducing central nervous system injury and exerting neuroprotective effects. LncRNA SNHG15 and LINGO-1 are key molecules mediating RA-induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway. These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms.
Animals ; RNA, Long Noncoding/physiology* ; Brain-Derived Neurotrophic Factor/genetics* ; Carbon Monoxide Poisoning/complications* ; Mice ; Tretinoin/pharmacology* ; Nerve Tissue Proteins/metabolism* ; Membrane Proteins/metabolism* ; Apoptosis/drug effects* ; Hippocampus/cytology* ; Receptor, trkB/metabolism* ; Neurons/drug effects* ; Male ; Brain Diseases/etiology* ; Oligodendroglia/drug effects* ; Signal Transduction ; Cell Line

Objective To investigate the influence of sodium bicarbonate Ringer's solution and compound Ringer's solution on patients'acid-base balance and liver and kidney function during controlled low central venous pressure(CLCVP)hepatectomy.Methods A total of 60 patients with primary liver cancer who underwent CLCVP hepatectomy in the Affiliated Cancer Hospital of Zhengzhou University from June 2020 to June 2022 were selected and randomly divided into the sodium bicarbonate Ringer's solution group and compound Ringer's solution group,with 30 patients in each group.Patients in the sodium bicarbonate Ringer's solution group were infused with sodium bicarbonate Ringer's solution,while patients in the compound Ringer's solution group were infused with compound Ringer's solution after anesthesia induction and before liver parenchymal disconnection.The pH value,base excess(BE)and blood lactic acid(Lac)levels were detected using the blood gas analyzer in the two groups before anesthesia induction(T,),at the beginning of surgery(T2),2 h during surgery(T3),4 h during surgery(T4),and at the end of surgery(T5),respectively.The levels of serum alanine aminotransferase(ALT),aspartate aminotransferase(AST),blood urea nitrogen(BUN),and serum creatinine(Scr)were detected using the automatic biochemical analyzer 24 h before and 24 h after surgery,respectively.The body mass,surgical time,intraoperative infusion volume,urine volume,changes in body acid-base balance during surgery,and changes in liver and kidney function before and after surgery between the two groups were compared.Results There was no statistically significant difference in body mass,surgical time,intraoperative infusion volume,and urine volume between the two groups of patients(P＞0.05).At T,,there was no statistically significant difference in pH value,BE and Lac levels between the two groups of patients(P＞0.05).Compared to T,,the pH value in the compound Ringer's solution group increased at T2 and decreased at T3,T4 and T5,while BE and Lac levels from T2 to T5 showed an increasing trend(P＜0.05);compared to T,,the pH value in the sodium bicarbonate Ringer's solution group increased at T2 and decreased at T3,BE and Lac levels increased at T2 and T3(P＜0.05),and there was no statistically significant difference in pH value,BE and Lac levels at T4 and T5 compared to T1(P＞0.05).At T5,the pH value in the sodium bicarbonate Ringer's solution group was significantly higher than that in the compound Ringer's solution group,while the BE and Lac levels were significantly lower than those in the compound Ringer's solution group(P＜0.05).There was no statisti-cally significant difference in the levels of ALT,AST,BUN and Scr 24 hours before surgery between the two groups of patients(P＞0.05);compared to 24 hours before surgery,there was no significant change in the levels of ALT,AST,BUN and Scr 24 hours after surgery(P＞0.05);there was no statistically significant difference in the levels of ALT,AST,BUN and Scr 24 hours after surgery between the two groups(P＞0.05).Conclusion Compared to compound Ringer's solution,sodium bicarbonate Ringer's solution has a smaller impact on the internal environment of the body during the CLCVP hepatectomy and can effectively maintain the stability of the body's acid-base balance.Both the two solutions have no significant impact on the patient's liver and kidney function.

The cold congeal and blood stasis syndrome is a common clinical traditional Chinese medicine（TCM） syndrome. The animal model of cold ongeal and blood stasis syndrome is the basis for exploring the essence of TCM cold congeal and blood stasis syndrome，and the premise of follow-up TCM clinical research.This paper summarized the preparation method， theoretical support，and evaluation method of animal models of cold congeal and blood stasis syndrome in recent years and analysed the strengthens and weaknesses of different models. At present，the common animal models of cold congeal and blood stasis syndrome mainly include etiological model，etiological and pathological composite model and disease-syndrome combination model. The etiological model was mainly prepared by cold exposure，which could be divided into whole-body freezing， ice bath and local frostbite. The etiological and pathological composite model was mainly prepared by cold stimulation combined with epinephrine injection. The common disease-syndrome combination models included the coronary heart disease model of cold congeal and blood stasis syndrome，primary dysmenorrhea model of cold congeal and blood stasis syndrome，endometriosis model of cold congeal and blood stasis syndrome， and arteriosclerosis obliterans model of cold congeal and blood stasis syndrome. The three models have both advantages and disadvantages. Specifically， the disease-syndrome combination model had the highest consistency with clinical practice and was more reliable and practical. However， the disease types of this model were specific，and the combination method of disease and syndrome was controversial. The evaluation indicators of the animal models of cold congeal and blood stasis syndrome focused on the characterization of the syndrome and the physico-chemical indicators related to blood flow，such as blood rheology，coagulation function and microcirculation. In addition， some scholars explored the evaluation indicators from the aspects of vasomotor function，endocrine and energy metabolism. The objectivity and specificity of the current model evaluation methods needed to be further improved. The research of animal model of cold congeal and blood stasis syndrome should be based on clinical practice and oriented by clinical demand. Only by establishing animal models that are highly consistent with the characteristics of clinical disease and syndrome can we better reveal the essence of cold congeal and blood stasis syndrome and promote the modernization of TCM.