β-Casomorphin-7 Ameliorates Sepsis-Induced Acute Kidney Injury by Targeting NF-κB Pathway

Worldwide research on the health effects of bovine milk containing A1 and A2 β-casein: Unraveling the current scenario and future trends through bibliometrics and text mining

The possible adverse effect of consuming bovine milk with A1 β-casein (but not with A2 β-casein) on health aspects due to the release of β-casomorphin-7 (BCM-7) is currently under debate. The aim of this study was to perform a bibliometric analysis of studies extracted from Scopus to explore the relationship between BCM-7, A1 or A2 bovine milk with different aspects of health. Over time, several research groups were formed that are no longer active and although some authors have returned to the field of study, they have focused their efforts mainly on conducting reviews that show the same imprecise conclusions due to the few original articles. Research is concentrated in Europe and Asia, where New Zealand, China and Germany are the countries with the most publications, records and citations on the subject, respectively. On the other hand, no country in Africa or South America has scientific production, which opens the possibility of building collaborations between countries and exploring areas that lack scientific studies. Based on conflicting information from primarily in vitro and animal studies, and limited clinical trials with poor designs, A1 milk presents pro-inflammatory and oxidative activity, but the evidence is insufficient to associate its consumption with negative health effects. However, A2 milk may be better tolerated by the digestive system of some individuals, suggesting its possible modulating role in the intestinal microbiota. Stronger scientific evidence is needed to reach a consensus on whether the presence of β-casein A1 can significantly negatively affect health. The information shown will allow a better understanding of the subject and consumers will be able to make their own decisions regarding A1 or A2 milk.

MicroRNAs in septic acute kidney injury

Sepsis is a potentially fatal complication of burns and trauma that can cause acute kidney injury (AKI) with substantial morbidity and mortality, but this disease is poorly understood. Despite medical advances, effective therapeutic regimens for septic AKI remain uncommon. MicroRNAs (miRNAs) are endogenous non-coding RNAs that influence the translation of target messenger RNAs in a variety of biological processes. Emerging evidence has shown that miRNAs are intimately associated with septic AKI. The goal of this review was to summarize recent advances in the profound understanding of the functional role of miRNAs in septic AKI, as well as to provide new insights into miRNAs as feasible biomarkers and therapeutic targets for septic AKI.

Protective Effect and Possible Mechanisms of Artemisinin and Its Derivatives for Diabetic Nephropathy: A Systematic Review and Meta-Analysis in Animal Models

Background

Artemisinin and its derivatives have potential antidiabetic effects. There is no evaluation of reported studies in the literature on the treatment of diabetic nephropathy (DN), one of the commonest diabetic microangiopathies, with artemisinins. Here, we aimed to evaluate preclinical evidence for the efficacy and possible mechanisms of artemisinins in reducing diabetic renal injury.

Methods

We conducted an electronic literature search in fourteen databases from their inception to November 2021. All animal studies assessing the efficacy and safety of artemisinins in DN were included, regardless of publication or language. Overall, 178 articles were screened according to predefined inclusion and exclusion criteria. Finally, 18 eligible articles were included in this systematic review. The SYstematic Review Center for Laboratory animal Experimentation (SYRCLE) risk-of-bias tool was used to assess the risk of bias in the included studies. The primary outcomes were kidney function, proteinuria, and renal pathology. Secondary endpoints included changes in fasting plasma glucose (FPG) levels, body weight, and relevant mechanisms.

Results

Of the 18 included articles involving 418 animal models of DN, 1, 2, 6, and 9 used dihydroartemisinin, artemether, artesunate, and artemisinin, respectively. Overall, artemisinins reduced indicators of renal function, including blood urea nitrogen (P < 0.00001), serum creatinine (P < 0.00001), and kidney index (P = 0.0001) compared with control group treatment. Measurements of proteinuria (P < 0.00001), microalbuminuria (P < 0.05), and protein excretion (P = 0.0002) suggested that treatment with artemisinins reduced protein loss in animals with DN. Artemisinins may lower blood glucose levels (P = 0.01), but there is a risk of weight gain (P < 0.00001). Possible mechanisms of action of artemisinins include delaying renal fibrosis, reducing oxidative stress, and exerting antiapoptotic and anti-inflammatory effects.

Conclusion

Available evidence suggests that artemisinins may be protective against renal injury secondary to diabetes in preclinical studies; however, high-quality and long-term trials are needed to reliably determine the balance of benefits and harms.

Enhancement of Anti-Tumoral Immunity by β-Casomorphin-7 Inhibits Cancer Development and Metastasis of Colorectal Cancer

β-Casomorphin-7 (BCM) is a degradation product of β-casein, a milk component, and has been suggested to affect the immune system. However, its effect on mucosal immunity, especially anti-tumor immunity, in cancer-bearing individuals is not clear. We investigated the effects of BCM on lymphocytes using an in vitro system comprising mouse splenocytes, a mouse colorectal carcinogenesis model, and a mouse orthotopic colorectal cancer model. Treatment of mouse splenocytes with BCM in vitro reduced numbers of cluster of differentiation (CD) 20⁺ B cells, CD4⁺ T cells, and regulatory T cells (Tregs), and increased CD8⁺ T cells. Administration of BCM and the CD10 inhibitor thiorphan (TOP) to mice resulted in similar alterations in the lymphocyte subsets in the spleen and intestinal mucosa. BCM was degraded in a concentration- and time-dependent manner by the neutral endopeptidase CD10, and the formed BCM degradation product did not affect the lymphocyte counts. Furthermore, degradation was completely suppressed by TOP. In the azoxymethane mouse colorectal carcinogenesis model, the incidence of aberrant crypt foci, adenoma, and adenocarcinoma was reduced by co-treatment with BCM and TOP. Furthermore, when CT26 mouse colon cancer cells were inoculated into the cecum of syngeneic BALB/c mice and concurrently treated with BCM and TOP, infiltration of CD8⁺ T cells was promoted, and tumor growth and liver metastasis were suppressed. These results suggest that by suppressing the BCM degradation system, the anti-tumor effect of BCM is enhanced and it can suppress the development and progression of colorectal cancer.

A1- and A2 beta-casein on health-related outcomes: a scoping review of animal studies

PURPOSE

Food-derived bioactive peptides may influence important physiological functions. An important example is beta-casomorphins, which are opioid peptides derived from A1 beta-casein in bovine milk and have been associated to be risk factors for non-communicable diseases in humans. A1 and A2 beta-casein are different with respect to the release of bioactive peptides, in particular BCM-7. However, evidence from human studies is limited and could be complemented with evidence derived from animal studies. We conducted a scoping review to identify animal studies investigating the effects of A1 beta-casein or BCM-7 compared to A2 beta-casein or any other intervention on health-related outcomes.

METHODS

We systematically searched for relevant studies in two electronic databases (Medline, Embase; last search performed March 2020). Two reviewers independently undertook study selection and data extraction of included references. Results were summarized tabularly and narratively.

RESULTS

We included 42 studies investigating various animal models, including rats, mice, rabbits, and dogs. Six studies investigated health-related outcomes of A1- vs. A2 milk, while most studies (n = 36) reported on physiological properties (e.g., analgesic effect) of BCM-7 as an opioid peptide. Included studies were extremely heterogeneous in terms of the study population, type of intervention and dose, and type of outcome measures.

CONCLUSIONS

Only a few studies comparing the effects of A1- and A2 milk were identified. More studies addressing this research question in animal models are needed to provide essential information to inform research gaps. Results from future studies could eventually complement research for humans, particularly when the body of evidence remains uncertain as is the case in the A1- and A2 milk debate.

MIR210HG Aggravates Sepsis-Induced Inflammatory Response of Proximal Tubular Epithelial Cell via the NF-κB Signaling Pathway

PURPOSE

Acute kidney injury (AKI) is a serious complication of sepsis and is characterized by inflammatory response. MicroRNA-210 host gene (MIR210HG) is upregulated in human proximal tubular epithelial cells under treatment of inflammatory cytokines. This study aimed to explore the role of MIR210HG in sepsis-induced AKI.

MATERIALS AND METHODS

Cell viability was detected by a cell counting kit 8 assay. The levels of proinflammatory cytokines were detected by enzyme-linked immunosorbent assay kits. The protein levels of p65, IκBα, and p-IκBα were examined by western blot analysis. The nuclear translocation of nuclear factor kappa B (NF-κB) was detected by immunofluorescence assay. The histological changes of kidneys were analyzed by hematoxylin and eosin staining assay.

RESULTS

Lipopolysaccharide (LPS) treatment significantly inhibited cell viability and increased productions of proinflammatory cytokines in proximal tubular epithelial cells (HKC-8). Additionally, MIR210HG levels in HKC-8 cells were increased by LPS treatment. MIR210HG silencing inhibited the LPS-induced cell inflammatory response. MIR210HG activated the NF-κB signaling pathway by promoting the phosphorylation of IκBα and nuclear translocation of p65. Rescue assays revealed that the MIR210HG-induced increase of cytokines levels and decline of cell viability were rescued by QNZ treatment. Knockdown of MIR210HG decreased blood urea nitrogen, serum creatinine, and proinflammatory cytokine levels in AKI rats. Moreover, the knockdown of MIR210HG protected against AKI-induced histological changes of kidneys in rats.

CONCLUSION

MIR210HG promotes sepsis-induced inflammatory response of HKC-8 cells by activating the NF-κB signaling pathway. This novel discovery may be helpful for the improvement of sepsis-induced AKI.

Keratin Scaffolds Containing Casomorphin Stimulate Macrophage Infiltration and Accelerate Full-Thickness Cutaneous Wound Healing in Diabetic Mice

Impaired wound healing is a major medical challenge, especially in diabetics. Over the centuries, the main goal of tissue engineering and regenerative medicine has been to invent biomaterials that accelerate the wound healing process. In this context, keratin-derived biomaterial is a promising candidate due to its biocompatibility and biodegradability. In this study, we evaluated an insoluble fraction of keratin containing casomorphin as a wound dressing in a full-thickness surgical skin wound model in mice (n = 20) with iatrogenically induced diabetes. Casomorphin, an opioid peptide with analgesic properties, was incorporated into keratin and shown to be slowly released from the dressing. An in vitro study showed that keratin-casomorphin dressing is biocompatible, non-toxic, and supports cell growth. In vivo experiments demonstrated that keratin-casomorphin dressing significantly (p < 0.05) accelerates the whole process of skin wound healing to the its final stage. Wounds covered with keratin-casomorphin dressing underwent reepithelization faster, ending up with a thicker epidermis than control wounds, as confirmed by histopathological and immunohistochemical examinations. This investigated dressing stimulated macrophages infiltration, which favors tissue remodeling and regeneration, unlike in the control wounds in which neutrophils predominated. Additionally, in dressed wounds, the number of microhemorrhages was significantly decreased (p < 0.05) as compared with control wounds. The dressing was naturally incorporated into regenerating tissue during the wound healing process. Applied keratin dressing favored reconstruction of more regular skin structure and assured better cosmetic outcome in terms of scar formation and appearance. Our results have shown that insoluble keratin wound dressing containing casomorphin supports skin wound healing in diabetic mice.

Endothelial progenitor cells-derived exosomal microRNA-21-5p alleviates sepsis-induced acute kidney injury by inhibiting RUNX1 expression

The role of microRNA-21-5p (miR-21-5p) in sepsis-induced acute kidney injury (AKI) has been seldom discussed. Therefore, the objective of this present study was to investigate the mechanism of endothelial progenitor cells-derived exosomes (EPCs-exos) in sepsis-induced AKI via miR-21-5p/runt-related transcription factor 1 (RUNX1) axis. miR-21-5p was downregulated and RUNX1 was upregulated in the kidney of cecal ligation and puncture (CLP) rats, and miR-21-5p targeted RUNX1. Elevation of miR-21-5p improved renal function and renal tissue pathological damage, attenuated serum inflammatory response, as well as reduced apoptosis and oxidative stress response in renal tissues, and regulated endothelial glycocalyx damage marker proteins syndecan-1 and heparanase-1 in CLP rats. Overexpression of RUNX1 abolished the impacts of elevated miR-21-5p in CLP rats. Also, EPCs-exos upregulated miR-21-5p expression, and functioned similar to elevation of miR-21-5p for CLP rats. Downregulating miR-21-5p partially reversed the effects of EPCs-exos on sepsis-induced AKI. Collectively, our study suggests that EPCs release miR-21-5p-containing exosomes to alleviate sepsis-induced AKI through RUNX1 silencing.

SHP2 inhibitor PHPS1 ameliorates acute kidney injury by Erk1/2-STAT3 signaling in a combined murine hemorrhage followed by septic challenge model

BACKGROUND

Hypovolemic shock and septic challenge are two major causes of acute kidney injury (AKI) in the clinic setting. Src homology 2 domain-containing phosphatase 2 (SHP2) is one of the major protein phosphatase tyrosine phosphatase (PTPs), which play a significant role in maintaining immunological homeostasis by regulating many facets of immune cell signaling. In this study, we explored whether SHP2 signaling contributed to development of AKI sequential hemorrhage (Hem) and cecal ligation and puncture (CLP) and whether inactivation of SHP2 through administration of its selective inhibitor, phenylhydrazonopyrazolone sulfonate 1 (PHPS1), attenuated this injury.

METHODS

Male C57BL/6 mice were subjected to Hem (a "priming" insult) followed by CLP or sham-Hem plus sham-CLP (S/S) as controls. Samples of blood and kidney were harvested at 24 h post CLP. The expression of neutrophil gelatinase-associated lipocalin (NGAL), high mobility group box 1 (HMGB1), caspase3 as well as SHP2:phospho-SHP2, extracellular-regulated kinase (Erk1/2): phospho-Erk1/2, and signal transducer and activator of transcription 3 (STAT3):phospho-STAT3 protein in kidney tissues were detected by Western blotting. The levels of creatinine (Cre) and blood urea nitrogen (BUN) in serum were measured according to the manufacturer's instructions. Blood inflammatory cytokine/chemokine levels were detected by ELISA.

RESULTS

We found that indices of kidney injury, including levels of BUN, Cre and NGAL as well as histopathologic changes, were significantly increased after Hem/CLP in comparison with that in the S/S group. Furthermore, Hem/CLP resulted in elevated serum levels of inflammatory cytokines/chemokines, and induced increased levels of HMGB1, SHP2:phospho-SHP2, Erk1/2:phospho-Erk1/2, and STAT3:phospho-STAT3 protein expression in the kidney. Treatment with PHPS1 markedly attenuated these Hem/CLP-induced changes.

CONCLUSIONS

In conclusion, our data indicate that SHP2 inhibition attenuates AKI induced by our double-hit/sequential insult model of Hem/CLP and that this protective action may be attributable to its ability to mitigate activation of the Erk1/2 and STAT3 signaling pathway. We believe this is a potentially important finding with clinical implications warranting further investigation.

The Protective Effects of Perindopril Against Acute Kidney Damage Caused by Septic Shock

Acute kidney injury (AKI) resulting from septic shock caused by sepsis is an important health problem encountered at rates of 55-73%. Increasing oxidative stress and inflammation following sepsis is a widely observed condition with rising mortality rates. The purpose of this study was to determine whether perindopril (PER) can prevent sepsis-associated AKI with its antioxidant, anti-inflammatory, and anti-apoptotic effects. The control group received an oral saline solution only for 4 days. Cecal ligation and puncture (CLP)-induced sepsis only was applied to the CLP group, while the CLP + PER (2 mg/kg) received CLP-induced sepsis together with 2 mg/kg PER via the oral route for 4 days before induction of sepsis. Finally, all rats were euthanized by anesthesia and sacrificed. TBARS, total SH levels and NF-κβ, TNF-α, and Caspase-3 expression were then calculated for statistical analysis. TBARS, total SH, NF-kβ/p65, TNF-a, and Caspase-3 levels increased in the CLP group. In contrast, oral administration of PER (2 mg/kg) to septic rats reduced TBARS levels and NF-kβ/p65, TNF-α, and Caspase-3 immunopositivity at biochemical analysis. PER treatment appears to be a promising method for preventing sepsis-induced acute kidney injury through its antioxidant anti-inflammation and anti-apoptotic activities.

β-Casomorphin: A complete health perspective

β-Casomorphin-7 (BCM-7) is a heptapeptide dietary molecule derived from the digestion of the β-casein of dairy and dairy products. In this review, we have covered the extensive details about BCM and its derived peptides out of the gastrointestinal and enzymatic digestion of milk and milk products, its structure and properties, and its immunological aspects related to human health among infants and adults of both genders. We have left judgment about BCM's pros and cons to the reader by describing the details in a cyclopedic perspective. In addition, a section on the possible ways to detect BCMs from their sources using proteomics, genome-based techniques, such as PCR and aptamers, and other analytical techniques equip the reader to get an idea about the details of the diagnostics available and possible applications in future. Overall, this review will provide information to the end-users of milk and milk products to enable them to make their own decisions about BCMs.

NEAT1 aggravates sepsis-induced acute kidney injury by sponging miR-22-3p

Background and aim

Acute kidney injury (AKI) is a common complication of sepsis. Long noncoding RNA nuclear-enriched abundant transcript 1 (NEAT1) plays a vital role in various diseases, including AKI. This study aimed to investigate the function and mechanism of NEAT1 in sepsis-induced AKI.

Materials and methods

A septic AKI model was established by treating HK-2 cells with lipopolysaccharide (LPS). The levels of NEAT1 and miR-22-3p were measured by quantitative real-time PCR. Cell apoptosis was assessed by flow cytometry. The levels of apoptosis-related protein and autophagy-related factors were examined by the western blot assay. An enzyme-linked immunosorbent assay was used to calculate the contents of inflammatory factors. The interaction between NEAT1 and miR-22-3p was validated by dual-luciferase reporter assay, RNA immunoprecipitation assay, and RNA pull-down assay. The levels of nuclear factor (NF)-κB pathway-related proteins were evaluated by the western blot assay.

Results

NEAT1 was upregulated, while miR-22-3p was downregulated in patients with sepsis and in LPS-stimulated HK-2 cells. LPS treatment triggered cell apoptosis, autophagy, and inflammatory response in HK-2 cells. NEAT1 knockdown attenuated LPS-induced cell injury. NEAT1 modulated LPS-triggered cell injury by targeting miR-22-3p. Furthermore, NEAT1 regulated the NF-κB pathway by modulating miR-22-3p.

Conclusion

Depletion of NEAT1 alleviated sepsis-induced AKI via regulating the miR-22-3p/NF-κB pathway.

Casein and Peptides Derived from Casein as Antileukaemic Agents

Milk is a heterogeneous lacteal secretion mixture of numerous components that exhibit a wide variety of chemical and functional activities. Casein, the main protein in milk, is composed of α-, β-, and κ-caseins, each of which is important for nutritional value and for promoting the release of cytokines, also are linked to the regulation of haematopoiesis and immune response and inhibit the proliferation and induce the differentiation of leukaemia cells. It has been shown that the digestive process of caseins leads to the release of bioactive peptides that are involved in the regulation of blood pressure and the inhibition or activation of the immune response by serving as agonists or antagonists of opioid receptors, thus controlling the expression of genes that exert epigenetic control. Later, they bind to opioid receptor, block nuclear factor κ-beta, increase the redox potential, and reduce oxidative stress and the pro-inflammatory agents that favour an antioxidant and anti-inflammatory environment. Therefore, the bioactive peptides of casein could be compounds with antileukaemia potential. This review provides a summary of current knowledge about caseins and casein peptides on the immune system as well as their roles in the natural defence against the development of leukaemia and as relevant epigenetic regulators that can help eradicate leukaemia.

miR-497a-5p attenuates lipopolysaccharide-induced inflammatory injury by targeting IRAK2

Acute lung injury (ALI) is a severe acute inflammatory reaction of the lungs caused by a variety of factors, which can lead to a high mortality rate. MicroRNAs are a novel therapeutic molecule that play a vital role in many diseases. However, its mechanism of action in lipopolysaccharide (LPS)-induced mouse ALI is not clear. The study aimed to investigate the mechanism of action of miR-497 in LPS-induced ALI. As a result, it was found that the expression of miR-497 in the inflammatory reaction showed a decrease in time and dose trends. Importantly, miR-497 reduced LPS-induced expression levels of related inflammatory factors. In addition, we also demonstrated that IRAK2 is a direct target molecule of miR-497. Interestingly, we further found that miR-497 inhibits the expression of IRAK2 by targeting IRAK2-3'UTR. Therefore, miR-497 can partially negatively regulate the activation of IRAK2-NF-κB pathway in LPS-induced inflammatory responses.