BCL2 genetic variants are associated with acute kidney injury in septic shock*

Genetic association studies in critically ill patients: a systematic review

BACKGROUND

Critical illness is complex, and genetic research holds the potential to uncover underlying disease mechanisms. However, existing research results have not been systematically summarized. This study aims to compile all genetic association studies in critically ill patients and assess their risks of bias.

METHODS

We systematically reviewed PubMed, EMBASE, and the Cochrane Library (PROSPERO protocol: CRD42021209744) and conducted a bias risk assessment of identified studies using a newly developed risk-of-bias assessment tool for genetic association studies. We compiled all significant single nucleotide polymorphisms (SNPs) from the studies identified in our systematic review and conducted a lookup in the results of two genome-wide association studies (GWASs) in critically ill patients.

FINDINGS

We identified a total of 61 studies that evaluated genetic variants with various traits in adult intensive care patients, encompassing a total of 126 genetic loci and focussing on six clustered critical care-related traits. Assessment of the risk of bias across these studies revealed that 97% of the studies demonstrated some concerns or high risk of bias and only two studies (3%, both GWAS), had an overall low risk of bias. Only two significantly associated SNPs emerged from the two studies assessed to have a low risk of bias. One SNP (rs4957796) in FER was associated with 28-day survival (p = 3.4 × 10-9) and mortality (p = 5.6 × 10-8), and rs9508032 in FLT1 was associated with respiratory failure (p = 5.2 × 10-8). Fifty-four significant associations were replicated in the candidate gene studies, but most had an overall high risk of bias. Only one association, of rs2569190 in CD14 with mortality, remained significant after multiple testing correction.

INTERPRETATION

Our systematic review underscored a deficiency in high-quality genetic research in critical care medicine. The detected gaps emphasize an urgent need for additional rigorous genetic association studies that are preferably genome-wide, to enhance our understanding of the underlying mechanisms of critical illness.

FUNDING

Wenbo Zhang was financially supported by a grant from the China Scholarship Council (File no. 202006210041). Carlos Flores was funded by Instituto de Salud Carlos III (PI23/00980 and CB06/06/1088) and co-financed by the European Regional Development Fund, "A way of making Europe" from the European Union; and the agreement OA23/043 with Instituto Tecnológico y de Energías Renovables (ITER) to strengthen scientific and technological education, training, research, development and scientific innovation in genomics, epidemiological surveillance based on massive sequencing, personalized medicine, and biotechnology. Eva Suarez-Pajes was financially supported by Agencia Canaria de Investigación, Innovación y Sociedad de la Información de la Consejería de Economía, Conocimiento y Empleo y por el Fondo Social Europeo (FSE) Programa Operativo Integrado de Canarias 2014-2020, Eje 3 Tema Prioritario 74 (85%) (TESIS2022010042).

Genetic variants associated with sepsis-associated acute kidney injury

BACKGROUND

Kidney dysfunction is a common complication in septic patients. Studies have identified numerous risk factors for sepsis-associated acute kidney injury (S-AKI), yet there is wide variability in the incidence even among patients with similar risk factors, suggesting the presence of additional uncharacterized risk factors, including genetic differences. The expansion of biobanks, advances in genotyping, and standardized diagnostic criteria have enabled large-scale, hypothesis-generating studies into the genetic mechanisms underlying S-AKI. We hypothesize that the genetic pathway behind S-AKI has overlapping mechanisms with key differences based upon the specific subtype of acute kidney injury (AKI).

METHODS

To test this hypothesis, we performed a genome-wide association study (GWAS) of S-AKI in three logistic regression models. Model 1, controlled for 1) age, 2) sex, 3) genotyping chip, and 4) the first five principal components. In Model 2, pre-sepsis baseline serum creatinine was added to the variables in Model 1. Finally, in Model 3, we controlled for the full range of patient, clinical, and ICU-related risk factors. Each of the 3-models were repeated in a pre-specified sensitivity analysis of higher severity S-AKI, defined as KDIGO Stage 2 or 3. We then compare associated variants and genes from our GWAS with previously published AKI sub-types and model other factors associated with S-AKI in our dataset.

FINDINGS

3,348 qualifying Sepsis-3 patients have been genotyped in our dataset. Of these patients, 383 (11.4%) developed Stage 1, 2, or 3 AKI (primary outcome) and 181 (5.4%) developed Stage 2 or 3 AKI (sensitivity analysis). The median age was 61 years (interquartile range (IQR): 51,69), 42% were female, and the increase in SOFA score (between 48-hours before to 24-hours after the onset of suspected infection) was 2 (2-3). No variants exceeded our threshold for genome-wide significance (P<5x10-8), however, a total of 13 variants exceeded the suggestive (P<1x10-6) threshold. Notably, rs184516290 (chr1:199814965:G:A), near the NR5A2 gene, chr1:199805801:T:TA, also near the NR5A2 gene, and rs117313146 (chr15:31999784:G:C), near the CHRNA7 gene, were associated with S-AKI at the suggestive level in all three models presented. Variants in the suppressor of fused homolog (SUFU) gene, previously shown to be correlated with renal function in bacteremic patients, consistently exceeded the P<0.05 threshold in our models.

CONCLUSIONS

While failing to identify any novel association for S-AKI at the level of genome-wide significance, our study did suggest multiple variants in previously characterized pathways for S-AKI including CHRNA7, NR5A2, and SUFU. We failed to replicate associations from multiple prior studies which may result from differences in how the phenotype was defined or, alternatively, limited genetic contribution and low heritability.

Immunotherapy in the context of sepsis-induced immunological dysregulation

Sepsis is a clinical syndrome caused by uncontrollable immune dysregulation triggered by pathogen infection, characterized by high incidence, mortality rates, and disease burden. Current treatments primarily focus on symptomatic relief, lacking specific therapeutic interventions. The core mechanism of sepsis is believed to be an imbalance in the host's immune response, characterized by early excessive inflammation followed by late immune suppression, triggered by pathogen invasion. This suggests that we can develop immunotherapeutic treatment strategies by targeting and modulating the components and immunological functions of the host's innate and adaptive immune systems. Therefore, this paper reviews the mechanisms of immune dysregulation in sepsis and, based on this foundation, discusses the current state of immunotherapy applications in sepsis animal models and clinical trials.

Genetic predisposition may not improve prediction of cardiac surgery-associated acute kidney injury

Background: The recent integration of genomic data with electronic health records has enabled large scale genomic studies on a variety of perioperative complications, yet genome-wide association studies on acute kidney injury have been limited in size or confounded by composite outcomes. Genome-wide association studies can be leveraged to create a polygenic risk score which can then be integrated with traditional clinical risk factors to better predict postoperative complications, like acute kidney injury. Methods: Using integrated genetic data from two academic biorepositories, we conduct a genome-wide association study on cardiac surgery-associated acute kidney injury. Next, we develop a polygenic risk score and test the predictive utility within regressions controlling for age, gender, principal components, preoperative serum creatinine, and a range of patient, clinical, and procedural risk factors. Finally, we estimate additive variant heritability using genetic mixed models. Results: Among 1,014 qualifying procedures at Vanderbilt University Medical Center and 478 at Michigan Medicine, 348 (34.3%) and 121 (25.3%) developed AKI, respectively. No variants exceeded genome-wide significance (p < 5 × 10-8) threshold, however, six previously unreported variants exceeded the suggestive threshold (p < 1 × 10-6). Notable variants detected include: 1) rs74637005, located in the exonic region of NFU1 and 2) rs17438465, located between EVX1 and HIBADH. We failed to replicate variants from prior unbiased studies of post-surgical acute kidney injury. Polygenic risk was not significantly associated with post-surgical acute kidney injury in any of the models, however, case duration (aOR = 1.002, 95% CI 1.000-1.003, p = 0.013), diabetes mellitus (aOR = 2.025, 95% CI 1.320-3.103, p = 0.001), and valvular disease (aOR = 0.558, 95% CI 0.372-0.835, p = 0.005) were significant in the full model. Conclusion: Polygenic risk score was not significantly associated with cardiac surgery-associated acute kidney injury and acute kidney injury may have a low heritability in this population. These results suggest that susceptibility is only minimally influenced by baseline genetic predisposition and that clinical risk factors, some of which are modifiable, may play a more influential role in predicting this complication. The overall impact of genetics in overall risk for cardiac surgery-associated acute kidney injury may be small compared to clinical risk factors.

Sepsis-associated acute kidney injury: consensus report of the 28th Acute Disease Quality Initiative workgroup

Sepsis-associated acute kidney injury (SA-AKI) is common in critically ill patients and is strongly associated with adverse outcomes, including an increased risk of chronic kidney disease, cardiovascular events and death. The pathophysiology of SA-AKI remains elusive, although microcirculatory dysfunction, cellular metabolic reprogramming and dysregulated inflammatory responses have been implicated in preclinical studies. SA-AKI is best defined as the occurrence of AKI within 7 days of sepsis onset (diagnosed according to Kidney Disease Improving Global Outcome criteria and Sepsis 3 criteria, respectively). Improving outcomes in SA-AKI is challenging, as patients can present with either clinical or subclinical AKI. Early identification of patients at risk of AKI, or at risk of progressing to severe and/or persistent AKI, is crucial to the timely initiation of adequate supportive measures, including limiting further insults to the kidney. Accordingly, the discovery of biomarkers associated with AKI that can aid in early diagnosis is an area of intensive investigation. Additionally, high-quality evidence on best-practice care of patients with AKI, sepsis and SA-AKI has continued to accrue. Although specific therapeutic options are limited, several clinical trials have evaluated the use of care bundles and extracorporeal techniques as potential therapeutic approaches. Here we provide graded recommendations for managing SA-AKI and highlight priorities for future research.

Personalizing Care for Critically Ill Adults Using Omics: A Concise Review of Potential Clinical Applications

Current guidelines for critically ill patients use broad recommendations to promote uniform protocols for the management of conditions such as acute kidney injury, acute respiratory distress syndrome, and sepsis. Although these guidelines have enabled the substantial improvement of care, mortality for critical illness remains high. Further outcome improvement may require personalizing care for critically ill patients, which involves tailoring management strategies for different patients. However, the current understanding of disease heterogeneity is limited. For critically ill patients, genomics, transcriptomics, proteomics, and metabolomics have illuminated such heterogeneity and unveiled novel biomarkers, giving clinicians new means of diagnosis, prognosis, and monitoring. With further engineering and economic development, omics would then be more accessible and affordable for frontline clinicians. As the knowledge of pathophysiological pathways mature, targeted treatments can then be developed, validated, replicated, and translated into clinical practice.

Morphogenetic dispositions for variability in acute kidney injury after cardiac surgery: Pilot study

Background

The aim of our study was to evaluate the degree of genetic homozygosity in cardiac surgical patients with postoperative acute kidney injury (AKI), compared to the subgroup without postoperative AKI, as well as to evaluate antropomorpho-genetic variability in cardiac surgical patients with regard to the presence and severity degree of AKI.

Materials and methods

The prospective cohort study included an analysis of 138 eligible coronary artery disease (CAD) surgical patients that were screened consecutively. The tested group was divided into three subgroups according to RIFLE criteria: Subgroup NoAKI (N = 91), risk (N = 31), and injury (N = 16). All individuals were evaluated for the presence of 19 observable recessive human traits (ORHT) as a marker of chromosomal homozygosity and variability.

Results

Comparing subgroups NoAKI and risk, four ORHTs were significantly more frequent in the risk subgroup. Comparing subgroups NoAKI and injury, nine ORHTs were significantly more frequent in the injury subgroup; while comparing the injury subgroup and risk, five ORHTs were significantly more frequent in injury than in the risk subgroup. Results also showed a significant increase in the mean value of ORHTs for the injury subgroup compared to NoAKI subgroup (p = 0.039). Variability decreased proportionally to the increase in the severity of AKI (V_NoAKI = 32.81%, V_Risk = 30.92%, and V_Injury = 28.62%).

Conclusion

Our findings pointed to the higher degree of recessive homozygosity and decreased variability in AKI patients vs. NoAKI individuals, thus presumably facilitating the development and severity degree expression of AKI in patients after cardiac surgery.

Multi-Omics Techniques Make it Possible to Analyze Sepsis-Associated Acute Kidney Injury Comprehensively

Sepsis-associated acute kidney injury (SA-AKI) is a common complication in critically ill patients with high morbidity and mortality. SA-AKI varies considerably in disease presentation, progression, and response to treatment, highlighting the heterogeneity of the underlying biological mechanisms. In this review, we briefly describe the pathophysiology of SA-AKI, biomarkers, reference databases, and available omics techniques. Advances in omics technology allow for comprehensive analysis of SA-AKI, and the integration of multiple omics provides an opportunity to understand the information flow behind the disease. These approaches will drive a shift in current paradigms for the prevention, diagnosis, and staging and provide the renal community with significant advances in precision medicine in SA-AKI analysis.

Potential impact of serpin peptidase inhibitor clade (A) member 4 SERPINA4 (rs2093266) and SERPINA5 (rs1955656) genetic variants on COVID-19 induced acute kidney injury

Background

SARS-CoV-2 has a number of targets, including the kidneys. Acute Kidney Injury (AKI) might develop in up to a quarter of SARS-CoV-2 patients. In the clinical environment, AKI is linked to a high rate of death and leads to the progression of AKI to chronic renal disease.

Aim

We aimed to investigate rs2093266 and rs1955656 polymorphisms in SERPINA4 and SERPINA5 genes, respectively, as risk factors for COVID-19 induced AKI.

Subjects and methods

A case-control study included 227 participants who were divided into three groups: 81 healthy volunteers who served as controls, 76 COVID-19 patients without AKI and 70 COVID -19 patients with AKI. The TaqMan assay was used for genotyping the SERPINA4 (rs2093266) and SERPINA5 (rs1955656) polymorphisms by real-time PCR technique.

Results

Lymphocytes and eGFR showed a significantly decreasing trend across the three studied groups, while CRP, d-Dimer, ferritin, creatinine, KIM-1and NGAL showed a significantly increasing trend across the three studied groups (P < 0.001). Rs2093266 (AG and AA) genotypes were significant risk factors among non-AKI and AKI groups in comparison to controls. Rs1955656 (AG and AA) were significant risk factors among the AKI group, while AA was the only significant risk factor among the non-AKI group. Recessive, dominant, co-dominant, and over-dominant models for genotype combinations were demonstrated. The GG v AA, GG + AG v AA, and GG v AG + AA models of the rs2093266 were all significant predictors of AKI, whilst only the GG v AA model of the rs1955656 SNP was a significant predictor. The logistic regression model was statistically significant, χ2 = 56.48, p < 0.001. AKI was associated with progressed age (OR = 0.95, 95% CI: 0.91–0.98, p = 0.006), suffering from chronic diseases (OR = 3.25, 95% CI: 1.31–8.01, p = 0.010), increased BMI (OR = 0.89, 95% CI: 0.81–0.98, p = 0.018), immunosuppressive (OR = 4.61, 95% CI: 1.24–17.16, p = 0.022) and rs2093266 (AG + AA) (OR = 3.0, 95% CI: 1.11–8.10, p = 0.030).

Conclusion

Single nucleotide polymorphisms (rs2093266) at SERPINA4 gene and (rs1955656) at SERPINA5 gene were strongly linked to the development of AKI in COVID-19 patients.

A Thrombomodulin Promoter Gene Polymorphism, rs2239562, Influences Both Susceptibility to and Outcome of Sepsis

Objective: Disseminated intravascular coagulation plays a key role in the pathophysiology of sepsis. Thrombomodulin is essential in the protein C system of coagulation cascade, and functional polymorphisms influence the human thrombomodulin gene (THBD). Therefore, we conducted a multicenter study to evaluate the influence of such polymorphisms on the pathophysiology of sepsis. Methods: A collaborative case-control study in the intensive care unit (ICU) of each of five tertiary emergency centers. The study included 259 patients (of whom 125 displayed severe sepsis), who were admitted to the ICU of Chiba University Hospital, Chiba, Japan between October 2001 and September 2008 (discovery cohort) and 793 patients (of whom 271 patients displayed severe sepsis), who were admitted to the five ICUs between October 2008 and September 2012 (multicenter validation cohort). To assess the susceptibility to severe sepsis, we further selected 222 critically ill patients from the validation cohort matched for age, gender, morbidity, and severity with the patients with severe sepsis, but without any evidence of sepsis. Results: We examined whether the eight THBD single nucleotide polymorphisms (SNPs) were associated with susceptibility to and/or mortality of sepsis. Higher mortality on severe sepsis in the discovery and combined cohorts was significantly associated with the CC genotype in a THBD promoter SNP (-1920^*C/G; rs2239562) [odds ratio [OR] 2.709 (1.067-6.877), P = 0.033 and OR 1.768 (1.060-2.949), P = 0.028]. Furthermore, rs2239562 SNP was associated with susceptibility to severe sepsis [OR 1.593 (1.086-2.338), P = 0.017]. Conclusions: The data demonstrate that rs2239562, the THBD promoter SNP influences both the outcome and susceptibility to severe sepsis.

Genetic Susceptibility to Acute Kidney Injury

Acute kidney injury (AKI) is a widely held concern related to a substantial burden of morbidity, mortality and expenditure in the healthcare system. AKI is not a simple illness but a complex conglomeration of syndromes that often occurs as part of other syndromes in its wide clinical spectrum of the disease. Genetic factors have been suggested as potentially responsible for its susceptibility and severity. As there is no current cure nor an effective treatment other than generally accepted supportive measures and renal replacement therapy, updated knowledge of the genetic implications may serve as a strategic tactic to counteract its dire consequences. Further understanding of the genetics that predispose AKI may shed light on novel approaches for the prevention and treatment of this condition. This review attempts to address the role of key genes in the appearance and development of AKI, providing not only a comprehensive update of the intertwined process involved but also identifying specific markers that could serve as precise targets for further AKI therapies.

The application of omic technologies to research in sepsis-associated acute kidney injury

Acute kidney injury (AKI) is common in critically ill children and adults, and sepsis-associated AKI (SA-AKI) is the most frequent cause of AKI in the ICU. To date, no mechanistically targeted therapeutic interventions have been identified. High-throughput "omic" technologies (e.g., genomics, proteomics, metabolomics, etc.) offer a new angle of approach to achieve this end. In this review, we provide an update on the current understanding of SA-AKI pathophysiology. Omic technologies themselves are briefly discussed to facilitate interpretation of studies using them. We next summarize the body of SA-AKI research to date that has employed omic technologies. Importantly, omic studies are helping to elucidate a pathophysiology of SA-AKI centered around cellular stress responses, metabolic changes, and dysregulation of energy production that underlie its clinical features. Finally, we propose opportunities for future research using clinically relevant animal models, integrating multiple omic technologies and ultimately progressing to translational human studies focusing therapeutic strategies on targeted disease mechanisms.

Rates, predictors, and mortality of sepsis-associated acute kidney injury: a systematic review and meta-analysis

BACKGROUND

Due to the high incidence and mortality of sepsis-associated acute kidney injury, a significant number of studies have explored the causes of sepsis-associated acute kidney injury (AKI). However, the opinions on relevant predictive risk factors remain inconclusive. This study aimed to provide a systematic review and meta-analysis to determine the predisposing factors for sepsis-associated AKI.

METHOD

A systematic literature search was performed in the Medline, Embase, Cochrane Library, PubMed, and Web of Science, databases, with an end-date of 25th May 2019. Valid data were retrieved in compliance with specific inclusion and exclusion criteria.

RESULT

Forty-seven observational studies were included for analysis, achieving a cumulative patient number of 55,911. The highest incidence of AKI was caused by septic shock. Thirty-one potential risk factors were included in the meta-analysis. Analysis showed that 20 factors were statistically significant. The odds ratio (OR) and 95% confidence interval (CI), as well as the prevalence of the most frequently-seen predisposing factors for sepsis-associated AKI, were as follows: septic shock [2.88 (2.36-3.52), 60.47%], hypertension [1.43 (1.20-1.70), 38.39%], diabetes mellitus [1.59 (1.47-1.71), 27.57%], abdominal infection [1.44 (1.32-1.58), 30.87%], the administration of vasopressors [2.95 (1.67-5.22), 64.61%], the administration of vasoactive drugs [3.85 (1.89-7.87), 63.22%], mechanical ventilation [1.64 (1.24-2.16), 68.00%], positive results from blood culture [1.60 (1.35-1.89), 41.19%], and a history of smoking [1.60 (1.09-2.36), 43.09%]. Other risk factors included cardiovascular diseases, coronary artery diseases, liver diseases, unknown infections, the administration of diuretics and ACEI/ARB, the infection caused by gram-negative bacteria, and organ transplantation.

CONCLUSION

Risk factors of S-AKI arise from a wide range of sources, making it difficult to predict and prevent this condition. Comorbidities, and certain drugs, are the main risk factors for S-AKI. Our review can provide guidance on the application of interventions to reduce the risks associated with sepsis-associated acute kidney injury and can also be used to tailor patient-specific treatment plans and management strategies in clinical practice.

Melittin Inducing the Apoptosis of Renal Tubule Epithelial Cells through Upregulation of Bax/Bcl-2 Expression and Activation of TNF-α Signaling Pathway

Background

Acute kidney injury (AKI) caused by bee stings is common, with characteristics of acute onset, severe illness, and high mortality. Melittin, a major component of bee venom, has been considered to play a key role in bee sting related AKI. This study aims to illustrate whether melittin could lead to apoptosis of renal tubular epithelial cells (RTECs) and to investigate its mechanism.

Methods

In vivo, 45 mice were randomly divided into the melittin group (n=30, injected with melittin into the tail vein according to the total dose of 4.0 ug/g weight) and the control group (n=15, injected with the same volume of saline into the tail vein). In vitro, human RTECs (HK-2) were cultured and treated with melittin (2ug/ml or 4ug/ml) and TNF-α (10ng/ml). Biochemical analysis, HE stains, and electron microscope were performed to evaluate renal function and pathological changes. TUNEL stains and flow cytometry were performed to detect apoptosis. Real-time PCR was performed to detect mRNA levels of Bax, Bcl-2, and TNF-α. Simple western assay and immunohistochemical (IH) and immunofluorescent (IF) stains were performed for protein detection.

Results

Melittin successfully induced AKI in mice. Compared with the control group, obvious injury and apoptosis of RTECs were observed in the melittin group; the mRNA and protein expressions of Bax were significantly increased, while the expression of Bcl-2 was significantly decreased. The serum TNF-αlevel in melittin group was significantly higher than that in control group. In vitro, the results confirmed that melittin can cause HK-2 cells apoptosis. The trends of expression of Bax and Bcl-2 were consistent with the results in vivo. The levels of TNF-α mRNA and protein by PCR and Western blot were significantly higher in melittin group than those in control group.

Conclusion

Melittin can lead to the apoptosis of RTECs, which may be mediated by upregulating the expression of Bax/Bcl-2 and activating the TNF-α signaling pathway.

CXCL8(3-72) K11R/G31P protects against sepsis-induced acute kidney injury via NF-κB and JAK2/STAT3 pathway

Background

Acute kidney injury (AKI), which is mainly caused by sepsis, has high morbidity and mortality rates. CXCL8_(3–72) K11R/G31P (G31P) can exert therapeutic effect on inflammatory diseases and malignancies. We aimed to investigate the effect and mechanism of G31P on septic AKI.

Methods

An AKI mouse model was established, and kidney injury was assessed by histological analysis. The contents of serum creatinine (SCr) and blood urea nitrogen (BUN) were measured by commercial kits, whereas neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) were detected by enzyme-linked immunosorbent assay (ELISA) kits. The expressions of CXCL8 in serum and kidney tissues were determined using ELISA and immunohistochemical analysis, respectively. Apoptosis rate of renal tissue was detected by terminal deoxynucleotidyl transfer-mediated dUTP nick end labeling (TUNEL) analysis. The expressions of inflammatory cytokines were measured by quantitative real-time PCR and Western blot, respectively. The apoptosis-related proteins, JAK2, STAT3, NF-κB and IκB were determined by Western blot.

Results

G31P could reduce the levels of SCr, BUN, HGAL and KIM-1 and inhibit the renal tissue injury in AKI mice. G31P was also found to suppress the serum and nephric CXCL8 expressions and attenuated the apoptosis rate. The levels of inflammatory cytokines, pro-apoptotic proteins were decreased, while the anti-apoptotic proteins were increased by G31P in AKI mice. G31P also inhibited the activation of JAK2, STAT3 and NF-κB in AKI mice.

Conclusion

These results suggest that G31P could protect renal function and attenuate the septic AKI. Our findings provide a potential target for the treatment of AKI.

Common Inflammation-Related Candidate Gene Variants and Acute Kidney Injury in 2647 Critically Ill Finnish Patients

Acute kidney injury (AKI) is a syndrome with high incidence among the critically ill. Because the clinical variables and currently used biomarkers have failed to predict the individual susceptibility to AKI, candidate gene variants for the trait have been studied. Studies about genetic predisposition to AKI have been mainly underpowered and of moderate quality. We report the association study of 27 genetic variants in a cohort of Finnish critically ill patients, focusing on the replication of associations detected with variants in genes related to inflammation, cell survival, or circulation. In this prospective, observational Finnish Acute Kidney Injury (FINNAKI) study, 2647 patients without chronic kidney disease were genotyped. We defined AKI according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria. We compared severe AKI (Stages 2 and 3, n = 625) to controls (Stage 0, n = 1582). For genotyping we used iPLEX^TM Assay (Agena Bioscience). We performed the association analyses with PLINK software, using an additive genetic model in logistic regression. Despite the numerous, although contradictory, studies about association between polymorphisms rs1800629 in TNFA and rs1800896 in IL10 and AKI, we found no association (odds ratios 1.06 (95% CI 0.89–1.28, p = 0.51) and 0.92 (95% CI 0.80–1.05, p = 0.20), respectively). Adjusting for confounders did not change the results. To conclude, we could not confirm the associations reported in previous studies in a cohort of critically ill patients.

MicroRNA-326 aggravates acute lung injury in septic shock by mediating the NF-κB signaling pathway

Our previous studies have demonstrated that the activation of the nuclear factor-kappa B (NF-κB) signaling pathway contributes to the development of lipopolysaccharide (LPS)-induced acute lung injury (ALI) as well as an inflammatory reaction, and its inhibition may provide future therapeutic values. Thereby, this study aims to explore the effects of miR-326 on inflammatory response and ALI in mice with septic shock via the NF-κB signaling pathway. The study included normal mice and LPS-induced mouse models of septic shock with ALI. Modeled mice were transfected with the blank plasmid, miR-326 mimic, miR-326 inhibitor, si-BCL2A1 and miR-326 inhibitor + si-BCL2A1. Mean arterial pressure (MAP), airway pressure (AP), heart rate (HR) and lung wet dry (W/D) ratio were determined. Serum levels of interleukin (IL)-6, IL-10, IL-1β, and tumor necrosis factor-α (TNF-α) were detected using ELISA. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis were performed to detect the miR-326 expression and expression levels of BCL2A1, related genes of inflammatory response and the NF-κB signaling pathway in lung tissues. Cell viability and apoptosis were measured using the CCK-8 assay and flow cytometry, respectively. Compared to the ALI models and those transfected with blank plasmid, the up-regulated miR-326 expression and silenced BCL2A1 lead to decreased levels of MAP, increased AP, HR and lung W/D, increased serum levels of IL-6, IL-10, IL-1β and TNF-α, increased expressions of IL-6, IL-1β, TNF-α, NF-κB p65 (p-NF-κB p65), and iNOS with decreased expressions of BCL2A1s as well as inhibition of cell viability and enhanced cell apoptosis; the down-regulated miR-326 expression reversed the aforementioned situation. MiR-326 targeting the BCL2A1 gene activated the NF-κB signaling pathway, resulting in aggravated inflammatory response and lung injury of septic shock with ALI in mice.

Long non-coding RNA PlncRNA-1 regulates cell proliferation, apoptosis, and autophagy in septic acute kidney injury by regulating BCL2

This study aimed to elucidate the potential role of long non-coding RNA PlncRNA-1 in the septic acute kidney injury (AKI). The expression of PlncRNA-1 in the serum of patients with septic AKI patient was detected. We then established lipopolysaccharide (LPS)-induced septic AKI model in NRK-52E cells to investigate the effects of the overexpression of PlncRNA-1 on cell proliferation, apoptosis, and autophagy. In addition, the regulatory relationship between PlncRNA-1 and B-cell lymphoma 2 (BCL2) was explored to further elucidate the regulatory mechanism of PlncRNA-1 in septic AKI. PlncRNA-1 is downregulated in the serum of patients with septic AKI and in LPS-induced septic AKI cells. The overexpression of PlncRNA-1 considerably increases proliferation and inhibits apoptosis and autophagy of LPS-induced septic AKI cells. In addition, PlncRNA-1 can promote BCL2 expression, and the overexpression of BCL2 enhances proliferation and inhibits apoptosis and autophagy of LPS-induced septic AKI cells. Our findings reveal that the overexpression of PlncRNA-1 may promote cell proliferation and inhibit apoptosis and autophagy in septic AKI by regulating BCL2 expression. PlncRNA-1 may serve as a potential biomarker or target for the diagnosis and treatment of septic AKI.

Genetic variants and acute kidney injury: A review of the literature

PURPOSE

Limited data exists on potential genetic contributors to acute kidney injury. This review examines current knowledge of AKI genomics.

MATERIALS AND METHODS

32 studies were selected from PubMed and GWAS Catalog queries for original data studies of human AKI genetics. Hand search of references identified 3 additional manuscripts.

RESULTS

33 of 35 studies were hypothesis-driven investigations of candidate polymorphisms that either did not consistently replicate statistically significant findings, or obtained significant results only in few small-scale studies. Vote-counting meta-analysis of 9 variants examined in >1 candidate gene study showed ≥50% non-significant studies, with larger studies generally finding non-significant results. The remaining 2 studies were large-scale unbiased investigations: One examining 2,100 genes linked with cardiovascular, metabolic, and inflammatory syndromes identified BCL2, SERPINA4, and SIK3 variants, while a genome-wide association study (GWAS) identified variants in BBS9 and the GRM7|LMCD1-AS1 intergenic region. All studies had relatively small sample sizes (<2300 subjects). Study heterogeneity precluded candidate gene and GWA meta-analysis.

CONCLUSIONS

Most studies of AKI genetics involve hypothesis-driven (rather than hypothesis-generating) candidate gene investigations that have failed to identify contributory variants consistently. A limited number of unbiased, larger-scale studies have been carried out, but there remains a pressing need for additional GWA studies.

Genetic variants in SERPINA4 and SERPINA5, but not BCL2 and SIK3 are associated with acute kidney injury in critically ill patients with septic shock

Background

Acute kidney injury (AKI) is a multifactorial syndrome, but knowledge about its pathophysiology and possible genetic background is limited. Recently the first hypothesis-free genetic association studies have been published to explore individual susceptibility to AKI. We aimed to replicate the previously identified associations between five candidate single nucleotide polymorphisms (SNP) in apoptosis-related genes BCL2, SERPINA4, SERPINA5, and SIK3 and the development of AKI, using a prospective cohort of critically ill patients with sepsis/septic shock, in Finland.

Methods

This is a prospective, observational multicenter study. Of 2567 patients without chronic kidney disease and with genetic samples included in the Finnish Acute Kidney Injury (FINNAKI) study, 837 patients had sepsis and 627 patients had septic shock. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria, considering stages 2 and 3 affected (severe AKI), stage 0 unaffected, and stage 1 indecisive. Genotyping was done using iPLEX^TM Assay (Agena Bioscience). The genotyped SNPs were rs8094315 and rs12457893 in the intron of the BCL2 gene, rs2093266 in the SERPINA4 gene, rs1955656 in the SERPINA5 gene and rs625145 in the SIK3 gene. Association analyses were performed using logistic regression with PLINK software.

Results

We found no significant associations between the SNPs and severe AKI in patients with sepsis/septic shock, even after adjustment for confounders. Among patients with septic shock (252 with severe AKI and 226 without AKI (149 with KDIGO stage 1 excluded)), the SNPs rs2093266 and rs1955656 were significantly (odds ratio 0.63, p = 0.04276) associated with stage 2–3 AKI after adjusting for clinical and demographic variables.

Conclusions

The SNPs rs2093266 in the SERPINA4 and rs1955656 in the SERPINA5 were associated with the development of severe AKI (KDIGO stage 2–3) in critically ill patients with septic shock. For the other SNPs, we did not confirm the previously reported associations.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1631-3) contains supplementary material, which is available to authorized users.

Biomarkers for the Early Detection and Prognosis of Acute Kidney Injury

AKI is an increasingly common disorder that is strongly linked to short- and long-term morbidity and mortality. Despite a growing heterogeneity in its causes, providing a timely and certain diagnosis of AKI remains challenging. In this review, we summarize the evolution of AKI biomarker studies over the past few years, focusing on two major areas of investigation: the early detection and prognosis of AKI. We highlight some of the lessons learned in conducting AKI biomarker studies, including ongoing attempts to address the limitations of creatinine as a reference standard and the recent shift toward evaluating the prognostic potential of these markers. Lastly, we suggest current gaps in knowledge and barriers that may be hindering their incorporation into care and a full ascertainment of their value.

Genetic predisposition to acute kidney injury--a systematic review

BACKGROUND

The risk of an individual to develop an acute kidney injury (AKI), or its severity, cannot be reliably predicted by common clinical risk factors. Whether genetic risk factors have an explanatory role poses an interesting question, however. Thus, we conducted a systematic literature review regarding genetic predisposition to AKI or outcome of AKI patients.

METHODS

We searched Ovid SP (MEDLINE) and EMBASE databases and found 4027 references to AKI. Based on titles and abstracts, we approved 37 articles for further analysis. Nine were published only as abstracts, leaving 28 original articles in the final analysis. We extracted the first author, year of publication, study design, clinical setting, number of studied patients, patients with AKI, ethnicity of patients, studied polymorphisms, endpoints, AKI definition, phenotype, significant findings, and data for quality scoring from each article. We summarized the findings and scored the quality of articles.

RESULTS

The articles were quite heterogeneous and of moderate quality (mean 6.4 of 10).

CONCLUSIONS

Despite different gene polymorphisms with suggested associations with development or severity or outcome of AKI, definitive conclusions would require replication of associations in independent cohort studies and, preferably a hypothesis-free study design.

Associations between single nucleotide polymorphisms in the FAS pathway and acute kidney injury

Introduction

To determine whether single nucleotide polymorphisms (SNPs) in FAS and related genes are associated with acute kidney injury (AKI) in patients with acute respiratory distress syndrome (ARDS).

Methods

We studied 401 (Caucasian N = 310 and African-American N = 91) patients aged ≥ 13 years with ALI who enrolled in the Fluid and Catheter Treatment Trial (FACTT) between 2000 and 2005 from 20 North American centers. We genotyped 367 SNPs in 45 genes of the Fas/Fas ligand pathway to identify associations between SNPs in Fas pathway genes and the development of AKI by day 2 after enrollment in FACTT, adapting Acute Kidney Injury Network (AKIN) criteria. Written informed consent was obtained from participants or legally authorized surrogates in the original FACTT study and available to use for secondary analysis.

Results

In Caucasian patients, we identified associations between two SNPs and the incidence of AKI (stage 1 and above): rs1050851 and rs2233417; both are found within the gene for nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (NFKBIA). For rs1050851 and rs2233417, the odds ratios (ORs) were 2.34 (95 % confidence interval (CI) = 1.58–3.46, p = 1.06 × 10⁻⁵, FDR = 0.003) and 2.46 (CI = 1.61–3.76, p = 1.81 × 10⁻⁵, FDR = 0.003) for each minor allele, respectively. The associations were stronger still for AKIN stage 2–3 with respective ORs 4.00 (CI = 2.10–7.62, p = 1.05 × 10⁻⁵, FDR = 0.003) and 4.03 (CI = 2.09–7.77, p = 1.88 × 10⁻⁵, FDR = 0.003) for each minor allele homozygote. We observed no significant association between these SNPs and AKI in the smaller subset of African Americans.

Conclusion

In Caucasian patients with ALI, the presence of minor alleles in two SNPs in NFKBIA was strongly associated with the development of AKI.

Trial registration

NCT00281268. Registered 20/01/2006.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-1084-5) contains supplementary material, which is available to authorized users.

AKI and Genetics: Evolving Concepts in the Genetics of Acute Kidney Injury: Implications for Pediatric AKI

In spite of recent advances in the field of acute kidney injury (AKI) research, morbidity and mortality remain high for AKI sufferers. The study of genetic influences in AKI pathways is an evolving field with potential for improving outcomes through the identification of risk and protective factors at the individual level that may in turn allow for the development of rational therapeutic interventions. Studies of single nucleotide polymorphisms, individual susceptibility to nephrotoxic medications, and epigenetic factors comprise a growing body of research in this area. While promising, this field is still only emerging, with a small number of studies in humans and very little data in pediatric patients.

Kallistatin treatment attenuates lethality and organ injury in mouse models of established sepsis

INTRODUCTION

Kallistatin levels in the circulation are reduced in patients with sepsis and liver disease. Transgenic mice expressing kallistatin are resistant to lipopolysaccharide (LPS)-induced mortality. Here, we investigated the effect of kallistatin on survival and organ damage in mouse models of established sepsis.

METHODS

Mice were rendered septic by cecal ligation and puncture (CLP), or endotoxemic by LPS injection. Recombinant human kallistatin was administered intravenously six hours after CLP, or intraperitoneally four hours after LPS challenge. The effect of kallistatin treatment on organ damage was examined one day after sepsis initiation, and mouse survival was monitored for four to six days.

RESULTS

Human kallistatin was detected in mouse serum of kallistatin-treated mice. Kallistatin significantly reduced CLP-induced renal injury as well as blood urea nitrogen, serum creatinine, interleukin-6 (IL-6), and high mobility group box-1 (HMGB1) levels. In the lung, kallistatin decreased malondialdehyde levels and HMGB1 and toll-like receptor-4 (TLR4) synthesis, but increased suppressor of cytokine signaling-3 (SOCS3) expression. Moreover, kallistatin attenuated liver injury, serum alanine transaminase (ALT) levels and hepatic tumor necrosis factor-α (TNF-α) synthesis. Furthermore, delayed kallistatin administration improved survival in CLP mice by 38%, and LPS-treated mice by 42%. In LPS-induced endotoxemic mice, kallistatin attenuated kidney damage in association with reduced serum creatinine, IL-6 and HMGB1 levels, and increased renal SOCS3 expression. Kallistatin also decreased liver injury in conjunction with diminished serum ALT levels and hepatic TNF-α and TLR4 expression. In cultured macrophages, kallistatin through its active site increased SOCS3 expression, but this effect was blocked by inhibitors of tyrosine kinase, protein kinase C and extracellular signal-regulated kinase (ERK), indicating that kallistatin stimulates a tyrosine-kinase-protein kinase C-ERK signaling pathway.

CONCLUSIONS

This is the first study to demonstrate that delayed human kallistatin administration is effective in attenuating multi-organ injury, inflammation and mortality in mouse models of polymicrobial infection and endotoxemia. Thus, kallistatin therapy may provide a promising approach for the treatment of sepsis in humans.

Genome-wide association study of survival from sepsis due to pneumonia: an observational cohort study

BACKGROUND

Sepsis continues to be a major cause of death, disability, and health-care expenditure worldwide. Despite evidence suggesting that host genetics can influence sepsis outcomes, no specific loci have yet been convincingly replicated. The aim of this study was to identify genetic variants that influence sepsis survival.

METHODS

We did a genome-wide association study in three independent cohorts of white adult patients admitted to intensive care units with sepsis, severe sepsis, or septic shock (as defined by the International Consensus Criteria) due to pneumonia or intra-abdominal infection (cohorts 1-3, n=2534 patients). The primary outcome was 28 day survival. Results for the cohort of patients with sepsis due to pneumonia were combined in a meta-analysis of 1553 patients from all three cohorts, of whom 359 died within 28 days of admission to the intensive-care unit. The most significantly associated single nucleotide polymorphisms (SNPs) were genotyped in a further 538 white patients with sepsis due to pneumonia (cohort 4), of whom 106 died.

FINDINGS

In the genome-wide meta-analysis of three independent pneumonia cohorts (cohorts 1-3), common variants in the FER gene were strongly associated with survival (p=9·7 × 10(-8)). Further genotyping of the top associated SNP (rs4957796) in the additional cohort (cohort 4) resulted in a combined p value of 5·6 × 10(-8) (odds ratio 0·56, 95% CI 0·45-0·69). In a time-to-event analysis, each allele reduced the mortality over 28 days by 44% (hazard ratio for death 0·56, 95% CI 0·45-0·69; likelihood ratio test p=3·4 × 10(-9), after adjustment for age and stratification by cohort). Mortality was 9·5% in patients carrying the CC genotype, 15·2% in those carrying the TC genotype, and 25·3% in those carrying the TT genotype. No significant genetic associations were identified when patients with sepsis due to pneumonia and intra-abdominal infection were combined.

INTERPRETATION

We have identified common variants in the FER gene that associate with a reduced risk of death from sepsis due to pneumonia. The FER gene and associated molecular pathways are potential novel targets for therapy or prevention and candidates for the development of biomarkers for risk stratification.

FUNDING

European Commission and the Wellcome Trust.

Injurious mechanical ventilation causes kidney apoptosis and dysfunction during sepsis but not after intra-tracheal acid instillation: an experimental study

Background

Intratracheal aspiration and sepsis are leading causes of acute lung injury that frequently necessitate mechanical ventilation (MV), which may aggravate lung injury thereby potentially increasing the risk of acute kidney injury (AKI). We compared the effects of ventilation strategies and underlying conditions on the development of AKI.

Methods

Spraque Dawley rats were challenged by intratracheal acid instillation or 24 h of abdominal sepsis, followed by MV with a low tidal volume (LV_T) and 5 cm H₂O positive end-expiratory pressure (PEEP) or a high tidal volume (HV_T) and no PEEP, which is known to cause more lung injury after acid instillation than in sepsis. Rats were ventilated for 4 hrs and kidney function and plasma mediator levels were measured. Kidney injury was assessed by microscopy; apoptosis was quantified by TUNEL staining.

Results

During sepsis, but not after acid instillation, MV with HV_T caused more renal apoptosis than MV with LV_T. Increased plasma active plasminogen activator inhibitor-1 correlated to kidney apoptosis in the cortex and medulla. Increased apoptosis after HV_T ventilation during sepsis was associated with a 40% decrease in creatinine clearance.

Conclusions

AKI is more likely to develop after MV induced lung injury during an indirect (as in sepsis) than after a direct (as after intra-tracheal instillation) insult to the lungs, since it induces kidney apoptosis during sepsis but not after acid instillation, opposite to the lung injury it caused. Our findings thus suggest using protective ventilatory strategies in human sepsis, even in the absence of overt lung injury, to protect the kidney.

Human kallistatin administration reduces organ injury and improves survival in a mouse model of polymicrobial sepsis

Kallistatin, a plasma protein, has been shown to exert multi-factorial functions including inhibition of inflammation, oxidative stress and apoptosis in animal models and cultured cells. Kallistatin levels are reduced in patients with sepsis and in lipopolysaccharide (LPS)-induced septic mice. Moreover, transgenic mice expressing kallistatin are more resistant to LPS-induced mortality. Here, we investigated the effects of human kallistatin on organ injury and survival in a mouse model of polymicrobial sepsis. In this study, mice were injected intravenously with recombinant kallistatin (KS3, 3 mg/kg; or KS10, 10 mg/kg body weight) and then rendered septic by caecal ligation and puncture 30 min later. Kallistatin administration resulted in a > 10-fold reduction of peritoneal bacterial counts, and significantly decreased serum tumour necrosis factor-α, interleukin-6 and high mobility group box-1 (HMGB1) levels. Kallistatin also inhibited HMGB1 and toll-like receptor-4 gene expression in the lung and kidney. Administration of kallistatin attenuated renal damage and decreased blood urea nitrogen and serum creatinine levels, but increased endothelial nitric oxide synthase and nitric oxide levels in the kidney. In cultured endothelial cells, human kallistatin via its heparin-binding site inhibited HMGB1-induced nuclear factor-κB activation and inflammatory gene expression. Moreover, kallistatin significantly reduced apoptosis and caspase-3 activity in the spleen. Furthermore, kallistatin treatment markedly improved the survival of septic mice by 23% (KS3) and 41% (KS10). These results indicate that kallistatin is a unique protecting agent in sepsis-induced organ damage and mortality by inhibiting inflammation and apoptosis, as well as enhancing bacterial clearance in a mouse model of polymicrobial sepsis.

The attributable mortality of acute kidney injury: a sequentially matched analysis*

OBJECTIVE

Acute kidney injury in the critically ill is an independent risk factor for adverse outcome. The magnitude of the impact of acute kidney injury on outcome, however, is still unclear. This study aimed to estimate the excess mortality attributable to acute kidney injury.

DESIGN

We performed a sequentially matched analysis according to the day of acute kidney injury diagnosis after ICU admission. Patients with acute kidney injury and those without acute kidney injury were matched according to age, sex, ICU admission diagnosis, Simplified Acute Physiology Score II without renal and age components, and the propensity to develop acute kidney injury at each of the four matching time points.

SETTING

Cohort of 16 participating ICUs from the prospective Finnish Acute Kidney Injury study.

PATIENTS

Cohort of 2,719 consecutive patients with either emergency admission or elective postsurgical patients with an expected ICU stay greater than 24 hours.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 2,719 patients included in the study, acute kidney injury developed in 1,081 patients (39.8%) according to the Kidney Disease: Improving Global Outcomes-definition during ICU treatment on days 1-5. Of these, 477 patients were successfully matched to 477 patients who did not develop acute kidney injury. The 90-day mortality of the matched patients with acute kidney injury was 125 of 477 (26.2%) compared with 84 of 477 (17.6%) for their matched controls without acute kidney injury. Thus, the absolute excess 90-day mortality attributable to acute kidney injury was estimated at 8.6 percentage points (95% CI, 2.6-17.6 percentage points). The population attributable risk (95% CI) of 90-day mortality associated with acute kidney injury was 19.6% (10.3-34.1%).

CONCLUSIONS

In general ICU patients, the absolute excess 90-day mortality statistically attributable to acute kidney injury is substantial (8.6%), and the population attributable risk was nearly 20%. Our findings are useful in planning suitably powered future clinical trials to prevent and treat acute kidney injury in critically ill patients.

Adiponectin gene polymorphisms and acute respiratory distress syndrome susceptibility and mortality

RATIONALE

Adiponectin is an anti-inflammatory adipokine that is the most abundant gene product of adipose tissue. Lower levels have been observed in obesity, insulin resistance, and in critical illness. However, elevated levels early in acute respiratory failure have been associated with mortality. Polymorphisms in adiponectin-related genes (ADIPOQ, ADIPOR1, ADIPOR2) have been examined for relationships with obesity, insulin resistance and diabetes, cardiovascular disease, and to circulating adipokine levels, but many gaps in knowledge remain. The current study aims to assess the association between potentially functional polymorphisms in adiponectin-related genes with acute respiratory distress syndrome (ARDS) risk and mortality.

METHODS

Consecutive patients with risk factors for ARDS admitted to the ICU were enrolled and followed prospectively for development of ARDS. ARDS cases were followed through day 60 for all-cause mortality. 2067 patients were successfully genotyped using the Illumina CVD BeadChip high-density platform. Of these, 567 patients developed ARDS. Forty-four single nucleotide polymorphisms (SNPs) on ADIPOQ, ADIPOR1 and ADIPOR2 were successfully genotyped. Of these, 9 SNPs were hypothesized to be functional based on their location (promoter, exon, or 3' untranslated region). These 9 SNPs were analyzed for association with ARDS case status and mortality among ARDS cases.

RESULTS

After multivariable analysis and adjustment for multiple comparisons, no SNPs were significantly associated with ARDS case status. Among ARDS cases, homozygotes for the minor allele of rs2082940 (ADIPOQ) had increased mortality (hazard ratio 2.61, 95% confidence interval 1.36-5.00, p = 0.0039) after adjustment for significant covariates. The significance of this association persisted after adjustment for multiple comparisons (FDR_q = 0.029).

CONCLUSIONS

A common and potentially functional polymorphism in ADIPOQ may impact survival in ARDS. Further studies are required to replicate these results and to correlate genotype with circulating adiponectin levels.

Kallistatin modulates immune cells and confers anti-inflammatory response to protect mice from group A streptococcal infection

Group A streptococcus (GAS) infection may cause severe life-threatening diseases, including necrotizing fasciitis and streptococcal toxic shock syndrome. Despite the availability of effective antimicrobial agents, there has been a worldwide increase in the incidence of invasive GAS infection. Kallistatin (KS), originally found to be a tissue kallikrein-binding protein, has recently been shown to possess anti-inflammatory properties. However, its efficacy in microbial infection has not been explored. In this study, we transiently expressed the human KS gene by hydrodynamic injection and investigated its anti-inflammatory and protective effects in mice via air pouch inoculation of GAS. The results showed that KS significantly increased the survival rate of GAS-infected mice. KS treatment reduced local skin damage and bacterial counts compared with those in mice infected with GAS and treated with a control plasmid or saline. While there was a decrease in immune cell infiltration of the local infection site, cell viability and antimicrobial factors such as reactive oxygen species actually increased after KS treatment. The efficiency of intracellular bacterial killing in neutrophils was directly enhanced by KS administration. Several inflammatory cytokines, including tumor necrosis factor alpha, interleukin 1β, and interleukin 6, in local infection sites were reduced by KS. In addition, KS treatment reduced vessel leakage, bacteremia, and liver damage after local infection. Therefore, our study demonstrates that KS provides protection in GAS-infected mice by enhancing bacterial clearance, as well as reducing inflammatory responses and organ damage.