Blocking Macrophage Migration Inhibitory Factor Protects Against Cisplatin-Induced Acute Kidney Injury in Mice

Macrophage Migration Inhibitory Factor (MIF) is a Key Player in Dry Eye Disease

PURPOSE

To explore the role of the proinflammatory cytokine, macrophage migration inhibitory factor (MIF), in a murine model of dry eye disease (DED).

METHODS

The role of MIF on DED was determined using genetically MIF deficient mice and pharmacological inhibition of MIF. DED was induced with 0.5 mg of scopolamine via subcutaneous injection in wild type (WT) and mice lacking MIF (Mif-/-), three times a day for 21 days. DED signs, tear volume, ferning pattern and cytology impression were evaluated. Also, eye tissues were collected to determine transcripts of key inflammatory mediators and histopathological damage. In a second set of experiments, we neutralized MIF with ISO-1, an isozaxiline-derivative MIF tautomerase activity-inhibiting small molecule in WT mice, following an acute DED model for 10 days. ISO-1 was given starting on day 3 after DED induction and signs were evaluated, including a recovery phase in both experimental approaches.

RESULTS

When compared to WT, Mif-/- mice showed attenuated signs of DED like preserved mucin pattern and increased tear volume. Also, Mif-/- mice maintained conjunctival epithelial cells and less corneal damage, associated with lower levels of TNFα and IL-1β. At recovery phase, Mif-/- mice presented improved signs. Interestingly, in cornea and conjunctiva the absence of MIF selectively downregulated the transcription of inflammatory enzymes like inos and nox4 whereas displayed enhanced transcripts of il-4, il-13, tgfβ and cox2. Finally, pharmacological inhibition of MIF using ISO-1, replicated the above findings in the mouse model.

CONCLUSION

MIF is a central positive mediator of the inflammatory process in experimental DED, thus, targeting MIF could be used as a novel therapy in ocular surface inflammatory pathologies.

CD8 + CD103 + iTregs protect against ischemia-reperfusion-induced acute kidney Injury by inhibiting pyroptosis

The occurrence of acute kidney injury (AKI) is elevated, one of the main causes is ischemia-reperfusion (I/R). However, no specific therapy is currently available to treat I/R-induced AKI (I/R-AKI). Treg cells have been demonstrated to perform an anti-inflammatory role in a range of autoimmune and inflammatory illnesses. However, there is limited available information about the possible functions of CD8 + CD103 + iTregs in I/R-AKI. We utilized renal tubular epithelial cells (RTECs) subjected to hypoxia-reoxygenation (H/R) and I/R-AKI mouse model to investigate whether CD8 + CD103 + iTregs could attenuate AKI and the underlying mechanism. In vitro, co-cultured with CD8 + CD103 + iTregs alleviated H/R-induced cell injury. After treatment of CD8 + CD103 + iTregs rather than control cells, a significant improvement of I/R-AKI was observed in vivo, including decreased serum creatinine (sCr) and blood urea nitrogen (BUN) levels, reduced renal pathological injury, lowered tubular apoptosis and inhibition of the transition from AKI to chronic kidney disease (CKD). Mechanically, CD8 + CD103 + iTregs alleviated H/R-induced cell injury and I/R-AKI partly by suppressing RTECs pyroptosis via inhibiting the NLRP3/Caspase-1 axis. Our study provides a novel perspective on the possibility of CD8 + CD103 + iTregs for the treatment of I/R-AKI.

Lymphocytes and innate immune cells in acute kidney injury and repair

Acute kidney injury (AKI) is a common and serious disease entity that affects native kidneys and allografts but for which no specific treatments exist. Complex intrarenal inflammatory processes driven by lymphocytes and innate immune cells have key roles in the development and progression of AKI. Many studies have focused on prevention of early injury in AKI. However, most patients with AKI present after injury is already established. Increasing research is therefore focusing on mechanisms of renal repair following AKI and prevention of progression from AKI to chronic kidney disease. CD4+ and CD8+ T cells, B cells and neutrophils are probably involved in the development and progression of AKI, whereas regulatory T cells, double-negative T cells and type 2 innate lymphoid cells have protective roles. Several immune cells, such as macrophages and natural killer T cells, can have both deleterious and protective effects, depending on their subtype and/or the stage of AKI. The immune system not only participates in injury and repair processes during AKI but also has a role in mediating AKI-induced distant organ dysfunction. Targeted manipulation of immune cells is a promising therapeutic strategy to improve AKI outcomes.

Calycosin inhibited MIF-mediated inflammatory chemotaxis of macrophages to ameliorate ischemia reperfusion-induced acute kidney injury

BACKGROUND

Inflammatory macrophage infiltration plays a critical role in acute kidney disease induced by ischemia-reperfusion (IRI-AKI). Calycosin is a natural flavone with multiple bioactivities. This study aimed to investigate the therapeutic role of calycosin in IRI-AKI and its underlying mechanism.

METHODS

The renoprotective and anti-inflammatory effects of calycosin were analyzed in C57BL/6 mice with IRI-AKI and lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. RNA-seq was used for mechanism investigation. The molecular target of calycosin was screened by in silico methods and validated by surface plasmon resonance (SPR). Macrophage chemotaxis was analyzed using Transwell and agarose gel spot assays.

RESULTS

Calycosin treatment significantly reduced serum creatinine and urea nitrogen and attenuated tubular destruction in IRI-AKI mice. Additionally, calycosin markedly suppressed NF-κB signaling activation and the expression of inflammatory mediators IL-1β and TNF-α in IRI-AKI kidneys and LPS-stimulated RAW 264.7 cells. Interestingly, RNA-seq revealed calycosin remarkably downregulated chemotaxis-related pathways in RAW 264.7 cells. Among the differentially expressed genes, Ccl2/MCP-1, a critical chemokine mediating macrophage inflammatory chemotaxis, was downregulated in both LPS-stimulated RAW 264.7 cells and IRI-AKI kidneys. Consistently, calycosin treatment attenuated macrophage infiltration in the IRI-AKI kidneys. Importantly, in silico target prediction, molecular docking, and SPR assay demonstrated that calycosin directly binds to macrophage migration inhibitory factor (MIF). Functionally, calycosin abrogated MIF-stimulated NF-κB signaling activation and Ccl2 expression and MIF-mediated chemotaxis in RAW 264.7 cells.

CONCLUSIONS

In summary, calycosin attenuates IRI-AKI by inhibiting MIF-mediated macrophage inflammatory chemotaxis, suggesting it could be a promising therapeutic agent for the treatment of IRI-AKI.

Macrophage-derived macrophage migration inhibitory factor mediates renal injury in anti-glomerular basement membrane glomerulonephritis

Macrophages are a rich source of macrophage migration inhibitory factor (MIF). It is well established that macrophages and MIF play a pathogenic role in anti-glomerular basement membrane crescentic glomerulonephritis (anti-GBM CGN). However, whether macrophages mediate anti-GBM CGN via MIF-dependent mechanism remains unexplored, which was investigated in this study by specifically deleting MIF from macrophages in MIFf/f-lysM-cre mice. We found that compared to anti-GBM CGN induced in MIFf/f control mice, conditional ablation of MIF in macrophages significantly suppressed anti-GBM CGN by inhibiting glomerular crescent formation and reducing serum creatinine and proteinuria while improving creatine clearance. Mechanistically, selective MIF depletion in macrophages largely inhibited renal macrophage and T cell recruitment, promoted the polarization of macrophage from M1 towards M2 via the CD74/NF-κB/p38MAPK-dependent mechanism. Unexpectedly, selective depletion of macrophage MIF also significantly promoted Treg while inhibiting Th1 and Th17 immune responses. In summary, MIF produced by macrophages plays a pathogenic role in anti-GBM CGN. Targeting macrophage-derived MIF may represent a novel and promising therapeutic approach for the treatment of immune-mediated kidney diseases.

Role of renal tubular epithelial cells and macrophages in cisplatin-induced acute renal injury

Acute kidney injury (AKI) is a clinical syndrome characterized by a sudden and continuous decline in renal function. The drug cisplatin is commonly used as chemotherapy for solid tumors, and cisplatin-induced acute kidney injury (CI-AKI), which is characterized by acute tubular necrosis and inflammation, frequently occurs in tumor patients. Renal tubular epithelial cells (RTECs) are severely damaged early in this process and play an important role in renal tubular injury and the recruitment of immune cells. Macrophages are the most common infiltrating immune cells in the kidney and have a significant impact on CI-AKI and subsequent repair. This article reviews the latest research progress on the effects of RTECs and macrophages on CI-AKI and their interactions in AKI to provide a direction for identifying therapeutic targets for treating AKI.

Role of epigenetically regulated inflammation in renal diseases

In recent decades, renal disease research has witnessed remarkable advances. Experimental evidence in this field has highlighted the role of inflammation in kidney disease. Epigenetic dynamics and immunometabolic reprogramming underlie the alterations in cellular responses to intrinsic and extrinsic stimuli; these factors determine cell identity and cell fate decisions and represent current research hotspots. This review focuses on recent findings and emerging concepts in epigenetics and inflammatory regulation and their effect on renal diseases. This review aims to summarize the role and mechanisms of different epigenetic modifications in renal inflammation and injury and provide new avenues for future research on inflammation-related renal disease and drug development.

Phosphorylation of MIF by PIP4K2a is necessary for cilia biogenesis

Primary cilia are microtubule-based organelles that play important roles in development and tissue homeostasis. Macrophage migration inhibitory factor (MIF) has long been recognized as a secreted cytokine in the pathogenesis of various human diseases, including cancer and autosomal dominant polycystic kidney disease (ADPKD). Unlike other cytokines, unique functional characteristics of intracellular MIF have emerged. In this study, we show that MIF is localized and formed a ring like structure at the proximal end of centrioles, where it regulates cilia biogenesis through affecting 1) the recruitment of TTBK2 to basal body and the removal of CP110 from mother centriole, 2) the accumulation of CEP290 at centriolar satellites, and 3) the trafficking of intraflagellar transport (IFT) related proteins. We also show that MIF functions as a novel transcriptional factor to regulate the expression of genes related to ciliogenesis via binding on the promotors of those genes. MIF also binds chromatin and regulates transcription of genes involved in diverse homeostatic signaling pathways. We identify phosphatidylinositol-5-phosphate 4-kinase type 2 alpha (PIP4K2a) as an upstream regulator of MIF, which interacts with and phosphorylates MIF at S91 to increase its interaction with 14-3-3ζ, resulting in its nuclear translocation and transcription regulation. This study suggests that MIF is a key player in cilia biogenesis and a novel transcriptional regulator in homeostasis, which forward our understanding of how MIF is able to carry out several nonoverlapping functions.

Targeting macrophage migration inhibitory factor (MIF): a promising therapy for inflammatory ocular diseases

Inflammatory ocular diseases are characterized by the presence of a persistent inflammatory response which cause tissue injury, decrease visual acuity and in severe cases, blindness. Several cytokines represent a therapeutic opportunity since they are key amplifiers of these pathologies, and thus neutralizing agents against them have been developed. Amongst others, macrophage migration inhibitory factor (MIF), an early produced inflammatory cytokine, has consistently been found elevated in patients with distinct ocular diseases (inflammatory and autoimmune). Here, we present and discuss evidence showing that preclinical trials using diverse strategies to neutralize MIF resulted in significant attenuation of disease signs and therefore MIF blockage might be a promising therapy for ocular diseases.

Macrophage-derived exosomal miR-195a-5p impairs tubular epithelial cells mitochondria in acute kidney injury mice

Macrophages (Mφ) infiltration is a common characteristic of acute kidney injury (AKI). Exosomes-mediated cell communication between tubular epithelial cells (TECs) and Mφ has been suggested to be involved in AKI. Exosomes-derived from injured TECs could regulate Mφ polarization during AKI. However, little is known regarding how activated Mφ regulates kidney injury. To explore the role of activated Mφ in the AKI process, we revealed that Mφ-derived exosomes from AKI mice (Exos^AKI ) caused mitochondria damage and induced TECs injury. Then, we detected the global miRNA expression profiles of Mφ^NC and Mφ^AKI and found that among the upregulated miRNAs, miR-195a-5p, which regulates mitochondria metabolism in cancer, was significantly increased in Mφ^AKI . Due to the enrichment of miR-195a-5p in Exos^AKI , the miR-195a-5p level in the kidney was elevated in AKI mice. More interestingly, based on the high expression of pri-miR-195a-5p in kidney-infiltrated Mφ, and the reduction of miR-195a-5p in kidney after depletion of Mφ in AKI mice, we confirmed that miR-195a-5p may be produced in infiltrated Mφ, and shuttled into TECs via Exos^Mφ . Furthermore, in vitro inhibition of miR-195a-5p alleviated the effect of Exos^AKI induced mitochondrial dysfunction and cell injury. Consistently, antagonizing miR-195a-5p with a miR-195a-5p antagomir attenuated cisplatin-induced kidney injury and mitochondrial dysfunction in mice. These findings revealed that the Mφ exosomal miR-195a-5p derived from AKI mice played a critical pathologic role in AKI progression, representing a new therapeutic target for AKI.

Neuropeptide Y protects kidney from acute kidney injury by inactivating M1 macrophages via the Y1R-NF-κB-Mincle-dependent mechanism

Neuropeptide Y (NPY) is produced by the nerve system and may contribute to the progression of CKD. The present study found the new protective role for NPY in AKI in both patients and animal models. Interestingly, NPY was constitutively expressed in blood and resident kidney macrophages by co-expressing NPY and CD68+ markers, which was lost in patients and mice with AKI-induced by cisplatin. Unexpectedly, NPY was renoprotective in AKI as mice lacking NPY developed worse renal necroinflammation and renal dysfunction in cisplatin and ischemic-induced AKI. Importantly, NPY was also a therapeutic agent for AKI because treatment with exogenous NPY dose-dependently inhibited cisplatin-induced AKI. Mechanistically, NPY protected kidney from AKI by inactivating M1 macrophages via the Y1R-NF-κB-Mincle-dependent mechanism as deleting or silencing NPY decreased Y1R but increased NF-κB-Mincle-mediated M1macrophage activation and renal necroinflammation, which were reversed by addition of NPY or by silencing Mincle but promoted by blocking Y1R with BIBP 3226. Thus, NPY is renoprotective and may be a novel therapeutic agent for AKI. NPY may act via Y1R to protect kidney from AKI by blocking NF-κB-Mincle-mediated M1 macrophage activation and renal necroinflammation.

Macrophage migration inhibitory factor in acute kidneyinjury

Acute kidney injury (AKI) is a complex clinical syndrome with multiple etiologies and pathogenesis, which lacks early biomarkers and targeted therapy. Recently, macrophage migration inhibitory factor (MIF) family protein have received increasing attention owing to its pleiotropic protein molecule character in acute kidney injury, where it performed a dual role in the pathological process. macrophage migration inhibitory factor and macrophage migration inhibitory factor-2 are released into the peripheral circulation when Acute kidney injury occurs and interact with various cellular pathways. On the one hand, macrophage migration inhibitory factor exerts a protective effect in anti-oxidation and macrophage migration inhibitory factor-2 promotes cell proliferation and ameliorates renal fibrosis. On the other hand, macrophage migration inhibitory factor aggravates renal injury as an upstream inflammation factor. Herein, we provide an overview on the biological role and possible mechanisms of macrophage migration inhibitory factor and macrophage migration inhibitory factor-2 in the process of Acute kidney injury and the clinical application prospects of macrophage migration inhibitory factor family proteins as a potential therapeutic target.

Pro-Inflammatory Signalling PRRopels Cisplatin-Induced Toxicity

Cisplatin is a platinum-based chemotherapeutic that has long since been effective against a variety of solid-cancers, substantially improving the five-year survival rates for cancer patients. Its use has also historically been limited by its adverse drug reactions, or cisplatin-induced toxicities (CITs). Of these reactions, cisplatin-induced nephrotoxicity (CIN), cisplatin-induced peripheral neuropathy (CIPN), and cisplatin-induced ototoxicity (CIO) are the three most common of several CITs recognised thus far. While the anti-cancer activity of cisplatin is well understood, the mechanisms driving its toxicities have only begun to be defined. Most of the literature pertains to damage caused by oxidative stress that occurs downstream of cisplatin treatment, but recent evidence suggests that the instigator of CIT development is inflammation. Cisplatin has been shown to induce pro-inflammatory signalling in CIN, CIPN, and CIO, all of which are associated with persisting markers of inflammation, particularly from the innate immune system. This review covered the hallmarks of inflammation common and distinct between different CITs, the role of innate immune components in development of CITs, as well as current treatments targeting pro-inflammatory signalling pathways to conserve the use of cisplatin in chemotherapy and improve long-term health outcomes of cancer patients.

MiR-155 deficiency protects renal tubular epithelial cells from telomeric and genomic DNA damage in cisplatin-induced acute kidney injury

Rationale: Cisplatin nephrotoxicity is an important cause of acute kidney injury (AKI), limiting cisplatin application in cancer therapy. Growing evidence has suggested that genome instability, telomeric dysfunction, and DNA damage were involved in the tubular epithelial cells (TECs) damage in cisplatin-induced AKI (cAKI). However, the exact mechanism is largely unknown. Methods: We subjected miR-155-/- mice and wild-type controls, as well as HK-2 cells, to cAKI models. We assessed kidney function and injury with standard techniques. The cell apoptosis and DNA damage of TECs were evaluated both in vivo and in vitro. Telomeres were measured by the fluorescence in situ hybridization. Results: The expression level of miR-155 was upregulated in cAKI. Inhibition of miR-155 expression protected cisplatin-induced AKI both in vivo and in vitro. Compared with wild-type mice, miR-155-/- mice had reduced mortality, improved renal function and pathological damage after cisplatin intervention. Moreover, inhibition of miR-155 expression attenuated TECs apoptosis and DNA damage. These protective effects were caused by increasing expression of telomeric repeat binding factor 1 (TRF1) and cyclin-dependent kinase 12 (CDK12), thereby limiting the telomeric dysfunction and the genomic DNA damage in cAKI. Conclusion: We demonstrated that miR-155 deficiency could significantly attenuate pathological damage and mortality in cAKI through inhibition of TECs apoptosis, genome instability, and telomeric dysfunction, which is possibly regulated by the increasing expression of TRF1 and CDK12. This study will provide a new molecular strategy for the prevention of cAKI.

Protective effect of food derived nutrients on cisplatin nephrotoxicity and its mechanism

Platinum-based metal complexes, especially cisplatin (cis-diamminedichloroplatinum II, CDDP), possess strong anticancer properties and a broad anticancer spectrum. However, the clinical application of CDDP has been limited by its side effects including nephrotoxicity, ototoxicity, and neurotoxicity. Furthermore, the therapeutic effects of current clinical protocols are imperfect. Accordingly, it is essential to identify key targets and effective clinical protocols to restrict CDDP-induced nephrotoxicity. Herein, we first analyzed the relevant molecular mechanisms during the process of CDDP-induced nephrotoxicity including oxidative stress, apoptosis, and inflammation. Evidence from current studies was collected and potential targets and clinical protocols are summarized. The evidence indicates an efficacious role of nutrition-based substances in CDDP-induced renal injury.

Macrophage Migration Inhibitory Factor (MIF) as a Stress Molecule in Renal Inflammation

Renal inflammation is an initial pathological process during progressive renal injury regardless of the initial cause. Macrophage migration inhibitory factor (MIF) is a truly proinflammatory stress mediator that is highly expressed in a variety of both inflammatory cells and intrinsic kidney cells. MIF is released from the diseased kidney immediately upon stimulation to trigger renal inflammation by activating macrophages and T cells, and promoting the production of proinflammatory cytokines, chemokines, and stress molecules via signaling pathways involving the CD74/CD44 and chemokine receptors CXCR2, CXCR4, and CXCR7 signaling. In addition, MIF can function as a stress molecule to counter-regulate the immunosuppressive effect of glucocorticoid in renal inflammation. Given the critical position of MIF in the upstream inflammatory cascade, this review focuses on the regulatory role and molecular mechanisms of MIF in kidney diseases. The therapeutic potential of targeting MIF signaling to treat kidney diseases is also discussed.

Betaine modulates MIF-mediated oxidative stress, inflammation, and fibrogenesis in Thioacetamide-induced Nephrotoxicity

BACKGROUND

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine with chemokine properties released by various immune and nonimmune cells. It contributes to the pathogenesis of many inflammatory, autoimmune diseases and malignant tumors.

OBJECTIVE

Our study aimed to investigate the role of betaine in the modulation of MIF-mediated oxidative stress, inflammation, and fibrogenesis during toxic kidney damage induced by thioacetamide (TAA).

METHODS

The experiment is performed on wild-type and knockout MIF-/- C57BL/6 mice. They are randomly divided into groups: Control; Bet-group, received betaine (2% wt/v dissolved in drinking water); MIF-/- mice group; MIF-/-+Bet; TAA-group, treated with TAA (200 mg/kg b.w.), intraperitoneally, 3x/week/8 weeks); TAA+Bet; MIF-/-+TAA, and MIF-/-+TAA+Bet group. After eight weeks of treatment, animals are sacrificed and kidney samples are taken to determine oxidative stress parameters, proinflammatory cytokines, profibrogenic factors, and histopathology of renal tissue Results: In MIF-/-mice, TAA decreases malondialdehyde (MDA) concentration, IL-6, tumor necrosis factor-alpha (TNF-, transforming growth factor-beta 1 (TGF-1) and plateled-derived growth factor-BB (PDGF-BB) and increases superoxide dismutases (SOD) and catalase (CAT) activities, as well as glutathione (GSH) content in kidneys, compared to TAA group. Betaine alleviates the mechanism of MIF-mediated effects in TAA-induced nephrotoxicity, reducing MDA, IL-6, TNF-, TGF-1, and PDGF-BB, and increasing SOD and CAT activity, as well as GSH levels.

CONCLUSION

MIF mediates TAA-induced nephrotoxicity by increasing oxidative stress, inflammation, and profibrogenic mediators. MIF-targeted therapy could potentially alleviate oxidative stress and inflammation in the kidney, as well as pathohistological changes in renal tissue, but the exact mechanism of its action is not completely clear. Betaine alleviates MIF nephrotoxic effects by increasing the antioxidative capacity of kidney cells, and decreasing lipid peroxidation and cytokine production in the renal tissue. It suggests that betaine can be used for the prevention of kidney damage.

Macrophage Migration Inhibitory Factor Provides A Predictive Performance of Septic Acute Kidney Injury

BACKGROUND

Septic acute kidney injury (AKI) is a common condition in ICU with poor outcomes. Septic AKI patients have a progressively decreased urine output and increased serum creatinine. However, urine volume and serum creatinine showed poor sensitivity to early diagnosis of septic AKI. Searching for potential biomarkers to early detect AKI is crucial in day-to-day clinical practice. Macrophage migration inhibitory factor (MIF), primarily released by renal tubular epithelial cells, vascular endothelial cells, and immune cells, was found to be closely associated with the inflammatory response in sepsis. MIF may be used as a biomarker of septic AKI indicating aggravation of systemic inflammatory response.

METHODS

Our study included sepsis patients admitted to the ICU. The KDIGO guideline was used to confirm the diagnosis and staging of septic AKI. Blood samples were collected and tested, as well as clinical data were recorded. Independent risk factors were selected via logistic regression analysis. By drawing the receiver operating characteristic (ROC) curves, the area under the ROC curves (AUC) was computed. The relationship between serum MIF level and mortality of septic AKI was analyzed using Cox regression analysis.

RESULTS

With high serum MIF level at ICU admission, the patients were more likely to develop AKI. The AUC of serum MIF (MIFAUC = 0.797) was found to be a good predictor of septic AKI. In addition, higher serum MIF levels corresponded to more severe AKI as well as a higher mortality rate.

CONCLUSIONS

Serum MIF might be a biomarker for predicting the occurrence, development, and outcomes of septic AKI. This conclusion will need to be confirmed by more robust investigations in the future.

Neuropeptide Y attenuates cardiac remodeling and deterioration of function following myocardial infarction

Plasma levels of neuropeptide Y (NPY) are elevated in patients with acute myocardial infarction (AMI), but its role in AMI remains unclear, which was examined here in NPY wild-type/knockout (WT/KO) mice treated with/without exogenous NPY and its Y1 receptor antagonist (Y1Ra) BIBP 3226. We found that AMI mice lacking NPY developed more severe AMI than WT mice with worse cardiac dysfunction, progressive cardiac inflammation and fibrosis, and excessive apoptosis but impairing angiogenesis. All of these changes were reversed when the NPY KO mice were treated with exogenous NPY in a dose-dependent manner. Interestingly, treatment with NPY also dose dependently attenuated AMI in WT mice, which was blocked by BIBP 3226. Phenotypically, cardiac NPY was de novo expressed by infiltrating macrophages during the repairing or fibrosing process in heart-failure patients and AMI mice. Mechanistically, NPY was induced by transforming growth factor (TGF)-β1 in bone marrow-derived macrophages and signaled through its Y1R to exert its pathophysiological activities by inhibiting p38/nuclear factor κB (NF-κB)-mediated M1 macrophage activation while promoting the reparative M2 phenotype in vivo and in vitro. In conclusion, NPY can attenuate AMI in mice. Inhibition of cardiac inflammation and fibrosis while enhancing angiogenesis but reducing apoptosis may be the underlying mechanisms through which NPY attenuates cardiac remodeling and deterioration of function following AMI.

Macrophage migration inhibitory factor family proteins are multitasking cytokines in tissue injury

The family of macrophage migration inhibitory factor (MIF) proteins in humans consist of MIF, its functional homolog D-dopachrome tautomerase (D-DT, also known as MIF-2) and the relatively unknown protein named DDT-like (DDTL). MIF is a pleiotropic cytokine with multiple properties in tissue homeostasis and pathology. MIF was initially found to associate with inflammatory responses and therefore established a reputation as a pro-inflammatory cytokine. However, increasing evidence demonstrates that MIF influences many different intra- and extracellular molecular processes important for the maintenance of cellular homeostasis, such as promotion of cellular survival, antioxidant signaling, and wound repair. In contrast, studies on D-DT are scarce and on DDTL almost nonexistent and their functions remain to be further investigated as it is yet unclear how similar they are compared to MIF. Importantly, the many and sometimes opposing functions of MIF suggest that targeting MIF therapeutically should be considered carefully, taking into account timing and severity of tissue injury. In this review, we focus on the latest discoveries regarding the role of MIF family members in tissue injury, inflammation and repair, and highlight the possibilities of interventions with therapeutics targeting or mimicking MIF family proteins.

Renoprotective effect of isoliquiritigenin on cisplatin-induced acute kidney injury through inhibition of FPR2 in macrophage

Acute kidney injury (AKI) is a serious complication in critically ill patients. Accumulating evidences indicated that macrophages play an important pro-inflammatory role in AKI and isoliquiritigenin (ISL) can inhibit macrophagic inflammation, but its role in AKI and the underlying mechanism are unknown. The present study aims to investigate the renoprotective effect of ISL on AKI and the role of Formyl peptide receptors 2 (FPR2) in this process. In this study, cisplatin-induced AKI model and lipopolysaccharide-induced macrophage inflammatory model were employed to perform the in vivo and in vitro experiments. The results showed that ISL strongly relieved kidney injury and inhibited renal inflammation in vivo and suppress macrophagic inflammatory response in vitro. Importantly, it was found that FPR2 was significantly upregulated compared to the control group in AKI and LPS-induced macrophage, whereas it was strongly suppressed by ISL. Interestingly, overexpression of FPR2 with transfection of pcDNA3.1-FPR2 effectively reversed the anti-inflammatory effect of ISL in macrophage, suggesting that FPR2 may be the potential target for ISL to prevent inflammation and improve kidney injury of AKI. Take together, these findings indicated that ISL improved cisplantin-induced kidney injury by inhibiting FPR2 involved macrophagic inflammation, which may provide a potential therapeutic option for AKI.

Calcium alleviates fluoride-induced kidney damage via FAS/FASL, TNFR/TNF, DR5/TRAIL pathways in rats

Long-term excessive intake of fluoride (F) can cause osseous and non-osseous damage. The kidney is the main fluoride excretion organ of the body. This study aimed to explore whether dietary calcium (Ca) supplementation can alleviate kidney damage caused by fluorosis and to further investigate the effects of Ca on the mitigation mechanism of renal cell apoptosis triggered by F. We evaluated the histopathological structure, renal function indicators, and gene and protein expression levels of death receptor-mediated apoptosis pathways in Sprague Dawley (SD) rats treated with sodium fluoride (NaF) and/or calcium carbonate (CaCO₃) for 120 days. The results showed that 100 mg/L NaF induced kidney histopathological injury and apoptosis, increased the concentrations of Creatinine (CRE), uric acid (UA), blood urea nitrogen (BUN), potassium (K), phosphorus (P) and F (p < 0.05), and decrease the level of serum magnesium (Mg) (p < 0.05). Moreover, NaF increased the mRNA and protein expression levels of Fas cell surface death receptor (FAS), tumor necrosis factor (TNF), TNF-related apoptosis-inducing ligand (TRAIL), Caspase 8, Caspase 3 and poly ADP-ribose polymerase (PARP) (p < 0.01), which finally activated the death receptor pathway. Inversely, Ca supplementation reversed the decrease of CRE, BUN, UA, F and P levels induced by F, alleviated histopathological damage and apoptosis, and reduced the gene and protein expression levels of death receptor pathway-related markers. In conclusion, 1% Ca alleviates F-induced kidney apoptosis through FAS/FASL, TNFR/TNF, DR5/TRAIL signaling pathways.

Up-regulation of VSIG4 alleviates kidney transplantation-associated acute kidney injury through suppressing inflammation and ROS via regulation of AKT signaling

Prolonged cold ischemia (CI) is a risk factor for acute kidney injury (AKI) after kidney transplantation (KT). AKI is an abrupt and rapid reduction in renal function due to multi-factors, including inflammation, oxidative stress and apoptosis. V-set immunoglobulin-domain-containing 4 (VSIG4) is a B7 family-related protein and specifically expressed in resting tissue-resident macrophages to mediate various cellular events. In the study, we attempted to explore the effects of VSIG4 on CI/KT-induced AKI in a mouse model. Our results showed that VSIG4 expression was markedly down-regulated in serum of kidney transplant recipients with acute rejection, and in renal tissues of cold ischemia-reperfusion (IR)-operated mice with AKI, which was confirmed in murine macrophages stimulated by oxygen glucose deprivation/reoxygenation (OGD/R). We then found that exogenous VSIG4 markedly ameliorated histological changes in kidney of CI/KT mice by suppressing inflammation and apoptosis through restraining nuclear factor-κB (NF-κB) and Caspase-3 activation, respectively. Oxidative stress and reactive oxygen species (ROS) accumulation in renal tissues were also mitigated by exogenous VSIG4 in CI/KT mice through improving nuclear factor-erythroid 2 related factor 2 (Nrf2) nuclear expression. The inhibitory effects of VSIG4 on inflammation, ROS generation and cell death were confirmed in OGD/R-treated macrophages, which further ameliorated oxidative damage and apoptosis in podocytes. More in vivo and in vitro studies showed that CI/KT- and OGD/R-induced AKI was further accelerated by VSIG4 knockdown. Mechanistically, VSIG4 directly interacted with AKT, and AKT activation was necessary for VSIG4 to govern all these above mentioned cellular processes. Collectively, our findings demonstrated that VSIG4 could mitigate AKI in a CI/KT mouse model, and we identified VSIG4/AKT axis as a promising therapeutic target for the treatment of the disease.

Artesunate relieves acute kidney injury through inhibiting macrophagic Mincle-mediated necroptosis and inflammation to tubular epithelial cell

Artesunate is a widely used derivative of artemisinin for malaria. Recent researches have shown that artesunate has a significant anti‐inflammatory effect on many diseases. However, its effect on acute kidney injury with a significant inflammatory response is not clear. In this study, we established a cisplatin‐induced AKI mouse model and a co‐culture system of BMDM and tubular epithelial cells (mTEC) to verify the renoprotective and anti‐inflammatory effects of artesunate on AKI, and explored the underlying mechanism. We found that artesunate strongly down‐regulated the serum creatinine and BUN levels in AKI mice, reduced the necroptosis of tubular cells and down‐regulated the expression of the tubular injury molecule Tim‐1. On the other hand, artesunate strongly inhibited the mRNA expression of inflammatory cytokines (IL‐1β, IL‐6 and TNF‐α), protein levels of inflammatory signals (iNOS and NF‐κB) and necroptosis signals (RIPK1, RIPK3 and MLKL) in kidney of AKI mouse. Notably, the co‐culture system proved that Mincle in macrophage can aggravate the inflammation and necroptosis of mTEC induced by LPS, and artesunate suppressed the expression of Mincle in macrophage of kidney in AKI mouse. Overexpression of Mincle in BMDM restored the damage and necroptosis inhibited by artesunate in mTEC, indicating Mincle in macrophage is the target of artesunate to protect tubule cells in AKI. Our findings demonstrated that artesunate can significantly improve renal function in AKI, which may be related to the inhibition of Mincle‐mediated macrophage inflammation, thereby reducing the damage and necroptosis to tubular cells that provide new option for the treatment of AKI.

Renal Inflammation and Innate Immune Activation Underlie the Transition From Gentamicin-Induced Acute Kidney Injury to Renal Fibrosis

Subjects recovering from acute kidney injury (AKI) are at risk of developing chronic kidney disease (CKD). The mechanisms underlying this transition are unclear and may involve sustained activation of renal innate immunity, with resulting renal inflammation and fibrosis. We investigated whether the NF-κB system and/or the NLRP3 inflammasome pathway remain activated after the resolution of AKI induced by gentamicin (GT) treatment, thus favoring the development of CKD. Male Munich-Wistar rats received daily subcutaneous injections of GT, 80 mg/kg, for 9 days. Control rats received vehicle only (NC). Rats were studied at 1, 30, and 180 days after GT treatment was ceased. On Day 1, glomerular ischemia (ISCH), tubular necrosis, albuminuria, creatinine retention, and tubular dysfunction were noted, in association with prominent renal infiltration by macrophages and myofibroblasts, along with increased renal abundance of TLR4, IL-6, and IL1β. Regression of functional and structural changes occurred on Day 30. However, the renal content of IL-1β was still elevated at this time, while the local renin-angiotensin system remained activated, and interstitial fibrosis became evident. On Day 180, recurring albuminuria and mild glomerulosclerosis were seen, along with ISCH and unabated interstitial fibrosis, whereas macrophage infiltration was still evident. GT-induced AKI activates innate immunity and promotes renal inflammation. Persistence of these abnormalities provides a plausible explanation for the transition of AKI to CKD observed in a growing number of patients.

Whole-genome sequencing suggests a role of MIF in the pathophysiology of TEMPI syndrome

TEMPI syndrome (telangiectasias, elevated erythropoietin level and erythrocytosis, monoclonal gammopathy, perinephric fluid collections, and intrapulmonary shunting) is a newly defined multisystemic disease with its pathophysiology largely unknown. Here, we report the whole-genome sequencing (WGS) analysis on the tumor-normal paired cells from a patient with TEMPI syndrome. WGS revealed somatic nonsynonymous single-nucleotide variants, including SLC7A8, NRP2, and AQP7. Complex structural variants of chromosome 2 were found, particularly within regions where some putative oncogenes reside. Of potential clinical relevance, duplication of 22q11.23 was identified, and the expression of the located gene macrophage migration inhibitory factor (MIF) was significantly upregulated in 3 patients with TEMPI syndrome. Importantly, the level of serum MIF in one patient with TEMPI syndrome was significantly decreased in accordance with the downtrend of plasma cells, M-protein, hemoglobin, and erythropoietin and the improvement of telangiectasias, perinephric fluid collections, and intrapulmonary shunting after treatment with plasma cell-directed therapy. In conclusion, our study provides insights into the genomic landscape and suggests a role of MIF in the pathophysiology of TEMPI syndrome.

Major signaling pathways and key mediators of macrophages in acute kidney injury (Review)

Acute kidney injury (AKI) has become a global public health problem with high morbidity and mortality rates, as well as high healthcare costs. Immune cells, particularly macrophages, which regulate tissue development, destroy pathogens, control homeostasis and repair wounds, play crucial and complex roles in AKI. In various types of AKI, numerous rapidly recruited monocytes and tissue-resident macrophages act in a coordinated manner. Thus, elucidating the phenotypic and functional characteristics of macrophages in AKI is essential for identifying potential therapeutic targets. Macrophage-sensing mediators and macrophage-derived mediators participate in the major macrophage-related signaling pathways in AKI, which regulate macrophage polarization and determine disease progression. In conclusion, macrophages change their roles and regulatory mechanisms during the occurrence and development of AKI. The aim of the present review was to contribute to an improved understanding of AKI and to the identification of novel therapeutic targets for this condition.

Changes of Urinary Cytokines in Non-Diabetic Obese Patients After Laparoscopic Sleeve Gastrectomy

Introduction

Adipose tissues synthesize and secrete various proinflammatory and anti-inflammatory mediators, termed cytokines. This work aims to assess different serum and urinary cytokine levels before and 12 months after laparoscopic sleeve gastrectomy (LSG).

Patients

This prospective study was performed on 61 obese non-diabetic patients who underwent LSG. All patients were followed up postoperatively at 12 months with the assessment of arterial blood pressure, microalbuminuria, urinary and serum levels of inflammatory cytokines (macrophage migration inhibitory factor "MIF," monocyte chemotactic protein "MCP"-1, chemokine (C-C motif) ligand 15 (CCL-15), and CCL-18), in addition to serum creatinine, total cholesterol, and C-reactive protein (CRP).

Results

Mean BMI showed decreased substantially from 44.78 ± 3.59 Kg/m² to 34.56 ± 2.45. Systolic blood pressure decreased from 147.03 ± 16.89 mmHg to 128.82 ± 12.52 and diastolic blood pressure decreased from 90.51 ± 12.71 mmHg to 79.69 ± 10.39. At one-year of follow-up, there was statistically significant decrease of mean serum creatinine, total cholesterol, CRP, CCL-15, CCL-18, MIF/creatinine ratio, MCP-1/creatinine ratio, CCL-15/creatinine ratio, and CCL-18/creatinine ratio (P value <0.001).

Conclusion

Improvement of systemic and renal inflammatory states after LSG may positively affect obesity-related renal disease by steering the adipokine levels towards anti-inflammatory profiles.

Extracellular MIF, but not its homologue D-DT, promotes fibroblast motility independently of its receptor complex CD74/CD44

Macrophage migration inhibitory factor (MIF) and its homologue D-dopachrome tautomerase (D-DT) are widely expressed pro-inflammatory cytokines with chemokine-like functions that coordinate a wide spectrum of biological activities, such as migration. Here, we biotin-tagged intracellular MIF/D-DT in vivo to identify important cytosolic interactors and found a plethora of actin cytoskeleton-associated proteins. Although the receptor complex between CD74 and CD44 (CD74/CD44) is essential for signalling transduction in fibroblasts via extracellular MIF/D-DT, our interactome data suggested direct effects. We, thus, investigated whether MIF/D-DT can modulate cell migration independently of CD74/CD44. To distinguish between receptor- and non-receptor-mediated motility, we used fibroblasts that are either deficient or that express CD74/CD44 proteins, and treated them with recombinant MIF/D-DT. Interestingly, only MIF could stimulate chemokinesis in the presence or absence of CD74/CD44. The pro-migratory effects of MIF depended on lipid raft/caveolae-mediated but not clathrin-mediated endocytosis, on its tautomerase activity and, probably, on its thiol protein oxidoreductase activity. As MIF treatment restrained actin polymerisation in vitro, our findings establish a new intracellular role for MIF/D-DT in driving cell motility through modulation of the actin cytoskeleton.

Downregulation of long non-coding RNA B-Raf proto-oncogene-activated non-coding RNA reverses cisplatin resistance in laryngeal squamous cell carcinoma

INTRODUCTION

This study was performed to explore the function of B-Raf proto-oncogene-activated non-coding RNA (BANCR) in laryngeal squamous cell carcinoma (LSCC) and cisplatin resistance.

MATERIAL AND METHODS

The relative expression level of long non-coding RNA (lncRNA) BANCR was examined by qRT-PCR in tumor tissues and adjacent tissues, normal laryngeal cells (Het-1A) and laryngeal squamous carcinoma cells (TU686, TU177). Cisplatin-resistant laryngeal squamous carcinoma cell lines (TU686-DDP-R, TU177-DDP-R) were established. Next, we inhibited BANCR expression by transfecting siRNA-BANCR and enhanced BANCR expression by transfecting pcDNA3.1-BANCR into TU686, TU177, TU686-DDP-R and TU177-DDP-R cells. The CCK-8 assay and clone formation assay were performed to detect colony proliferation ability and formation ability of cells. Further, to investigate through which BANCR cell viability/formation is regulated, we detected the expression of MRP1, Bcl-2, p-PKB, and Bax by western blot.

RESULTS

BANCR was highly expressed in laryngeal squamous carcinoma tissues and cells. Chemoresistance was generated in TU686-DDP-R and TU177-DDP-R compared with TU686 and TU177 cells after cisplatin treatment. In addition, upregulated lncRNA BANCR reduced or postponed cell sensitivity to cisplatin by enhancing cell proliferation in TU686 and TU177 cells. Meanwhile, the expression of MRP1, Bcl-2, and p-PKB was increased, while Bax was reduced. After cisplatin treatment, down-regulation of BANCR could consequently attenuate TU686-DDP-R and TU177-DDP-R cell proliferation, and the expression of MRP1, Bcl-2, and p-PKB was decreased and Bax was increased.

CONCLUSIONS

Down-regulation of BANCR reverses cisplatin resistance of cisplatin-resistant LSCC cell lines.

Macrophage migration inhibitory factor is regulated by HIF-1α and cAMP and promotes renal cyst cell proliferation in a macrophage-independent manner

Progressive cyst growth leads to decline of renal function in polycystic kidney disease. Macrophage migration inhibitory factor (MIF) was found to be upregulated in cyst-lining cells in a mouse model of polycystic kidney disease and to promote cyst growth. In addition, MIF can be secreted by tubular cells and may contribute to cyst growth in an autocrine manner. However, the underlying mechanisms leading to induction of MIF in cyst-lining cells remained elusive. Here, we demonstrate that hypoxia-inducible transcription factor (HIF) 1α upregulates MIF in cyst-lining cells in a tubule-specific PKD1 knockout mouse. Pharmacological stabilization of HIF-1α resulted in significant increase of MIF in cyst epithelial cells whereas tubule-specific knockout of HIF-1α prevented MIF upregulation. Identical regulation could be found for ABCA1, which has been shown to act as a transport protein for MIF. Furthermore, we show that MIF and ABCA1 are direct target genes of HIF-1α in human primary tubular cells. Next to HIF-1α and hypoxia, we found MIF being additionally regulated by cAMP which is a strong promotor of cyst growth. In line with these findings, HIF-1α- and cAMP-dependent in vitro cyst growth could be decreased by the MIF-inhibitor ISO-1 which resulted in reduced cyst cell proliferation. In conclusion, HIF-1α and cAMP regulate MIF in primary tubular cells and cyst-lining epithelial cells, and MIF promotes cyst growth in the absence of macrophages. In line with these findings, the MIF inhibitor ISO-1 attenuates HIF-1α- and cAMP-dependent in vitro cyst enlargement. KEY MESSAGES: • MIF is upregulated in cyst-lining cells in a polycystic kidney disease mouse model. • MIF upregulation is mediated by hypoxia-inducible transcription factor (HIF) 1α. • ABCA1, transport protein for MIF, is also regulated by HIF-1α in vitro and in vivo. • MIF is additionally regulated by cAMP, a strong promotor of cyst growth. • MIF-inhibitor ISO-1 reduces HIF-1α- and cAMP-dependent cyst growth.

Long Non-coding RNA LRNA9884 Promotes Acute Kidney Injury via Regulating NF-kB-Mediated Transcriptional Activation of MIF

Acute kidney injury (AKI) is one of the most common complications affecting hospitalized patients associated with an extremely high mortality rate. However, the underlying pathogenesis of AKI remains unclear that largely limits its effective management in clinic. Increasing evidence demonstrated the importance of long non-coding RNAs (lncRNAs) in the pathogenesis of AKI, because of their regulatory roles in transcription, translation, chromatin modification, and cellular organization. Here, we reported a new role of LRNA9884 in AKI. Using experimental cisplatin-induced AKI model, we found that LRNA9884 was markedly up-regulated in the nucleus of renal tubular epithelium in mice with AKI. We found that silencing of LRNA9884 effectively inhibited the production of inflammatory cytokines MCP-1, IL-6, and TNF-α in the mouse renal tubular epithelial cells (mTECs) under IL-1β stimulation in vitro. Mechanistically, LRNA9884 was involved into NF-κB-mediated inflammatory cytokines production especially on macrophage migration inhibitory factor (MIF). Collectedly, our study suggested LRNA9884 promoted MIF-triggered the production of inflammatory cytokines via NF-κB pathway after AKI injury. This study uncovered LRNA9884 has an adverse impact in AKI, and targeting LRNA9884 might represent a potential therapeutic target for AKI.

High RPS3A expression correlates with low tumor immune cell infiltration and unfavorable prognosis in hepatocellular carcinoma patients

Despite the use of immune checkpoint blockade (ICB) therapy for hepatocellular carcinoma (HCC), developing more effective immunotherapy and predicting HCC's response to ICB therapy remain top priorities. Ribosomal protein S3A (RPS3A) is a multifunctional molecule, but its association with tumor immune cell infiltration and prognosis in HCC patients is unknown. Thus, we aimed to investigate the correlation of RPS3A with HCC immune cell infiltration and prognosis to explore novel therapeutic strategies and prognostic biomarkers for this disease. Here, we showed that RPS3A expression levels were higher in HCC cell lines and samples than in normal hepatocytes and adjacent tumor-free tissues, respectively, and patients with high RPS3A expression had worse overall and recurrence-free survival durations than did patients with low expression. Moreover, single-sample gene set enrichment analysis (ssGSEA) and immunohistochemistry demonstrated a strongly negative correlation between RPS3A expression and tumor immune cell infiltration. Meanwhile, RPS3A was revealed to be positively correlated with that of most examined immune checkpoint molecules. GSEA also suggested that high RPS3A expression promoted the biological processes related to tumorigenesis, metastasis, and immunosuppression. Finally, RPS3A-based nomograms were constructed and exhibited better predictive accuracy for HCC prognosis and more net clinical benefits when compared with traditional prognosis-prediction staging systems. In short, these findings suggest that high RPS3A expression correlates with low tumor immune cell infiltration and poor prognosis in HCC patients. Furthermore, RPS3A-based nomograms are robust HCC prognostic predictors. RPS3A therefore may serve as a therapeutic target in and predict the efficacy of ICB therapy for HCC.

miR-20a-5p is enriched in hypoxia-derived tubular exosomes and protects against acute tubular injury

Exosomes have been shown to effectively regulate the biological functions of target cells. Here, we investigated the protective effect and mechanism of hypoxia-induced renal tubular epithelial cells (TECs)-derived exosomes on acute tubular injury. We found that in vitro hypoxia-induced tubular exosomes (Hy-EXOs) were protective in acute tubular injury by promoting TECs proliferation and improving mitochondrial functions. By using exosome miRNA sequencing, we identified miR-20a-5p was abundant and was a key mechanism for the protective effect of Hy-EXOs on tubular injury as up-regulation of miR-20a-5p enhanced but down-regulation of miR-20a-5p inhibited the protective effect of Hy-EXOs on tubular injury under hypoxia conditions. Further study in a mouse model of ischemia–reperfusion-induced acute kidney injury (IRI-AKI) also confirmed this notion as pre-treating mice with the miR-20a-5p agomir 48 h prior to AKI induction was capable of inhibiting IRI-AKI by lowering serum levels of creatinine and urea nitrogen, and attenuating the severity of tubular necrosis, F4/80(+) macrophages infiltration and vascular rarefaction. Mechanistically, the protective effect of miR-20a-5p on acute kidney injury (AKI) was associated with inhibition of TECs mitochondrial injury and apoptosis in vitro and in vivo. In conclusion, miR-20a-5p is enriched in hypoxia-derived tubular exosomes and protects against acute tubular injury. Results from the present study also reveal that miR-20a-5p may represent as a novel therapy for AKI.

Associations of Serological Biomarkers of sICAM-1, IL-1β, MIF, and su-PAR with 3-Month Mortality in Acute Exacerbation of Idiopathic Pulmonary Fibrosis

Objective

To investigate prognostic values of serum biomarkers of soluble intercellular adhesion molecule 1 (sICAM-1), macrophage migration inhibitor factor (MIF), interleukin 1β (IL-1β), and soluble urokinase plasminogen activator receptor (su-PAR) in patients with acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF).

Methods

From August 2017 to November 2019, 122 consecutive IPF patients treated in our center were classified as stable IPF and AE-IPF based on the newly published international guidelines. Serum levels of four biomarkers at admission were measured by the enzyme-linked immunosorbent assay (ELISA). The primary endpoint was 3-month mortality. The log-rank test and logistic regression analysis were used to evaluate the effects of these biomarkers for survival in patients with AE-IPF. Cox proportional hazards analysis was performed to evaluate the prognostic values of serological biomarkers and clinical data.

Results

Eighty-one patients were diagnosed with stable IPF, and 41 AE-IPF patients were enrolled in the study. Serum levels of sICAM-1 (p < 0.001), IL-1β (p < 0.001), MIF (p < 0.001), and su-PAR (p < 0.001) in patients with IPF were significantly increased compared to those in healthy controls. All the four biomarkers were elevated in patients with AE-IPF compared to those with stable IPF. The 3-month mortality in AE-IPF was 56.1% (23/41). Increased levels of MIF (p = 0.01) and IL-1β (>5 pg/mL, p = 0.033) were independent risk factors for 3-month mortality in patients with AE-IPF.

Conclusions

We showed the higher serum levels of IL-1β, and MIF had prognostic values for 3-month mortality in AE-IPF. This study provided a clue to promote our understanding in the pathogenesis of the disease.

The Mincle/Syk/NF-κB Signaling Circuit Is Essential for Maintaining the Protumoral Activities of Tumor-Associated Macrophages

Tumor-associated macrophages (TAM) have important roles in cancer progression, but the signaling behind the formation of protumoral TAM remains understudied. Here, by single-cell RNA sequencing, we revealed that the pattern recognition receptor Mincle was highly expressed in TAM and significantly associated with mortality in patients with non-small cell lung cancer. Cancer cells markedly induced Mincle expression in bone marrow-derived macrophages (BMDM), thus promoting cancer progression in invasive lung carcinoma LLC and melanoma B16F10 in vivo and in vitro Mincle was predominately expressed in the M2-like TAM in non-small cell lung carcinoma and LLC tumors, and silencing of Mincle unexpectedly promoted M1-like phenotypes in vitro Mechanistically, we discovered a novel Mincle/Syk/NF-κB signaling pathway in TAM needed for executing their TLR4-independent protumoral activities. Adoptive transfer of Mincle-silenced BMDM significantly suppressed TAM-driven cancer progression in the LLC-bearing NOD/SCID mice. By modifying our well-established ultrasound microbubble-mediated gene transfer protocol, we demonstrated that tumor-specific silencing of Mincle effectively blocked Mincle/Syk/NF-κB signaling, therefore inhibiting the TAM-driven cancer progression in the syngeneic mouse cancer models. Thus, our findings highlight the function of Mincle as a novel immunotherapeutic target for cancer via blocking the Mincle/Syk/NF-κB circuit in TAM.

Vagus nerve stimulation even after injury ameliorates cisplatin-induced nephropathy via reducing macrophage infiltration

The efficacy of prior activation of an anti-inflammatory pathway called the cholinergic anti-inflammatory pathway (CAP) through vagus nerve stimulation (VNS) has been reported in renal ischemia-reperfusion injury models. However, there have been no reports that have demonstrated the effectiveness of VNS after injury. We investigated the renoprotective effect of VNS in a cisplatin-induced nephropathy model. C57BL/6 mice were injected with cisplatin, and VNS was conducted 24 hours later. Kidney function, histology, and a kidney injury marker (Kim-1) were evaluated 72 hours after cisplatin administration. To further explore the role of the spleen and splenic macrophages, key players in the CAP, splenectomy, and adoptive transfer of macrophages treated with the selective α7 nicotinic acetylcholine receptor agonist GTS-21 were conducted. VNS treatment significantly suppressed cisplatin-induced kidney injury. This effect was abolished by splenectomy, while adoptive transfer of GTS-21-treated macrophages improved renal outcomes. VNS also reduced the expression of cytokines and chemokines, including CCL2, which is a potent chemokine attracting monocytes/macrophages, accompanied by a decline in the number of infiltrating macrophages. Taken together, stimulation of the CAP protected the kidney even after injury in a cisplatin-induced nephropathy model. Considering the feasibility and anti-inflammatory effects of VNS, the findings suggest that VNS may be a promising therapeutic tool for acute kidney injury.

Irreversible Electroporation versus Radiofrequency Ablation: Comparison of Systemic Immune Responses in Patients with Hepatocellular Carcinoma

PURPOSE

Irreversible electroporation (IRE) differs from thermal radiofrequency (RF) ablation, especially in terms of the reparative process in the ablation zone induced. To elucidate this, the systemic immune responses after 2 mechanistically different types of ablation (IRE and RF ablation) were evaluated in patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Twenty-one patients with HCC who underwent either RF ablation (n = 11) or IRE (n = 10) were studied. Peripheral blood samples were collected from all patients at 4 timepoints: before ablation, within 1 hour after ablation, 1 day after ablation, and 4 days after ablation. The phenotypes and functions of immune cells in peripheral blood and serum levels of cytokines and chemokines were monitored and analyzed using the mixed-effects model. Follow-up radiological images were also obtained to assess temporal changes in the ablation zone.

RESULTS

The most significant difference was seen in the levels of macrophage migration inhibitory factor (MIF) in the IRE group compared to the RF ablation group (P = .0011): the serum levels of MIF in the IRE group significantly increased immediately after IRE and then rapidly decreased to the pre-ablation range 1 day after IRE, but, in contrast, no consistent trend was observed in the RF ablation group. The axial diameter (P = .0009) and area (P = .0192) of the ablation zone of IRE were significantly smaller than those of RF ablation 1 year after ablation.

CONCLUSIONS

IRE was found to be associated with a significant early increase in MIF levels, which may facilitate the early reparative process and result in significant shrinkage of the ablation zone.

Mesenchymal stem cells alleviate acute kidney injury via miR-107-mediated regulation of ribosomal protein S19

Background

The characteristics of mesenchymal stem cells (MSCs) in the repair of acute kidney injury (AKI) have been extensively studied. However, some potential molecular mechanisms remain indistinct. The aim of this study was to combine published microRNA (miRNA) transcriptional profiling with quantitative proteomic analyses to reveal specific miRNAs or genes for MSC-based therapy in AKI.

Methods

Transcriptome data containing significantly changed miRNAs in renal tissue from AKI mice treated with and without MSCs were downloaded. Proteomics resources were downloaded from a human proximal renal tubule cell line (HK-2) that served as a good in vitro model for AKI treated with MSCs. We connected the proteomics data with transcriptional records based on miRNA function. Differentially expressed genes (DEGs) were sorted. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was conducted, and protein-protein interaction (PPI) chains were formed. The genes identified in the analyses were verified in a cisplatin-induced AKI rat model and in HK-2 cells exposed to cisplatin and cocultured with MSCs.

Results

A total of 207 specific DEGs were sorted. The ribosomal pathway was identified in pathway enrichment, and ribosomal proteins were identified from the PPI network complex. The targeting of the microRNAs, miR-107 to RPS19, was directly verified by the dual-luciferase method. miR-107 knockdown induced RPS19 expression, protected HK-2 cells from cisplatin-induced apoptosis, and promoted cell proliferation.

Conclusions

By analyzing comprehensive bioinformatics data, we have confirmed the DEGs and pathways in AKI treated with MSCs. Bone marrow-derived MSCs reduce miR-107 expression and increase RPS19 expression by repressing the proliferation of cisplatin-induced AKI cells and initiating apoptosis.

Design and optimization strategies for the development of new drugs that treat chronic kidney disease

Introduction: Chronic kidney disease (CKD) is characterized by increased risks of progression to end-stage kidney disease requiring dialysis and cardiovascular mortality, predicted to be among the five top causes of death by 2040. Only the design and optimization of novel strategies to develop new drugs to treat CKD will contain this trend. Current therapy for CKD includes nonspecific therapy targeting proteinuria and/or hypertension and cause-specific therapies for diabetic kidney disease, autosomal dominant polycystic kidney disease, glomerulonephritides, Fabry nephropathy, hemolytic uremic syndrome and others.Areas covered: Herein, the authors review the literature on new drugs under development for CKD as well as novel design and development strategies.Expert opinion: New therapies for CKD have become a healthcare priority. Emerging therapies undergoing clinical trials are testing expanded renin-angiotensin system blockade with double angiotensin receptor/endothelin receptor blockers, SGLT2 inhibition, and targeting inflammation, the immune response, fibrosis and the Nrf2 transcription factor. Emerging therapeutic targets include cell senescence, complement activation, Klotho expression preservation and microbiota. Novel approaches include novel model systems that can be personalized (e.g. organoids), unbiased systems biology-based identification of new therapeutic targets, drug databases that speed up drug identification and repurposing, nanomedicines that improve drug delivery and RNA targeting to expand the number of targetable proteins.

New Insights in the Pathogenesis of Cisplatin-Induced Nephrotoxicity

Cisplatin (cis-diamminedichloroplatinum II) is a widely used chemotherapeutic agent. However, efficacy and clinical utility of this drug is significantly limited by severe side effects such as nephrotoxicity which develops due to renal accumulation and bio-transformation in proximal tubular epithelial cells. Cisplatin-induced nephrotoxicity can be manifested as acute kidney injury (AKI), or as different types of tubulopathies, salt wasting, loss of urinary concentrating ability, and magnesium wasting. The attenuation of cisplatin-caused AKI is currently accomplished by hydration, magnesium supplementation or mannitol-induced forced diuresis. However, mannitol treatment causes over-diuresis and consequent dehydration, indicating an urgent need for the clinical use of newly designed, safe and efficacious renoprotective drug, as an additive therapy for high dose cisplatin-treated patients. Accordingly, we emphasized current knowledge regarding molecular mechanisms responsible for cisplatin-caused nephrotoxicity and we described in detail the main clinical manifestations of cisplatin-induced renal dysfunction in order to pave the way for the design of new therapeutic approaches that can minimize detrimental effects of cisplatin in the kidneys. Having in mind that most of cisplatin-induced cytotoxic effects against renal cells are, at the same time, involved in anti-tumor activity of cisplatin, new nephroprotective therapeutic strategies have to prevent renal injury and inflammation without affecting cisplatin-induced toxicity against malignant cells.

Inflammation in Renal Diseases: New and Old Players

Inflammation, a process intimately linked to renal disease, can be defined as a complex network of interactions between renal parenchymal cells and resident immune cells, such as macrophages and dendritic cells, coupled with recruitment of circulating monocytes, lymphocytes, and neutrophils. Once stimulated, these cells activate specialized structures such as Toll-like receptor and Nod-like receptor (NLR). By detecting danger-associated molecules, these receptors can set in motion major innate immunity pathways such as nuclear factor ĸB (NF-ĸB) and NLRP3 inflammasome, causing metabolic reprogramming and phenotype changes of immune and parenchymal cells and triggering the secretion of a number of inflammatory mediators that can cause irreversible tissue damage and functional loss. Growing evidence suggests that this response can be deeply impacted by the crosstalk between the kidneys and other organs, such as the gut. Changes in the composition and/or metabolite production of the gut microbiota can influence inflammation, oxidative stress, and fibrosis, thus offering opportunities to positively manipulate the composition and/or functionality of gut microbiota and, consequentially, ameliorate deleterious consequences of renal diseases. In this review, we summarize the most recent evidence that renal inflammation can be ameliorated by interfering with the gut microbiota through the administration of probiotics, prebiotics, and postbiotics. In addition to these innovative approaches, we address the recent discovery of new targets for drugs long in use in clinical practice. Angiotensin II receptor antagonists, NF-ĸB inhibitors, thiazide diuretics, and antimetabolic drugs can reduce renal macrophage infiltration and slow down the progression of renal disease by mechanisms independent of those usually attributed to these compounds. Allopurinol, an inhibitor of uric acid production, has been shown to decrease renal inflammation by limiting activation of the NLRP3 inflammasome. So far, these protective effects have been shown in experimental studies only. Clinical studies will establish whether these novel strategies can be incorporated into the arsenal of treatments intended to prevent the progression of human disease.

Heat shock transcription factor 1 affects kidney tubular cell migration by regulating the TGF‑β1‑Smad2/3 signaling pathway

Cell migration is important for renal recovery from tubular cell injury. Heat shock transcription factor 1 (HSF1) is a well‑studied regulatory factor that is active during acute kidney injury. HSF1 is also involved in the migration process during tumor metastasis. Therefore, we hypothesized that HSF1 may promote the recovery of renal function by affecting kidney tubular cell migration. A wound healing assay was used to examine the cell migration rate. The results demonstrated that the migration of rat kidney proximal tubular cells (RPTCs) was increased following knockdown of HSF1. In addition, the invasion ability of HSF1 knockdown RPTCs was also significantly upregulated. The present study also identified that transforming growth factor‑β1 (TGF‑β1) was highly expressed at the edge of the wound in control cells, and its expression was further increased upon knockdown of HSF1. Inhibition of TGF‑β1 signaling prevented RPTC HSF1 knockdown cell migration, suggesting that HSF1‑regulated RPTC cell migration was dependent on the TGF‑β1 signaling pathway. Furthermore, phosphorylation of TGF‑β1 and Smad2/3 was induced in HSF1 knockdown cells. Together, these results suggest that HSF1 may suppress RPTC migration by inhibiting the activation of the TGF‑β1‑Smad2/3 signaling pathway.

Macrophage migration inhibitory factor promotes renal injury induced by ischemic reperfusion

Macrophage migration inhibitory factor (MIF) is pleiotropic cytokine that has multiple effects in many inflammatory and immune diseases. This study reveals a potential role of MIF in acute kidney injury (AKI) in patients and in kidney ischemic reperfusion injury (IRI) mouse model in MIF wild‐type (WT) and MIF knockout (KO) mice. Clinically, plasma and urinary MIF levels were largely elevated at the onset of AKI, declined to normal levels when AKI was resolved and correlated tightly with serum creatinine independent of disease causes. Experimentally, MIF levels in plasma and urine were rapidly elevated after IRI‐AKI and associated with the elevation of serum creatinine and the severity of tubular necrosis, which were suppressed in MIF KO mice. It was possible that MIF may mediate AKI via CD74/TLR4‐NF‐κB signalling as mice lacking MIF were protected from AKI by largely suppressing CD74/TLR‐4‐NF‐κB associated renal inflammation, including the expression of MCP‐1, TNF‐α, IL‐1β, IL‐6, iNOS, CXCL15(IL‐8 in human) and infiltration of macrophages, neutrophil, and T cells. In conclusion, our study suggests that MIF may be pathogenic in AKI and levels of plasma and urinary MIF may correlate with the progression and regression of AKI.