Biomedical subjects

Mei Sun

Publications and source records attributed to Mei Sun.

At least 19 recordsLinked to original sources

PubMed2026

Effectiveness and implementation of task-sharing cognitive-behavioral interventions for perinatal mental health: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the effectiveness of cognitive-behavioral interventions (CBIs) delivered by nonspecialist providers (NSPs) on perinatal depressive (PND) and anxiety symptoms, and to narratively synthesize their implementation processes and reported implementation outcomes, including acceptability, feasibility, fidelity, cost, and sustainability. METHODS: We systematically searched eight databases from inception to April 8, 2025. Eligible studies were randomised controlled trials (RCTs) assessing CBIs delivered by NSPs for PND and/or anxiety. Two reviewers independently screened, extracted, and assessed trials. Meta-analyses employed random-effects models, with subgroup, sensitivity, meta-regression, and publication bias analyses conducted in Stata 18.0. Implementation processes and outcomes were reported as frequencies or percentages across trials. RESULTS: A total of 47 trials (11, 357 participants) were included in the systematic review, of which 37 trials (8,709 participants) were included for meta-analyses. CBIs were conducted in 12 countries. Nurses and midwives delivered 45% of CBIs. CBIs were associated with reduced PND post-intervention compared with control conditions (standardized mean difference [SMD] -0.49, 95% CI -0.63 to -0.35; I² = 86.8%). Limited evidence from four trials suggested a small sustained effect at 12 months (SMD -0.14, 95% CI -0.27 to -0.02; I² = 26.4%). Reductions in anxiety symptoms were observed immediately post-intervention (SMD, -0.45, 95% CI -0.65 to -0.25; I²=81%), but evidence for longer-term effects was limited. Subgroup analyses confirmed consistent effects across diverse settings, populations, and intervention characteristics. Reporting of implementation processes (e.g., training, supervision, fidelity) was limited, with only 23.4% of trials assessing fidelity and 10.6% evaluating costs. CONCLUSIONS: NSP-delivered CBIs showed beneficial effects on PND and anxiety, with generally encouraging evidence for acceptability and feasibility. However, evidence for sustained effects beyond the immediate post-intervention period remains limited. Future studies should strengthen long-term follow-up and improve reporting of implementation processes and outcomes, particularly in rural and adolescent perinatal populations, to inform scalable and equitable task-sharing models.

Humans↗

PubMed2026

Assessing perinatal depression identifying abilities among maternal and child health workers in rural China using smartphone-based virtual patients: a multi-center cross-sectional study.

OBJECTIVE: To assess rural maternal and child health (MCH) workers' virtual patients (VPs)-assessed performance in identifying perinatal depression (PND) using smartphone-based VPs, and to identify factors associated with this performance in rural Hunan, China. METHODS: A multicentre cross-sectional study was conducted in Hunan Province, China. A standardized questionnaire collected demographic and work-related characteristics of rural MCH workers. Smartphone-based VPs were used to assess PND identification performance in a simulated clinical scenario. An overall score ≥60 was used as a prespecified operational benchmark across consultation, ancillary assessment, diagnosis, management, and health education domains. Data were analyzed using SPSS 26.0. RESULTS: A total of 375 rural MCH workers participated, yielding an effective response rate of 90.4%. Only 25.9% met the prespecified operational benchmark for VP-assessed PND identification performance. The mean accuracy scores for consultation, ancillary assessment, diagnosis, management, and health education were 94%, 48%, 64%, 58%, and 74%, respectively. Complete consultation accuracy was higher among MCH workers from township health centers than among those from county-level MCH hospitals. MCH workers aged 18-39 years showed higher odds of complete diagnostic accuracy for PND than those aged ≥40 years. CONCLUSIONS: Smartphone-based VP assessment was feasible in rural MCH settings and revealed suboptimal PND identification performance. Mobile VPs may help identify frontline performance gaps and inform targeted training, but further validation against real-world clinical performance, or standardized patient encounters is needed before large-scale implementation. These findings may support targeted capacity-building for rural MCH workers and more equitable perinatal mental health care.

Humans↗

PubMed2006

Isolation of an enhancer from the rat tyrosine hydroxylase promoter that supports long-term, neuronal-specific expression from a neurofilament promoter, in a helper virus-free HSV-1 vector system.

Direct gene transfer into neurons, using a virus vector, has been used to study neuronal physiology and learning, and has potential for supporting gene therapy treatments for specific neurological diseases. Many of these applications require high-level, long-term recombinant gene expression, in forebrain neurons. We previously showed that addition of upstream sequences from the rat tyrosine hydroxylase (TH) promoter to a neurofilament heavy gene (NF-H) promoter supports long-term expression in forebrain neurons, from helper virus-free Herpes Simplex Virus (HSV-1) vectors. This element in the TH promoter satisfied the definition of an enhancer; it displayed activity at a distance from the basal promoter, and in both orientations. This enhancer supported physiological studies that required long-term expression; a modified neurofilament promoter, containing an insulator upstream of the TH-NFH promoter, supported expression in approximately 11,400 striatal neurons at 6 months after gene transfer, and expression for 7, 8, or 14 months, the longest times tested. In contrast, the NF-H promoter alone does not support long-term expression, indicating that the critical sequences are in the 6.3 kb fragment of the TH promoter. In this study, we performed a deletion analysis to identify the critical sequences in the TH promoter that support long-term expression. We localized these critical sequences to an approximately 320 bp fragment, and two subfragments of approximately 100 bp each. Vectors that contained each of these small fragments supported levels of long-term, neuronal-specific expression that were similar to the levels supported by a vector that contained the initial 6.3 kb fragment of the TH promoter. These small fragments of the TH promoter may benefit construction of vectors for physiological studies, and may support studies on the mechanism by which this enhancer supports long-term expression.

Animals↗

PubMed2006

Effects of ceramide-1-phosphate on cultured cells: dependence on dodecane in the vehicle.

Ceramide-1-phosphate (C1P), the product of ceramide kinase, is a sphingophospholipid with recently recognized signaling properties. In particular, it was reported to be mitogenic and capable of direct stimulation of cytosolic phospholipase A(2alpha). Much of the present knowledge has relied on the use of C1P of various acyl chain lengths, together with diverse protocols to deliver it to cultured cells. A mixture of ethanol (or methanol) with dodecane, as the vehicle, has become popular. However, the contribution of this solvent to the observed effects of C1P has not been documented. Here, we show that addition of C1P in ethanol-dodecane to culture medium leads to irreversible cytotoxic effects. These culminate in mitochondrial swelling, vacuole formation, and cell death. Not only the toxicity of C1P, but also its ability to trigger prostaglandin E2 release, is fully dependent upon addition of a premade C1P-dodecane mixture. Furthermore, we show that these effects are not restricted to C1P. They result from the capacity of dodecane to interact with phospholipids; hence, they go undetected with a vehicle control. This study should raise awareness about the use of dodecane for phospholipid delivery and, in turn, help in unraveling C1P signaling, which is still poorly understood.

Alkanes↗

PubMed2006

Rapid identification of betacyanins from Amaranthus tricolor, Gomphrena globosa, and Hylocereus polyrhizus by matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight mass spectrometry (MALDI-QIT-TOF MS).

Natural betacyanins have attracted great attention as food colorants and potential antioxidants. Matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight mass spectrometry (MALDI-QIT-TOF MS) is a new and powerful technique for the identification of low molecular weight compounds. This study is the first to employ MALDI-QIT-TOF MS to rapidly identify, within a few minutes, a great number of betacyanins in crude extracts from Amaranthus tricolor seedlings, Gomphrena globosa flowers, and Hylocereus polyrhizus fruits. The fresh crude extract samples without any purification were directly used for MALDI-QIT-TOF MS analysis with 2,5-dihydroxybenzoic acid as a matrix. The MS2 and MS3 spectrometric data acquired could provide important characteristic information for structural elucidation of the betacyanins. Fourteen free and acylated betacyanins, belonging to amaranthin-type, betanin-type, and gomphrenin-type betacyanins, respectively, were identified. However, the related isomers should be differentiated with the aid of HPLC.

Amaranthaceae↗

PubMed2006

Lysosomal exocytosis is impaired in mucolipidosis type IV.

Mucolipidosis type IV (MLIV) is an autosomal recessive disease characterized by severe neurological impairment, ophthalmologic defects, and gastric dysfunction. MLIV cells have a deficiency in the late endosomal/lysosomal (LEL) pathway that results in the buildup of lysosomal inclusions. Using a Xenopus oocyte expression system, we previously showed that mucolipin-1 (MLN1), the protein encoded by the MCOLN1 gene is a Ca2+ -permeable non-selective cation channel that is transiently modulated by elevations in intracellular Ca2+. We further showed that MLN1 is translocated to the plasma membrane during lysosomal exocytosis. In this study we show that lysosomal exocytosis is impaired in fibroblasts from MLIV patients, indicating that MLN1 plays an active role in this process. Further, we show that transfection with wild type MLN1 cDNA rescues exocytosis, suggesting the possibility of treatments based on the restoration of this crucial cellular function.

Animals↗

PubMed2006

Long-term inducible expression in striatal neurons from helper virus-free HSV-1 vectors that contain the tetracycline-inducible promoter system.

Direct gene transfer into neurons in the brain via a virus vector system has potential for both examining neuronal physiology and for developing gene therapy treatments for neurological diseases. Many of these applications require precise control of the levels of recombinant gene expression. The preferred method for controlling the levels of expression is by use of an inducible promoter system, and the tetracycline (tet)-inducible promoter system is the preferred system. Helper virus-free Herpes Simplex Virus (HSV-1) vectors have a number of the advantages, including their large size and efficient gene transfer. Also, we have reported long-term (14 months) expression from HSV-1 vectors that contain a modified neurofilament heavy gene promoter. A number of studies have reported short-term, inducible expression from helper virus-containing HSV-1 vector systems. However, long-term, inducible expression has not been reported using HSV-1 vectors. The goal of this study was to obtain long-term, inducible expression from helper virus-free HSV-1 vectors. We examined two different vector designs for adapting the tet promoter system to HSV-1 vectors. One design was an autoregulatory design; one transcription unit used a tet-regulated promoter to express the tet-regulated transcription factor tet-off, and another transcription unit used a tet-regulated promoter to express the Lac Z gene. In the other vector design, one transcription unit used the modified neurofilament heavy gene promoter to express tet-off, and another transcription unit used a tet-regulated promoter to express the Lac Z gene. The results showed that both vector designs supported inducible expression in cultured fibroblast or neuronal cell lines and for a short time (4 days) in the rat striatum. Of note, only the vector design that used the modified neurofilament promoter to express tet-off supported long-term (2 months) inducible expression in striatal neurons.

Animals↗

PubMed2006

Infection of human cancer cells with myxoma virus requires Akt activation via interaction with a viral ankyrin-repeat host range factor.

We demonstrate that the susceptibility of human cancer cells to be infected and killed by an oncolytic poxvirus, myxoma virus (MV), is related to the basal level of endogenous phosphorylated Akt. We further demonstrate that nonpermissive tumor cells will switch from resistant to susceptible for MV infection after expression of ectopically active Akt (Myr-Akt) and that permissive cancer cells can be rendered nonpermissive by blocking Akt activation with a dominant-negative inhibitor of Akt. Finally, the activation of Akt by MV involves the formation of a complex between the viral host range ankyrin-repeat protein, M-T5, and Akt. We conclude that the Akt pathway is a key restriction determinant for permissiveness of human cancer cells by MV.

Animals↗

PubMed2006

Stem cell factor receptor induces progenitor and natural killer cell-mediated cardiac survival and repair after myocardial infarction.

Inappropriate cardiac remodeling and repair after myocardial infarction (MI) predisposes to heart failure. Studies have reported on the potential for lineage negative, steel factor positive (c-kit+) bone marrow-derived hematopoetic stem/progenitor cells (HSPCs) to repair damaged myocardium through neovascularization and myogenesis. However, the precise contribution of the c-kit signaling pathway to the cardiac repair process has yet to be determined. In this study, we sought to directly elucidate the mechanistic contributions of c-kit+ bone marrow-derived hematopoetic stem/progenitor cells in the maintenance and repair of damaged myocardium after MI. Using c-kit-deficient mice, we demonstrate the importance of c-kit signaling in preventing ventricular dilation and hypertrophy, and the maintenance of cardiac function after MI in c-kit-deficient mice. Furthermore, we show phenotypic rescue of cardiac repair after MI of c-kit-deficient mice by bone marrow transplantation of wild-type HSPCs. The transplanted group also had reduced apoptosis and collagen deposition, along with an increase in neovascularization. To better understand the mechanisms underlying this phenotypic rescue, we investigated the gene expression pattern within the infarcted region by using microarray analysis. This analysis suggested activation of inflammatory pathways, specifically natural killer (NK) cell-mediated mobilization after MI in rescued hearts. This finding was confirmed by immunohistology and by using an NK blocker. Thus, our investigation revealed a previously uncharacterized role for c-kit signaling after infarction by mediating bone marrow-derived NK and angiogenic cell mobilization, which contributes to improved remodeling and cardiac function after MI.

Animals↗

PubMed2006

Influence of heterozygosity for parkin mutation on onset age in familial Parkinson disease: the GenePD study.

BACKGROUND: The PARK2 gene at 6q26 encodes parkin, whose inactivation is implicated in an early-onset autosomal recessive form of Parkinson disease (PD). OBJECTIVE: To evaluate the influence of heterozygosity for parkin mutation on onset age in a sample of families with at least 2 PD-affected members. DESIGN: Clinical and genetic study. SETTING: Twenty collaborative clinical sites. PATIENTS: Patients with familial PD collected in the GenePD study. Studied families were selected for (1) affected sibling pairs sharing 2 alleles identical by state at PARK2 (D6S305) or (2) 1 or more family members with onset age younger than 54 years, regardless of D6S305 status. At least 1 member from each of 183 families underwent comprehensive screening for deletion/insertion variants and point mutations in PARK2. MAIN OUTCOME MEASURES: Mutations in the parkin gene were screened by means of single-stranded conformation polymorphism and sequencing in all 12 coding exons and flanking intronic sequences for point mutations and duplex quantitative polymerase chain reaction in all exons for rearrangement, duplication, and deletion. RESULTS: Mutations were found in 23 families (12.6% of those screened). Among the mutation-positive families, 10 (43%) contained compound heterozygotes; 3 (13%), homozygotes; and 10 (43%), heterozygotes. The onset age in patients with parkin gene mutations ranged from 20 to 76 years. Patients with 1 parkin mutation had an 11.7-year age at onset than did patients with none (P = .04), and patients with 2 or more parkin mutations had a 13.2-year decrease in age at onset compared with patients with 1 mutation (P = .04). CONCLUSIONS: These data indicate that parkin mutations are not rare in multiply affected sibships, and that heterozygous mutation carrier status in PARK2 significantly influences age at onset of PD.

Adult↗

PubMed2006

Matrix metalloproteinases in cardiovascular disease.

Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that are regulated by inflammatory signals to mediate changes in extracellular matrix. Members of the MMP family share sequence homology, act on interstitial protein substrates, acutely participate in inflammatory processes and chronically mediate tissue remodelling. MMPs are important in vascular remodelling, not only in the overall vasculature architecture but also, more importantly, in the advancing atherosclerotic plaque. MMP activation modifies the architecture of the plaque and may directly participate in the process of plaque rupture. MMPs also participate in cardiac remodelling following myocardial infarction and development of dilated cardiomyopathy. Soluble MMPs are now potential biomarkers in delineating cardiovascular risk for plaque rupture and coronary risk. They also constitute innovative direct or indirect targets to modify cardiovascular tissue remodelling in atherosclerosis and heart failure.

Animals↗

PubMed2006

Characterization of frequently deleted 6q locus in prostate cancer.

The long arm of chromosome 6 is frequently deleted in diverse human neoplasms. Our previous study showed a minimum deletion region between markers D6S1056 and D6S300 on chromosome 6q in primary prostate cancer (CaP). In this study, we further refined a 200-kb minimal region of deletion (6qTSG1) centered around D6S1013 marker. The 6qTSG1 transcripts contained complex multiple splicing variants with low or absent expression in CaP cells. None of the transcripts identified contained open reading frames that code for a protein in the NCBI database. The expression of 6qTSG transcripts revealed interesting hormonal regulation relevant to CaP biology. Expression of 6q TSG transcript was induced in LNCaP cells that were cultured in charcoal-stripped serum medium suggesting an upregulation of 6qTSG transcript by androgen ablation and cell growth inhibition/apoptosis. Induction of 6qTSG1 expression in response to androgen ablation was abrogated in androgen-independent derivatives of LNCaP cells. In summary, we have defined a candidate CaP suppressor locus on chromosome 6q16.1, and deletions of this locus are frequently associated with prostate tumorigenesis. In the light of emerging role of noncoding RNAs in cancer biology including CaP, future investigations of 6qTSG11 locus is warranted.

Apoptosis↗

PubMed2006

[Role of platelet activating factor in the injury of intestinal immuno-barrier function in young rats].

OBJECTIVE: Gastrointestinal dysfunction is closely correlated with the destruction of intestinal barrier function induced by serious infection. Platelet activating factor (PAF) may induce intestinal injuries. This study aimed to investigate the effect of PAF on the injury of intestinal mucosal immuno-barrier function in young rats. METHODS: Eighteen-day-old Wistar rats were randomized to lipopolysaccharide (LPS) (5 mg/kg), LPS plus PAF receptor antagonist and normal saline injection (Control). PAF receptor antagonist BN52021 5 mg/kg was administered before or 30 minutes after LPS injection (pretreatment or treatment). The ileum specimens (n=8) were harvested at 1.5, 3, 6, 24, 48 and 72 hrs after LPS injection. Double antibody-PEG radioimmunoassay was used to determine the secretory IgA (sIgA) content in intestinal mucosa. Hematoxylin and erosin staining was used for histological evaluation. The ratio of wet and dry weight (W/D) of ileum tissues was calculated. RESULTS: Intestinal villi edema, capillary congestion, extension of the subepithelial lympho channel, and polymorphonuclear infiltration in enteric cavity were noted in the LPS group at 1.5, 3, 6 and 24 hrs after LPS injection. In the PAF receptor antagonist group only villi edema was found. The W/D ratio in the LPS group was significantly higher than that in the Control group at all time points, but it was slightly reduced by the PAF receptor antagonist pretreatment or treatment. The sIgA content was obviously decreased after 1.5, 3, 6, 24 and 48 hrs of LPS challenge compared with that in the Control group (P < 0.01). It reached to a nadir at 6 hrs (0.15 +/- 0.04 microg/mL). The level of sIgA in the PAF receptor antagonist group was higher than that in the LPS group at each time point. There was no statistical difference in the sIgA level between the PAF receptor pretreatment and treatment groups. CONCLUSIONS: PAF plays roles in the injury of intestinal immuno-barrier function. Preventive and remedial use of PAF receptor antagonist BN52021 may relieve intestinal injury.

Animals↗

PubMed2006

[Study on manpower allocation criteria of center of disease prevention and control in the context of province level, city level and county level].

OBJECTIVE: To set the manpower allocation criteria of center of disease prevention and control. METHODS: Expected allocation manpower criteria was obtained through adjusting the current manpower allocation of disease prevention and control centers. The principle was to fulfill public function and promote professional efficiency. RESULTS: Based on function requirement, in 3 - 5 years, the manpower allocation criteria of center of disease prevention and control at provincial-level is 336 persons, at city-level is 102 persons, and at county-level is 33 persons, that means in whole country 140016 persons should be needed. In 10 years, the manpower allocation criteria of center of disease prevention and control at provincial-level is 386 persons, at city-level is 112 persons, and at county-level is 38 persons, that means in whole country 159086 persons should be needed. CONCLUSION: The manpower allocation criteria advanced in the study indicated that current manpower quantity should be greatly reduced. It is an inevitable trend that disease prevention and control centers reduce the staff quantity and promote their quality.

China↗

PubMed2006

[Study on the function of decoction for invigorating the kidney and improving blood circulation to thrombosis on rabbit blood stasis model].

OBJECTIVE: To evaluate the effect of decoction for invigorating the kidney and improving blood circulation to thrombosis and pathology on rabbit blood stasis model. METHOD: Thirty rabbits were ramdomly divided into normal group, model group, high dose group, low dose group and Xue Shuan Ning group. Tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor (PAI), fibrinogen (Fbg) and D-dimer (DD) were investigated after those rabbits had been treated. One rot was solected randomly from each group to observe pathological changes. RESULT: There were significant differences in t-PA, PAI, Fbg and DD between normal group and other groups is very obvious (P < 0.01) . Between groups of high dose low dose Xue Shuan Ning and model, the statistical differeces were significant, as well as between groups of high dose, low dose and Xue Shuan Ning groups (P < 0.05). However, there was no statistical difference between high dose group and high dose group (P > 0.05). The pathological changes in model group were most serious, those in Xue Shuan Ning were less serious. There were slight pathological changes in high dose group and low dose group. CONCLUSION: Models ware made successfully. High dose group and low dose group have stronger effect on thrombosis than Xue Shuan Ning group.

Animals↗

PubMed2006

[Protective effects of recombinant intestinal trefoil factor against intestinal injuries induced by endotoxin in young rats].

OBJECTIVE: This study aimed to investigate the protective effects of recombinant intestinal trefoil factor (rITF) against intestinal injuries and the possible mechanism by examining the changes of diamine oxidase (DAO) and TNF-alpha and the intestinal ultrastructural changes in lipopolysaccharide (LPS) induced intestinal injuries. METHODS: Ninety-six ten-day-old Wistar rats were randomly injected with either normal saline (1 mL/kg, Control group), LPS (1 mL/kg) or LPS (1 mL/kg) + rITF (0.1 mL) intraperioneally. At 2, 6, 24 and 72 hrs after administration plasma DAO activity was determined using absorption spectrometry; and the intestinal protein and mRNA expression of TNF-alpha were measured using immunohistochemistry and RT-PCR methods. The intestinal ultrastructural changes were observed by electron microscopy. RESULTS: The plasma DAO activity in the LPS group began to increase at 2 hrs, peaked at 6 hrs and remained at significantly higher levels until 72 hrs after administration compared with the Control group (P < 0.01). The plasma DAO activity in the LPS + rITF group decreased noticeably compared with the LPS group at all time points (P < 0.01 or 0.05). A significant difference in the plasma DAO activity was only observed at 6 hrs after administration between the LPS + rITF and the Control group. The expression of TNF-alpha protein in the LPS group significantly increased at each time point, peaking at 6 hrs after LPS administration, with the IODT of TNF-alpha of 37,247.64 +/- 3,387.59 vs 6,191.02 +/- 482.32 (P < 0.01) compared with the Control group. rITF treatment decreased the expression of TNF-alpha protein although it remained significantly higher than in the Control group (P < 0.01). The TNF-alpha mRNA was weakly expressed in the Control group but strikingly increased after LPS injection (P < 0.01). Compared with the LPS group, the TNF-alpha mRNA expression in the LPS + rITF group decreased at all time points (P < 0.01 or 0.05). Vacuole changes of mitochodrium, cell nucleus condense, break and depletion of part of microvilli, and widen and disrupted tight junction were observed in the LPS group. The ultrastructural changes of intestinal tissues were improved in the LPS + rITF group. CONCLUSIONS: rITF can decrease the plasma DAO activity and inhibit the expression of TNF-alpha, resulting in a protective effect against intestinal injuries induced by LPS in young rats.

Amine Oxidase (Copper-Containing)↗

PubMed2006

[Effects of glutamine on matrix metalloproteinase-3 and tissue inhibitor of metalloproteinase-3 expressions in myocardium of rats with sepsis].

OBJECTIVE: The underlying mechanisms for cardiac dysfunction in sepsis include the inhibitory effect of endotoxin and inflammatory factors on myocardium and the decrease in cardiac myocardial cells in number. However, whether there is ventricular remodeling resulted from the abnormalities of extracellular collagen metabolism and whether glutamine (Gln) can protect myocardium from LPS-induced damage as in reperfusion are unknown. The aim of the present study was to examine the effects of Gln on the expressions of matrix metalloproteinase-3 (MMP-3), tissue inhibitor of metalloproteinase-3 (TIMP-3) and their mRNA in myocardium of rats with sepsis. METHODS: Classical rat model of sepsis was established by intraperitoneal injection of lipopolysaccharide (LPS) (4 mg/kg, from Escherichia coli O(55): B(5), Sigma). from 121 Wistar rats aged 18 days were divided into three groups randomly, 0 h control group (normal saline: 1 ml/kg, n = 11), LPS group (LPS: 4 mg/kg, n = 55) and Gln group (LPS: 4 mg/kg and immediately 13.64% glutamine 1 ml/kg, Fresenus, n = 55). Furthermore, LPS and Gln groups were examined at 2 h, 4 h, 6 h, 24 h and 72 h time points (n = 11). On each time point, rats of LPS and Gln groups as well as control group were anesthetized with 1% chloral hydrate injected intraperitoneally at a dosage of 1 ml/kg. Then, rats were sacrificed, and the hearts were isolated. Eight of them were frozen at minus 80 degrees C to measure the expression of TIMP-3 mRNA by using RT-PCR. The expressions of MMP-3 and TIMP-3 were observed with immunohistochemistry and the expression of MMP-3 mRNA was observed by using in situ hybridization. RESULTS: (1) Compared to 0 h, the mRNA expressions of MMP-3 and TIMP-3 in LPS group significantly increased (P < 0.01) with the peak at 6 - 24 h. While, in Gln group, they were significantly higher than those in controls but significantly lower than those in LPS group with the peak at 24 h (P < 0.01). Even at 72 h, they were still higher than those at 0 h (P < 0.05 and P < 0.01). (2) Compared to 0 h, the expressions of MMP-3 and TIMP-3 in LPS group were significantly lower at any other time point with the lowest at 6 h (P < 0.01). In Gln group, these expressions were also significantly lower than those in controls, but significantly higher than those in LPS group with the lowest being postponed to 24 h (P < 0.01). (3) The ultra structure changed obviously. Z line was unclear and the ridge of mitochondrion disappeared. While, in Gln group, the myocardial injury was slight compared to that in LPS group. CONCLUSIONS: MMP-3 mRNA expression was increased and TIMP-3 mRNA expression was depressed in LPS-induced sepsis. Myocardial extracellular matrix was damaged in sepsis. Glutamine might decrease the effects of LPS on MMP-3 and TIMP-3 expressions and postpone the time of myocardial matrix injury.

Animals↗

PubMed2006

[Effect of glutamine on apoptosis of the small intestine in young rats with endotoxemia and its mechanism].

OBJECTIVE: To study the effect of glutamine on intestinal epithelial apoptosis by examining changes regarding Bcl-2 and Bax mRNA expressions in the small intestine of young rats with endotoxemia and to explore the protective mechanism that glutamine may have. METHODS: A total of 120 18-day-old rats were randomly assigned into Endotoxemia, Glutamine-treated and Control groups (n = 40 each). The endotoxemia model was established by intraperitoneal injection of endotoxin (4 mg/kg of O55B5 Escherichia coli lipopolysaccharide). Rats in the Glutamine-treated group were intraperitoneally injected with N (2)-L-alanyl-L-glutamine (2 g/kg) along with endotoxin. Rats in the Control group were intraperitoneally injected with an equal volume of normal saline. The entire ileum was collected at 2, 4, 6, 24, and 72 hrs after injection. Bcl-2 and Bax mRNA expressions were detected by semi-quantities reverse transcriptase chain reaction. RESULTS: Bcl-2 mRNA was not expressed in the Control and the Endotoxemia groups but increased in the Glutamine-treated group at each time point. Bax mRNA expression was weak in the Control group, and significantly increased in the Endotoxemia group at each time point. The Glutamine-treated group showed noticeably reduced Bax mRNA expression at 2 hrs post-injection while other time points were similar to the Control group. The ratio of Bax and Bcl-2 mRNA expression at each time point in the Endotoxemia group was significantly higher than that in the Control group while the Glutamine-treated group demonstrated significantly lower ratio of Bax and Bcl-2 mRNA expression than both. CONCLUSIONS: Glutamine treatment increased Bcl-2 mRNA expression and decreased Bax mRNA expression, as a result, the ratio of Bax and Bcl-2 mRNA expression decreased. The effects of glutamine resulted in a suppression of intestinal epithelial apoptosis and maintained the integrity of the gut barrier structure.

Animals↗