Targeted delivery of celastrol to mesangial cells is effective against mesangioproliferative glomerulonephritis

Mesangial cell-derived CircRNAs in chronic glomerulonephritis: RNA sequencing and bioinformatics analysis

BACKGROUND

Circular RNAs (circRNAs) have been shown to play critical roles in the initiation and progression of chronic glomerulonephritis (CGN), while their role from mesangial cells in contributing to the pathogenesis of CGN is rarely understood. Our study aims to explore the potential functions of mesangial cell-derived circRNAs using RNA sequencing (RNA-seq) and bioinformatics analysis.

METHODS

Mouse mesangial cells (MMCs) were stimulated by lipopolysaccharide (LPS) to establish an in vitro model of CGN. Pro-inflammatory cytokines and cell cycle stages were detected by Enzyme-linked immunosorbent assay (ELISA) and Flow Cytometry experiment, respectively. Subsequently, differentially expressed circRNAs (DE-circRNAs) were identified by RNA-seq. GEO microarrays were used to identify differentially expressed mRNAs (DE-mRNAs) between CGN and healthy populations. Weighted co-expression network analysis (WGCNA) was utilized to explore clinically significant modules of CGN. CircRNA-associated CeRNA networks were constructed by bioinformatics analysis. The hub mRNAs from CeRNA network were identified using LASSO algorithms. Furthermore, utilizing protein-protein interaction (PPI), gene ontology (GO), pathway enrichment (KEGG), and GSEA analyses to explore the potential biological function of target genes from CeRNA network. In addition, we investigated the relationships between immune cells and hub mRNAs from CeRNA network using CIBERSORT.

RESULTS

The expression of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α was drastically increased in LPS-induced MMCs. The number of cells decreased significantly in the G1 phase but increased significantly in the S/G2 phase. A total of 6 DE-mRNAs were determined by RNA-seq, including 4 up-regulated circRNAs and 2 down-regulated circRNAs. WGCNA analysis identified 1747 DE-mRNAs of the turquoise module from CGN people in the GEO database. Then, the CeRNA networks, including 6 circRNAs, 38 miRNAs, and 80 mRNAs, were successfully constructed. The results of GO and KEGG analyses revealed that the target mRNAs were mainly enriched in immune, infection, and inflammation-related pathways. Furthermore, three hub mRNAs (BOC, MLST8, and HMGCS2) from the CeRNA network were screened using LASSO algorithms. GSEA analysis revealed that hub mRNAs were implicated in a great deal of immune system responses and inflammatory pathways, including IL-5 production, MAPK signaling pathway, and JAK-STAT signaling pathway. Moreover, according to an evaluation of immune infiltration, hub mRNAs have statistical correlations with neutrophils, plasma cells, monocytes, and follicular helper T cells.

CONCLUSIONS

Our findings provide fundamental and novel insights for further investigations into the role of mesangial cell-derived circRNAs in CGN pathogenesis.

Prolonged Retention of Albumin Nanoparticles Alleviates Renal Ischemia-Reperfusion Injury through Targeted Pyroptosis

Acute kidney injury (AKI) represents a prevalent and complex clinical event, characterized by irreversible damage to renal tubular epithelial cells and high intensive care unit (ICU) admission rates and mortality. The kidneys are highly susceptible to oxidative stress, inflammation, pyroptosis, and programmed cell death. Pyroptosis poses a significant risk, exacerbating the damage and inflammation of renal tubular cells. Disulfiram (DSF), an FDA-approved medication for alcohol cessation, inhibits the pyroptotic pore-forming protein Gasdermin-D (GSDMD), positioning it as a potential solution for emergency relief against an inflammatory response. However, current obstacles include poor water solubility, rapid metabolism, and off-target effects. Inspired by this discovery, bovine serum albumin (BSA), which has already entered clinical application, has been utilized to produce safe and long-lasting nanoparticles (BSA@DSF NPs), addressing the challenges posed by DSF's physicochemical properties. By targeting the GSDMD protein, the potent pro-inflammatory effects of pyroptosis were mitigated, leading to the alleviation of AKI induced by ischemia-reperfusion injury. This research offers a straightforward and efficient concept for treating AKI, potentially enhancing the transition to clinical practice.

Mechanistic study of celastrol-mediated inhibition of proinflammatory activation of macrophages in IgA nephropathy via down-regulating ECM1

Increasing evidence suggests that the mononuclear/macrophage system is vital in amplifying the inflammatory cascade in IgA Nephropathy (IgAN). However, the pathogenic mechanism of macrophages in IgAN and targeted treatment strategies still need to be explored. This study found that botanical triterpene celastrol (CLT) effectively alleviated renal lesions, M1-like macrophage infiltration, inflammatory factors production, and improved renal function in IgAN mice. We found that the renal macrophages of IgAN patients had high expression of ECM1, a crucial molecule involved in macrophage inflammatory polarization, positively correlated with the IgAN clinical severity. In murine macrophage Raw 264.7 cells, CLT inhibited macrophage M1-like polarization and the output of TNF-α and IL-6 by downregulating the ECM1/STAT5 pathway. Mechanistically, molecular docking, CESTA, and immunoprecipitation verified that CLT directly bound to ECM1 and increased the ubiquitination of ECM1. Collectively, these results illustrated that CLT inhibited proinflammatory macrophage in IgAN by directly targeting ECM1 to promote ubiquitination degradation of ECM1. Therefore, this study may provide a theoretical basis for exploring the pathogenesis of IgAN and identifying new perspectives for targeted therapy of IgAN.

Application of galactosylated albumin for targeted delivery of triptolide to suppress hepatocellular carcinoma progression through inhibiting de novo lipogenesis

Hepatocellular carcinoma (HCC) remains the fourth leading cause of cancer-associated death globally with a lack of efficient therapy. The pathogenesis of HCC is a complex and multistep process, highly reliant on de novo lipogenesis, from which tumor cells can incorporate fatty acids to satisfy the necessary energy demands of rapid proliferation and provide survival advantages. Triptolide (TP) is a bioactive ingredient exhibiting potent abilities of anti-proliferation and lipid metabolism regulation, but its clinical application is constrained because of its toxicity and non-specific distribution. The present study has developed galactosylated bovine serum albumin nanoparticles loaded with TP (Gal-BSA-TP NPs) to alleviate systemic toxicity and increase tumor-targeting and antitumor efficacy. Furthermore, Gal-BSA-TP NPs could inhibit de novo lipogenesis via the p53-SREBP1C-FASN pathway to deprive the fuel supply of HCC, offering a specific strategy for HCC treatment. In general, this study provided a biocompatible delivery platform for targeted therapy for HCC from the perspective of de novo lipogenesis.

NLC Delivery of EGFP Plasmid to TM4 Cell Nuclei for Targeted Gene Therapy

Purpose

This study evaluated whether a nanostructured lipid carrier (NLC) delivery system could safely and accurately deliver nucleic acids to the cell nucleus using the enhanced green fluorescent protein (EGFP)-C1 plasmid model.

Methods

The NLC was formulated using the emulsification method and equipped for cationic lipid-mediated transfection with 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), which interacts electrostatically with nucleic acid. The NLC attributes, including size, polydispersity index, and zeta potential, were assessed by dynamic light scattering (DLS). The morphological structure was analyzed using transmission electron microscopy. Entrapment efficiency was evaluated by a direct method. Cellular uptake mechanisms of pEGFP-C1-NLC and the ability of pEGFP-C1 to penetrate the nucleus of TM4 cells to express EGFP were observed using confocal microscopy.

Results

pEGFP-C1-NLC exhibited particle sizes in the range 56-88 nm with a particle charge range of -6.0 to+1.3 mV. The polydispersity index<0.5 showed good size uniformity, and entrapment efficiency of pEGFP-C1in the NLC was 92.06±2.295%. The NLC formulation was internalized predominantly via caveolae-mediated endocytosis, as indicated by EGFP expression following successful delivery of pEGFP by the NLC into the cells.

Conclusion

NLC formulation could deliver genetic material to the nucleus and could be considered a gene therapy candidate for spermatogenesis.

Celastrol: A century-long journey from the isolation to the biotechnological production and the development of an antiobesity drug

Celastrol, a triterpenoid found in the root of the traditional medicinal plant Tripterygium wilfordii, is a potent anti-inflammatory and antiobesity agent. However, pharmacological exploitation of celastrol has been hindered by the limited accessibility of plant material, the co-existence of other toxic compounds in the same plant tissue, and the lack of an efficient chemical synthesis method. In this review, we highlight recent progress in elucidating celastrol biosynthesis and discuss how this knowledge can facilitate its scalable bioproduction using cell factories and its further development as an antiobesity and anti-inflammatory drug.

Prodrug-inspired adenosine triphosphate-activatable celastrol-Fe(III) chelate for cancer therapy

Celastrol (CEL), an active compound isolated from the root of Tripterygium wilfordii, exhibits broad anticancer activities. However, its poor stability, narrow therapeutic window and numerous adverse effects limit its applications in vivo. In this study, an adenosine triphosphate (ATP) activatable CEL-Fe(III) chelate was designed, synthesized, and then encapsulated with a reactive oxygen species (ROS)-responsive polymer to obtain CEL-Fe nanoparticles (CEL-Fe NPs). In normal tissues, CEL-Fe NPs maintain structural stability and exhibit reduced systemic toxicity, while at the tumor site, an ATP-ROS-rich tumor microenvironment, drug release is triggered by ROS, and antitumor potency is restored by competitive binding of ATP. This intelligent CEL delivery system improves the biosafety and bioavailability of CEL for cancer therapy. Such a CEL-metal chelate strategy not only mitigates the challenges associated with CEL but also opens avenues for the generation of CEL derivatives, thereby expanding the therapeutic potential of CEL in clinical settings.

Glomerulus-Targeted ROS-Responsive Polymeric Nanoparticles for Effective Membranous Nephropathy Therapy

Membranous nephropathy (MN) is a common immune-mediated glomerular disease that requires the development of safe and highly effective therapies. Celastrol (CLT) has shown promise as a therapeutic molecule candidate, but its clinical use is currently limited due to off-target toxicity. Given that excess levels of reactive oxygen species (ROS) contributing to podocyte damage is a key driver of MN progression to end-stage renal disease, we rationally designed ROS-responsive cationic polymeric nanoparticles (PPS-CPNs) with a well-defined particle size and surface charge by employing poly(propylene sulfide)-polyethylene glycol (PPS-PEG) and poly(propylene sulfide)-polyethylenimine (PPS-PEI) to selectively deliver CLT to the damaged glomerulus for MN therapy. Experimental results show that PPS-CPNs successfully crossed the fenestrated endothelium, accumulated in the glomerular basement membrane (GBM), and were internalized by podocytes where rapid drug release was triggered by the overproduction of ROS, thereby outperforming nonresponsive CLT nanotherapy to alleviate subepithelial immune deposits, podocyte foot process effacement, and GBM expansion in a rat MN model. Moreover, the ROS-responsive CLT nanotherapy was associated with significantly lower toxicity to major organs than free CLT. These results suggest that encapsulating CLT into PPS-CPNs can improve efficacy and reduce toxicity as a promising treatment option for MN.

Advances in drug delivery-based therapeutic strategies for renal fibrosis treatment

Renal fibrosis is the result of all chronic kidney diseases and is becoming a major global health hazard. Currently, traditional treatments for renal fibrosis are difficult to meet clinical needs due to shortcomings such as poor efficacy or highly toxic side effects. Therefore, therapeutic strategies that target the kidneys are needed to overcome these shortcomings. Drug delivery can be attained by improving drug stability and addressing controlled release and targeted delivery of drugs in the delivery category. By combining drug delivery technology with nanosystems, controlled drug release and biodistribution can be achieved, enhancing therapeutic efficacy and reducing toxic cross-wise effects. This review discusses nanomaterial drug delivery strategies reported in recent years. Firstly, the present review describes the mechanisms of renal fibrosis and anti-renal fibrosis drug delivery. Secondly, different nanomaterial drug delivery strategies for the treatment of renal injury and fibrosis are highlighted. Finally, the limitations of these strategies are also discussed. Investigating various anti-renal fibrosis drug delivery strategies reveals the characteristics and therapeutic effects of various novel nanosystem-derived drug delivery approaches. This will serve as a reference for future research on drug delivery strategies for renal fibrosis treatment.

Targeted therapy of kidney disease with nanoparticle drug delivery materials

With the development of nanomedicine, nanomaterials have been widely used, offering specific drug delivery to target sites, minimal side effects, and significant therapeutic effects. The kidneys have filtration and reabsorption functions, with various potential target cell types and a complex structural environment, making the strategies for kidney function protection and recovery after injury complex. This also lays the foundation for the application of nanomedicine in kidney diseases. Currently, evidence in preclinical and clinical settings supports the feasibility of targeted therapy for kidney diseases using drug delivery based on nanomaterials. The prerequisite for nanomedicine in treating kidney diseases is the use of carriers with good biocompatibility, including nanoparticles, hydrogels, liposomes, micelles, dendrimer polymers, adenoviruses, lysozymes, and elastin-like polypeptides. These carriers have precise renal uptake, longer half-life, and targeted organ distribution, protecting and improving the efficacy of the drugs they carry. Additionally, attention should also be paid to the toxicity and solubility of the carriers. While the carriers mentioned above have been used in preclinical studies for targeted therapy of kidney diseases both in vivo and in vitro, extensive clinical trials are still needed to ensure the short-term and long-term effects of nano drugs in the human body. This review will discuss the advantages and limitations of nanoscale drug carrier materials in treating kidney diseases, provide a more comprehensive catalog of nanocarrier materials, and offer prospects for their drug-loading efficacy and clinical applications.

Celastrol enhances the viability of random-pattern skin flaps by regulating autophagy through the AMPK-mTOR-TFEB axis

In reconstructive and plastic surgery, random-pattern skin flaps (RPSF) are often used to correct defects. However, their clinical usefulness is limited due to their susceptibility to necrosis, especially on the distal side of the RPSF. This study validates the protective effect of celastrol (CEL) on flap viability and explores in terms of underlying mechanisms of action. The viability of different groups of RPSF was evaluated by survival zone analysis, laser doppler blood flow, and histological analysis. The effects of CEL on flap angiogenesis, apoptosis, oxidative stress, and autophagy were evaluated by Western blot, immunohistochemistry, and immunofluorescence assays. Finally, its mechanistic aspects were explored by autophagy inhibitor and Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) inhibitor. On the seventh day after surgery, the survival area size, blood supply, and microvessel count of RPSF were augmented following the administration of CEL. Additionally, CEL stimulated angiogenesis, suppressed apoptosis, and lowered oxidative stress levels immediately after elevated autophagy in ischemic regions; These effects can be reversed using the autophagy inhibitor chloroquine (CQ). Specifically, CQ has been observed to counteract the protective impact of CEL on the RPSF. Moreover, it has also been discovered that CEL triggers the AMPK-mTOR-TFEB axis activation in the area affected by ischemia. In CEL-treated skin flaps, AMPK inhibitors were demonstrated to suppress the AMPK-mTOR-TFEB axis and reduce autophagy levels. This investigation suggests that CEL benefits the survival of RPSF by augmenting angiogenesis and impeding oxidative stress and apoptosis. The results are credited to increased autophagy, made possible by the AMPK-mTOR-TFEB axis activation.

Physiological principles underlying the kidney targeting of renal nanomedicines

Kidney disease affects more than 10% of the global population and is associated with considerable morbidity and mortality, highlighting a need for new therapeutic options. Engineered nanoparticles for the treatment of kidney diseases (renal nanomedicines) represent one such option, enabling the delivery of targeted therapeutics to specific regions of the kidney. Although they are underdeveloped compared with nanomedicines for diseases such as cancer, findings from preclinical studies suggest that renal nanomedicines may hold promise. However, the physiological principles that govern the in vivo transport and interactions of renal nanomedicines differ from those of cancer nanomedicines, and thus a comprehensive understanding of these principles is needed to design nanomedicines that effectively and specifically target the kidney while ensuring biosafety in their future clinical translation. Herein, we summarize the current understanding of factors that influence the glomerular filtration, tubular uptake, tubular secretion and extrusion of nanoparticles, including size and charge dependency, and the role of specific transporters and processes such as endocytosis. We also describe how the transport and uptake of nanoparticles is altered by kidney disease and discuss strategic approaches by which nanoparticles may be harnessed for the detection and treatment of a variety of kidney diseases.

Celastrol alleviates diabetic vascular injury via Keap1/Nrf2-mediated anti-inflammation

Introduction: Celastrol (Cel) is a widely used main component of Chinese herbal medicine with strong anti-inflammatory, antiviral and antitumor activities. In the present study, we aimed to elucidate the cellular molecular protective mechanism of Cel against diabetes-induced inflammation and endothelial dysfunction. Methods: Type 2 diabetes (T2DM) was induced by db/db mice, and osmotic pumps containing Cel (100 μg/kg/day) were implanted intraperitoneally and were calibrated to release the drug for 28 days. In addition, human umbilical vein endothelial cells (HUVECs) were cultured in normal or high glucose and palmitic acid-containing (HG + PA) media in the presence or absence of Cel for 48 h. Results: Cel significantly ameliorated the hyperglycemia-induced abnormalities in nuclear factor (erythroid-derived 2)-like protein 2 (Nrf2) pathway activity and alleviated HG + PA-induced oxidative damage. However, the protective effect of Cel was almost completely abolished in HUVECs transfected with short hairpin (sh)RNA targeting Nrf2, but not by nonsense shRNA. Furthermore, HG + PA reduced the phosphorylation of AMP-activated protein kinase (AMPK), the autophagic degradation of p62/Kelch-like ECH-associated protein 1 (Keap1), and the nuclear localization of Nrf2. However, these catabolic pathways were inhibited by Cel treatment in HUVECs. In addition, compound C (AMPK inhibitors) and AAV9-sh-Nrf2 reduced Cel-induced Nrf2 activation and angiogenesis in db/db mice. Discussion: Taking these findings together, the endothelial protective effect of Cel in the presence of HG + PA may be at least in part attributed to its effects to reduce reactive oxygen species (ROS) and inflammation through p62/Keap1-mediated Nrf2 activation.

Application and design considerations of ROS-based nanomaterials in diabetic kidney disease

Diabetic nephropathy (DKD) is a common chronic complication of diabetes mellitus and an important cause of cardiovascular-related death. Oxidative stress is a key mechanism leading to diabetic nephropathy. However, the current main therapeutic approach remains combination therapy and lacks specific therapies targeting oxidative stress. With the development of nanotechnology targeting ROS, therapeutic fluids regarding their treatment of diabetic nephropathy have attracted attention. In this review, we provide a brief overview of various ROS-based nanomaterials for DKD, including ROS-scavenging nanomaterials, ROS-associated nanodelivery materials, and ROS-responsive nanomaterials. In addition, we summarize and discuss key factors that should be considered when designing ROS-based nanomaterials, such as biosafety, efficacy, targeting, and detection and monitoring of ROS.

Targeting the Kidneys at the Nanoscale: Nanotechnology in Nephrology

Kidney diseases, both acute and chronic, are a substantial burden on individual and public health, and they continue to increase in frequency. Despite this and an intense focus on the study of disease mechanisms, few new therapeutic approaches have extended to the clinic. This is in part due to poor pharmacology of many, if not most, therapeutics with respect to the sites of kidney disease within the glomerulus or nephron. Considering this, within the past decade, and more pointedly over the past 2 years, there have been substantial developments in nanoparticle systems to deliver therapeutics to the sites of kidney disease. Here, we provide a broad overview of the various classes of nanomaterials that have been developed to improve therapeutic development for kidney diseases, the strategy used to provide kidney accumulation, and briefly the disease models they focused on, if any. We then focus on one specific system, polymeric mesoscale nanoparticles, which has broadly been used over 13 publications, demonstrating targeting of the tubular epithelium with 26-fold specificity compared with other organs. While there have been several nanomedicines that have advanced to the clinic in the past several decades, including mRNA-based coronavirus disease vaccines and others, none have focused on kidney diseases specifically. In total, we are confident that the rapid advancement of nanoscale-based kidney targeting and a concerted focus by clinicians, scientists, engineers, and other stakeholders will push one or more of these technologies into clinical trials over the next decade.

Collision of herbal medicine and nanotechnology: a bibliometric analysis of herbal nanoparticles from 2004 to 2023

BACKGROUND

Herbal nanoparticles are made from natural herbs/medicinal plants, their extracts, or a combination with other nanoparticle carriers. Compared to traditional herbs, herbal nanoparticles lead to improved bioavailability, enhanced stability, and reduced toxicity. Previous research indicates that herbal medicine nanomaterials are rapidly advancing and making significant progress; however, bibliometric analysis and knowledge mapping for herbal nanoparticles are currently lacking. We performed a bibliometric analysis by retrieving publications related to herbal nanoparticles from the Web of Science Core Collection (WoSCC) database spanning from 2004 to 2023. Data processing was performed using the R package Bibliometrix, VOSviewers, and CiteSpace.

RESULTS

In total, 1876 articles related to herbal nanoparticles were identified, originating from various countries, with China being the primary contributing country. The number of publications in this field increases annually. Beijing University of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, and Saveetha University in India are prominent research institutions in this domain. The Journal "International Journal of Nanomedicine" has the highest number of publications. The number of authors of these publications reached 8234, with Yan Zhao, Yue Zhang, and Huihua Qu being the most prolific authors and Yan Zhao being the most frequently cited author. "Traditional Chinese medicine," "drug delivery," and "green synthesis" are the main research focal points. Themes such as "green synthesis," "curcumin," "wound healing," "drug delivery," and "carbon dots" may represent emerging research areas.

CONCLUSIONS

Our study findings assist in identifying the latest research frontiers and hot topics, providing valuable references for scholars investigating the role of nanotechnology in herbal medicine.

A quantitative review of nanotechnology-based therapeutics for kidney diseases

Kidney-specific nanocarriers offer a targeted approach to enhance therapeutic efficacy and reduce off-target effects in renal treatments. The nanocarriers can achieve organ or cell specificity via passive targeting and active targeting mechanisms. Passive targeting capitalizes on the unique physiological traits of the kidney, with factors like particle size, charge, shape, and material properties enhancing organ specificity. Active targeting, on the other hand, achieves renal specificity through ligand-receptor interactions, modifying nanocarriers with molecules, peptides, or antibodies for receptor-mediated delivery. Nanotechnology-enabled therapy targets diseased kidney tissue by modulating podocytes and immune cells to reduce inflammation and enhance tissue repair, or by inhibiting myofibroblast differentiation to mitigate renal fibrosis. This review summarizes the current reports of the drug delivery systems that have been tested in vivo, identifies the nanocarriers that may preferentially accumulate in the kidney, and quantitatively compares the efficacy of various cargo-carrier combinations to outline optimal strategies and future research directions. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Recent advances in drug delivery of celastrol for enhancing efficiency and reducing the toxicity

Celastrol is a quinone methyl triterpenoid monomeric ingredient extracted from the root of Tripterygium wilfordii. Celastrol shows potential pharmacological activities in various diseases, which include inflammatory, obesity, cancer, and bacterial diseases. However, the application prospect of celastrol is largely limited by its low bioavailability, poor water solubility, and undesired off-target cytotoxicity. To address these problems, a number of drug delivery methods and technologies have been reported to enhance the efficiency and reduce the toxicity of celastrol. We classified the current drug delivery technologies into two parts. The direct chemical modification includes nucleic acid aptamer-celastrol conjugate, nucleic acid aptamer-dendrimer-celastrol conjugate, and glucolipid-celastrol conjugate. The indirect modification includes dendrimers, polymers, albumins, and vesicular carriers. The current technologies can covalently bond or encapsulate celastrol, which improves its selectivity. Here, we present a review that focalizes the recent advances of drug delivery strategies in enhancing the efficiency and reducing the toxicity of celastrol.

Inflammation-Targeted Drug Delivery Strategies via Albumin-Based Systems

Albumin, being the most abundant serum protein, has the potential to significantly enhance the physicochemical properties of therapeutic payloads, thereby improving their pharmacological effects. Apart from its passive transport via the enhanced permeability and retention effect, albumin can actively accumulate in tumor microenvironments or inflammatory tissues via receptor-mediated processes. This unique property makes albumin a promising scaffold for targeted drug delivery. This review focuses on exploring different delivery strategies that combine albumin with drug payloads to achieve targeted therapy for inflammatory diseases. Also, albumin-derived therapeutic products on the market or undergoing clinical trials in the past decade have been summarized to gain insight into the future development of albumin-based drug delivery systems. Given the involvement of inflammation in numerous diseases, drug delivery systems utilizing albumin demonstrate remarkable advantages, including enhanced properties, improved in vivo behavior and efficacy. Albumin-based drug delivery systems have been demonstrated in clinical trials, while more advanced strategies for improving the capacity of drug delivery systems with the help of albumin remain to be discovered. This could pave the way for biomedical applications in more effective and precise treatments.

Celastrol ameliorates experimental autoimmune uveitis through STAT3 targeting and gut microenvironment reprofiling

BACKGROUND

Extensive research has revealed the favorable effects of celastrol (CEL) against various diseases, but the role of CEL in autoimmune uveitis remains unexplored.

METHODS

We first assessed the prophylactical and therapeutical effects of CEL on autoimmune uveitis via rat experimental autoimmune uveitis model. After network pharmacology, functional enrichment and molecular docking analyses, we predicted the potential target of CEL and validated its effect on EAU by clinical and histopathological scores, Evans blue staining, immunofluorescence assay and western blotting. Then we evaluated the role of CEL in the gut environment by 16S rRNA sequencing and untargeted metabolomic analysis.

RESULTS

We confirmed that CEL treatment suppressed the pathological TH17 response, inhibited the migration of inflammatory cells, and preserved the integrity of BRB via targeting STAT3-IL17 pathway. Furthermore, CEL was found to reduce the relative abundance of opportunistic pathogenic bacteria including Clostridium_sensu_stricto_1, Parasutterella and GCA-900066575, and enrich the relative abundance of beneficial Oscillospirales and Ruminococcus_torques_group in EAU rats by fecal 16S rRNA sequencing. Meanwhile, CEL treatment reshaped the gut metabolites in the EAU rats by increasing the relative concentrations of cholic acid, progesterone and guggulsterone, and decreasing the relative levels of isoproterenol, creatinine and phenylacetylglutamine.

CONCLUSIONS

CEL exerts its ameliorative effects on the experimental autoimmune uveitis through the dual mechanisms of targeting STAT3 and reprofiling the gut microenvironment.

Sequentially Released Liposomes Enhance Anti-Liver Cancer Efficacy of Tetrandrine and Celastrol-Loaded Coix Seed Oil

Background

A sequential release co-delivery system is an effective strategy to improve anti-cancer efficacy. Herein, multicomponent-based liposomes (TET-CTM/L) loaded with tetrandrine (TET) and celastrol (CEL)-loaded coix seed oil microemulsion (CTM) were fabricated, which showed synergistic anti-liver cancer activities. By virtue of Enhanced Permeability and Retention (EPR) effect, TET-CTM/L can achieve efficient accumulation at the tumor site. TET was released initially to repair abnormal vessels and decrease the fibroblasts, and CTM was released subsequently for eradication of tumor tissue.

Methods

TEM (transmission electron microscopy) and DLS (dynamic light scattering) were adopted to characterize the TET-CTM/L. Flow cytometry was adopted to examine the cellular uptake and cytotoxicity of HepG2 cells. The HepG2 xenograft nude mice were adopted to evaluate the anti-tumor efficacy and systemic safety of TET-CTM/L.

Results

TEM images of TET-CTM/L showed the structure of small particle size of CTM within large-size liposomes, indicating that CTM can be encapsulated in liposomes by film dispersion method. In in vitro studies, TET-CTM/L induced massive apoptosis toward HepG2 cells, indicating synergistic cytotoxicity against HepG2 cells. In in vivo studies, TET-CTM/L displayed diminished systemic toxicity compared to celastrol or TET used alone. TET-CTM/L showed the excellent potential for tumor-targeting ability in a biodistribution study.

Conclusion

Our study provides a new strategy for combining anti-cancer therapy that has good potential not only in the treatment of liver cancer but also can be applied to the treatment of other solid tumors.

Application of nanotechnology in the treatment of glomerulonephritis: current status and future perspectives

Glomerulonephritis (GN) is the most common cause of end-stage renal failure worldwide; in most cases, it cannot be cured and can only delay the progression of the disease. At present, the main treatment methods include symptomatic therapy, immunosuppressive therapy, and renal replacement therapy. However, effective treatment of GN is hindered by issues such as steroid resistance, serious side effects, low bioavailability, and lack of precise targeting. With the widespread application of nanoparticles in medical treatment, novel methods have emerged for the treatment of kidney diseases. Targeted transportation of drugs, nucleic acids, and other substances to kidney tissues and even kidney cells through nanodrug delivery systems can reduce the systemic effects and adverse reactions of drugs and improve treatment effectiveness. The high specificity of nanoparticles enables them to bind to ion channels and block or enhance channel gating, thus improving inflammation. This review briefly introduces the characteristics of GN, describes the treatment status of GN, systematically summarizes the research achievements of nanoparticles in the treatment of primary GN, diabetic nephropathy and lupus nephritis, analyzes recent therapeutic developments, and outlines promising research directions, such as gas signaling molecule nanodrug delivery systems and ultrasmall nanoparticles. The current application of nanoparticles in GN is summarized to provide a reference for better treatment of GN in the future.

Biofunctional coacervate-based artificial protocells with membrane-like and cytoplasm-like structures for the treatment of persistent hyperuricemia

Coacervate droplets formed by liquid-liquid phase separation have attracted considerable attention due to their ability to enrich biomacromolecules while preserving their bioactivities. However, there are challenges to develop coacervate droplets as delivery vesicles for therapeutics resulting from the lack of physiological stability and inherent lack of membranes in coacervate droplets. Herein, polylysine-polynucleotide complex coacervate droplets with favorable physiological stability are formulated to efficiently and facilely concentrate small molecules, biomacromolecules and nanoparticles without organic solvents. To improve the biocompatibility, the PEGylated phospholipid membrane is further coated on the surface of the coacervate droplets to prepare coacervate-based artificial protocells (ArtPC) with membrane-like and cytoplasm-like structures. The ArtPC can confine the cyclic catalytic system of uricase and catalase inside to degrade uric acid and deplete the toxicity of H2O2. This biofunctional ArtPC effectively reduces blood uric acid levels and prevents renal injuries in mice with persistent hyperuricemia. The ArtPC-based therapy can bridge the disciplines of synthetic biology, pharmaceutics and therapeutics.

Precisely Regulating M2 Subtype Macrophages for Renal Fibrosis Resolution

Macrophages are central to the pathogenesis of kidney disease and serve as an effective therapeutic target for kidney injury and fibrosis. Among them, M2-type macrophages have double-edged effects regarding anti-inflammatory effects and tissue repair. Depending on the polarization of the M2 subtypes (M2a or M2c) in the diseased microenvironment, they can either mediate normal tissue repair or drive tissue fibrosis. In renal fibrosis, M2a promotes disease progression through macrophage-to-myofibroblast transition (MMT) cells, while M2c possesses potent anti-inflammatory functions and promotes tissue repair, and is inhibited. The mechanisms underlying this differentiation are complex and are currently not well understood. Therefore, in this study, we first confirmed that M2a-derived MMT cells are responsible for the development of renal fibrosis and demonstrated that the intensity of TGF-β signaling is a major factor determining the differential polarization of M2a and M2c. Under excessive TGF-β stimulation, M2a undergoes a process known as MMT cells, whereas moderate TGF-β stimulation favors the polarization of M2c phenotype macrophages. Based on these findings, we employed targeted nanotechnology to codeliver endoplasmic reticulum stress (ERS) inhibitor (Ceapin 7, Cea or C) and conventional glucocorticoids (Dexamethasone, Dex or D), precisely modulating the ATF6/TGF-β/Smad3 signaling axis within macrophages. This approach calibrated the level of TGF-β stimulation on macrophages, promoting their polarization toward the M2c phenotype and suppressing excessive MMT polarization. The study indicates that the combination of ERS inhibitor and a first-line anti-inflammatory drug holds promise as an effective therapeutic approach for renal fibrosis resolution.

Targeted Delivery of Celastrol via Chondroitin Sulfate Derived Hybrid Micelles for Alleviating Symptoms in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is caused by an accumulation of excess fat in the liver leading to oxidative stress and liver cell injury, as well as overproduction of inflammatory cytokines. CD44 has been identified as a potential therapeutic target in the development of NAFLD to nonalcoholic steatohepatitis. Here, chondroitin sulfate (CS) is selected to construct a CD44-targeted delivery system for the treatment of NAFLD. Specifically, two CS-derived amphiphilic materials including CS conjugated with either 4-aminophenylboronic acid pinacol ester (CS-PBE) or phenformin (CS-PFM) were synthesized, respectively. The presence of PBE moieties on CS-PBE rendered the vehicle with enhanced loading capacity and scavenging potential against reactive oxygen species, while the presence of guanidine moieties on CS-PFM enhanced the internalization of vehicles in the differentiated hepatocytes. Next, celastrol (CLT) was encapsulated in the hybrid micelle to afford CS-Hybrid/CLT, which demonstrates sufficient stability, enhanced cellular uptake efficiencies in differentiated HepG2 cells, and therapeutic potential to alleviate lipid accumulation in differentiated HepG2 cells. In a high-fat-diet-induced NAFLD rat model, CS-Hybrid/CLT micelles demonstrated the capacity to dramatically decrease hepatic lipid accumulation and free fatty acid levels with greatly improved pathologic liver histology and downregulated hepatic inflammation levels. These results suggest that CS-based amphiphilic micelles may offer a promising strategy to effectively deliver therapeutic cargos to the liver for the treatment of NAFLD.

Nanomedicines for the management of diabetic nephropathy: present progress and prospects

Diabetic nephropathy (DN) is a serious microvascular consequence of diabetes mellitus (DM), posing an encumbrance to public health worldwide. Control over the onset and progress of DN depend heavily on early detection and effective treatment. DN is a major contributor to end-stage renal disease, and a complete cure is yet to be achieved with currently available options. Though some therapeutic molecules have exhibited promise in treating DN complications, their poor solubility profile, low bioavailability, poor permeation, high therapeutic dose and associated toxicity, and low patient compliance apprehend their clinical usefulness. Recent research has indicated nano-systems as potential theranostic platforms displaying futuristic promise in the diagnosis and treatment of DN. Early and accurate diagnosis, site-specific delivery and retention by virtue of ligand conjugation, and improved pharmacokinetic profile are amongst the major advantages of nano-platforms, defining their superiority. Thus, the emergence of nanoparticles has offered fresh approaches to the possible diagnostic and therapeutic strategies regarding DN. The present review corroborates an updated overview of different types of nanocarriers regarding potential approaches for the diagnosis and therapy of DN.

Biotin decorated celastrol-loaded ZIF-8 nano-drug delivery system targeted epithelial ovarian cancer therapy

Ovarian cancer (OC) stands as the second most prominent factor leading to cancer-related fatalities, characterized by a notably low five-year survival rate. The insidious onset of OC combined with its resistance to chemotherapy poses significant challenges in terms of treatment, emphasizing the utmost importance of developing innovative therapeutic agents. Despite its remarkable anti-tumor efficacy, celastrol (CEL) faces challenges regarding its clinical utilization in OC due to its restricted water solubility and notable side effects. In this study, celastrol (CEL) was encapsulated into Zeolitic imidazolate framework-8(ZIF-8) nanoparticle and grafted with biotin-conjugated polyethylene glycol (CEL@ZIF-8@PEG-BIO). Comprehensive comparisons of the physicochemical properties and anticancer activities of CEL and CEL@ZIF-8@PEG-BIO were conducted. Our findings revealed that CEL@ZIF-8@PEG-BIO exhibited favorable characteristics, including hydrodynamic diameters of 234.5 nm, excellent water solubility, high drug loading (31.60% ± 2.85), encapsulation efficiency (60.52% ± 2.79), and minimal side effects. Furthermore, CEL@ZIF-8@PEG-BIO can release chemicals in response to an acidic micro-environment, which is more likely a tumor micro-environment. In vitro, studies showed that CEL@ZIF-8@BIO inhibited cell proliferation, led to mitochondrial membrane potential (MMP) decline, and generated reactive oxygen species in OC cells. Both in vitro and in vivo experiments indicated that CEL@ZIF-8@PEG-BIO enhanced anti-tumor activity against OC via up-regulated apoptosis-promoting biomarkers and rendered cancer cell apoptosis via the P38/JNK MAPK signaling pathway. In conclusion, we have successfully developed a novel drug delivery system (CEL@ZIF-8@PEG-BIO), resulting in significant improvements in both water solubility and anti-tumor efficacy thereby providing valuable insights for future clinical drug development.

Theranostic Lipid Nanoparticles for Renal Cell Carcinoma

Renal cell carcinoma (RCC) is a common urological malignancy and represents a leading threat to healthcare. Recent years have seen a series of progresses in the early diagnosis and management of RCC. Theranostic lipid nanoparticles (LNPs) are increasingly becoming one of the focuses in this field, because of their suitability for tumor targeting and multimodal therapy. LNPs can be precisely fabricated with desirable chemical compositions and biomedical properties, which closely match the physiological characteristics and clinical needs of RCC. Herein, a comprehensive review of theranostic LNPs is presented, emphasizing the generic tool nature of LNPs in developing advanced micro-nano biomaterials. It begins with a brief overview of the compositions and formation mechanism of LNPs, followed with an introduction to kidney-targeting approaches, such as passive, active, and stimulus responsive targeting. With examples provided, a series of modification strategies for enhancing the tumor targeting and functionality of LNPs are discussed. Thereafter, research advances on applications of these LNPs for RCC including bioimaging, liquid biopsy, drug delivery, physical therapy, and gene therapy are summarized and discussed from an interdisciplinary perspective. The final part highlights the milestone achievements of translation medicine, current challenges as well as future development directions of LNPs for the diagnosis and treatment of RCC.

The therapeutic effect of Shenhua tablet against mesangial cell proliferation and renal inflammation in mesangial proliferative glomerulonephritis

Shenhua tablet (SH), a formulation of traditional Chinese medicine, exerts renoprotective effect on chronic kidney diseases, and it has been found to restrain inflammation, but the mechanism is still unclear. Here, we explored the potential renoprotection of SH in mesangial proliferative glomerulonephritis (MsPGN) rat model induced by anti-Thy1 antibody. Administration of SH reduced urinary albumin/creatinine ratio (UACR) and significantly attenuated mesangial cell proliferation and renal inflammation. Notably, SH protected rats against renal inflammation, which was associated with decreasing macrophage infiltration and promoting macrophage anti-inflammatory activity. Network analysis combined with arrays identified the Janus kinase signal transducer and activator of transcription (JAK-STAT) signaling pathway as the main pathways of SH could target inflammation. Furthermore, it was confirmed that mesangial cell proliferation, which response to inflammation, were alleviated by ASS1 expression enhanced after SH administration both in vivo and in vitro. Collectively, SH has the beneficial on relieving the progression of MsPGN to alleviate inflammation and mesangial proliferation by inhibiting STAT3 phosphorylation and maintains the expression level of ASS1, might be an effective strategy for treating MsPGN.

Biopolymer-Based Nanosystems: Potential Novel Carriers for Kidney Drug Delivery

Kidney disease has become a serious public health problem throughout the world, and its treatment and management constitute a huge global economic burden. Currently, the main clinical treatments are not sufficient to cure kidney diseases. During its development, nanotechnology has shown unprecedented potential for application to kidney diseases. However, nanotechnology has disadvantages such as high cost and poor bioavailability. In contrast, biopolymers are not only widely available but also highly bioavailable. Therefore, biopolymer-based nanosystems offer new promising solutions for the treatment of kidney diseases. This paper reviews the biopolymer-based nanosystems that have been used for renal diseases and describes strategies for the specific, targeted delivery of drugs to the kidney as well as the physicochemical properties of the nanoparticles that affect the targeting success.

Acid-Responsive Macroporous Silica Nanoparticles for Bcl-2-Functional-Converting Peptide Release and Synergism with Celastrol for Enhanced Therapy against Resistant Cancer

Combination of chemotherapeutics with polypeptide/protein drugs has been demonstrated to be an effective approach for treatment against cancer multidrug resistance. However, due to the low biostability and weak cell penetrating ability of biomacromolecules, intracellular delivery and release of biomacromolecules in a spatiotemporally controllable manner in target sites in vivo face great challenges, and synergistic effects will not be achieved as expected just by simple drug combination. Here, we conceived an inspired strategy to combat the drug-resistant tumors by fabricating multiarm PEG-gated large pore-sized mesoporous silica nanoparticles for the Bcl-2-functional-converting peptide (denoted as N9@M-CA∼8P) payload and controlled release and realizing synergistic effects with celastrol integration at a low dosage as a curative sensitizer. Our results demonstrated that the N9 peptide could be pH-responsively released from the macropores of the M-CA∼8P nanosystem both in simulated physiological environments and in cancer cells and at tumor sites. Biosafe and enhanced therapeutic outcomes (90% tumor inhibition) were obtained by combination of the N9@M-CA∼8P nanosystem with celastrol coordinatively inducing mitochondrion-mediated cell apoptosis in resistant cancer cell lines and in the corresponding xenografted mice models. Overall, this study provides convincing evidence for effective and safe resistant cancer treatment through a stimulus-responsive biomacromolecule nanosystem combined with a low dosage of a natural compound.

Targeted nanotherapy for kidney diseases: a comprehensive review

Kidney diseases represent a major public health problem, affecting millions of people worldwide. Moreover, the treatment of kidney diseases is burdened by the problematic effects of conventional drug delivery, such as systemic drug toxicity, rapid drug clearance, and the absence of precise targeting of the kidney. Although the use of nanotechnology in medicine is in its early stage and lacks robust translational studies, nanomedicines have already shown great promise as novel drug-delivery systems for the treatment of kidney disease. On the basis of our current knowledge of renal anatomy and physiology, pathophysiology of kidney diseases, and physicochemical characteristics of nanoparticles, an expansive repertoire and wide use of nanomedicines could be developed for kidney diseases in the near future. Some limitations have slowed the transition of these agents from preclinical studies to clinical trials, however. In this review, we summarize the current knowledge on renal drug-delivery systems and recent advances in renal cell targeting; we also demonstrate their important potential as future paradigm-shifting therapies for kidney diseases.

Effect of Albumin Corona Conformation on In Vitro and In Vivo Profiles of Intravenously Administered Nanoparticles

Under physiological conditions, nanoparticles (NPs) inevitably interact with proteins, resulting in extensive protein adsorption and the formation of a protein corona. Recent studies have shown that the different surface properties of NPs lead to varying degrees of conformational changes of adsorbed proteins. However, the impact of corona protein conformation on the in vitro and in vivo profiles of NPs remain largely unexplored. Herein, d-α-tocopherol polyethylene glycol 1000 succinate-based NPs with natural human serum albumin (HSA_N) corona or thermally denatured HSA (HSA_D) corona were synthesized following a previously established method. We then conducted a systematic study of the protein conformation as well as adsorption behaviors. Additionally, the impact of protein corona conformation on the NPs profiles in vitro and in vivo were elucidated to gain insight into its biological behaviors as a targeted delivery system for renal tubule diseases. Overall, NPs modified by HSA_N corona showed improved serum stability, greater cell uptake efficiency, better renal tubular targetability, and therapeutic efficacy on acute kidney injury in rats than NPs modified by HSA_D corona. Hence, the conformation of protein adsorbed on the surface of NPs may impact the in vitro and in vivo profiles of NPs.

Self-assembling nanoarchitectonics of size-controllable celastrol nanoparticles for efficient cancer chemotherapy with reduced systemic toxicity

Celastrol, extracted from Tripterygium wilfordii Hook F, is one of the most promising natural extract for cancer treatment. Nevertheless, insufficient tumor retention and severe systemic toxicity still hinder its application. Herein, we report for the first time that Celastrol can directly self-assemble into size-controllable nanoparticles through the anti-solvent method by using different good solvent or by the variation of Celastrol concentrations. In vitro anti-cancer experiment revealed that the as-prepared nanoparticles can kill MCF-7 cells more effectively. Moreover, the nanoparticles can efficiently accumulate in tumors of the tumor bearing mice after tail vein injection. Under the administration of lethal dosage of Celastrol, the tumors are greatly suppressed and the mice maintain the activity. These results demonstrate that anti-solvent method may be a promising strategy to fabricate Celastrol nano-drugs with controllable size and less systemic toxicity for further clinical cancer treatment.

Kidney fibrosis: from mechanisms to therapeutic medicines

Chronic kidney disease (CKD) is estimated to affect 10-14% of global population. Kidney fibrosis, characterized by excessive extracellular matrix deposition leading to scarring, is a hallmark manifestation in different progressive CKD; However, at present no antifibrotic therapies against CKD exist. Kidney fibrosis is identified by tubule atrophy, interstitial chronic inflammation and fibrogenesis, glomerulosclerosis, and vascular rarefaction. Fibrotic niche, where organ fibrosis initiates, is a complex interplay between injured parenchyma (like tubular cells) and multiple non-parenchymal cell lineages (immune and mesenchymal cells) located spatially within scarring areas. Although the mechanisms of kidney fibrosis are complicated due to the kinds of cells involved, with the help of single-cell technology, many key questions have been explored, such as what kind of renal tubules are profibrotic, where myofibroblasts originate, which immune cells are involved, and how cells communicate with each other. In addition, genetics and epigenetics are deeper mechanisms that regulate kidney fibrosis. And the reversible nature of epigenetic changes including DNA methylation, RNA interference, and chromatin remodeling, gives an opportunity to stop or reverse kidney fibrosis by therapeutic strategies. More marketed (e.g., RAS blockage, SGLT2 inhibitors) have been developed to delay CKD progression in recent years. Furthermore, a better understanding of renal fibrosis is also favored to discover biomarkers of fibrotic injury. In the review, we update recent advances in the mechanism of renal fibrosis and summarize novel biomarkers and antifibrotic treatment for CKD.

Recent advances of CREKA peptide-based nanoplatforms in biomedical applications

Nanomedicine technology is a rapidly developing field of research and application that uses nanoparticles as a platform to facilitate the diagnosis and treatment of diseases. Nanoparticles loaded with drugs and imaging contrast agents have already been used in clinically, but they are essentially passive delivery carriers. To make nanoparticles smarter, an important function is the ability to actively locate target tissues. It enables nanoparticles to accumulate in target tissues at higher concentrations, thereby improving therapeutic efficacy and reducing side effects. Among the different ligands, the CREKA peptide (Cys-Arg-Glu-Lys-Ala) is a desirable targeting ligand and has a good targeting ability for overexpressed fibrin in different models, such as cancers, myocardial ischemia-reperfusion, and atherosclerosis. In this review, the characteristic of the CREKA peptide and the latest reports regarding the application of CREKA-based nanoplatforms in different biological tissues are described. In addition, the existing problems and future application perspectives of CREKA-based nanoplatforms are also addressed.

Nanosystems for oxidative stress regulation in the anti-inflammatory therapy of acute kidney injury

Acute kidney injury (AKI) is a clinical syndrome that results from a rapid decline in renal structure or renal functional impairment with the main pathological feature of sublethal and lethal damage to renal tubular cells. However, many potential therapeutic agents cannot achieve the desired therapeutic effect because of their poor pharmacokinetics and short retention time in the kidneys. With the recent emergence and progress of nanotechnology, nanodrugs with unique physicochemical properties could prolong circulation time, enhance efficient targeted delivery, and elevate the accumulation of therapeutics that can cross the glomerular filtration barrier and indicate comprehensive application prospects in the prevention and treatment of AKI. In this review, various types of nanosystems (such as liposomes, polymeric nanosystems, inorganic nanoparticles and cell-derived extracellular vesicles) are designed and applied to improve the pharmacokinetics of drug formation, which could further relieve the burden on the kidneys caused by the final cumulative dose of drugs in conventional treatments. Moreover, the passive or active targeting effect of nanosystems can also reduce the total therapeutic dose and off-target adverse effects on other organs. Nanodelivery systems for treating AKI that alleviate oxidative stress-induced renal cell damage and regulate the inflammatory kidney microenvironment are summarized.

Advanced Drug Delivery Systems for Renal Disorders

Kidney disease management and treatment are currently causing a substantial global burden. The kidneys are the most important organs in the human urinary system, selectively filtering blood and metabolic waste into urine via the renal glomerulus. Based on charge and/or molecule size, the glomerular filtration apparatus acts as a barrier to therapeutic substances. Therefore, drug distribution to the kidneys is challenging, resulting in therapy failure in a variety of renal illnesses. Hence, different approaches to improve drug delivery across the glomerulus filtration barrier are being investigated. Nanotechnology in medicine has the potential to have a significant impact on human health, from illness prevention to diagnosis and treatment. Nanomaterials with various physicochemical properties, including size, charge, surface and shape, with unique biological attributes, such as low cytotoxicity, high cellular internalization and controllable biodistribution and pharmacokinetics, have demonstrated promising potential in renal therapy. Different types of nanosystems have been employed to deliver drugs to the kidneys. This review highlights the features of the nanomaterials, including the nanoparticles and corresponding hydrogels, in overcoming various barriers of drug delivery to the kidneys. The most common delivery sites and strategies of kidney-targeted drug delivery systems are also discussed.

Albiflorin ameliorates mesangial proliferative glomerulonephritis by PI3K/AKT/NF-κB pathway

Background: The most common type of glomerulonephritis in China is mesangial proliferative glomerulonephritis (MPGN) featured with mesangial cell overproliferation and inflammation, as well as fibrosis. Albiflorin (AF) is an effective composition extracted from Paeonia Alba Radix and has been administrated for various diseases. Nevertheless, there is no research reporting the effect of AF on MPGN.Purpose: Our work aims to probe into the role and possible mechanism of AF on MPGN.Research Design: We investigated the effects of AF on mesangial cell overproliferation, inflammation, and fibrosis in vitro and in vivo and identified the related signaling pathways.Study Sample: human mesangial cells (HMCs) and male Sprague Dawley (SD) rats.Data Analysis: SPSS 18.0 was used to analyze the data.Results: AF attenuated the proliferation and inflammation both in vitro and in vivo. In detail, AF decreased the ki67 expression in lipopolysaccharides (LPS)-treated HMCs and MPGN rats, and the mRNA expression or contents of inflammatory cytokines were reduced after AF treatment. The fibrosis of LPS-treated HMCs and MPGN rats was also reduced by AF. Moreover, AF effectively restrained 24 h urinary protein, improved kidney function, and mitigated dyslipidemia and pathological injury of MPGN rats. Additionally, we found that the protective effects of AF were accompanied by the blocking of PI3K/AKT/NF-κB pathway, and the inhibitory effects of AF on MPGN were reversed by insulin-like growth factor (IGF-1), the PI3K agonist.Conclusions: AF alleviates MPGN via restraining mesangial cell overproliferation, inflammation, and fibrosis via PI3K/AKT/NF-κB signaling.

Network Pharmacology and Experimental Validation to Explore That Celastrol Targeting PTEN is the Potential Mechanism of Tripterygium wilfordii (Lév.) Hutch Against IgA Nephropathy

Purpose

Accumulating clinical evidence showed that Tripterygium hypoglaucum (Lév.) Hutch (THH) is effective against IgA nephropathy (IgAN), but the mechanism is still unclear. This study is to evaluate the renal protective effect and molecular mechanism of THH against IgAN via network pharmacology, molecular docking strategy and experimental validation.

Methods

Several databases were used for obtaining the active ingredients of THH, the corresponding targets, as well as the IgAN-related genes. The critical active ingredients, functional pathways, and potential for the combination of the hub genes and their corresponding active components were determined through bioinformatics analysis and molecular docking. The IgAN mouse model was treated with celastrol (1 mg/kg/d) for 21 days, and the aggregated IgA1-induced human mesangial cell (HMC) was treated with various concentrations of celastrol (25, 50 or 75 nM) for 48 h. The immunohistochemistry and Western blot techniques were applied to evaluate the protein expression of the predicted target. The cell counting kit 8 (CCK8) was used to detect HMC proliferation.

Results

A total of 17 active ingredients from THH were screened, covering 165 IgAN-related targets. The PPI network identified ten hub targets, including PTEN. The binding affinity between the celastrol and PTEN was the highest (-8.69 kJ/mol). The immunohistochemistry showed that celastrol promoted the expression of PTEN in the glomerulus of IgAN mice. Furthermore, the Western blot techniques showed that celastrol significantly elevated the expression of PTEN and inhibited PCNA and Cyclin D1 in vitro and in vivo. The CCK8 assay determined that celastrol decreased HMC proliferation in a concentration-dependent manner.

Conclusion

This study suggests that activating PTEN by celastrol may play a pivotal role in THH alleviating IgAN renal injury.

An intra-articular injectable phospholipids-based gel for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory and destructive arthropathy with a high deformity rate. Despite numerous studies and clinical trials, no curative treatment is available for large weight-bearing joints. Intra-articular (IA) injections could deliver high concentrations of drug to the afflicted joint and improve the drug efficacy while reducing systemic toxicity. However, free drugs are rapidly cleared from synovial fluid and do not significantly halt the progression of joint disease. Herein, a phospholipids-based controlled-release gel was prepared for sustained IA delivery of celastrol (CEL) and the therapeutic efficiency was evaluated in a rheumatoid arthritis rabbit model. The CEL-loaded gel (CEL-gel) contained up to 70% phospholipids yet was easy to inject. After injecting into the joint cavity, CEL-gel achieved sol to gel phase transition without special stimuli and gelling agent. In vitro release and in vivo pharmacokinetic studies evidenced the stable and sustained release action of CEL-gel. A single IA injection of CEL-gel could maintain therapeutic efficiency for about 25 d and showed much better anti-arthritic efficacy compared to repeated injections of free drug solution (CEL-sol). Furthermore, the IA injection of CEL-gel greatly reduced the systemic toxicity of CEL. With good biocompatibility and biodegradability, CEL-gel might be a promising IA drug delivery system.

Tripterin liposome relieves severe acute respiratory syndrome as a potent COVID-19 treatment

For coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), 15-30% of patients are likely to develop COVID-19-related acute respiratory distress syndrome (ARDS). There are still few effective and well-understood therapies available. Novel variants and short-lasting immunity are posing challenges to vaccine efficacy, so finding antiviral and antiinflammatory treatments remains crucial. Here, tripterin (TP), a traditional Chinese medicine, was encapsulated into liposome (TP lipo) to investigate its antiviral and antiinflammatory effects in severe COVID-19. By using two severe COVID-19 models in human ACE2-transgenic (hACE2) mice, an analysis of TP lipo's effects on pulmonary immune responses was conducted. Pulmonary pathological alterations and viral burden were reduced by TP lipo treatment. TP lipo inhibits SARS-CoV-2 replication and hyperinflammation in infected cells and mice, two crucial events in severe COVID-19 pathophysiology, it is a promising drug candidate to treat SARS-CoV-2-induced ARDS.

Renal Proximal Tubular Cells: A New Site for Targeted Delivery Therapy of Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a major complication of diabetes mellitus (DM) and the leading cause of end-stage kidney disease (ESKD) worldwide. A significant number of drugs have been clinically investigated for the treatment of DKD. However, a large proportion of patients still develop end-stage kidney disease unstoppably. As a result, new effective therapies are urgently needed to slow down the progression of DKD. Recently, there is increasing evidence that targeted drug delivery strategies such as large molecule carriers, small molecule prodrugs, and nanoparticles can improve drug efficacy and reduce adverse side effects. There is no doubt that targeted drug delivery strategies have epoch-making significance and great application prospects for the treatment of DKD. In addition, the proximal tubule plays a very critical role in the progression of DKD. Consequently, the purpose of this paper is to summarize the current understanding of proximal tubule cell-targeted therapy, screen for optimal targeting strategies, and find new therapeutic approaches for the treatment of DKD.

Kidney targeting of formoterol containing polymeric nanoparticles improves recovery from ischemia reperfusion-induced acute kidney injury in mice

The β₂ adrenergic receptor agonist, formoterol, is an inducer of mitochondrial biogenesis and restorer of mitochondrial and kidney function in acute and chronic models of kidney injury. Unfortunately, systemic administration of formoterol has the potential for adverse cardiovascular effects, increased heart rate, and decreased blood pressure. To minimize these effects, we developed biodegradable and biocompatible polymeric nanoparticles containing formoterol that target the kidney, thereby decreasing the effective dose, and lessen cardiovascular effects while restoring kidney function after injury. Male C57Bl/6 mice, treated with these nanoparticles daily, had reduced ischemia-reperfusion-induced serum creatinine and kidney cortex kidney injury molecule-1 levels by 78% and 73% respectively, compared to control mice six days after injury. With nanoparticle therapy, kidney cortical mitochondrial number and proteins reduced by ischemic injury, recovered to levels of sham-operated mice. Tubular necrosis was reduced 69% with nanoparticles treatment. Nanoparticles improved kidney recovery even when the dosing frequency was reduced from daily to two days per week. Finally, compared to treatment with formoterol-free drug alone, these nanoparticles did not increase heart rate nor decrease blood pressure. Thus, targeted kidney delivery of formoterol-containing nanoparticles is an improvement in standard formoterol therapy for ischemia-reperfusion-induced acute kidney injuries by decreasing the dose, dosing frequency, and cardiac side effects.

In vitro activity of celastrol in combination with thymol against carbapenem-resistant Klebsiella pneumoniae isolates

Klebsiella pneumoniae is an opportunistic pathogen causing nosocomial and community-acquired infections. Klebsiella has developed resistance against antimicrobials including the last resort class; carbapenem. Currently, treatment options for carbapenem-resistant-Klebsiella (CRK) are very limited. This study aims to restore carbapenem effectiveness against CRK using celastrol and thymol. Clinical Klebsiella isolates were identified using biochemical and molecular methods. Antimicrobial susceptibility was determined using disk-diffusion method. Carbapenemase-production was tested phenotypically and genotypically. Celastrol and thymol-MICs were determined and the carbapenemase-inhibitory effect of sub-MICs was investigated. Among 85 clinical Klebsiella isolates, 72 were multi-drug-resistant and 43 were meropenem-resistant. Phenotypically, 39 isolates were carbapenemase-producer. Genotypically, bla_NDM1 was detected in 35 isolates, bla_VIM in 17 isolates, bla_OXA in 18 isolates, and bla_KPC was detected only in 6 isolates. Celastrol showed significant inhibitory effect against carbapenemase-hydrolytic activity. Meropenem-MIC did not decrease in presence of celastrol, only 2-fold decrease was observed with thymol, while 4-64 fold decrease was observed when meropenem was combined with both celastrol and thymol. Furthermore, thymol increased CRK cell wall-permeability. Molecular docking revealed that celastrol is superior to thymol for binding to KPC and VIM-carbapenemase. Our study showed that celastrol is a promising inhibitor of multiple carbapenemases. While meropenem-MIC were not affected by celastrol alone and decreased by only 2-folds with thymol, it decreased by 4-64 folds in presence of both celastrol and thymol. Thymol increases the permeability of CRK-envelope to celastrol. The triple combination (meropenem/celastrol/thymol) could be useful for developing more safe and effective analogues to restore the activity of meropenem and other β-lactams.

Co-delivery of celastrol and lutein with pH sensitive nano micelles for treating acute kidney injury

To treat acute kidney injury with high efficiency and low toxicity, a novel nanoplatform was developed to remove excess reactive oxygen species (ROS). Lutein (LU) and celastrol (Cel) were loaded into low molecular weight chitosan (CS) to prepare Cel@LU-CA-CS nanomicelles. Renal tubular epithelial (HK-2) cell uptake experiments showed that the drugs could be internalized in renal tubular via the megalin receptor. In this study, the amide bond formed by the reaction of citraconic anhydride (CA) with an amino group of CS could be destroyed under acidic conditions. Therefore, the drugs were released in HK-2 cells due to the acidic environment of the lysosome. In vitro studies showed that the nanomicelles could reduce toxicity in non-target organs and enhance therapeutic efficacy in acute kidney injury (AKI). In addition, Cel@LU-CA-CS micelles had alleviated kidney oxidative stress disorder and stabilized the mitochondrial membrane potential quickly. Next, in vivo studies proved that Cel@LU-CA-CS micelles could inhibit the activation of the NF-κB p65 and p38 MAPK inflammatory signaling pathways. Therefore, the micelles further reduced the overexpression of related inflammatory factors. In conclusion, Cel@LU-CA-CS nanomicelles could treat AKI with high efficiency and low toxicity, and inhibit renal fibrosis.

SHP2 inhibition improves celastrol-induced growth suppression of colorectal cancer

This study aimed to explore novel targets for celastrol sensitization in colorectal cancer (CRC) based on differentially regulated signals in response to high- or low-dose celastrol. Targeting signals were investigated using Western blotting or phosphorylated receptor tyrosine kinase (RTK) arrays. Corresponding inhibitors for the signals were individually combined with low-dose celastrol for the assessment of combined anti-CRC effects, based on proliferation, apoptosis, colony assays, and xenograft models. The potential mechanism for the combination of celastrol and SHP2 inhibition was further examined. Low-dose celastrol (&lt;1 µM) did not effectively suppress AKT and ERK signals in CRC cells compared to high-dose celastrol (&gt;1 µM). However, when combined with an AKT or ERK inhibitor, low-dose celastrol could cooperatively suppress CRC proliferation. Furthermore, failed AKT or ERK inhibition by low-dose celastrol may be due to reactivated RTK-SHP2 signaling with negative feedback. The combination of celastrol and the SHP2 inhibitor resulted in greatly reduced AKT and ERK signals, as well as greater inhibition of CRC growth than celastrol alone. Moreover, the mechanism underlying combination suppression was also involved in the activation of immune cell infiltration (mainly for CD8+ cells) in CRC tissues. Failure to inhibit RTK-SHP2-AKT/ERK signaling contributed to the lack of CRC growth suppression by low-dose celastrol. However, the combination of celastrol and the SHP2 inhibitor resulted in synergistic inhibition of CRC growth and provided a promising therapeutic target.

Novel Drug Delivery Technologies and Targets for Renal Disease

The burden of acute and chronic kidney diseases to the health care system is exacerbated by the high mortality that this disease carries paired with the still limited availability of comprehensive therapies. A reason partially resides in the complexity of the kidney, with multiple potential target cell types and a complex structural environment that complicate strategies to protect and recover renal function after injury. Management of both acute and chronic renal disease, irrespective of the cause, are mainly focused on supportive treatments and renal replacement strategies when needed. Emerging preclinical evidence supports the feasibility of drug delivery technology for the kidney, and recent studies have contributed to building a robust catalog of peptides, proteins, nanoparticles, liposomes, extracellular vesicles, and other carriers that may be fused to therapeutic peptides, proteins, nucleic acids, or small molecule drugs. These fusions can display a precise renal uptake, an enhanced circulating time, and a directed intraorgan biodistribution while protecting their cargo to improve therapeutic efficacy. However, several hurdles that slow the transition towards clinical applications are still in the way, such as solubility, toxicity, and sub-optimal renal targeting. This review will discuss the feasibility and current limitations of drug delivery technologies for the treatment of renal disease, offering an update on their potential and the future directions of these promising strategies.

Assembly of Celastrol to Zeolitic Imidazolate Framework-8 by Coordination as a Novel Drug Delivery Strategy for Cancer Therapy

Celastrol (Cel), a compound derived from traditional Chinese medicine Tripterygium wilfordii Hook. F, has attracted considerable attention as an anticancer drug. However, its clinical application is limited due to its low bioavailability and potential toxicity. With the advancement of nanoscale metal organic frameworks (MOF), the nano-delivery of drugs can effectively improve those disadvantages. Nevertheless, hydrophobic drugs apparently cannot be encapsulated by the hydrophilic channels of MOF-based drug delivery systems. To address these issues, a new assembly strategy for hydrophobic Cel was developed by coordinating the deprotonated Cel to zeolitic imidazolate framework-8 (ZIF-8) with the assistance of triethylamine (Cel-ZIF-8). This strategy greatly elevates the assembly efficiency of Cel from less than 1% to ca. 80%. The resulted Cel-ZIF-8 remains stable in the physiological condition while dissociating and releasing Cel after a 45-minute incubation in an acidic tumor microenvironment (pH 5.5). Furthermore, Cel-ZIF-8 is proved to be easily taken up by cancer cells and exhibits a better therapeutic effect on tumor cells than free Cel. Overall, the Cel-ZIF-8 provides a novel assembly strategy for hydrophobic drugs, and the findings are envisaged to facilitate the application of Cel in cancer therapies.