Emerging role of tumor suppressor p53 in acute and chronic kidney diseases

A Novel Mechanism of the p53 Isoform Δ40p53α in Regulating Collagen III Expression in TGFβ1-Induced LX-2 Human Hepatic Stellate Cells

Injured liver cells undergoing chronic wound healing produce excessive amounts of extracellular matrix (ECM) components, such as collagen and fibronectin, leading to fibrosis. This process is largely mediated by transforming growth factor-β (TGFβ) signaling, which intersects with the tumor suppressor p53 pathway. However, the roles of specific p53 isoforms in this interaction remain unclear. In this study, we report the involvement of the Δ40p53α isoform, an N-terminal truncated variant of p53, in regulating ECM gene expression in TGFβ1-activated LX-2 human hepatic stellate cells. RT-PCR analysis of cirrhotic liver tissues revealed clinically relevant increases in Δ40p53 expression. Knockdown of Δ40p53 using antisense oligonucleotides in LX-2 cells attenuated TGFβ1-induced activation and significantly reduced collagen production and deposition, particularly fibrillar collagen III. Conversely, overexpression of Δ40p53α upregulated collagen III expression in concert with full-length p53 (FLp53). Co-immunoprecipitation analysis demonstrated that Δ40p53α forms a complex with FLp53, which associates with phosphorylated Smad3 following TGFβ1 stimulation. These findings suggest that Δ40p53 enhances collagen III expression by interacting with FLp53 and Smads, highlighting its role in profibrogenic ECM expression.

Berberine-based hypercrosslinked polymer: Advanced solid-phase microextraction for high-throughput analysis of aristolochic acids in environmental water and herbal plants

In this study, a novel berberine based anion-exchanged hypercrosslinked polymer (BBR-HCPs) was synthesized via Friedel-Crafts alkylation using dimethoxymethane as a cross-linking agent. The proposed BBR-HCPs polymer exhibited excellent adsorption capacities for aristolochic acids (AAs). Moreover, there are various interactions such as hydrophobic, π-π stacking, hydrogen bonding, and electrostatic interactions between BBR-HCPs and AAs. A solid phase microextraction (SPME) coating, prepared with BBR-HCPs as the sorbent and polyacrylonitrile (PAN) as the binder, was applied for the determination of AAs in herbal plants using a 24-well plate for high-throughput, with instrumental analysis carried out via high performance liquid chromatography with diode array detector (HPLC-DAD). The optimized and validated BBR-HCPs-SPME/HPLC-DAD method exhibited excellent linearity over range of 5-400 ng mL-1 with R2 > 0.9974. Detection limits (S/N = 3) for AAs were found to be 0.03-0.150 ng mL-1, with recoveries ranging from 82.6 to 117.8 % and relative standard deviations (RSDs) less than 10.49 %. This study underscores the potential of BBR-HCPs as a promising adsorbent for selective extraction and enrichment of AAs while introducing a reliable novel strategy for monitoring trace amounts of AAs in water and herbal plant samples.

Minichromosome maintenance 4 plays a key role in protecting against acute kidney injury by regulating tubular epithelial cells survival and regeneration

INTRODUCTION

Minichromosome maintenance 4 (MCM4), a constituent of the MCM family, playing a pivotal role in DNA replication. Although MCM4 expression has been widely linked to various malignant tumors, its role in kidney diseases is not well-studied. This study primarily investigates the role and underlying mechanism of MCM4 in acute kidney injury (AKI).

OBJECTIVES

Characterizing a novel target of MCM4 in patients with AKI.

METHODS

We used CRISPR/Cas9 gene editing to delete MCM4 gene in tubular cells from C57BL/6J mice. Adeno-associated virus 9 harboring MCM4 was administered via intraparenchymal injection into the kidney to enhance MCM4 expression in vivo. These mice were used to established cisplatin- and ischemic reperfusion injury (IRI)-induced AKI mouse models, for detecting the functional role of MCM4 in the pathological process of AKI.

RESULTS

MCM4 level was increased in the tubules of cisplatin- and IRI-induced AKI mouse models. Compare to wide-type mice, MCM4 knockout mice demonstrated greater degree of histological damage and a higher ratio of apoptotic tubular cells, as well as kidney dysfunction upon cisplatin- and IRI-induced AKI models. Conversely, MCM4 overexpression ameliorated the severity of kidney injury and promoted regenerative capacity of tubular cells during AKI development. Mechanically, loss of MCM4 induced the expression of p53-binding protein 1, activating the p53/p21 pathway and exacerbating AKI progression. Additional, MAD2B, as an upstream molecule of MCM4, regulates the transcription level of MCM4 by affecting the level of E2F1.

CONCLUSIONS

These findings demonstrate that MCM4 upregulation during AKI development is an adaptive response that preserves tubular cell regenerative capacity and limits the severity of renal injury, thus highlighting the potential value of MCM4 as a biomarker or therapeutic target in patients with AKI.

Ubiquitin-specific peptidase 10 promotes renal interstitial fibrosis progression through deubiquitinating and stabilizing P53 protein

Renal interstitial fibrosis is the main factor determining chronic kidney disease (CKD) progression, and renal tubular epithelial cells are the key drivers of this pathological process. Herein, we revealed significantly increased ubiquitin-specific peptidase 10 (USP10) expression in the kidney tissues of both patients with CKD and mice induced by unilateral ureteral obstruction, as well as in transforming growth factor-beta 1 (TGFβ1)-induced renal tubular epithelial cells. In vivo, treatment with the USP10 small molecule inhibitor Spautin-1, which inhibits its deubiquitinating activity, weakened renal interstitial fibrosis progression and alleviated the subsequent inflammatory response and oxidative stress in male mice. In vitro, knocking down USP10 or inhibiting its deubiquitinating activity through Spautin-1 significantly reduced fibronectin expression and ameliorated TGFβ1-induced renal tubular epithelial cell dedifferentiation. Additionally, our results revealed that USP10 directly binds to P53 and removes the K48-linked polyubiquitin chains from P53, thereby affecting its ubiquitination, stability, and nuclear translocation, which subsequently leads to the upregulation of P21 and promotes fibrotic gene expression in injured renal tubular epithelial cells, ultimately exacerbating renal interstitial fibrosis. In conclusion, USP10 is inhibited through the P53 signaling pathway to alleviate the progression of renal interstitial fibrosis and serve as a potential target for treating CKD.

Inhibition of p75NTR/p53 axis by ambrisentan suppresses apoptosis and oxidative stress-mediated renal damage in a cisplatin AKI model

Cisplatin (CP) is a potent antineoplastic agent that triggers nephrotoxicity as a major adverse effect which can cause treatment interruptions and limitations to its clinical use. Nephrotoxicity associated with CP involves inflammation, oxidative stress, and apoptosis in kidney tubules. The objective of this work was to assess the effect of the blockade of endothelin-1 (ET-1) receptor with ambrisentan on altered renal function induced by CP. Swiss albino mice were assigned into control, CP, CP/Amb-5, and CP/Amb-10 groups. Ambrisentan improved kidney function (serum creatinine and BUN) and histopathological changes in comparison to CP-treated group. Ambrisentan significantly reduced protein expression of p75NTR and protein level of JNK influencing renal apoptosis as evidenced by reducing p53, caspase-3, and Bax levels and elevating Bcl-2 level (p < 0.05 vs CP group). Moreover, vasodilatory effect of ambrisentan was indicated by significant increase in level of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) (p < 0.05 vs CP group). Ambrisentan also significantly restored oxidative balance in renal tissues as evidenced by reduced malondialdehyde and increased total antioxidant capacity and superoxide dismutase activity, in addition to decreasing nitric oxide levels (p < 0.05 vs CP group). This protective effect of ambrisentan might be mediated through the downregulation of death receptor, P75NTR that in turn restores renal blood flow and oxidative balance and regulates p53, VEGF/eNOS, NF-κB, and Bcl-2/Bax/caspase-3 signaling.

CMAP prediction and experimental validation of Forskolin as a podocyte protective and anti-proteinuric drug for nephrotoxic serum-treated mice

Podocyte injury leads to proteinuria and glomerular diseases. Different podocyte injuries have distinct mechanisms. It is desirable to use a regimen that targets the mechanism of a given podocyte injury for a specific and improved result. However, the mechanisms of the most podocyte injuries are largely elusive, preventing optimal drug choices. Here, we test the feasibility of combining kidney single-cell RNA-seq databases and the Connectivity Map database (CMAP) to predict drugs for a specific podocyte injury. We downloaded glomerular single-cell RNA-seq dataset of nephrotoxic serum (NTS)-treated and control mice from the GEO, and compared their podocyte gene expression, resulting in identification of genes with altered expression in NTS-treated podocytes. GO and KEGG enrichment of them revealed activations of podocyte injurious NFκB, TNFα, AGE-RAGE, apoptosis, cellular senescence, MAPK, and p53 pathways, and dedifferentiation. CMAP analysis of the genes ranked Forskolin top 3. Indeed, we found that NTS-treated mice developed massive proteinuria, which was prevented by Forskolin, accompanied by pathological improvement of podocytes. In treating overdose NTS-induced severe podocyte injury, Forskolin exhibited a comparable efficacy as glucocorticoids (methylprednisolone). In vitro, Forskolin prevented NTS-induced cellular injury in cultured podocytes as shown by cell viability and cytoskeletal integrity assays. Mechanistically, Forskolin inhibited STAT3, p53, NFκB, FAK, and TGF-β pathways, while upregulated podocyte essential genes, WT1, SYNPO, and VEGFA, independently of NTS. In conclusion, Forskolin protects podocytes by directly inhibiting harmful pathways and the associated genes while enhancing podocyte essential gene expression independently of insults, resulting in an efficacy comparable with that of glucocorticoids in NTS-treated mice.

Genome-wide CRISPR-based screen identifies E2F transcription factor 1 as a regulator and therapeutic target of aristolochic acid-induced nephrotoxicity

Aristolochic Acid I (AAI) is widely present in traditional Chinese medicines derived from the Aristolochia genus and is known to cause significant damage to renal tubular epithelial cells. Genome-wide screening has proven to be a powerful tool in identifying critical genes associated with the toxicity of exogenous substances. To identify undiscovered key genes involved in AAI-induced renal toxicity, a genome-wide CRISPR library screen was conducted in the human kidney-2 (HK-2) cell line. Among the altered sgRNAs, a significant enrichment of those targeting the E2F transcription factor 1 (E2F1) gene was observed in surviving HK-2 cells in the AAI-treated group. Interestingly, the role of E2F1 had not been previously explored in studies of AAI nephrotoxicity. Further investigations revealed that E2F1 promotes apoptosis by activating the p53 signaling pathway and upregulating pro-apoptotic genes, such as BAK and BAX. Additionally, using the high-throughput experiment- and reference-guided database of traditional Chinese medicine (HERB), cannabidiol (CBD) was identified as an inhibitor of E2F1 by suppressing the activity of NF-κB pathway. In vitro and in vivo models confirmed that CBD inhibits AAI-induced upregulation of E2F1, thereby suppressing p53-mediated apoptosis. In conclusion, this study highlights the crucial role of E2F1 in AAI-induced renal cell apoptosis and identifies CBD as a novel therapeutic candidate for mitigating AAI nephrotoxicity.

Tumor hypoxia evidences the differential regulation of Mdm2-p53 axis by PTEN in tumor derived vs. normal endothelial cells

Hypoxia, a condition of oxygen tension lower than physiological level, plays a crucial role in shaping the tumor microenvironment and modulates distinct cell populations activity. The tumor suppressor PTEN regulates angiogenesis, a process involving endothelial cells (ECs). Pathological in tumors, it is crucial for growth. As PTEN modulates p53, a key regulator of the ECs growth/angiogenic activity, it appears to be a target enabling the repair of the pathologic angiogenesis. This study aims to compare ECs derived from breast cancer (HBCa.MEC) site with those derived from the healthy breast tissue (HBH.MEC). Hypoxia increased angiogenic activity in HBCa.MEC vs. HBH.MEC, as showed an increased. Ability to form vessels in vitro. Low pO2 reduced the total level of Mdm2 and PTEN protein expression leading to elevated levels of their phosphorylation-dependent activity in HBCa.MEC, what was not changed in healthy ECs. Additionally, when Mdm2-p53 interaction was inhibited, hypoxic HBCa.MEC angiogenic activity was reduced reaching the normoxic ECs response. In conclusion, the PTEN-mediated control of pathological angiogenesis occurs by modulation of Mdm2/p53 interaction in the context of breast tumor microenvironment. PTEN emerges as a potential therapeutic target for normalizing tumor vessels in breast cancer treatment strategies.

Interleukin-12p40 deficiency attenuates myocardial ferroptosis in doxorubicin-induced chronic cardiomyopathy by inhibiting Th17 differentiation and interleukin-17A production

AIMS

Interleukin (IL)-12p40 is a common subunit of the bioactive cytokines IL-12 and IL-23, and it also has its own intrinsic functional activity. However, its role in doxorubicin-induced chronic cardiomyopathy (DICCM) as well as the underlying mechanisms are still unknown.

METHODS AND RESULTS

In this study, we used IL-12p40-knockout mice, IL-23p19-knockout mice, Rag1-knockout mice, a ferroptosis inhibitor, recombinant IL-12 (rIL-12), rIL-23, rIL-12p40, rIL-12p80, and anti-IL17A to investigate the effects of IL-12p40 on DICCM and elucidate the underlying mechanisms. We found that myocardial ferroptosis were increased in DICCM and that the inhibition of ferroptosis protected against DICCM. The expression of IL-12p40 was upregulated, and IL-12p40 was predominantly expressed by CD4+ T cells in the hearts of mice with DICCM. IL-12p40 knockout attenuated cardiac dysfunction, fibrosis and ferroptosis in DICCM, and similar results were observed in the context of CD4+ T cell IL-12p40 deficiency in Rag1-/- mice. Treatment with rIL-23, but not rIL-12, rIL-12p40 monomer or rIL-12p80, abolished the protective effects of IL-12p40 knockout. Moreover, rIL-23 treatment and IL-23p19 knockout exacerbated and ameliorated DICCM, respectively. IL-12p40 knockout might protect against DICCM by inhibiting Th17 differentiation and IL-17A production but not Th1, Th2 and Treg differentiation. Neutralizing IL-17A with an antibody also attenuated cardiac dysfunction, fibrosis, and ferroptosis. The IL-12p40/Th17/IL-17A axis might promote cardiomyocyte ferroptosis by activating TNF receptor-associated factor 6 (TRAF6)/mitogen-activated protein kinase (MAPK)/P53 signalling in DICCM.

CONCLUSION

Interleukin-12p40 deficiency protects against DICCM by inhibiting Th17 differentiation and the production of IL-17A, which plays critical roles in cardiomyocyte ferroptosis in DICCM via activating TRAF6/MAPK/P53 signalling. Our study may provide novel insights for the identification of therapeutic targets for treating DICCM in the clinic.

Podocyte Death in Diabetic Kidney Disease: Potential Molecular Mechanisms and Therapeutic Targets

Cell deaths maintain the normal function of tissues and organs. In pathological conditions, the abnormal activation or disruption of cell death often leads to pathophysiological effects. Diabetic kidney disease (DKD), a significant microvascular complication of diabetes, is linked to high mortality and morbidity rates, imposing a substantial burden on global healthcare systems and economies. Loss and detachment of podocytes are key pathological changes in the progression of DKD. This review explores the potential mechanisms of apoptosis, necrosis, autophagy, pyroptosis, ferroptosis, cuproptosis, and podoptosis in podocytes, focusing on how different cell death modes contribute to the progression of DKD. It recognizes the limitations of current research and presents the latest basic and clinical research studies targeting podocyte death pathways in DKD. Lastly, it focuses on the future of targeting podocyte cell death to treat DKD, with the intention of inspiring further research and the development of therapeutic strategies.

The role of Testis-Specific Protein Y-encoded-Like 2 in kidney injury

Renal ischemia-reperfusion injury (IRI) is a major cause of acute kidney injury (AKI). Recent findings suggest that Testis-Specific Protein Y-encoded-Like 2 (TSPYL2) plays a fibrogenic role in diabetes-associated renal injury. However, the role of TSPYL2 in IRI-induced kidney damage is not entirely clear. In this study, we found that the expression of TSPYL2 was upregulated in a mouse model of AKI and in the hypoxia/reoxygenation (H/R) cell model. Knockdown of TSPYL2 attenuated kidney injury after IRI. More specifically, the knockdown of TSPYL2 or aminocarboxymuconate-semialdehyde decarboxylase (ACMSD) alleviated renal IRI-induced mitochondrial dysfunction and oxidative stress in vitro and in vivo. Further investigation showed that TSPYL2 regulated SREBP-2 acetylation by inhibiting SIRT1 and promoting p300 activity, thereby promoting the transcriptional activity of ACMSD. In conclusion, TSPYL2 was identified as a pivotal regulator of IRI-induced kidney damage by activating ACMSD, which may lead to NAD+ content and the damaging response in the kidney.

Transcriptome Profiling of Oncorhynchus mykiss Infected with Low or Highly Pathogenic Viral Hemorrhagic Septicemia Virus (VHSV)

The rainbow trout (Oncorhynchus mykiss) is the most important produced species in freshwater within the European Union, usually reared in intensive farming systems. This species is highly susceptible to viral hemorrhagic septicemia (VHS), a severe systemic disease widespread globally throughout the world. Viral hemorrhagic septicemia virus (VHSV) is the etiological agent and, recently, three classes of VHSV virulence (high, moderate, and low) have been proposed based on the mortality rates, which are strictly dependent on the viral strain. The molecular mechanisms that regulate VHSV virulence and the stimulated gene responses in the host during infection are not completely unveiled. While some preliminary transcriptomic studies have been reported in other fish species, to date there are no publications on rainbow trout. Herein, we report the first time-course RNA sequencing analysis on rainbow trout juveniles experimentally infected with high and low VHSV pathogenic Italian strains. Transcriptome analysis was performed on head kidney samples collected at different time points (1, 2, and 5 days post infection). A large set of notable genes were found to be differentially expressed (DEGs) in all the challenged groups (e.s. trim63a, acod1, cox-2, skia, hipk1, cx35.4, ins, mtnr1a, tlr3, tlr7, mda5, lgp2). Moreover, the number of DEGs progressively increased especially during time with a greater amount found in the group infected with the high VHSV virulent strain. The gene ontology (GO) enrichment analysis highlighted that functions related to inflammation were modulated in rainbow trout during the first days of VHSV infection, regardless of the pathogenicity of the strain. While some functions showed slight differences in enrichments between the two infected groups, others appeared more exclusively modulated in the group challenged with the highly pathogenic strain.

Emerging role and therapeutic implications of p53 in intervertebral disc degeneration

Lower back pain (LBP) is a common degenerative musculoskeletal disease that imposes a huge economic burden on both individuals and society. With the aggravation of social aging, the incidence of LBP has increased globally. Intervertebral disc degeneration (IDD) is the primary cause of LBP. Currently, IDD treatment strategies include physiotherapy, medication, and surgery; however, none can address the root cause by ending the degeneration of intervertebral discs (IVDs). However, in recent years, targeted therapy based on specific molecules has brought hope for treating IDD. The tumor suppressor gene p53 produces a transcription factor that regulates cell metabolism and survival. Recently, p53 was shown to play an important role in maintaining IVD microenvironment homeostasis by regulating IVD cell senescence, apoptosis, and metabolism by activating downstream target genes. This study reviews research progress regarding the potential role of p53 in IDD and discusses the challenges of targeting p53 in the treatment of IDD. This review will help to elucidate the pathogenesis of IDD and provide insights for the future development of precision treatments.

Pregnane X receptor activation alleviates renal fibrosis in mice via interacting with p53 and inhibiting the Wnt7a/β-catenin signaling

Renal fibrosis is a common pathological feature of chronic kidney disease (CKD) with various etiologies, which seriously affects the structure and function of the kidney. Pregnane X receptor (PXR) is a member of the nuclear receptor superfamily and plays a critical role in regulating the genes related to xenobiotic and endobiotic metabolism in mammals. Previous studies show that PXR is expressed in the kidney and has protective effect against acute kidney injury (AKI). In this study, we investigated the role of PXR in CKD. Adenine diet-induced CKD (AD) model was established in wild-type and PXR humanized (hPXR) mice, respectively, which were treated with pregnenolone-16α-carbonitrile (PCN, 50 mg/kg, twice a week for 4 weeks) or rifampicin (RIF, 10 mg·kg-1·d-1, for 4 weeks). We showed that both PCN and RIF, which activated mouse and human PXR, respectively, improved renal function and attenuated renal fibrosis in the two types of AD mice. In addition, PCN treatment also alleviated renal fibrosis in unilateral ureter obstruction (UUO) mice. On the contrary, PXR gene deficiency exacerbated renal dysfunction and fibrosis in both adenine- and UUO-induced CKD mice. We found that PCN treatment suppressed the expression of the profibrotic Wnt7a and β-catenin in AD mice and in cultured mouse renal tubular epithelial cells treated with TGFβ1 in vitro. We demonstrated that PXR was colocalized and interacted with p53 in the nuclei of tubular epithelial cells. Overexpression of p53 increased the expression of Wnt7a, β-catenin and its downstream gene fibronectin. We further revealed that p53 bound to the promoter of Wnt7a gene to increase its transcription and β-catenin activation, leading to increased expression of the downstream profibrotic genes, which was inhibited by PXR. Taken together, PXR activation alleviates renal fibrosis in mice via interacting with p53 and inhibiting the Wnt7a/β-catenin signaling pathway.

Oryza sativa L. Indica Seed Coat Ameliorated Concanavalin A-Induced Acute Hepatitis in Mice via MDM2/p53 and PKCα/MAPK1 Signaling Pathways

Acute hepatitis (AH) is a common liver disease with an increasing number of patients each year, requiring the development of new treatments. Hence, our work aimed to evaluate the therapeutic effect of Oryza sativa L. indica (purple rice) seed coat on concanavalin A (ConA)-induced AH and further reveal its potential mechanisms. Purple rice seed coat extract (PRE) was extracted with hydrochloric acid ethanol and analyzed through a widely targeted components method. We evaluated the effects of PRE on AH through histopathological examination, liver function, gut microbiota composition, and the intestinal barrier. The potential targets of PRE on AH were predicted by bioinformatics. Western blotting, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL) staining, and corresponding kits were used to investigate PRE effects on predicting targets and associated signaling pathways in AH mice. In AH model mice, PRE treatment increased transformed mouse 3T3 cell double minute 2 (MDM2) expression to inhibit apoptosis; it also markedly downregulated protein kinase C alpha (PKCα), prostaglandin-endoperoxide synthase 1 (PTGS1), and mitogen-activated protein kinase 1 (MAPK1) activity to alleviate inflammation. Thus, PRE treatment also recovered the intestinal barrier, decreased the lipopolysaccharide (LPS) levels of plasma and the liver, enhanced liver function, and improved the composition of intestinal microbiota. In general, PRE targeting MDM2, PKCα, MAPK1, and PTGS1 ameliorated ConA-induced AH by attenuating inflammation and apoptosis, restoring the intestinal barrier, enhancing the liver function, and improving the gut microbiota, which revealed that the purple rice seed coat might hold possibilities as a therapeutic option for AH.

Formation of a traditional Chinese medicine self-assembly nanostrategy and its application in cancer: a promising treatment

Traditional Chinese medicine (TCM) has been used for centuries to prevent and treat a variety of illnesses, and its popularity is increasing worldwide. However, the clinical applications of natural active components in TCM are hindered by the poor solubility and low bioavailability of these compounds. To address these issues, Chinese medicine self-assembly nanostrategy (CSAN) is being developed. Many active components of TCM possess self-assembly properties, allowing them to form nanoparticles (NPs) through various noncovalent forces. Self-assembled NPs (SANs) are also present in TCM decoctions, and they are closely linked to the therapeutic effects of these remedies. SAN is gaining popularity in the nano research field due to its simplicity, eco-friendliness, and enhanced biodegradability and biocompatibility compared to traditional nano preparation methods. The self-assembly of active ingredients from TCM that exhibit antitumour effects or are combined with other antitumour drugs has generated considerable interest in the field of cancer therapeutics. This paper provides a review of the principles and forms of CSAN, as well as an overview of recent reports on TCM that can be used for self-assembly. Additionally, the application of CSAN in various cancer diseases is summarized, and finally, a concluding summary and thoughts are proposed. We strongly believe that CSAN has the potential to offer fresh strategies and perspectives for the modernization of TCM.

Targeting the p53 signaling pathway in cancers: Molecular mechanisms and clinical studies

Tumor suppressor p53 can transcriptionally activate downstream genes in response to stress, and then regulate the cell cycle, DNA repair, metabolism, angiogenesis, apoptosis, and other biological responses. p53 has seven functional domains and 12 splice isoforms, and different domains and subtypes play different roles. The activation and inactivation of p53 are finely regulated and are associated with phosphorylation/acetylation modification and ubiquitination modification, respectively. Abnormal activation of p53 is closely related to the occurrence and development of cancer. While targeted therapy of the p53 signaling pathway is still in its early stages and only a few drugs or treatments have entered clinical trials, the development of new drugs and ongoing clinical trials are expected to lead to the widespread use of p53 signaling-targeted therapy in cancer treatment in the future. TRIAP1 is a novel p53 downstream inhibitor of apoptosis. TRIAP1 is the homolog of yeast mitochondrial intermembrane protein MDM35, which can play a tumor-promoting role by blocking the mitochondria-dependent apoptosis pathway. This work provides a systematic overview of recent basic research and clinical progress in the p53 signaling pathway and proposes that TRIAP1 is an important therapeutic target downstream of p53 signaling.

Role of p53 in Cisplatin-Induced Myotube Atrophy

Chemotherapy-induced sarcopenia is an unfavorable prognostic factor implicated in the development of postoperative complications and reduces the quality of life of patients with cancer. Skeletal muscle loss due to cisplatin use is caused by mitochondrial dysfunction and activation of muscle-specific ubiquitin ligases Atrogin-1 and muscle RING finger 1 (MuRF1). Although animal studies suggest the involvement of p53 in age-, immobility-, and denervation-related muscle atrophy, the association between cisplatin-induced atrophy and p53 remains unknown. Herein, we investigated the effect of a p53-specific inhibitor, pifithrin-alpha (PFT-α), on cisplatin-induced atrophy in C2C12 myotubes. Cisplatin increased the protein levels of p53, phosphorylated p53, and upregulated the mRNA expression of p53 target genes PUMA and p21 in C2C12 myotubes. PFT-α ameliorated the increase in intracellular reactive oxygen species production and mitochondrial dysfunction, and also reduced the cisplatin-induced increase in the Bax/Bcl-2 ratio. Although PFT-α also reduced the cisplatin-induced increase in MuRF1 and Atrogin-1 gene expression, it did not ameliorate the decrease in myosin heavy chain mRNA and protein levels and muscle-specific actin and myoglobin protein levels. We conclude that cisplatin increases muscle degradation in C2C12 myotubes in a p53-dependent manner, but p53 has minimal involvement in the reduction of muscle protein synthesis.

p53 and Myofibroblast Apoptosis in Organ Fibrosis

Organ fibrosis represents a dysregulated, maladaptive wound repair response that results in progressive disruption of normal tissue architecture leading to detrimental deterioration in physiological function, and significant morbidity/mortality. Fibrosis is thought to contribute to nearly 50% of all deaths in the Western world with current treatment modalities effective in slowing disease progression but not effective in restoring organ function or reversing fibrotic changes. When physiological wound repair is complete, myofibroblasts are programmed to undergo cell death and self-clearance, however, in fibrosis there is a characteristic absence of myofibroblast apoptosis. It has been shown that in fibrosis, myofibroblasts adopt an apoptotic-resistant, highly proliferative phenotype leading to persistent myofibroblast activation and perpetuation of the fibrotic disease process. Recently, this pathological adaptation has been linked to dysregulated expression of tumour suppressor gene p53. In this review, we discuss p53 dysregulation and apoptotic failure in myofibroblasts and demonstrate its consistent link to fibrotic disease development in all types of organ fibrosis. An enhanced understanding of the role of p53 dysregulation and myofibroblast apoptosis may aid in future novel therapeutic and/or diagnostic strategies in organ fibrosis.

Potential therapeutic effects of Chinese meteria medica in mitigating drug-induced acute kidney injury

Drug-induced acute kidney injury (DI-AKI) is one of the leading causes of kidney injury, is associated with high mortality and morbidity, and limits the clinical use of certain therapeutic or diagnostic agents, such as antineoplastic drugs, antibiotics, immunosuppressants, non-steroidal anti-inflammatory drugs, and contrast media. In recent years, numerous studies have shown that many Chinese meteria medica, metabolites derived from botanical drugs, and Chinese medicinal formulas confer protective effects against DI-AKI by targeting a variety of cellular or molecular mechanisms, such as oxidative stress, inflammatory, cell necrosis, apoptosis, and autophagy. This review summarizes the research status of common DI-AKI with Chinese meteria medica interventions, including cisplatin, gentamicin, contrast agents, methotrexate, and acetaminophen. At the same time, this review introduces the metabolites with application prospects represented by ginseng saponins, tetramethylpyrazine, panax notoginseng saponins, and curcumin. Overall, this review provides a reference for the development of promising nephroprotectants.

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.

Curcumin-loaded graphene oxide quantum dots enhance otoprotective effects via blocking cuproptosis

Background: Cisplatin (CIS) is widely used to treat various cancers but can cause ototoxicity and sensory hair cell loss in the inner ear. Copper induces an excessive production of reactive oxygen species (ROS) in hair cells, leading to the development of various antioxidants. Methods and results: This study aimed to evaluate the potential antioxidant properties of curcumin (CUR) in the inner ear organ of corti-1 cells (OC1) and animal models (zebrafish and guinea pigs). Graphene oxide quantum dots (GOQDs) enabled CUR to penetrate the round window membrane (RWM) and maintain the concentration in the perilymph after inner ear administration. The results showed that CUR/GOQDs had favorable biocompatibility and strongly affected ROS generation induced by CIS in OC1 cells. DCFHDA Green staining demonstrated that CUR/GOQDs successfully reversed the decrease in mitochondrial membrane potential induced by CIS in vitro and rescued cells from early cuproptosis, which was confirmed by FDX1 staining. Additionally, the experiment found that CUR decreased the expression of cuproptosis proteins (FDX1, LIAS, and LIPT1) and increased the expression of the Bcl-2 protein. Conclusion: The results demonstrate that CUR/GOQDs is a promising therapeutic agent that can prevent CIS-induced ototoxicity by blocking the cuproptosis signal pathway.

Comparative analysis of markers for H2O2-induced senescence in renal tubular cells

To address what marker(s) is/are most suitable for determining renal cell senescence, cell area, granularity, cycle shift/arrest, SA-β-Gal, SIRT1 and p16 were evaluated after inducing senescence in HK-2 cells with 0.2-0.8 mM H₂O₂. Only cell area and granularity concentration-dependently increased at all time-points, whereas SA-β-Gal, SIRT1 and p16 showed significant coefficient of determination (R²) at two time-points. Cell granularity had significant correlation coefficient (R) with other six, whereas SA-β-Gal had significant R with five, and cell area, SIRT1 and p16 had significant R with four others. Comparing to SA-β-Gal, other markers had significantly lower fold-changes only at 72-h with 0.8 mM H₂O₂, whereas p16 provided greater fold-changes at 48-h with 0.4 and 0.8 mM H₂O₂. Therefore, cell area, granularity, SA-β-Gal and p16 may serve as the most suitable markers for determining H₂O₂-induced senescence in HK-2 renal cells, whereas other markers can be also used but with inferior quantitative precision.

Urinary-derived extracellular vesicles reveal a distinct microRNA signature associated with the development and progression of Fabry nephropathy

Introduction

Early initiation is essential for successful treatment of Fabry disease, but sensitive and noninvasive biomarkers of Fabry nephropathy are lacking. Urinary extracellular vesicles (uEVs) represent a promising source of biomarkers of kidney involvement. Among them, microRNAs (miRNAs) are important post-transcriptional regulators of gene expression that contribute to the development and progression of various kidney diseases. We aimed to identify uEV-derived miRNAs involved in the development and/or progression of Fabry nephropathy.

Methods

Patients with genetically confirmed Fabry disease and matched control subjects were included. EVs were isolated from the second morning urine by size exclusion chromatography, from which miRNAs were extracted. miRNA urine exosome PCR panels were used to characterize the miRNA signature in a discovery cohort. Individual qPCRs were performed on a validation cohort that included chronological samples. We identified the target genes of dysregulated miRNAs and searched for potential hub genes. Enrichment analyses were performed to identify their potential function.

Results

The expression of miR-21-5p and miR-222-3p was significantly higher in patients with stable renal function and those with progressive nephropathy compared with the corresponding controls. In addition, the expression of miR-30a-5p, miR-10b-5p, and miR-204-5p was significantly lower in patients with progressive nephropathy, however, in the chronological samples, this was only confirmed for miR-204-5p. Some of the identified hub genes controlled by the dysregulated miRNAs have been associated with kidney impairment in other kidney diseases.

Conclusion

The miRNA cargo in uEVs changes with the development and progression of Fabry nephropathy and, therefore, represents a potential biomarker that may provide a new option to prevent or attenuate the progression of nephropathy. Furthermore, dysregulated miRNAs were shown to be potentially associated with pathophysiological pathways in the kidney.

AZD6738 Inhibits fibrotic response of conjunctival fibroblasts by regulating checkpoint kinase 1/P53 and PI3K/AKT pathways

Trabeculectomy can effectively reduce intraocular pressure (IOP) in glaucoma patients, the long-term surgical failure is due to the excessive proliferation and fibrotic response of conjunctival fibroblasts which causes the subconjunctival scar and non-functional filtering bleb. In this study, we demonstrated that AZD6738 (Ceralasertib), a novel potent ataxia telangiectasia and Rad3-related (ATR) kinase inhibitor, can inhibit the fibrotic response of conjunctival fibroblasts for the first time. Our in vitro study demonstrated that AZD6738 inhibited the level and the phosphorylation of checkpoint kinase 1 (CHK1), reduced TGF-β1-induced cell proliferation and migration, and induced apoptosis of human conjunctival fibroblasts (HConFs) in the high-dose group (5 μM). Low-dose AZD6738 (0.1 μM) inhibited the phosphorylation of CHK1 and reduce fibrotic response but did not promote apoptosis of HConFs. Further molecular research indicated that AZD6738 regulates survival and apoptosis of HConFs by balancing the CHK1/P53 and PI3K/AKT pathways, and inhibiting TGF-β1-induced fibrotic response including myofibroblast activation and relative extracellular matrix (ECM) protein synthesis such as fibronectin (FN), collagen Ⅰ (COL1) and collagen Ⅳ (COL4) through a dual pharmacological mechanism. Hence, our results show that AZD6738 inhibits fibrotic responses in cultured HConFs in vitro and may become a potential therapeutic option for anti-subconjunctival scarring after trabeculectomy.