Lineage Tracing and Single-Nucleus Multiomics Reveal Novel Features of Adaptive and Maladaptive Repair after Acute Kidney Injury.

SIGNIFICANCE STATEMENT: Understanding the mechanisms underlying adaptive and maladaptive renal repair after AKI and their long-term consequences is critical to kidney health. The authors used lineage tracing of cycling cells and single-nucleus multiomics (profiling transcriptome and chromatin accessibility) after AKI. They demonstrated that AKI triggers a cell-cycle response in most epithelial and nonepithelial kidney cell types. They also showed that maladaptive proinflammatory proximal tubule cells (PTCs) persist until 6 months post-AKI, although they decreased in abundance over time, in part, through cell death. Single-nucleus multiomics of lineage-traced cells revealed regulatory features of adaptive and maladaptive repair. These included activation of cell state-specific transcription factors and cis-regulatory elements, and effects in PTCs even after adaptive repair, weeks after the injury event. BACKGROUND: AKI triggers a proliferative response as part of an intrinsic cellular repair program, which can lead to adaptive renal repair, restoring kidney structure and function, or maladaptive repair with the persistence of injured proximal tubule cells (PTCs) and an altered kidney structure. However, the cellular and molecular understanding of these repair programs is limited. METHODS: To examine chromatin and transcriptional responses in the same cell upon ischemia-reperfusion injury (IRI), we combined genetic fate mapping of cycling ( Ki67+ ) cells labeled early after IRI with single-nucleus multiomics-profiling transcriptome and chromatin accessibility in the same nucleus-and generated a dataset of 83,315 nuclei. RESULTS: AKI triggered a broad cell cycle response preceded by cell type-specific and global transcriptional changes in the nephron, the collecting and vascular systems, and stromal and immune cell types. We observed a heterogeneous population of maladaptive PTCs throughout proximal tubule segments 6 months post-AKI, with a marked loss of maladaptive cells from 4 weeks to 6 months. Gene expression and chromatin accessibility profiling in the same nuclei highlighted differences between adaptive and maladaptive PTCs in the activity of cis-regulatory elements and transcription factors, accompanied by corresponding changes in target gene expression. Adaptive repair was associated with reduced expression of genes encoding transmembrane transport proteins essential to kidney function. CONCLUSIONS: Analysis of genome organization and gene activity with single-cell resolution using lineage tracing and single-nucleus multiomics offers new insight into the regulation of renal injury repair. Weeks to months after mild-to-moderate IRI, maladaptive PTCs persist with an aberrant epigenetic landscape, and PTCs exhibit an altered transcriptional profile even following adaptive repair.

Castanopsis sieboldii Extract Alleviates Acute Liver Injury by Antagonizing Inflammasome-Mediated Pyroptosis.

Castanopsis sieboldii (CS), a subtropical species, was reported to have antioxidant and antibacterial effects. However, the anti-inflammatory effects of CS have not been studied. This study aimed to investigate whether the 70% ethanol extract of the CS leaf (CSL3) inhibited lipopolysaccharide (LPS)-induced inflammatory responses and LPS and ATP-induced pyroptosis in macrophages. CSL3 treatment inhibited NO release and iNOS expression in LPS-stimulated cells. CSL3 antagonized NF-κB and AP-1 activation, which was due to MAPK (p38, ERK, and JNK) inhibition. CSL3 successfully decreased NLRP3 inflammasome activation and increased IL-1ß expression. CSL3 treatment diminished LPS and ATP-induced pore formation in GSDMD. The in vivo effect of CSL3 on acute liver injury was evaluated in a CCl4-treated mouse model. CCl4 treatment increased the activity of serum alanine aminotransferase and aspartate aminotransferase, which decreased by CSL3. In addition, CCl4-induced an increase in TNF-α, and IL-6 levels decreased by CSL3 treatment. Furthermore, we verified that the CCl4-induced inflammasome and pyroptosis-related gene expression in liver tissue and release of IL-1ß into serum were suppressed by CSL3 treatment. Our results suggest that CSL3 protects against acute liver injury by inhibiting inflammasome formation and pyroptosis.

Parkin-Mediated Mitophagy by TGF-ß Is Connected with Hepatic Stellate Cell Activation.

Hepatic stellate cells (HSCs) are the main contributors to the development and progression of liver fibrosis. Parkin is an E3 ligase involved in mitophagy mediated by lysosomes that maintains mitochondrial homeostasis. Unfortunately, there is little information regarding the regulation of parkin by transforming growth factor-ß (TGF-ß) and its association with HSC trans-differentiation. This study showed that parkin is upregulated in fibrotic conditions and elucidated the underlying mechanism. Parkin was observed in the cirrhotic region of the patient liver tissues and visualized using immunostaining and immunoblotting of mouse fibrotic liver samples and primary HSCs. The role of parkin-mediated mitophagy in hepatic fibrogenesis was examined using TGF-ß-treated LX-2 cells with mitophagy inhibitor, mitochondrial division inhibitor 1. Parkin overexpression and its colocalization with desmin in human tissues were found. Increased parkin in fibrotic liver homogenates of mice was observed. Parkin was expressed more abundantly in HSCs than in hepatocytes and was upregulated under TGF-ß. TGF-ß-induced parkin was due to Smad3. TGF-ß facilitated mitochondrial translocation, leading to mitophagy activation, reversed by mitophagy inhibitor. However, TGF-ß did not change mitochondrial function. Mitophagy inhibitor suppressed profibrotic genes and HSC migration mediated by TGF-ß. Collectively, parkin-involved mitophagy by TGF-ß facilitates HSC activation, suggesting mitophagy may utilize targets for liver fibrosis.

Protective Effect of Castanopsis sieboldii Extract against UVB-Induced Photodamage in Keratinocytes.

Ultraviolet B (UVB) rays disrupt the skin by causing photodamage via processes such as reactive oxygen species (ROS) production, endoplasmic reticulum (ER) stress, DNA damage, and/or collagen degradation. Castanopsis sieboldii is an evergreen tree native to the southern Korean peninsula. Although it is known to have antioxidant and anti-inflammatory effects, its protective effect against photodamage in keratinocytes has not been investigated. Thus, in the present study, we investigated the effect of 70% ethanol extract of C. sieboldii leaf (CSL3) on UVB-mediated skin injuries and elucidated the underlying molecular mechanisms. CSL3 treatment restored the cell viability decreased by UVB irradiation. Moreover, CSL3 significantly inhibited UVB- or tert-butyl hydroperoxide-mediated ROS generation in HaCaT cells. ER stress was inhibited, whereas autophagy was upregulated by CSL3 treatment against UVB irradiation. Additionally, CSL3 increased collagen accumulation and cell migration, which were decreased by UVB exposure. Notably, epigallocatechin gallate, the major component of CSL3, improved the cell viability decreased by UVB irradiation through regulation of ER stress and autophagy. Conclusively, CSL3 may represent a promising therapeutic candidate for the treatment of UVB-induced skin damage.

Ferroelectric Polymer Nanofibers Reminiscent of Morphotropic Phase Boundary Behavior for Improved Piezoelectric Energy Harvesting.

Ferroelectric and piezoelectric polymers have attracted great attention from many research and engineering fields due to its mechanical robustness and flexibility as well as cost-effectiveness and easy processibility. Nevertheless, the electrical performance of piezoelectric polymers is very hard to reach that of piezoelectric ceramics basically and physically, even in the case of the representative ferroelectric polymer, poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)). Very recently, the concept for the morphotropic phase boundary (MPB), which has been exclusive in the field of high-performance piezoelectric ceramics, has been surprisingly confirmed in P(VDF-TrFE) piezoelectric copolymers by the groups. This study demonstrates the exceptional behaviors reminiscent of MPB and relaxor ferroelectrics in the feature of widely utilized electrospun P(VDF-TrFE) nanofibers. Consequently, an energy harvesting device that exceeds the performance limitation of the existing P(VDF-TrFE) materials is developed. Even the unpoled MPB-based P(VDF-TrFE) nanofibers show higher output than the electrically poled normal P(VDF-TrFE) nanofibers. This study is the first step toward the manufacture of a new generation of piezoelectric polymers with practical applications.

Alpha-Lipoic Acid Attenuates Apoptosis and Ferroptosis in Cisplatin-Induced Ototoxicity via the Reduction of Intracellular Lipid Droplets.

Alpha-lipoic acid (α-LA) is a potent antioxidant that can prevent apoptosis associated with cisplatin-induced ototoxicity through ROS. Ferroptosis is defined as an iron-dependent cell death pathway that has recently been highlighted and is associated with the accumulation of intracellular lipid droplets (LDs) due to an inflammatory process. Herein, we investigated the impact of α-LA on ferroptosis and analyzed the characteristics of LDs in auditory hair cells treated with cisplatin using high-resolution 3D quantitative-phase imaging with reconstruction of the refractive index (RI) distribution. HEI-OC1 cells were treated with 500 µM α-LA for 24 h and then with 15 µM cisplatin for 48 h. With 3D optical diffraction tomography (3D-ODT), the RI values of treated cells were analyzed. Regions with high RI values were considered to be LDs and labelled to measure the count, mass, and volume of LDs. The expression of LC3-B, P62, GPX4, 4-hydroxynonenal (4-HNE), and xCT was evaluated by Western blotting. HEI-OC1 cells damaged by cisplatin showed lipid peroxidation, depletion of xCT, and abnormal accumulation of 4-HNE. Additionally, the count, mass, and volume of LDs increased in the cells. Cells treated with α-LA had inhibited expression of 4-HNE, while the expression of xCT and GPX4 was recovered, which restored LDs to a level that was similar to that in the control group. Our research on LDs with 3D-ODT offers biological evidence of ferroptosis and provides insights on additional approaches for investigating the molecular pathways.

Protective Effect of Cudrania tricuspidata Extract against High-Fat Diet Induced Nonalcoholic Fatty Liver Disease through Nrf-2/HO-1 Pathway.

Nonalcoholic fatty liver disease is the most common chronic disease affecting a wide range of the world's population and associated with obesity-induced metabolic syndrome. It is possibly emerging as a leading cause of life-threatening liver diseases for which a drug with a specific therapeutic target has not been developed yet. Previously, there have been reports on the benefits of Cudrania tricuspidata (CT) for treating obesity and diabetes via regulation of metabolic processes, such as lipogenesis, lipolysis, and inflammation. In this study, we investigated the ameliorative effect of orally administered 0.25% and 0.5% (w/w) CT mixed with high-fat diet (HFD) to C57BL/6J mice for 7 weeks. It was found that body weight, fat mass, hepatic mass, serum glucose level, and liver cholesterol levels were significantly reduced after CT treatment. In CT-treated HFD-fed mice, the mRNA expression levels of hepatic lipogenic and inflammatory cytokine-related genes were markedly reduced, whereas the expression level of epididymal lipogenic genes was increased. The mRNA expression level of beta-oxidation and Nrf-2/HO-1 genes significantly increased in CT-treated obese mice livers. We propose that CT alleviates hepatic steatosis by reducing oxidative stress and inflammation.

Hepatoprotective Effect of Neoagarooligosaccharide via Activation of Nrf2 and Enhanced Antioxidant Efficacy.

Neoagarooligosaccharides (NAOS) are generated by ß-agarases, which cleave the ß-1,4 linkage in agarose. Previously, we reported that NAOS inhibited fat accumulation in the liver and decreased serum cholesterol levels. However, the hepatoprotective effect of NAOS on acute liver injury has not yet been investigated. Thus, we examined whether NAOS could activate nuclear factor (NF)-E2-related factor 2 (Nrf2)-antioxidant response element (ARE) and upregulates its target gene, and has hepatoprotective effect in vivo. In hepatocytes, phosphorylation and subsequent nuclear translocation of Nrf2 are increased by treatment with NAOS, in a manner dependent on p38 and c-Jun N-terminal kinase (JNK). Consistently, NAOS augmented ARE reporter gene activity and the antioxidant protein levels, resulting in increased intracellular glutathione levels. NAOS antagonized tert-butylhydroperoxide-induced reactive oxygen species (ROS) generation. Moreover, NAOS inhibited acetaminophen (APAP)-induced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and significantly decreased hepatocyte degeneration and inflammatory cell infiltration. Moreover, ROS production and glutathione depletion by APAP were reversed by NAOS. APAP-mediated apoptotic signaling pathways were also inhibited in NAOS-treated mice. Upregulalted hepatic expression of genes related to inflammation by APAP were consistently diminished by NAOS. Collectively, our results demonstrate that NAOS exhibited a hepatoprotective effect against APAP-mediated acute liver damage through its antioxidant capacity.

5-Caffeoylquinic acid ameliorates oxidative stress-mediated cell death via Nrf2 activation in hepatocytes.

CONTEXT: 5-Caffeoylquinic acid (5-CQA) is one of the most abundant compounds found in natural foods including coffee. OBJECTIVE: We investigated whether 5-CQA had a cytoprotective effect through the NF-E2-related factor 2 (Nrf2)-antioxidant response element (ARE) signalling pathway. MATERIALS AND METHODS: Nrf2 activation in response to 5-CQA treatment at the concentration of 10-100 µM is evaluated by Western blotting of Nrf2 and ARE reporter gene assay as well as its target gene expression in HepG2 cells. Intracellular reactive oxygen species (ROS) and glutathione (GSH) levels were measured in the tert-butyl hydroperoxide-induced hepatocytes to examined cytoprotective effect of 5-CQA (10-100 µM). The specific role of 5-CQA on Nrf2 activation was examined using Nrf2 knockout cells or Nrf2 specific inhibitor, ML-385. RESULTS: Nuclear translocation of Nrf2 is increased by 5-CQA in HepG2 cells which peaked at 6 h. Consequently, 5-CQA significantly increases the ARE reporter gene activity and downstream antioxidant proteins, including glutamate cysteine ligase (GCL), hemeoxygenase-1 (HO-1), NAD(P)H quinone oxidoreductase 1, and Sestrin2. Nrf2 deficiency or inhibition completely antagonized ability of 5-CQA to induce HO-1 and GCL expression. Cells pre-treated with 5-CQA were rescued from tert-butyl hydroperoxide-induced ROS production and GSH depletion. Nrf2 activation by 5-CQA was due to increased phosphorylation of MAPKs, AMPK and PKCδ. DISCUSSION AND CONCLUSIONS: Taken together, our results demonstrate that as a novel Nrf2 activator, 5-CQA, may be a promising candidate against oxidative stress-mediated liver injury. Additional efforts are needed to assess 5-CQA, as a potential therapeutic in liver diseases in vivo and in humans.

Protective effect of sestrin2 against iron overload and ferroptosis-induced liver injury.

Ferroptosis is the non-apoptotic form of cell death caused by small molecules or conditions that inhibit glutathione biosynthesis or resulting in iron-dependent accumulation of lipid peroxidation by lipid reactive oxygen species (ROS). Sestrin2 (Sesn2), a conserved antioxidant protein, is responsive to various stresses including genotoxic, metabolic, and oxidative stresses and acts to restore homeostatic balance. Sesn2 expression was reported to be regulated via stress-responsive transcription factors including p53, Nrf2, and HIF-1α. However, the role of Sesn2 in regulating ferroptosis is not known. In the current study, we investigated whether ferroptosis inducing compounds including erastin, sorafenib, and buthionine sulfoximine affect Sesn2 expression and the role of Sesn2 in cytoprotection against ferroptosis-mediated cell death. Our data demonstrate that ferroptosis inducers significantly increased Sesn2 in hepatocytes in a dose- and time-dependent manner. Treatment with erastin upregulated Sesn2 mRNA levels and luciferase reporter gene activity, and erastin-mediated Sesn2 induction was transcriptionally regulated by NF-E2-related factor 2 (Nrf2). Furthermore, deletion of the antioxidant response element (ARE) in the Sesn2 promoter or Nrf2 knockout or knockdown abolished erastin-induced Sesn2 expression. In cells expressing Sesn2, erastin-induced cell death, ROS formation, and glutathione depletion were almost completely inhibited compared to that in control cells. Treatment with phenylhydrazine in mice, well-reported iron overload liver injury model, increased ALT and AST levels and altered histological features, which were almost completely inhibited by adenoviral Sesn2 infection. Collectively, our results suggest that ferroptosis-mediated Sesn2 induction is dependent on Nrf2 and plays a protective role against iron overload and ferroptosis-induced liver injury.

Activating transcription factor 6-dependent sestrin 2 induction ameliorates ER stress-mediated liver injury.

Endoplasmic reticulum (ER) stress is characterized by an accumulation of misfolded proteins, and ER stress reduction is essential for maintaining tissue homeostasis. However, the molecular mechanisms that protect cells from ER stress are not completely understood. The present study investigated the role of sestrin 2 (SESN2) on ER stress and sought to elucidate the mechanism responsible for the hepatoprotective effect of SESN2 in vitro and in vivo. Treatment with tunicamycin (Tm) increased SESN2 protein and mRNA levels and reporter gene activity. Activating transcription factor 6 (ATF6) bound to unfolded protein response elements of SESN2 promoter, transactivated SESN2, and increased SESN2 protein expression. In addition, dominant negative mutant of ATF6α and siRNA against ATF6α blocked the ER stress-mediated SESN2 induction, whereas chemical inhibition of PERK or IRE1 did not affect SESN2 induction by Tm. Ectopic expression of SESN2 in HepG2 cells inhibited CHOP and GRP78 expressions by Tm. Moreover, SESN2 decreased the phosphorylations of JNK and p38 and PARP cleavage, and blocked the cytotoxic effect of excessive ER stress. In a Tm-induced liver injury model, adenoviral delivery of SESN2 in mice decreased serum ALT, AST and LDH activities and the mRNA levels of CHOP and GRP78 in hepatic tissues. Moreover, SESN2 reduced numbers of degenerating hepatocytes, and inhibited caspase 3 and PARP cleavages. These results suggest ATF6 is essential for ER stress-mediated SESN2 induction, and that SESN2 acts as a feedback regulator to protect liver from excess ER stress.

Gα12 overexpression induced by miR-16 dysregulation contributes to liver fibrosis by promoting autophagy in hepatic stellate cells.

BACKGROUND & AIMS: Hepatic stellate cells (HSCs) have a role in liver fibrosis. Guanine nucleotide-binding α-subunit 12 (Gα12) converges signals from G-protein-coupled receptors whose ligand levels are elevated in the environment during liver fibrosis; however, information is lacking on the effect of Gα12 on HSC trans-differentiation. This study investigated the expression of Gα12 in HSCs and the molecular basis of the effects of its expression on liver fibrosis. METHODS: Gα12 expression was assessed by immunostaining, and immunoblot analyses of mouse fibrotic liver tissues and primary HSCs. The role of Gα12 in liver fibrosis was estimated using a toxicant injury mouse model with Gα12 gene knockout and/or HSC-specific Gα12 delivery using lentiviral vectors, in addition to primary HSCs and LX-2 cells using microRNA (miR) inhibitors, overexpression vectors, or adenoviruses. miR-16, Gα12, and LC3 were also examined in samples from patients with fibrosis. RESULTS: Gα12 was overexpressed in activated HSCs and fibrotic liver, and was colocalised with desmin. In a carbon tetrachloride-induced fibrosis mouse model, Gα12 ablation prevented increases in fibrosis and liver injury. This effect was attenuated by HSC-specific lentiviral delivery of Gα12. Moreover, Gα12 activation promoted autophagy accompanying c-Jun N-terminal kinase-dependent ATG12-5 conjugation. In addition, miR-16 was found to be a direct inhibitor of the de novo synthesis of Gα12. Modulations of miR-16 altered autophagy in HSCs. In a fibrosis animal model or patients with severe fibrosis, miR-16 levels were lower than in their corresponding controls. Consistently, cirrhotic patient liver tissues showed Gα12 and LC3 upregulation in desmin-positive areas. CONCLUSIONS: miR-16 dysregulation in HSCs results in Gα12 overexpression, which activates HSCs by facilitating autophagy through ATG12-5 formation. This suggests that Gα12 and its regulatory molecules could serve as targets for the amelioration of liver fibrosis. LAY SUMMARY: Guanine nucleotide-binding α-subunit 12 (Gα12) is upregulated in activated hepatic stellate cells (HSCs) as a consequence of the dysregulation of a specific microRNA that is abundant in HSCs, facilitating the progression of liver fibrosis. This event is mediated by c-Jun N-terminal kinase-dependent ATG12-5 formation and the promotion of autophagy. We suggest that Gα12 and its associated regulators could serve as new targets in HSCs for the treatment of liver fibrosis.

Progressive paraplegia after upper thoracic epidural block-related pneumorachis: A case report.

INTRODUCTION AND IMPORTANCE: While the typical symptom associated with pneumorachis after an epidural block is radiculopathy in one or several corresponding segments, there has been a rare case report of significant complications such as cardiac arrest leading to death, or paraplegia. CASE PRESENTATION: We present a case of an eighty-nine-year-old male patient who developed progressive paraplegia following an upper thoracic epidural block-associated pneumorachis. The procedure was performed at a different hospital using the loss of resistance (LOR) technique. Interestingly, the onset of paraplegia was delayed, occurring six hours after the procedure. Furthermore, there was a discrepancy between the clinical symptoms and the identified lesion in imaging studies. Despite the performance of an emergency laminectomy to remove the epidural gas, the paralysis continued to progress proximally. CLINICAL DISCUSSION: Healthcare professionals should observe patients for an appropriate duration after the procedure to detect and manage any delayed symptoms. And it is crucial to recognize the potential for lesion extension beyond the symptomatic segment and perform thorough imaging examinations. CONCLUSION: These findings emphasize the importance of exercising caution during the procedure, even when using a minimal amount of air with the LOR technique in the thoracic spine.

Practice preference and evidence analysis on topical use of tobramycin powder in lumbar spine surgery: A Multi-National AO spine survey with systematic review of the literature.

Study design: Cross-sectional study with systematic review of literature. Objective: There is an increasing interest in the topical use of antibiotics to prevent infection following spine surgery. To extend the antibiotic coverage to the gram-negative spectrum, the usage of tobramycin powder is being considered. We surveyed to analyze the current practice preference on the use of topical tobramycin in lumbar spine surgery and also aimed to analyze the literature for current evidence on the same. Methods: A multinational cross-sectional survey was conducted among AO Spine members worldwide to understand the use of topical tobramycin in 1 or 2-level open lumbar fusion surgeries. Also, an independent systematic review of four scientific databases (PubMed, Scopus, clinicaltrials.gov, Web of Science) was performed by two authors to identify relevant articles in adherence to the preferred reporting in systematic reviews and meta-analysis (PRISMA) guidelines. Studies reporting the usage of tobramycin in lumbar spine surgeries were included for analysis. Results: Among the 231 participating surgeons, only 1.7 %(n = 4) reported utilizing tobramycin in 1 or 2-level open lumbar fusion surgery. Upon systematic review of the literature, two studies with 484 patients were included for analysis. With the usage of tobramycin as a topical antibiotic powder, both studies noted a reduction in the incidence of infection with change in the spectrum of infective organisms. Conclusion: Topical Tobramycin is not the commonly preferred topical antibiotic to prevent SSI among spine surgeons worldwide. There is a lack of sufficient evidence to support the routine use of topical tobramycin in lumbar spine surgery.

CCCP induces hepatic stellate cell activation and liver fibrogenesis via mitochondrial and lysosomal dysfunction.

Hepatic stellate cells (HSCs) are primary cells for development and progression of liver fibrosis. Mitophagy is an essential lysosomal process for mitochondrial homeostasis, which can be activated by carbonyl cyanide m-chlorophenyl hydrazone (CCCP), a representative mitochondrial uncoupler. However, little information is available on the role of CCCP-mediated mitophagy in HSC activation and liver fibrogenesis. In this study, we showed that CCCP treatment in HSCs caused mitochondrial dysfunction proved by decreased mitochondrial membrane potential, mitochondrial DNA, and ATP contents and increased mitochondrial ROS. Moreover, CCCP induced mitophagy and impaired mitophagy flux at the later stage. This blockade of mitophagic flux effect was mediated by suppression of lysosomal activity; CCCP decreased expression of lysosomal markers and cathepsin B activity, and increased lysosomal pH. Intriguingly, CCCP treatment in LX-2 cells or primary HSCs elevated plasminogen activator inhibitor-1 (PAI-1), a typical fibrogenic marker of HSCs which was attenuated by mitochondrial division inhibitor 1, a mitophagy inhibitor. The up-regulation of PAI-1 by CCCP was not due to altered transcriptional activity but lysosomal dysfunction. In vivo acute or sub-chronic treatment of CCCP to mice induced mitophagy and fibrogenesis of liver. Hepatic fibrogenic marker (PAI-1) was incremented with mitophagy markers (parkin and PTEN-induced putative kinase 1) in the livers of CCCP injected mice. Furthermore, we found that 5-aminoimidazole-4-carboxyamide ribonucleoside reversed CCCP-mediated mitophagy and subsequent HSC activation. To conclude, CCCP facilitated HSC activation and hepatic fibrogenesis via mitochondrial dysfunction and lysosomal blockade, implying that attenuation of CCCP-related signaling molecules may contribute to treat liver fibrosis.

An inducible sphingosine kinase 1 in hepatic stellate cells potentiates liver fibrosis.

Hepatic stellate cells (HSCs) play a role in hepatic fibrosis and sphingosine kinase (SphK) is involved in biological processes. As studies on the regulatory mechanisms and functions of SphK in HSCs during liver fibrosis are currently limited, this study aimed to elucidate the regulatory mechanism and connected pathways of SphK upon HSC activation. The expression of SphK1 was higher in HSCs than in hepatocytes, and upregulated in activated primary HSCs. SphK1 was also increased in liver homogenates of carbon tetrachloride-treated or bile duct ligated mice and in transforming growth factor-ß (TGF-ß)-treated LX-2 cells. TGF-ß-mediated SphK1 induction was due to Smad3 signaling in LX-2 cells. SphK1 modulation altered the expression of liver fibrogenesis-related genes. This SphK1-mediated profibrogenic effect was dependent on SphK1/sphingosine-1-phosphate/sphingosine-1-phosphate receptor signaling through ERK. Epigallocatechin gallate blocked TGF-ß-induced SphK1 expression and hepatic fibrogenesis by attenuating Smad and MAPK activation. SphK1 induced by TGF-ß facilitates HSC activation and liver fibrogenesis, which is reversed by epigallocatechin gallate. Accordingly, SphK1 and related signal transduction may be utilized to treat liver fibrosis.

Identification of Histone Lysine Acetoacetylation as a Dynamic Post-Translational Modification Regulated by HBO1.

Ketone bodies have long been known as a group of lipid-derived alternative energy sources during glucose shortages. Nevertheless, the molecular mechanisms underlying their non-metabolic functions remain largely elusive. This study identified acetoacetate as the precursor for lysine acetoacetylation (Kacac), a previously uncharacterized and evolutionarily conserved histone post-translational modification. This protein modification is comprehensively validated using chemical and biochemical approaches, including HPLC co-elution and MS/MS analysis using synthetic peptides, Western blot, and isotopic labeling. Histone Kacac can be dynamically regulated by acetoacetate concentration, possibly via acetoacetyl-CoA. Biochemical studies show that HBO1, traditionally known as an acetyltransferase, can also serve as an acetoacetyltransferase. In addition, 33 Kacac sites are identified on mammalian histones, depicting the landscape of histone Kacac marks across species and organs. In summary, this study thus discovers a physiologically relevant and enzymatically regulated histone mark that sheds light on the non-metabolic functions of ketone bodies.

LDHA Desuccinylase Sirtuin 5 as A Novel Cancer Metastatic Stimulator in Aggressive Prostate Cancer.

Prostate cancer (PCa) is the most commonly diagnosed genital cancer in men worldwide. Around 80% of the patients who developed advanced PCa suffered from bone metastasis, with a sharp drop in the survival rate. Despite great efforts, the detailed mechanisms underlying castration-resistant PCa (CRPC) remain unclear. Sirtuin 5 (SIRT5), an NAD+-dependent desuccinylase, is hypothesized to be a key regulator of various cancers. However, compared to other SIRTs, the role of SIRT5 in cancer has not been extensively studied. Here, we revealed significantly decreased SIRT5 levels in aggressive PCa cells relative to the PCa stages. The correlation between the decrease in the SIRT5 level and the patient's reduced survival rate was also confirmed. Using quantitative global succinylome analysis, we characterized a significant increase in the succinylation at lysine 118 (K118su) of lactate dehydrogenase A (LDHA), which plays a role in increasing LDH activity. As a substrate of SIRT5, LDHA-K118su significantly increased the migration and invasion of PCa cells and LDH activity in PCa patients. This study reveals the reduction of SIRT5 protein expression and LDHA-K118su as a novel mechanism involved in PCa progression, which could serve as a new target to prevent CPRC progression for PCa treatment.

Pharmacokinetic and bioavailability studies of 5 mg mosapride tablets in healthy Korean volunteers.

AIM: Mosapride is a gastroprokinetic agent, a 5-HT4 receptor agonist and 5-HT3 receptor antagonist exhibiting no activity at dopamine D2, 5-HT1 and 5-HT2 receptors. This study was performed to compare basic pharmacokinetic (PK) characteristics of mosapride for Korean young adults and to evaluate the bioequivalence (BE) of two formulations of drugs mosapride. VOLUNTEERS AND METHODS: For pharmacokinetic and bioavailability of 5 mg mosapride tablets in healthy Korean adults, a randomized, two way, crossover bioequivalence study in 23 healthy Korean volunteers (M : F = 16 : 7) was conducted to compare bioavailability of two formulation of 5 mg mosapride citrate tablets, Moprid® (Chung Kun Dang Pharm Co., Ltd., Korea) as a test and Gasmotin® (Daewoong Pharm Co., Ltd., Korea) as a reference drug. Subjects were administered single dosage of 3 tablets of each formulation with 240 ml water after 10 h overnight fasting on 2 treatment days separated by 1-week washout period. Before and after dosing, blood sample were collected at 0, 0.25, 0.5, 0.8, 1.0, 1.5, 2, 2.5, 3, 4, 6, 8, 12 and 24 h and analyzed by validated liquid chromatography- tandem mass spectrometry (LC-MS/ MS) in the range 1.28 - 192 ng/ml with the lowest limit of quantification of 1.28 ng/ml. RESULTS: Several PK characteristics were determined from the plasma samples, and data from reference and test formulations in the plasma were represented such as AUC0- t (184.4 vs. 179.6 ng×h/ml), AUC0-∞ (192.8 vs. 186.6 ng×h/ml), Cmax (98.9 vs. 84.4 ng/ ml), tmax (0.8 vs. 0.7 h), half-life (2.4 vs. 2.3 h), Ke (0.289 vs. 0.301), respectively. AUC0- t and Cmax were tested for bioequivalence after log-transformation of plasma data. PK characteristics with 90% confidence interval (CI) of test/reference ratio based on ANOVA analysis were 0.842 - 1.163 for AUC0-t and 0.753 - 1.088 for Cmax. PK characteristics with 90% CI were within the bioequivalence range of 80 - 125% of FDA statistical limit. Cmax with 90% CI were not within the bioequivalence range of 80 - 125% of FDA statistical limit. However, this result was assessed to bioequivalence in accordance with the "Bioequivalence Test Guidelines" outlined in No. 2005-31 of the KFDA. CONCLUSION: Therefore, both mosapride formulations were bioequivalent during fasting state in healthy Korean adults.

Collision of three histologically distinct endometrial cancers of the uterus.

A collision tumor is defined by the presence of two separate masses in one organ, which are pathologically distinct. We described a 70-yr-old patient who complained of abnormal vaginal bleeding with a collision tumor of the uterine corpus. The patient received total hysterectomy, bilateral salphingo-oophorectomy, bilateral pelvic-paraaortic lymphadenectomy, omentectomy, and intraperitoneal chemotherapy. The uterine corpus revealed three separate masses, which were located at the fundus, anterior and posterior wall. Each tumor revealed three pathologically different components, which were malignant mixed müllerian tumor, papillary serous carcinoma, and endometrioid adenocarcinoma. Among these components, only the papillary serous carcinoma component invaded the underlying myometrium and metastasized to the regional lymph node. Adjuvant chemotherapy and radiation therapy were performed. The patient is still alive and has been healthy for the last 8 yr. We have reviewed previously reported cases of collision tumors which have occurred in the uterine corpus.