Protective effect of L-glutamine against diabetes-induced nephropathy in experimental animal: Role of KIM-1, NGAL, TGF-β1, and collagen-1

The role of perirenal adipose tissue deposition in chronic kidney disease progression: Mechanisms and therapeutic implications

Chronic kidney disease (CKD) represents a significant and escalating global health challenge, with morbidity and mortality rates rising steadily. Evidence increasingly implicates perirenal adipose tissue (PRAT) deposition as a contributing factor in the pathogenesis of CKD. This review explores how PRAT deposition may exert deleterious effects on renal structure and function. The anatomical proximity of PRAT to the kidneys not only potentially causes mechanical compression but also leads to the dysregulated secretion of adipokines and inflammatory mediators, such as adiponectin, leptin, visfatin, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and exosomes. Additionally, PRAT deposition may contribute to renal lipotoxicity through elevated levels of free fatty acids (FFA), triglycerides (TAG), diacylglycerol (DAG), and ceramides (Cer). PRAT deposition is also linked to the hyperactivation of the renin-angiotensin-aldosterone system (RAAS), which further exacerbates CKD progression. Recognizing PRAT deposition as an independent risk factor for CKD underscores the potential of targeting PRAT as a novel strategy for the prevention and management of CKD. This review further discusses interventions that could include measuring PRAT thickness to establish a baseline, managing metabolic risk factors that promote its deposition, and inhibiting key PRAT-induced signaling pathways.

Current updates on metabolites and its interlinked pathways as biomarkers for diabetic kidney disease: A systematic review

Diabetic kidney disease (DKD) is a major microvascular complication of diabetes mellitus (DM) that poses a serious risk as it can lead to end-stage renal disease (ESRD). DKD is linked to changes in the diversity, composition, and functionality of the microbiota present in the gastrointestinal tract. The interplay between the gut microbiota and the host organism is primarily facilitated by metabolites generated by microbial metabolic processes from both dietary substrates and endogenous host compounds. The production of numerous metabolites by the gut microbiota is a crucial factor in the pathogenesis of DKD. However, a comprehensive understanding of the precise mechanisms by which gut microbiota and its metabolites contribute to the onset and progression of DKD remains incomplete. This review will provide a summary of the current scenario of metabolites in DKD and the impact of these metabolites on DKD progression. We will discuss in detail the primary and gut-derived metabolites in DKD, and the mechanisms of the metabolites involved in DKD progression. Further, we will address the importance of metabolomics in helping identify potential DKD markers. Furthermore, the possible therapeutic interventions and research gaps will be highlighted.

Optimizing diabetic kidney disease animal models: Insights from a meta-analytic approach

Diabetic kidney disease (DKD) is a prevalent complication of diabetes, often leading to end-stage renal disease. Animal models have been widely used to study the pathogenesis of DKD and evaluate potential therapies. However, current animal models often fail to fully capture the pathological characteristics of renal injury observed in clinical patients with DKD. Additionally, modeling DKD is often a time-consuming, costly, and labor-intensive process. The current review aims to summarize modeling strategies in the establishment of DKD animal models by utilizing meta-analysis related methods and to aid in the optimization of these models for future research. A total of 1215 articles were retrieved with the keywords of "diabetic kidney disease" and "animal experiment" in the past 10 years. Following screening, 84 articles were selected for inclusion in the meta-analysis. Review manager 5.4.1 was employed to analyze the changes in blood glucose, glycosylated hemoglobin, total cholesterol, triglyceride, serum creatinine, blood urea nitrogen, and urinary albumin excretion rate in each model. Renal lesions shown in different models that were not suitable to be included in the meta-analysis were also extensively discussed. The above analysis suggested that combining various stimuli or introducing additional renal injuries to current models would be a promising avenue to overcome existing challenges and limitations. In conclusion, our review article provides an in-depth analysis of the limitations in current DKD animal models and proposes strategies for improving the accuracy and reliability of these models that will inspire future research efforts in the DKD research field.

Exogenous glutamine ameliorates diabetic nephropathy in a rat model of type 2 diabetes mellitus through its antioxidant and anti-inflammatory activities

This study aimed to evaluate the effects of glutamine (Gln) on diabetic nephropathy and other complications in a rat model of type 2 diabetes mellitus. Streptozotocin/nicotinamide induced diabetic rats were enrolled as an animal model of type 2 diabetes mellitus. Animals were divided into control, diabetic, and Gln (1000 mg/l in drinking water, eight weeks) treated diabetic groups. Gln alleviated renal inflammatory and oxidative stress biomarkers (tumour necrosis factor-alpha, interleukin 6, glutathione peroxidase, total superoxide dismutase, and glutathione), decreased serum uric acid and creatinine, and restored renal histopathological changes (glomerular volume, sclerosis, and leukocyte infiltration). Additionally, Gln ameliorated other complications, including systemic oxidative stress (serum malondialdehyde and nitric oxide, serum and liver glutathione, glutathione peroxidase, and total superoxide dismutase, and liver catalase), insulin resistance, hyperglycaemia, and hyperlipidaemia. Collectively, Gln attenuates diabetic nephropathy and other complications in type 2 diabetes mellitus in rats through its antioxidant and anti-inflammatory activities.

Repurposing Pitavastatin and L-Glutamine: Replenishing β-Cells in Hyperlipidemic Type 2 Diabetes Mouse Model

Type 2 diabetes (T2D) is associated with obesity and declining β-cells. L-glutamine has been implicated in the amelioration of T2D by virtue of its incretin secretagogue property while, there are mixed reports on pitavastatin's adiponectin potentiating ability. We aimed to investigate the effect of pitavastatin (P), L-glutamine (LG), and combination (P + LG) on glycemic control and β-cell regeneration in a high-fat diet (HFD) + streptozotocin (STZ)-induced T2D mouse model. C57BL6/J mice treated with HFD + STZ were divided into four groups: diabetes control (HFD + STZ), P, LG, and P + LG, while the control group (NCD) was fed with the normal-chow diet. Significant amelioration was observed in the combination therapy as compared to monotherapies in respect of (i) insulin resistance, glucose intolerance, lipid profile, adiponectin levels, and mitochondrial complexes I, II, and III activities, (ii) reduced phosphoenolpyruvate carboxykinase, glucose 6-phophatase, glycogen phosphorylase, and GLUT2 transcript levels with increased glycogen content in the liver, (iii) restoration of insulin receptor 1β, pAkt/Akt, and AdipoR1 protein levels in skeletal muscle, and (iv) significant increase in islet number due to β-cell regeneration and reduced β-cell death. L-glutamine and pitavastatin in combination can ameliorate T2D by inducing β-cell regeneration and regulating glucose homeostasis.

Metabolic Homeostasis of Amino Acids and Diabetic Kidney Disease

Diabetic kidney disease (DKD) occurs in 25-40% of patients with diabetes. Individuals with DKD are at a significant risk of progression to end-stage kidney disease morbidity and mortality. At present, although renal function-decline can be retarded by intensive glucose lowering and strict blood pressure control, these current treatments have shown no beneficial impact on preventing progression to kidney failure. Recently, in addition to control of blood sugar and pressure, a dietary approach has been recommended for management of DKD. Amino acids (AAs) are both biomarkers and causal factors of DKD progression. AA homeostasis contributes to renal hemodynamic response and glomerular hyperfiltration alteration in diabetic patients. This review discusses the links between progressive kidney dysfunction and the metabolic homeostasis of histidine, tryptophan, methionine, glutamine, tyrosine, and branched-chain AAs. In addition, we emphasize the regulation effects of special metabolites on DKD progression, with a focus on causality and potential mechanisms. This paper may offer an optimized protein diet strategy with concomitant management of AA homeostasis to reduce the risks of DKD in a setting of hyperglycemia.

Widely Targeted Metabolomics Analysis of Soybean and Chickpea and Their Different Advantages and New Functional Compounds for Diabetes

Soybean is widely used as a kind of bean for daily consumption. Chickpea is increasingly utilised because of its good healthcare function. At present, using chickpeas could have better results than soybeans in some areas. Previous studies of the two legumes focused on certain components and failed to fully reveal the differences between the two legumes. Thus, understanding the comprehensive similarities and differences between the two legumes is necessary to apply and develop these legumes effectively. In this study, we performed a UPLC-ESI-MS/MS-based widely targeted metabolomics analysis on two legumes. A total of 776 metabolites (including primary metabolites and secondary metabolites) were detected, which were divided into more than a dozen broad categories. The differential analysis of these metabolites showed that there were 480 metabolites with significant differences in relative contents between the two legumes. Compared with soybean, the expression of 374 metabolites of chickpea was down-regulated and that of 106 metabolites was up-regulated. The metabolic pathway analysis showed significant differences in the flavonoids biosynthesis, phenylpropanoid biosynthesis, linoleic acid metabolism and alkaloid biosynthesis between the two legumes. The advantages and applicability of the two kinds of legumes were confirmed through the analysis of anti-diabetic components. Moreover, some novel compounds (with contents higher than that of soybean) with hypoglycaemic activity were found in chickpea. This study provides an important reference for the in-depth study and comparative application of soybean and chickpea.

Angiotensin-Converting Enzyme 2 Inhibits Lipopolysaccharide-Caused Lung Fibrosis via Downregulating the Transforming Growth Factor β-1/Smad2/Smad3 Pathway

BACKGROUND

In our previous studies, angiotensin-converting enzyme 2 (ACE2) was shown to alleviate the severity of acute lung injury, but its effects on the development of lung injury-caused lung fibrosis have not been studied.

METHODS

In the present study, the effects of ACE2 on lipopolysaccharide (LPS)-induced fibrosis in the lung were studied. The role of epithelial-mesenchymal transition (EMT) and that of the transforming growth factor β-1 (TGF-β1)/Smad2/Smad3 pathway in LPS-induced fibrosis in the lung were investigated.

RESULTS

ACE2 expression in the mouse model of LPS-induced lung fibrosis was significantly increased. ACE2 activator diminazene aceturate (DIZE) significantly reduced pulmonary fibrosis, decreased alpha-smooth muscle actin expression, collagen I, hydroxyproline, and TGF-β1 in the lung. DIZE significantly decreased TGF-β1 expression and the activation of Smad2 and Smad3. ACE2 overexpression inhibited the LPS-induced EMT in MLE-12 cells (lung epithelial cells) and small interfering RNA treatment of ACE2 stimulated EMT. ACE2 overexpression also inhibited TGF-β1 expression and activation of Smad2 and Smad3 in MLE-12 cells. Finally, after MLE-12 cells were treated with both ACE2 and TGF-β1 plasmid, TGF-β1 plasmid significantly abolished the effect of ACE2 plasmid on the EMT in MLE-12 cells.

CONCLUSION

Combined with the in vivo study, it was revealed that ACE2 can suppress the TGF-β1/Smad2/Smad3 pathway in lung type II epithelial cells, thus reversing their EMT and lung fibrosis. The present study provides basic research data for the application of ACE2 in lung injury-caused lung fibrosis treatment and clarifies the intervention mechanism of ACE2 in pulmonary fibrosis, which has potential value for clinical application.

SIGNIFICANCE STATEMENT

Angiotensin-converting enzyme 2 (ACE2) can inhibit the epithelial-mesenchymal transition (EMT) in lung type II epithelial cells and lung fibrosis. ACE2 can regulate the transforming growth factor β-1/Smad2/Smad3 pathway in lung type II epithelial cells, which may be the underlying mechanism of ACE2's effect on EMT and lung fibrosis.

Urinary metabolic characterization with nephrotoxicity for residents under cadmium exposure

Cadmium is a well-known hazardous pollutant that mainly comes from dietary, tobacco and occupational exposure, posing threat to kidney. However, there is still a lack of systematic study on metabolic pathways and urinary biomarkers related to its nephrotoxicity under cadmium exposure for both females and males. In this study, a mass spectrometry-based metabolomics investigation of a cohort of 144 volunteers was conducted to explore sex-specific metabolic alteration and to screen biomarkers related to cadmium-induced nephrotoxicity. When the concentration of urinary cadmium increased, creatine pathway, amino acid metabolism especially the tryptophan metabolism, aminoacyl-tRNA biosynthesis, and purine metabolism were primarily influenced regardless of the gender. Also, the most specific biomarkers linked with nephrotoxicity based on the statistical analysis were detected including creatine, creatinine, l-tryptophan, adenine and uric acid. The study outcome might provide information to reflect the body burden and help improve health policy for risk assessment.

Knockout of NGAL aggravates tubulointerstitial injury in a mouse model of diabetic nephropathy by enhancing oxidative stress and fibrosis

Neutrophil gelatinase-associated lipocalin (NGAL), also called lipocalin 2, is considered a promising biomarker for acute and chronic kidney injuries. Several studies have demonstrated that its levels increase in plasma and urine in diabetic nephropathy (DN), and its urine concentration increases upon kidney function deterioration. However, its role in DN progression remains unclear. The current study used in vitro gene expression knockdown in human proximal tubular cell line human kidney (HK)2 to investigate the role of NGAL in oxidation and extracellular matrix secretion under high-glucose (HG) incubation. In addition, type 1 diabetes was induced in vivo in knockout NGAL^-/- and wild-type mice in order to investigate role of NGAL in the progression of DN. The results demonstrated that NGAL knockdown in HK2 cells significantly increased oxidative stress under HG stimulation tested by flow cytometry, and increased the secretion of interleukin-6, fibronectin (FN) and collagen IV examined by ELISA. Western blotting demonstrated that the phosphorylation of Smad2/3 also increased in HK2 cells under transforming growth factor-β1 stimulation. In vivo experiments demonstrated that diabetic NGAL^-/- mice showed deteriorated renal function compared with that of diabetic wild-type mice. Histopathological analysis suggests that diabetic NGAL^-/- mice had more serious glomerulosclerosis and tubular vascular degeneration than wild-type mice. Immunohistochemistry suggested that the absence of NGAL lead to increased FN deposition in glomeruli in a mouse model of DN. In conclusion, NGAL appears to have renal protective effects by slowing down the progression of DN, and its effect may be associated with a reduction in oxidation, fibrosis and inflammation.

Kidney Diseases: The Age of Molecular Markers

Kidney diseases are conditions that increase the morbidity and mortality of those afflicted. Diagnosis of these conditions is based on parameters such as the glomerular filtration rate (GFR), measurement of serum and urinary creatinine levels and equations derived from these measurements (Wasung, Chawla, Madero. Clin Chim Acta 438:350-357, 2015). However, serum creatinine as a marker for measuring renal dysfunction has its limitations since it is altered in several other physiological situations, such as in patients with muscle loss, after intense physical exercise or in people on a high protein diet (Riley, Powers, Welch. Res Q Exerc Sport 52(3):339-347, 1981; Juraschek, Appel, Anderson, Miller. Am J Kidney Dis 61(4):547-554, 2013). Besides the fact that serum creatinine is a marker that indicates glomerular damage, it is necessary the discovery of new biomarkers that reflect not only glomerular damage but also tubular impairment. Recent advances in Molecular Biology have led to the generation or identification of new biomarkers for kidney diseases such as: Acute Kidney Failure (AKI), chronic kidney disease (CKD), nephritis or nephrotic syndrome. There are recent markers that have been used to aid in diagnosis and have been shown to be more sensitive and specific than classical markers, such as neutrophil gelatinase associated lipocalin (NGAL) or kidney injury molecule-1 (KIM-1) (Wasung, Chawla, Madero. Clin Chim Acta 438:350-357, 2015; George, Gounden. Adv Clin Chem 88:91-119, 2019; Han, Bailly, Abichandani, Thadhani, Bonventre. Kidney Int 62(1):237-244, 2002; Fontanilla, Han. Expert Opin Med Diagn 5(2):161-173, 2011). However, early diagnostic biomarkers are still necessary to assist the intervention and monitor of the progression of these conditions.

NGAL protects in nasopharyngeal carcinoma by inducing apoptosis and blocking epithelial-mesenchymal transition

In recent years, neutrophil gelatinase-associated lipocalin (NGAL) has been considered to be a key molecule in different cancer types and its carcinogenesis may be related to the NGAL/MMP-9 complex. However, its expression pattern and role in nasopharyngeal carcinoma (NPC) has rarely been reported. In the current study, 158 tumor tissues from NPC patients were collected and immunohistochemistry was performed to determine the NGAL protein expression, to investigate the correlation between its expression and clinical and pathological parameters using Chi square analysis. Furthermore, by over-expressing NGAL in NPC cell lines, biological alteration of NPC cells with respect to cell proliferation, migration and invasion was analyzed. Results suggested that high expression of NGAL predicts better prognosis and longer survival. Overexpression of NGAL significantly reduced the proliferation and migration of NPC cells, and induced the apoptosis by activating caspase 3, 8 and 9, and blocking epithelial-mesenchymal transition by inhibiting mothers against decapentaplegic homolog 2/3 phosphorylation.

Chronic exposure to arsenic and high fat diet induces sex-dependent pathogenic effects on the kidney

Both obesity and arsenic exposure are global public health problems that are associated with increased risk of renal disease. The effect of whole-life exposure to environmentally relevant levels of arsenic within dietary high fat diet on renal pathogenesis were examined. In this study, C57BL/6 J mice were parentally exposed to 100 ppb arsenic before conception. After weaning, both male and female offspring were maintained on 100 ppb arsenic and fed either a normal (LFD) or high fat diet (HFD). At 10 and 24 weeks of age, the offspring were sacrificed and kidneys collected. Exposure to arsenic led to an increase body-weight in LFD diet-fed female but not male mice. This response was not observed in HFD-fed female mice; however male mice showed significant increases in body weight in both As- and non-treated animals. Histological analysis shows that arsenic exposure significantly increases HFD-induced glomerular area expansion, mesangial matrix accumulation and fibrosis compared to LFD control animals. HFD alone increases renal inflammation and fibrosis; reflected by increases in IL-1β, ICAM-1 and fibronectin levels. Arsenic exposure significantly increases HFD-induced inflammatory and oxidative stress responses. In general, male mice have more severe responses than female mice to HFD or arsenic treatment. These results demonstrate that arsenic exposure causes sex-dependent alterations in HFD-induced kidney damage.

Hydrogen sulfide inhibits Ca2+-induced mitochondrial permeability transition pore opening in type-1 diabetes

Hydrogen sulfide (H2S) attenuates N-methyl-d-aspartate receptor-R1 (NMDA-R1) and mitigates diabetic renal damage; however, the molecular mechanism is not well known. Whereas NMDA-R1 facilitates Ca2+ permeability, H2S is known to inhibit L-type Ca2+ channel. High Ca2+ activates cyclophilin D (CypD), a gatekeeper protein of mitochondrial permeability transition pore (MPTP), thus facilitating molecular exchange between matrix and cytoplasm causing oxidative outburst and cell death. We tested the hypothesis of whether NMDA-R1 mediates Ca2+ influx causing CypD activation and MPTP opening leading to oxidative stress and renal injury in diabetes. We also tested whether H2S treatment blocks Ca2+ channel and thus inhibits CypD and MPTP opening to prevent renal damage. C57BL/6J and Akita (C57BL/6J-Ins2Akita) mice were treated without or with H2S donor GYY4137 (0.25 mg·kg-1·day-1 ip) for 8 wk. In vitro studies were performed using mouse glomerular endothelial cells. Results indicated that low levels of H2S and increased expression of NMDA-R1 in diabetes induced Ca2+ permeability, which was ameliorated by H2S treatment. We observed cytosolic Ca2+ influx in hyperglycemic (HG) condition along with mitochondrial-CypD activation, increased MPTP opening, and oxidative outburst, which were mitigated with H2S treatment. Renal injury biomarker KIM-1 was upregulated in HG conditions and normalized following H2S treatment. Inhibition of NMDA-R1 by pharmacological blocker MK-801 revealed similar results. We conclude that NMDA-R1-mediated Ca2+ influx in diabetes induces MPTP opening via CypD activation leading to increased oxidative stress and renal injury, and H2S protects diabetic kidney from injury by blocking mitochondrial Ca2+ permeability through NMDA-R1 pathway.

Albuminuria and low bone mineral density in paediatric patients with type 1 diabetes

AIM

To evaluate glycaemic control and its influence on albuminuria and bone mineral density (BMD) in children and adolescents with type 1 diabetes (T1D).

METHODS

We collectively assessed 84 T1D children/adolescents (T1D group), aged between 6 and 17 years, and then divided them into two groups according to their glycaemic profile (T1D with good glycaemic control (T1DG group) and T1D with poor glycaemic control (T1DP group)). Serum glucose, glycated haemoglobin, serum urea, serum creatinine, urinary albumin-to-creatinine ratio (ACR), estimated glomerular filtration rate and BMD levels were assessed.

RESULTS

Of the patients studied, 77% presented with poor glycaemic control. Patients with T1DP showed an increased ACR (P < 0.001) and a low BMD (P = 0.025) when compared to the T1DG group. In addition, five patients in the T1DP group presented with concomitant albuminuria and a low BMD for their chronological age. Significant negative correlations were identified between the ACR and glycated haemoglobin (r = 0.655, P < 0.001), BMD and glycated haemoglobin (r = -0.262, P = 0.047) and BMD and the ACR (r = -0.631, P = <0.001). In linear regression analysis, the ACR showed a negative effect on BMD (P = 0.044) in the T1D patient group.

CONCLUSION

Poor glycaemic control was correlated with albuminuria, suggestive of a negative effect on bone tissue, leading to a low BMD in children and adolescents with T1D.

Elabela protects against podocyte injury in mice with streptozocin-induced diabetes by associating with the PI3K/Akt/mTOR pathway

Diabetic nephropathy is a common complication of diabetes characterized by an increased rate of protein excretion in urine and kidney function loss. Elabela is a newly discovered peptide whose role in the regulation of diabetes is the major focus of this research. We established an in vivo model of Type 1 diabetes mellitus by injecting mice intraperitoneally with streptozotocin. The treatment group was administered Elabela for 6 months. In the present study, Elabela administration under diabetic conditions was found to reduce renal inflammation and fibrosis markers, leading to improvement in renal pathology and kidney dysfunction. Furthermore, Elabela acts through the phosphoinositide 3-kinase /Akt/mammalian target of rapamycin signaling pathway and decreases podocyte apoptosis, thereby exhibiting a nephroprotective effect against diabetic nephropathy. Our findings provide the first evidence that Elabela has a potential renoprotective effect in patients of diabetes.

Glutamine Enhances the Hypoglycemic Effect of Insulin in L6 Cells via Phosphatidylinositol-3-Kinase (PI3K)/Protein Kinase B (AKT)/Glucose Transporter 4 (GLUT4) Signaling Pathway

Background

Diabetes mellitus (DM) is characterized by a decreased blood level of glutamine (Gln), which may contribute to the disturbance in the effect of insulin on skeletal muscle. Therefore, it is crucial to study how to improve the effect of insulin on skeletal muscle by increasing Gln. In the present study, we investigated the effect of Gln on the hypoglycemic action of insulin in skeletal muscle L6 cells at high glucose levels through the insulin signaling pathway and glycogen synthesis pathway.

Material/Methods

The L6 cells were cultured in and stimulated by Gln and insulin. The glutamine analogue, L-Gamma-Glutamyl-p-nitroanilide (GPNA), was used for verifying the effect of Gln. The expression of insulin signaling molecules, including phosphatidylinositol-3-kinase (PI3K), 3-phosphoinositide-dependent protein kinase-1 (PDK1), protein kinase B (AKT), protein kinase C zeta (PKCζ), and glucose transporter 4 (GLUT4), were detected by real-time PCR and Western blot analysis, GLUT4 translocation was observed by immunofluorescence staining, glycogen synthase kinase (GSK) was analyzed by Western blotting, and glucose uptake was measured by glucose oxidase method (GOD).

Results

The results demonstrated that Gln combined with insulin remarkably up-regulated PI3K and PDK1 and also increased AKT and PKCζ phosphorylation. The present study shows that Gln enhanced the impact of insulin on GLUT4 and its translocation. The results of glucose uptake and GSK phosphorylation further confirmed the hypoglycemic effect of Gln accompanied with insulin. The hypoglycemic effect of Gln was reversed by GPNA.

Conclusions

These findings suggest that Gln enhances the hypoglycemic role of insulin through the PI3K/AKT/GLUT4 signaling pathway and glycogen synthesis pathway.

Antimicrobial Activity of Mesenchymal Stem Cells: Current Status and New Perspectives of Antimicrobial Peptide-Based Therapies

While mesenchymal stem cells (MSCs)-based therapy appears to be promising, there are concerns regarding possible side effects related to the unwanted suppression of antimicrobial immunity leading to an increased risk of infection. Conversely, recent data show that MSCs exert strong antimicrobial effects through indirect and direct mechanisms, partially mediated by the secretion of antimicrobial peptides and proteins (AMPs). In fact, MSCs have been reported to increase bacterial clearance in preclinical models of sepsis, acute respiratory distress syndrome, and cystic fibrosis-related infections. This article reviews the current evidence regarding the direct antimicrobial effector function of MSCs, focusing mainly on the role of MSCs-derived AMPs. The strategies that might modulate the expression and secretion of these AMPs, leading to enhanced antimicrobial effect, are highlighted. Furthermore, studies evaluating the presence of AMPs in the cargo of extracellular vesicles (EVs) are underlined as perspective opportunities to develop new drug delivery tools. The antimicrobial potential of MSCs-derived EVs can also be heightened through cell conditioning and/or drug loading. Finally, improving the pharmacokinetics and delivery, in addition to deciphering the multi-target drug status of AMPs, should synergistically lead to key advances against infections caused by drug-resistant strains.

Antimicrobial Activity of Mesenchymal Stem Cells: Current Status and New Perspectives of Antimicrobial Peptide-Based Therapies

While mesenchymal stem cells (MSCs)-based therapy appears to be promising, there are concerns regarding possible side effects related to the unwanted suppression of antimicrobial immunity leading to an increased risk of infection. Conversely, recent data show that MSCs exert strong antimicrobial effects through indirect and direct mechanisms, partially mediated by the secretion of antimicrobial peptides and proteins (AMPs). In fact, MSCs have been reported to increase bacterial clearance in preclinical models of sepsis, acute respiratory distress syndrome, and cystic fibrosis-related infections. This article reviews the current evidence regarding the direct antimicrobial effector function of MSCs, focusing mainly on the role of MSCs-derived AMPs. The strategies that might modulate the expression and secretion of these AMPs, leading to enhanced antimicrobial effect, are highlighted. Furthermore, studies evaluating the presence of AMPs in the cargo of extracellular vesicles (EVs) are underlined as perspective opportunities to develop new drug delivery tools. The antimicrobial potential of MSCs-derived EVs can also be heightened through cell conditioning and/or drug loading. Finally, improving the pharmacokinetics and delivery, in addition to deciphering the multi-target drug status of AMPs, should synergistically lead to key advances against infections caused by drug-resistant strains.