MicroRNA-29a promotes apoptosis of monocytes by targeting STAT3 during sepsis

Classic Signaling Pathways in Alveolar Injury and Repair Involved in Sepsis-Induced ALI/ARDS: New Research Progress and Prospect

Sepsis is a common critical clinical disease with high mortality that can cause approximately 10 million deaths worldwide each year. Acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) is a common clinical complication of sepsis, which occurs primarily as diffuse alveolar injury, hypoxemia, and respiratory distress. The mortality rate of ALI/ARDS is as high as 30%-40%, which greatly endangers human health. Due to the unclear pathogenesis of ALI/ARDS, its treatment is still a worldwide problem. At present, clinical treatment mainly relies on lung-protective ventilation, prone position ventilation, and fluid management. However, there is a lack of effective and specific treatment measures. In recent years, domestic and foreign scholars have committed to basic research on ALI/ARDS, trying to further clarify its pathogenesis and find new targets and methods for the treatment of ALI/ARDS. In this review, we summarize the signaling pathways related to alveolar injury and repair in sepsis-induced ALI/ARDS and their latest research progress. They include the NF-κB, JAK2/STAT3, mitogen-activated protein kinase (MAPK), mTOR, and Notch signaling pathways. Understanding the molecular mechanisms of these signaling pathways in sepsis-induced ALI/ARDS may provide new targets and ideas for the clinical treatment of this disease.

Plasma miRNA profile at COVID-19 onset predicts severity status and mortality

BACKGROUND

MicroRNAs (miRNAs) have a crucial role in regulating immune response against infectious diseases, showing changes early in disease onset and before the detection of the pathogen. Thus, we aimed to analyze the plasma miRNA profile at COVID-19 onset to identify miRNAs as early prognostic biomarkers of severity and survival.

METHODS AND RESULTS

Plasma miRNome of 96 COVID-19 patients that developed asymptomatic/mild, moderate and severe disease was sequenced together with a group of healthy controls. Plasma immune-related biomarkers were also assessed. COVID-19 patients showed 200 significant differentially expressed (SDE) miRNAs concerning healthy controls, with upregulated putative targets of SARS-CoV-2, and inflammatory miRNAs. Among COVID-19 patients, 75 SDE miRNAs were observed in asymptomatic/mild compared to symptomatic patients, which were involved in platelet aggregation and cytokine pathways, among others. Moreover, 137 SDE miRNAs were identified between severe and moderate patients, where miRNAs targeting the SARS CoV-2 genome were the most strongly disrupted. Finally, we constructed a mortality predictive risk score (miRNA-MRS) with ten miRNAs. Patients with higher values had a higher risk of 90-days mortality (hazard ratio=4.60; p-value<0.001). Besides, the discriminant power of miRNA-MRS was significantly higher than the observed for age and gender (AUROC=0.970 vs. 0.881; p=0.042).

CONCLUSIONS

SARS-CoV-2 infection deeply disturbs the plasma miRNome from an early stage of COVID-19, making miRNAs highly valuable as early predictors of severity and mortality.

microRNA-193-3p attenuates myocardial injury of mice with sepsis via STAT3/HMGB1 axis

Objective

Little is known regarding the functional role of microRNA-193-3p (miR-193-3p) in sepsis. Hence, the aim of the present study was to investigate the effect of miR-193-3p on myocardial injury in mice with sepsis and its mechanism through the regulation of signal transducers and activators of transcription 3 (STAT3).

Methods

The mice model of sepsis was established by cecal ligation and puncture (CLP), septic mice were injected with miR-193-3p agomir, miR-193-3p antagomir or siRNA-STAT3. The expression of miR-193-3p, STAT3 and HMGB1 in the myocardial tissue of septic mice were detected. Cardiac ultrasound, hemodynamics, myocardial injury markers, inflammatory factors and cardiomyocyte apoptosis in septic mice were measured.

Results

MiR-193-3p expression was reduced while STAT3 expression was increased in septic mice. Down-regulated STAT3 or up-regulated miR-193-3p improved cardiac function, attenuated myocardial injury, inflammation and cardiomyocyte apoptosis in septic mice. Knockdown STAT3 reversed the role of inhibited miR-193-3p for mice with sepsis. miR-193-3p targeted STAT3, thereby inhibiting HMGB1 expression.

Conclusion

This study provides evidence that miR-193-3p targets STAT3 expression to reduce HMGB1 expression, thereby reducing septic myocardial damage. MiR-193-3p might be a potential candidate marker and therapeutic target for sepsis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03022-x.

17β-Estradiol Attenuates LPS-Induced Macrophage Inflammation In Vitro and Sepsis-Induced Vascular Inflammation In Vivo by Upregulating miR-29a-5p Expression

Excessive release of cytokines such as IL-1β and other inflammatory mediators synthesized and secreted by macrophages is the fundamental link of uncontrolled inflammatory response in sepsis. 17β-Estradiol (E2) plays anti-inflammatory and vascular protective effects by regulating leukocyte infiltration and the expression of chemokines or cytokines induced by injury. However, the role of E2 in the inflammatory response of macrophages in sepsis and its mechanism are still not fully understood. In the present study, we show that E2 alleviates vascular inflammation in sepsis mice induced by cecal ligation puncture (CLP). E2 significantly decreases RAW 264.7 cell inflammation response by downregulating the expression of NLRP3. Furthermore, we found that miR-29a-5p was significantly downregulated in LPS-treated macrophages. Treating RAW 264.7 cells with E2 markedly upregulated the miR-29a-5p expression level. More importantly, we demonstrated that miR-29a-5p repressed NLRP3 expression by directly targeting its 3′-UTR. Loss- and gain-of-function experiments revealed that transfection of the miR-29a-5p mimic abrogates LPS-induced macrophage inflammation. Moreover, depletion of miR-29a-5p by its inhibitor largely promotes LPS-induced macrophage inflammation. In summary, miR-29a-5p upregulation induced by E2 alleviated RAW 264.7 cell inflammation response by aggravating miR-29a-5p repression of NLRP3 expression. E2 exerts significant anti-inflammatory efficacy in macrophages by regulating the miR-29a-5p/NLRP3 axis. Targeting miR-29a-5p may be a novel therapeutic strategy to suppress sepsis-induced vascular inflammation.

Targeting STAT3: A crucial modulator of sepsis

Signal transducer and activator of transcription 3 (STAT3) is a cellular signal transcription factor that has recently attracted a great deal of attention. It can trigger a variety of genes transcription in response to cytokines and growth factors stimulation, which plays an important role in many cellular biological processes involved in anti/proinflammatory responses. Sepsis is a life-threatening organ dysfunction resulting from dysregulated host responses to infection. As a converging point of multiple inflammatory responses pathways, accumulating studies have presented the elaborate network of STAT3 in sepsis pathophysiology; these results generally indicate a promising therapeutic application for targeting STAT3 in the treatment of sepsis. In the present review, we evaluated the published literature describing the use of STAT3 in the treatment of experimental and clinical sepsis. The information presented here may be useful for the design of future studies and may highlight the potential of STAT3 as a future biomarker and therapeutic target for sepsis.

[Electroacupuncture protects septic rats from acute lung injury through the JAK1/STAT3 pathway]

OBJECTIVE

To explore the protective effect of electroacupuncture against acute lung injury (ALI) in septic rats and explore the mechanism.

METHODS

Sixty male SD rats were randomly divided into cecal ligation and puncture (CLP)-induced sepsis group (n=45) and sham operation group (n=15; with laparotomy but without CLP). The rat models of sepsis were randomized into ALI group (n=15) without further treatment, ALI + SEA group (n=15) treated with electroacupuncture at the point far from the Zusanli acupoint for 30 min, and ALI + EA group (n=15) with electroacupuncture at Zusanli with identical frequency, intensity and duration of electrical stimulation. All the rats were sacrificed at 12 h after CLP for measurement of the weight and the wet/dry weight (W/D) ratio of the lungs. Pathological changes of the lung tissues were examined using HE staining, and the contents of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the homogenate of the lung tissues were detected using enzyme-linked immunosorbent assay (ELISA). TUNEL staining was used to detect the apoptotic cells, and the expressions of Bax, caspase-3 and the important proteins in the JAK1/STAT3 signaling pathway (JAK1 and STAT3) were detected with Western blotting.

RESULTS

Compared with those in the sham operation group, the rats in ALI group showed obvious lung pathologies with significantly increased lung W/D ratio (P < 0.01), pulmonary expressions of TNF-α and IL-6 (P < 0.01), and obvious up-regulation of JAK1, STAT3, caspase-3, and Bax expressions (P < 0.01); similar changes were also observed in ALI+SEA group (P > 0.05). Compared with those in ALI+SEA group, the rats in ALI+EA group showed significantly milder lung pathologies, lowered lung W/D ratio (P < 0.01) and decreased pulmonary expressions of TNF-α, IL-6, JAK1, STAT3, caspase-3 and Bax (P < 0.01).

CONCLUSIONS

Electroacupuncture can inhibit the release of inflammatory mediators and cell apoptosis via the JAK1/STAT3 pathway to reduce lung injuries in septic rats.

Non-coding RNAs and Exosomes: Their Role in the Pathogenesis of Sepsis

Sepsis is characterized as an uncontrolled host response to infection, and it represents a serious health challenge, causing excess mortality and morbidity worldwide. The discovery of sepsis-related epigenetic and molecular mechanisms could result in improved diagnostic and therapeutic approaches, leading to a reduced overall risk for affected patients. Accumulating data show that microRNAs, non-coding RNAs, and exosomes could all be considered as novel diagnostic markers for sepsis patients. These biomarkers have been demonstrated to be involved in regulation of sepsis pathophysiology. However, epigenetic modifications have not yet been widely reported in actual clinical settings, and further investigation is required to determine their importance in intensive care patients. Further studies should be carried out to explore tissue-specific or organ-specific epigenetic RNA-based biomarkers and their therapeutic potential in sepsis patients.

Relationship Between IL-10 Gene Polymorphism and Spinal Tuberculosis

Background

To investigate the relation between interleukin-10 (IL-10) gene rs1800871 (A/G) polymorphism and spinal tuberculosis.

Material/Methods

A total of 129 patients with spinal tuberculosis (spinal tuberculosis group) and 106 healthy subjects receiving physical examination (control group) were enrolled in this study. The general data of these subjects were collected, and the C-reactive protein, erythrocyte sedimentation rate (ESR) and baseline hematologic function were examined. The rs1800871 (A/G) polymorphism in IL-10 gene was detected by TaqMan-MGB probe method.

Results

The C-reactive protein, ESR, white blood cell count, absolute neutrophil count and relative neutrophil count in spinal tuberculosis group were higher than those in control group, while the absolute lymphocyte count and relative lymphocyte count were lower than those in control group (p<0.05). Compared with AA genotype, GG and AG+GG genotypes showed statistically significant difference in distribution frequency (p<0.05), but no significant difference was detected between AG genotype and AA genotype (p>0.05). In spinal tuberculosis group, the frequency of G allele was higher than that of A allele (p<0.01). The C-reactive protein, ESR, white blood cell count and relative neutrophil count in GG genotype were increased compared with those in AG+GG genotype (p<0.05).

Conclusions

The rs1800871 (A/G) polymorphism in IL-10 gene is related to the susceptibility to spinal tuberculosis. Moreover, carrying G allele increases the risk of spinal tuberculosis.

Exosomes Released from Tumor-Associated Macrophages Transfer miRNAs That Induce a Treg/Th17 Cell Imbalance in Epithelial Ovarian Cancer

The immune microenvironment is crucial for epithelial ovarian cancer (EOC) progression and consists of tumor-associated macrophages (TAM) and T lymphocytes, such as regulatory T cells (Treg) and T helper 17 (Th17) cells. In this study, the Treg/Th17 ratio was significantly higher in EOC in situ and in metastatic peritoneal tissues than in benign ovarian tumors and benign peritoneum. The Treg/Th17 ratio was associated with histologic grade and was an independent prognostic factor for overall survival of EOC patients. On the basis of microarray analysis of exosomes derived from TAMs, we identified miRNAs enriched in the exosomes, including miR-29a-3p and miR-21-5p. When the two miRNA mimics were transfected into CD4⁺ T cells, they directly suppressed STAT3 and regulated Treg/Th17 cells, inducing an imbalance, and they had a synergistic effect on STAT3 inhibition. Taken together, these results indicate that exosomes mediate the interaction between TAMs and T cells, generating an immune-suppressive microenvironment that facilitates EOC progression and metastasis. These findings suggest that targeting these exosomes or their associated miRNAs might pave the way for the development of novel treatments for EOC.

Upregulation of microRNA-335-5p reduces inflammatory responses by inhibiting FASN through the activation of AMPK/ULK1 signaling pathway in a septic mouse model

Sepsis, as a systemic inflammatory response syndrome (SIRS) subtype, is generally characterized by infection. Emerging evidence has highlighted dysregulated microRNAs (miRNAs) are involved in the progression of sepsis. The aim of the study was to investigate the effects of miR-335-5p on inflammatory responses in a septic mouse model. The hypothesis was subsequently asserted that the FASN gene and AMPK/ULK1 signaling pathway may participate in the regulation of miR-335-5p. A septic mouse model was established in order to validate the effect of miR-335-5p on the inflammatory response by means of suppressing the endogenous expression of FASN by siRNA against FASN in endothelial cells. A target prediction program and luciferase activity was employed to ascertain as to whether miR--335-5p targets FASN. The levels of inflammatory factors including IL-6 and IL-1β were determined by means of ELISA assay. RT-qPCR and western blot analysis were used to determine the AMPK/ULK1 signaling pathway-, apoptosis- and autophagy-related genes. Flow cytometry was employed in order to evaluate sepsis-induced cell apoptosis in response to miR-335-5p and FASN alternations. FASN was identified as a target gene of miR--335-5p. Gain- and loss-of-function studies revealed that miR-335-5p acted to enhance autophagy, reduce cell apoptosis, promote cell cycle entry in endothelial cells, and reduce inflammatory response through the modulation of pro- and anti-apoptotic factors in endothelial cells. The effect of miR-335-5p on endothelial cells was increased when FASN was suppressed by siRNA as well as when the AMPK/ULK1 signaling pathway was activated, suggesting that miR-335-5p influences sepsis by targeting and inhibiting FASN, and activating the AMPK/ULK1 signaling pathway. Our study provides evidence indicating that overexpressed miR-335-5p enhances autophagy by targeting FASN through activation of the AMPK/ULK1 signaling pathway working to alleviate the inflammatory response in septic mouse models, emphasizing the value of the functional upregulation of miR-335-5p as therapeutic strategy for sepsis.

Dehydrocostus lactone suppresses cell growth and induces apoptosis in recombinant human papilloma virus‑18 HaCaT cells via the PI3K/Akt signaling pathway

Dehydrocostus lactone is considered to be the major cholagogic ingredient of the Costus genus of plants. It exhibits strong cholagogic effects, and also exerts antimicrobial and antineoplastic activity. The present study aimed to investigate the effects of dehydrocostus lactone on the cell growth and apoptosis of recombinant human papilloma virus (HPV)‑18 HaCaT cells. The HPV‑18 genome was transfected into HaCaT cells, which were subsequently used for analysis. The results demonstrated that dehydrocostus lactone reduced the cell proliferation and induced apoptosis of HPV‑18 HaCaT cells, as determined by MTT and N‑acetyl‑Asp‑Glu‑Val‑Asp p‑nitroanilide assays, respectively. Furthermore, caspase‑3/9 activity was determined using a caspase‑3/9 activity kit and western blotting was performed to investigate the expression of certain proteins. The results demonstrated that caspase‑3/9 activities, and the protein expression of Bcl‑2‑associated X and p53, in HPV‑18 HaCaT cells were significantly increased, while cyclin D1 protein expression was suppressed by dehydrocostus lactone. Additionally, dehydrocostus lactone significantly upregulated the protein expression of phosphatase and tensin homolog and inhibited the phosphatidylinositol 3‑kinase (PI3K)/Akt signaling pathway in HPV‑18 HaCaT cells. Therefore, the results of the present study indicate that dehydrocostus lactone may suppress cell growth and induce apoptosis in recombinant HPV‑18 HaCaT cells via the PI3K/Akt signaling pathway, and may be a represent a novel potential therapeutic agent for the treatment of condyloma acuminatum.

MicroRNA-29a inhibits proliferation and induces apoptosis in rheumatoid arthritis fibroblast-like synoviocytes by repressing STAT3

Rheumatoid arthritis-fibroblast-like synoviocytes (RA-FLS) with aberrant expression of microRNA (miRNA) have been reported to be involved in the initiation, progression, and perpetuation of rheumatoid arthritis (RA). In this study, we explored the biological function and underlying mechanism of microRNA-29a (miR-29a) in cultured RA-FLS from RA patients. The expression of miR-29a in serum, synovial tissues, and FLS from RA patients and health donors was detected by real-time quantitative RT-PCR (qRT-PCR). The effects of miR-29a on cell proliferation, apoptosis, and inflammatory cytokine levels in RA-FLS were also determined using Counting Assay Kit-8 (CCK-8), flow cytometry, and enzyme-linked immunosorbent assay (ELISA) respectively. Luciferase reporter assay was carried out to identify the target genes of miR-29a. We observed that expression of miR-29a was markedly downregulated in serum, synovial tissues and FLS of RA patients. miR-29a overexpression in RA-FLS significantly inhibited proliferation, promoted apoptosis, and suppressed expression of inflammatory cytokines. Signal transducer and activator of transcription 3 (STAT3) was identified to be a direct target of miR-29a in RA-FLS. miR-29a overexpression suppressed the expression of STAT3, as well as phosphorylated STAT3(p-STAT3) and its downstream targets protein (Cyclin D1 and Bcl-2). In addition, the levels of miR-29a were inversely correlated with that of STAT3 in synovial tissues. Rescue experiments showed that overexpression of STAT3 effectively reversed the effect of miR-29a on proliferation and apoptosis in RA-FLS. These data indicate that miR-29a inhibits proliferation and induces apoptosis in RA-FLS by targeting STAT3, suggesting that promoting miR-29a expression may yield therapeutic benefits in the treatment of RA.

Non-coding RNA: a potential biomarker and therapeutic target for sepsis

Sepsis, a syndrome of physiologic, pathologic, and biochemical abnormalities caused by an altered systemic host response to infection, has become the main cause of death among patients admitted to the intensive care units. Recently, genome-wide expression analysis revealed that over 80% of the essential genetic elements were altered in critically ill patients. Notably, non-coding RNAs, including microRNAs, long non-coding RNAs and circular RNAs, have been proven to play essential roles in innate immunity, mitochondrial dysfunction and organ dysfunction. In this review, we introduced the biogenesis of non-coding RNAs briefly and summed up different kinds of non-coding RNAs in regulation of sepsis, which could provide a more comprehensive understanding about pathogenesis of the disease. Additionally, we summarized the limitations of current biomarkers and then recommended some non-coding RNAs as novel potential biomarkers for sepsis and sepsis-induced organ dysfunction. Besides, we also introduced some problems and challenges that need to be overcome during the clinical application of non-coding RNAs. Future research should focus on elucidating their molecular mechanisms, particularly long non-coding RNAs as well as circular RNAs and sepsis, to further understanding of the disease process. With the in-depth understanding of the mechanism of sepsis, non-coding RNAs provide a new insight into sepsis and could become the novel therapeutic targets in the future.

Unique microRNA expression in the colonic mucosa during chronic HIV-1 infection

OBJECTIVE

Chronic HIV-1 infection leads to widespread inflammation and immune dysregulation. The gastrointestinal mucosa, a primary site for HIV-1 replication, is thought to play a significant role in this response. MicroRNAs (miRs) are small noncoding RNAs that regulate gene expression, including immune activation and inflammation. Here we investigate miR expression and function in the colonic mucosa during HIV-1 infection.

DESIGN AND METHODS

Using miR profiling, we examined miR expression in the colonic mucosa of HIV-infected patients. These miRs were further parsed to identify those that most likely function in HIV-related inflammation. Using bioinformatics tools, we identified potential target genes which were confirmed using in-vitro functional testing.

RESULTS

We identified 12 miRs that were differentially expressed in the colonic mucosa of HIV-infected patients with high versus undetectable plasma viral concentrations. Of these, both miR-26a and miR-29a were downregulated in untreated HIV-1 infection, yet not in the colonic mucosa from inflammatory bowel disease. This downregulation occurs within the first hours after infection. These miRs were further shown to directly target IL-6 and STAT3, respectively, with similar changes confirmed in an ex-vivo explant infection model.

CONCLUSION

miR-26a and miR-29a levels are decreased in the colonic mucosa during chronic HIV-1 infection, and this change may be initiated during acute infection. Both miRs de-repress the IL-6/STAT3 signaling pathway, which could contribute to increased inflammation during infection. These miRs may represent novel therapeutic targets for HIV-1-associated inflammation in the colonic mucosa.

miR-429 is involved in regulation of NF-κBactivity by targeting IKKβ and suppresses oncogenic activity in cervical cancer cells

Dysregulation of microRNAs (miRNAs) can contribute to tumorigenesis in cancers. In this study, we found that miR-429 was downregulated in cervical cancer (CC) tissues and suppressed cell viability and proliferation while promoting apoptosis in CC cells. IKKβ was a novel target gene of miR-429 and ectopic expression of IKKβ abrogated the phenotypes induced by miR-429. When IKKβ was downregulated by miR-429, nuclear factor κB (NF-κB) pathway activation, interleukin-6 (IL-6), and interferon-β (IFN-β) production were decreased in CC cells. These findings indicate that miR-429 is involved in regulation of the NF-κB pathway by targeting IKKβ and functions as a tumor suppressor in cervical carcinogenesis.

The involvement of regulatory non-coding RNAs in sepsis: a systematic review

Background

Sepsis coincides with altered gene expression in different tissues. Accumulating evidence has suggested that microRNAs, long non-coding RNAs, and circular RNAs are important molecules involved in the crosstalk with various pathways pertinent to innate immunity, mitochondrial functions, and apoptosis.

Methods

We searched articles indexed in PubMed (MEDLINE), EMBASE and Europe PubMed Central databases using the Medical Subject Heading (MeSH) or Title/Abstract words (“microRNA”, “long non-coding RNA”, “circular RNA”, “sepsis” and/or “septic shock”) from inception to Sep 2016. Studies investigating the role of host-derived microRNA, long non-coding RNA, and circular RNA in the pathogenesis of and as biomarkers or therapeutics in sepsis were included. Data were extracted in terms of the role of non-coding RNAs in pathogenesis, and their applicability for use as biomarkers or therapeutics in sepsis. Two independent researchers assessed the quality of studies using a modified guideline from the Systematic Review Center for Laboratory animal Experimentation (SYRCLE), a tool based on the Cochrane Collaboration Risk of Bias tool.

Results

Observational studies revealed dysregulation of non-coding RNAs in septic patients. Experimental studies confirmed their crosstalk with JNK/NF-κB and other cellular pathways pertinent to innate immunity, mitochondrial function, and apoptosis. Of the included studies, the SYRCLE scores ranged from 3 to 7 (average score of 4.55). This suggests a moderate risk of bias. Of the 10 articles investigating non-coding RNAs as biomarkers, none of them included a validation cohort. Selective reporting of sensitivity, specificity, and receiver operating curve was common.

Conclusions

Although non-coding RNAs appear to be good candidates as biomarkers and therapeutics for sepsis, their differential expression across tissues complicated the process. Further investigation on organ-specific delivery of these regulatory molecules may be useful.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1555-3) contains supplementary material, which is available to authorized users.

MicroRNAs: New regulators of IL-22

Interleukin-22 (IL-22) is a cytokine that belongs to the IL-10 family of interleukins. It can be produced by T helper 22 (Th22) cells, T helper 1 (Th1) cells, T helper 17 (Th17) cells, natural killer 22 (NK22) cells, natural killer T (NKT) cells, innate lymphoid cells (ILCs), and γδ T cells. IL-22 acts via binding to a heterodimeric transmembrane receptor complex that consists of IL-22R1 and IL-10R2 and mainly contributes to the tissue repair and host defense. Transcription factors such as retinoid orphan receptor γt (RORγt) and signal transducer and activator of transcription 3 (STAT3), have been reported to play important roles in regulation of IL-22 expression. Recently, it has been demonstrated in several studies that microRNAs (miRNAs) potently regulate expression of interleukins, including production of IL-22. Here, we review current knowledge about regulators of IL-22 expression with a particular emphasis on the role of miRNAs.

Direct Peritoneal Resuscitation Alters Hepatic miRNA Expression after Hemorrhagic Shock

BACKGROUND

MicroRNAs (miRNAs) are small segments of noncoding RNA that regulate gene expression and protein function, and therefore are key regulators of cellular processes including those of the inflammatory cascade after hemorrhagic shock (HS). We have previously shown that direct peritoneal resuscitation (DPR), as an adjunct to traditional IV fluid resuscitation, improves visceral blood flow and reduces pro-inflammatory cytokines released during HS. The effects of DPR on hepatic miRNA (miR) expression patterns after resuscitated HS are not known.

STUDY DESIGN

Male Sprague-Dawley rats were divided into 3 groups: sham (no HS); conventional resuscitation (CR; HS, then resuscitated with shed blood and 2 volumes of saline); and DPR (CR plus 30 mL peritoneal dialysis solution). Animals were sacrificed at 4 hours, and miRNAs were measured using reverse transcription polymerase chain reaction.

RESULTS

Use of DPR downregulated 68 of 92 hepatic miRNAs compared with only 2 of 92 upregulated when compared with CR alone, p < 0.01). Specifically, miR-9-5p, miR-122-5p, and miR-146, which regulate NFκB, were downregulated 4.1-, 3.4-, and 0.86-fold, respectively; miR-29a and miR-126 were upregulated 0.88- and 3.7-fold when DPR was compared with CR.

CONCLUSIONS

Adding DPR downregulated most hepatic miRNAs compared with CR alone. Some miRNAs were affected more significantly, suggesting that although this clinical intervention causes a near-global downregulation of hepatic miRNA, it still targets specific inflammatory pathways. Use of DPR for resuscitation of patients in HS may reduce hepatic inflammation to improve patient outcomes after hemorrhage.