Mature microRNA-binding protein QKI suppresses extracellular microRNA let-7b release.

Argonaute (AGO), a component of RNA-induced silencing complexes (RISCs), is a representative RNA-binding protein (RBP) known to bind with mature microRNA (miRNA) and is directly involved in post-transcriptional gene silencing. However, despite the biological significance of miRNA, the roles of other micro RNA-binding proteins (miRBPs) remain unclear in regulation of miRNA loading, dissociation from RISC, and extracellular release. In this study, we perform protein arrays to profile miRBPs and identify 118 RNA-binding proteins directly binding with miRNAs. Among those proteins, RBP quaking (QKI) inhibits extracellular release of mature microRNA let-7b by controlling the loading of let-7b into extracellular vesicles via additional miRBPs such as hnRNPD/AUF1 and hnRNPK. The enhanced extracellular release of let-7b after QKI depletion activates the Toll-like Receptor 7 (TLR7) and promotes the production of proinflammatory cytokines in recipient cells, leading to brain inflammation in mouse cortex. Thus, this study reveals contribution of QKI to the inhibition of brain inflammation via regulation of extracellular let-7b release.

Hypermethylation leads to the loss of HOXA5, resulting in JAG1 expression and NOTCH signaling contributing to kidney fibrosis.

Epigenetic regulations, including DNA methylation, are critical to the development and progression of kidney fibrosis, but the underlying mechanisms remain elusive. Here, we show that fibrosis of the mouse kidney was associated with the induction of DNA methyltransferases and increases in global DNA methylation and was alleviated by the DNA methyltransferase inhibitor 5-Aza-2'-deoxycytidine (5-Aza). Genome-wide analysis demonstrated the hypermethylation of 94 genes in mouse unilateral ureteral obstruction kidneys, which was markedly reduced by 5-Aza. Among these genes, Hoxa5 was hypermethylated at its gene promoter, and this hypermethylation was associated with reduced HOXA5 expression in fibrotic mouse kidneys after ureteral obstruction or unilateral ischemia-reperfusion injury. 5-Aza prevented Hoxa5 hypermethylation, restored HOXA5 expression, and suppressed kidney fibrosis. Downregulation of HOXA5 was verified in human kidney biopsies from patients with chronic kidney disease and correlated with the increased kidney fibrosis and DNA methylation. Kidney fibrosis was aggravated by conditional knockout of Hoxa5 and alleviated by conditional knockin of Hoxa5 in kidney proximal tubules of mice. Mechanistically, we found that HOXA5 repressed Jag1 transcription by directly binding to its gene promoter, resulting in the suppression of JAG1-NOTCH signaling during kidney fibrosis. Thus, our results indicate that loss of HOXA5 via DNA methylation contributes to fibrogenesis in kidney diseases by inducing JAG1 and consequent activation of the NOTCH signaling pathway.

Phosphorylation of slit diaphragm proteins NEPHRIN and NEPH1 upon binding of HGF promotes podocyte repair.

Phosphorylation (activation) and dephosphorylation (deactivation) of the slit diaphragm proteins NEPHRIN and NEPH1 are critical for maintaining the kidney epithelial podocyte actin cytoskeleton and, therefore, proper glomerular filtration. However, the mechanisms underlying these events remain largely unknown. Here we show that NEPHRIN and NEPH1 are novel receptor proteins for hepatocyte growth factor (HGF) and can be phosphorylated independently of the mesenchymal epithelial transition receptor in a ligand-dependent fashion through engagement of their extracellular domains by HGF. Furthermore, we demonstrate SH2 domain-containing protein tyrosine phosphatase-2-dependent dephosphorylation of these proteins. To establish HGF as a ligand, purified baculovirus-expressed NEPHRIN and NEPH1 recombinant proteins were used in surface plasma resonance binding experiments. We report high-affinity interactions of NEPHRIN and NEPH1 with HGF, although NEPHRIN binding was 20-fold higher than that of NEPH1. In addition, using molecular modeling we constructed peptides that were used to map specific HGF-binding regions in the extracellular domains of NEPHRIN and NEPH1. Finally, using an in vitro model of cultured podocytes and an ex vivo model of Drosophila nephrocytes, as well as chemically induced injury models, we demonstrated that HGF-induced phosphorylation of NEPHRIN and NEPH1 is centrally involved in podocyte repair. Taken together, this is the first study demonstrating a receptor-based function for NEPHRIN and NEPH1. This has important biological and clinical implications for the repair of injured podocytes and the maintenance of podocyte integrity.

Extracellular Vesicles in Acute Kidney Injury and Clinical Applications.

Acute kidney injury (AKI)--the sudden loss of kidney function due to tissue damage and subsequent progression to chronic kidney disease--has high morbidity and mortality rates and is a serious worldwide clinical problem. Current AKI diagnosis, which relies on measuring serum creatinine levels and urine output, cannot sensitively and promptly report on the state of damage. To address the shortcomings of these traditional diagnosis tools, several molecular biomarkers have been developed to facilitate the identification and ensuing monitoring of AKI. Nanosized membrane-bound extracellular vesicles (EVs) in body fluids have emerged as excellent sources for discovering such biomarkers. Besides this diagnostic purpose, EVs are also being extensively exploited to deliver therapeutic macromolecules to damaged kidney cells to ameliorate AKI. Consequently, many successful AKI biomarker findings and therapeutic applications based on EVs have been made. Here, we review our understanding of how EVs can help with the early identification and accurate monitoring of AKI and be used therapeutically. We will further discuss where current EV-based AKI diagnosis and therapeutic applications fall short and where future innovations could lead us.

Reliability of the Patient and Observer Scar Assessment Scale in Evaluating Linear Scars after Thyroidectomy.

OBJECTIVE: To compare the reliability of the Patient and Observer Scar Assessment Scale (POSAS) with the Vancouver Scar Scale (VSS) in evaluating thyroidectomy scars. METHODS: At 6 months after the operation, 112 patients who underwent thyroid surgery via collar neck incision were evaluated by two blinded plastic surgeons and two senior residents using the VSS and the observer component of the POSAS. In addition, the observer-reported VAS score and patient-reported Likert score were evaluated. Internal consistency, interobserver reliability, and correlations between the patient- and observer-reported outcomes were examined. RESULTS: The observer component of POSAS scores demonstrated higher internal consistency and interobserver reliability than the VSS. However, the correlations between the observer-reported VAS score and the patient-reported Likert score (0.450) and between the total sum of patient and observer component scores (0.551) were low to moderate. CONCLUSIONS: The POSAS is more consistent over repeated measurements; accordingly, it may be considered a more objective and reliable scar assessment tool than the VSS. However, a clinician's perspective may not exactly match the patient's perception of the same scar.

Primary cilia and the exocyst are linked to urinary extracellular vesicle production and content.

The recently proposed idea of "urocrine signaling" hypothesizes that small secreted extracellular vesicles (EVs) contain proteins that transmit signals to distant cells. However, the role of renal primary cilia in EV production and content is unclear. We previously showed that the exocyst, a highly conserved trafficking complex, is necessary for ciliogenesis; that it is present in human urinary EVs; that knockdown (KD) of exocyst complex component 5 (EXOC5), a central exocyst component, results in very short or absent cilia; and that human EXOC5 overexpression results in longer cilia. Here, we show that compared with control Madin-Darby canine kidney (MDCK) cells, EXOC5 overexpression increases and KD decreases EV numbers. Proteomic analyses of isolated EVs from EXOC5 control, KD, and EXOC5-overexpressing MDCK cells revealed significant alterations in protein composition. Using immunoblotting to specifically examine the expression levels of ADP-ribosylation factor 6 (ARF6) and EPS8-like 2 (EPS8L2) in EVs, we found that EXOC5 KD increases ARF6 levels and decreases EPS8L2 levels, and that EXOC5 overexpression increases EPS8L2. Knockout of intraflagellar transport 88 (IFT88) confirmed that the changes in EV number/content were due to cilia loss: similar to EXOC5, the IFT88 loss resulted in very short or absent cilia, decreased EV numbers, increased EV ARF6 levels, and decreased Eps8L2 levels compared with IFT88-rescued EVs. Compared with control animals, urine from proximal tubule-specific EXOC5-KO mice contained fewer EVs and had increased ARF6 levels. These results indicate that perturbations in exocyst and primary cilia affect EV number and protein content.

Stress granules are formed in renal proximal tubular cells during metabolic stress and ischemic injury for cell survival.

Stress granules (SGs) are a type of cytoplasmic structures formed in eukaryotic cells upon cell stress, which mainly contain RNA-binding proteins and RNAs. The formation of SGs is generally regarded as a mechanism for cells to survive a harsh insult. However, little is known about SG formation and function in kidneys. To address this, we applied different kinds of stressors to cultured proximal tubular cells as well as a short period of ischemia-reperfusion to mouse kidneys. It was found that glycolytic inhibitors such as 2-deoxy-d-glucose and 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one induced SG formation within 30 min in these cells. Similarly, SGs were induced by inhibitors of mitochondrial respiration such as sodium azide and CCCP. Renal ischemia-reperfusion induced SG formation in the cells of proximal tubules. To test the role of SGs, we stably knocked down G3bp1, a SG core protein, in renal tubular cells by shRNA viral transduction. As expected, knockdown of G3bp1 largely disrupted the assembly of SGs. After azide or cisplatin treatment, more dead cells were found in knockdown cells compared with controls, accompanied by increases in cleaved/active caspase-3. Reintroduction of exogenous G3bp1 into knockdown cells could rescue the cell death phenotype. Taken together, our data provide the first evidence of SG formation in renal tubular cells during metabolic stress and acute kidney injury. SGs are formed to protect proximal tubular cells under these conditions. Modulation of SG biogenesis may provide a novel approach to lessen the severity of renal diseases.

Development of a novel cell-based assay to diagnose recurrent focal segmental glomerulosclerosis patients.

Definitive diagnosis of glomerular disease requires a kidney biopsy, an invasive procedure that may not be safe or feasible to perform in all patients. We developed a noninvasive, accurate, and economical diagnostic assay with easy commercial adaptability to detect recurrent focal segmental glomerulosclerosis (rFSGS) after kidney transplant. Since FSGS involves podocyte damage and death, our approach involved mRNA profiling of cultured podocytes treated with plasma from patients with rFSGS to identify upregulated genes involved in podocyte damage. For concept validation, three upregulated pro-apoptotic candidate genes (IL1ß, BMF, and IGFBP3) were selected, and their promoter regions were cloned into a luciferase-based reporter vector and transfected into podocytes to generate stable podocyte cell lines. Strikingly, when exposed to rFSGS patient plasma, these cell lines showed increased reporter activity; in contrast, no reporter activity was noted with plasma from patients with non-recurrent FSGS or membranous nephropathy. Area under the receiver operating characteristics curves (AUCs) for models discriminating between rFSGS and other nephropathies (non-recurrent FSGS and membranous nephropathy) and between rFSGS and non-recurrent FSGS ranged from 0.81 to 0.86, respectively. Estimated sensitivities and specificities for the diagnosis of rFSGS were greater than 80% for the IL1ß and BMF cell lines, and were slightly lower for the IGFBP3 cell line. Importantly, the novel approach outlined here for the diagnosis of rFSGS is widely applicable to the design of sensitive and specific diagnostic/prognostic assays for other glomerular diseases.

Mitochondrial biogenesis induced by the ß2-adrenergic receptor agonist formoterol accelerates podocyte recovery from glomerular injury.

Podocytes have limited ability to recover from injury. Here, we demonstrate that increased mitochondrial biogenesis, to meet the metabolic and energy demand of a cell, accelerates podocyte recovery from injury. Analysis of events induced during podocyte injury and recovery showed marked upregulation of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), a transcriptional co-activator of mitochondrial biogenesis, and key components of the mitochondrial electron transport chain. To evaluate our hypothesis that increasing mitochondrial biogenesis enhanced podocyte recovery from injury, we treated injured podocytes with formoterol, a potent, specific, and long-acting ß2-adrenergic receptor agonist that induces mitochondrial biogenesis in vitro and in vivo. Formoterol increased mitochondrial biogenesis and restored mitochondrial morphology and the injury-induced changes to the organization of the actin cytoskeleton in podocytes. Importantly, ß2-adrenergic receptors were found to be present on podocyte membranes. Their knockdown attenuated formoterol-induced mitochondrial biogenesis. To determine the potential clinical relevance of these findings, mouse models of acute nephrotoxic serum nephritis and chronic (Adriamycin [doxorubicin]) glomerulopathy were used. Mice were treated with formoterol post-injury when glomerular dysfunction was established. Strikingly, formoterol accelerated the recovery of glomerular function by reducing proteinuria and ameliorating kidney pathology. Furthermore, formoterol treatment reduced cellular apoptosis and increased the expression of the mitochondrial biogenesis marker PGC-1α and multiple electron transport chain proteins. Thus, our results support ß2-adrenergic receptors as novel therapeutic targets and formoterol as a therapeutic compound for treating podocytopathies.

The motor protein Myo1c regulates transforming growth factor-ß-signaling and fibrosis in podocytes.

Transforming growth factor-ß (TGF-ß) is known to play a critical role in the pathogenesis of many progressive podocyte diseases. However, the molecular mechanisms regulating TGF-ß signaling in podocytes remain unclear. Using a podocyte-specific myosin (Myo)1c knockout, we demonstrate whether Myo1c is critical for TGF-ß-signaling in podocyte disease pathogenesis. Specifically, podocyte-specific Myo1c knockout mice were resistant to fibrotic injury induced by Adriamycin or nephrotoxic serum. Further, loss of Myo1c also protected from injury in the TGF-ß-dependent unilateral ureteral obstruction mouse model of renal interstitial fibrosis. Mechanistic analyses showed that loss of Myo1c significantly blunted TGF-ß signaling through downregulation of canonical and non-canonical TGF-ß pathways. Interestingly, nuclear rather than the cytoplasmic Myo1c was found to play a central role in controlling TGF-ß signaling through transcriptional regulation. Differential expression analysis of nuclear Myo1c-associated gene promoters showed that nuclear Myo1c targeted the TGF-ß responsive gene growth differentiation factor (GDF)-15 and directly bound to the GDF-15 promoter. Importantly, GDF15 was found to be involved in podocyte pathogenesis, where GDF15 was upregulated in glomeruli of patients with focal segmental glomerulosclerosis. Thus, Myo1c-mediated regulation of TGF-ß-responsive genes is central to the pathogenesis of podocyte injury. Hence, inhibiting this process may have clinical application in treating podocytopathies.

Mutations in KIRREL1, a slit diaphragm component, cause steroid-resistant nephrotic syndrome.

Steroid-resistant nephrotic syndrome is a frequent cause of chronic kidney disease almost inevitably progressing to end-stage renal disease. More than 58 monogenic causes of SRNS have been discovered and majority of known steroid-resistant nephrotic syndrome causing genes are predominantly expressed in glomerular podocytes, placing them at the center of disease pathogenesis. Herein, we describe two unrelated families with steroid-resistant nephrotic syndrome with homozygous mutations in the KIRREL1 gene. One mutation showed high frequency in the European population (minor allele frequency 0.0011) and this patient achieved complete remission following treatment, but later progressed to chronic kidney disease. We found that mutant KIRREL1 proteins failed to localize to the podocyte cell membrane, indicating defective trafficking and impaired podocytes function. Thus, the KIRREL1 gene product has an important role in modulating the integrity of the slit diaphragm and maintaining glomerular filtration function.

Electromyographic activity of superficial masseter and anterior temporal muscles during unilateral mastication of artificial test foods with different textures in healthy subjects.

OBJECTIVES: This study aimed to examine the electromyographic activity of superficial masseter and anterior temporal muscles during chewing gum and gummy jelly mastication in healthy subjects to reveal the difference of neuromuscular control of jaw-closing muscles, according to the food texture. MATERIALS AND METHODS: Electromyographic activity was recorded in 30 adults with Angle Class I occlusion and unimpaired function from the bilateral superficial masseter and anterior temporal muscles during unilateral mastication of two test foods: standardized gummy jelly and color-changeable chewing gum. Differences in normalized electromyographic activity and asymmetry index values between gummy jelly and chewing gum mastication were analyzed during the early, middle, and late phases of mandibular closure. Furthermore, changes among the three closing phases were compared for each test food. RESULTS: High electromyographic activity of both muscles tended to occur bilaterally during the middle and late closing phases during gummy jelly mastication, but increased muscle activity in the late closing phase was not observed during chewing gum mastication. The asymmetry index of the superficial masseter muscle increased significantly from early to late closure, regardless of the food texture, but it tended to decrease for the anterior temporal muscle during gummy jelly mastication. CONCLUSION: The different aspects of the chewing process between the comminution and mixing test measures are necessary to elicit the different human neuromuscular strategies of chewing for different test foods. CLINICAL RELEVANCE: These characteristic EMG activities of the superficial masseter and anterior temporalis muscles may be used as supporting diagnostic information during patient assessments and a reference during evaluation of masticatory system disharmony or dysfunction.

Willingness to pay for family education and counselling services provided by critical care advanced practice nurses.

AIM: The aim of this study was to estimate the economic value of a family education and counselling service provided by critical care advanced practice nurses in South Korea utilizing a contingent valuation approach. METHODS: A double-bounded dichotomous choice contingent valuation method was utilized to estimate the public's willingness to pay value for an education and counselling service provided by critical care advanced practice nurses. A web-based self-administered survey was conducted. RESULTS: Median willingness to pay was 43 112 Korean won (35 US dollars). Higher income and younger age were associated with higher willingness to pay. CONCLUSION: This study captured the economic value of an education and counselling service provided by critical care advanced practice nurses that is not on the benefit list under the fee-for-service system of the Korean National Health System. Policy makers should consider including such services in the health care system.

Adaptor Protein CD2AP and L-type Lectin LMAN2 Regulate Exosome Cargo Protein Trafficking through the Golgi Complex.

Exosomes, 40-150-nm extracellular vesicles, transport biological macromolecules that mediate intercellular communications. Although exosomes are known to originate from maturation of endosomes into multivesicular endosomes (also known as multivesicular bodies) with subsequent fusion of the multivesicular endosomes with the plasma membrane, it remains unclear how cargos are selected for exosomal release. Using an inducible expression system for the exosome cargo protein GPRC5B and following its trafficking trajectory, we show here that newly synthesized GPRC5B protein accumulates in the Golgi complex prior to its release into exosomes. The L-type lectin LMAN2 (also known as VIP36) appears to be specifically required for the accumulation of GPRC5B in the Golgi complex and restriction of GPRC5B transport along the exosomal pathway. This may occur due to interference with the adaptor protein GGA1-mediated trans Golgi network-to-endosome transport of GPRC5B. The adaptor protein CD2AP-mediated internalization following cell surface delivery appears to contribute to the Golgi accumulation of GPRC5B, possibly in parallel with biosynthetic/secretory trafficking from the endoplasmic reticulum. Our data thus reveal a Golgi-traversing pathway for exosomal release of the cargo protein GPRC5B in which CD2AP facilitates the entry and LMAN2 impedes the exit of the flux, respectively.

Dynamin Binding Protein (Tuba) Deficiency Inhibits Ciliogenesis and Nephrogenesis in Vitro and in Vivo.

Dysfunction of renal primary cilia leads to polycystic kidney disease. We previously showed that the exocyst, a protein trafficking complex, is essential for ciliogenesis and regulated by multiple Rho and Rab family GTPases, such as Cdc42. Cdc42 deficiency resulted in a disruption of renal ciliogenesis and a polycystic kidney disease phenotype in zebrafish and mice. Here we investigate the role of Dynamin binding protein (also known as Tuba), a Cdc42-specific guanine nucleotide exchange factor, in ciliogenesis and nephrogenesis using Tuba knockdown Madin-Darby canine kidney cells and tuba knockdown in zebrafish. Tuba depletion resulted in an absence of cilia, with impaired apical polarization and inhibition of hepatocyte growth factor-induced tubulogenesis in Tuba knockdown Madin-Darby canine kidney cell cysts cultured in a collagen gel. In zebrafish, tuba was expressed in multiple ciliated organs, and, accordingly, tuba start and splice site morphants showed various ciliary mutant phenotypes in these organs. Co-injection of tuba and cdc42 morpholinos at low doses, which alone had no effect, resulted in genetic synergy and led to abnormal kidney development with highly disorganized pronephric duct cilia. Morpholinos targeting two other guanine nucleotide exchange factors not known to be in the Cdc42/ciliogenesis pathway and a scrambled control morpholino showed no phenotypic effect. Given the molecular nature of Cdc42 and Tuba, our data strongly suggest that tuba and cdc42 act in the same ciliogenesis pathway. Our study demonstrates that Tuba deficiency causes an abnormal renal ciliary and morphogenetic phenotype. Tuba most likely plays a critical role in ciliogenesis and nephrogenesis by regulating Cdc42 activity.

Quantitative analysis of radiosensitizing effect for magnetic hyperthermia-radiation combined therapy on prostate cancer cells.

BACKGROUND: Magnetic hyperthermia (MHT) has emerged as a promising therapeutic approach in the field of radiation oncology due to its superior precision in controlling temperature and managing the heating area compared to conventional hyperthermia. Recent studies have proposed solutions to address clinical safety concerns associated with MHT, which arise from the use of highly concentrated magnetic nanoparticles and the strong magnetic field needed to induce hyperthermic effects. Despite these efforts, challenges remain in quantifying therapeutic outcomes and developing treatment plan systems for combining MHT with radiation therapy (RT). PURPOSE: This study aims to quantitatively measure the therapeutic effect, including radiation dose enhancement (RDE) in the magnetic hyperthermia-radiation combined therapy (MHRT), using the equivalent radiation dose (EQD) estimation method. METHODS: To conduct EQD estimation for MHRT, we compared the therapeutic effects between the conventional hyperthermia-radiation combined therapy (HTRT) and MHRT in human prostate cancer cell lines, PC3 and LNCaP. We adopted a clonogenic assay to validate RDE and the radiosensitizing effect induced by MHT. The data on survival fractions were analyzed using both the linear-quadradic model and Arrhenius model to estimate the biological parameters describing RDE and radiosensitizing effect of MHRT for both cell lines through maximum likelihood estimation. Based on these parameters, a new survival fraction model was suggested for EQD estimation of MHRT. RESULTS: The newly designed model describing the MHRT effect, effectively captures the variations in thermal and radiation dose for both cell lines (R2 > 0.95), and its suitability was confirmed through the normality test of residuals. This model appropriately describes the survival fractions up to 10 Gy for PC3 cells and 8 Gy for LNCaP cells under RT-only conditions. Furthermore, using the newly defined parameter r, the RDE effect was calculated as 29% in PC3 cells and 23% in LNCaP cells. EQDMHRT calculated through this model was 9.47 Gy for PC3 and 4.71 Gy for LNCaP when given 2 Gy and MHT for 30 min. Compared to EQDHTRT, EQDMHRT showed a 26% increase for PC3 and a 20% increase for LNCaP. CONCLUSIONS: The proposed model effectively describes the changes of the survival fraction induced by MHRT in both cell lines and adequately represents actual data values through residual analysis. Newly suggested parameter r for RDE effect shows potential for quantitative comparisons between HTRT and MHRT, and optimizing therapeutic outcomes in MHRT for prostate cancer.

The GAP portion of Pseudomonas aeruginosa type III secreted toxin ExoS upregulates total and surface levels of wild type CFTR.

BACKGROUND: Pseudomonas aeruginosa (PA) infections account for a large percentage of fatal hospital acquired pneumonias. One of the PA Type III secreted toxin (TTST) ExoS, a bifunctional protein with N-terminal GTPase activating protein (GAP) and C-terminal ADP rybosyl transferase (ADPRT) activities, significantly contributes to PA virulence by targeting small molecular weight G-proteins (SMWGP). In this study, we have looked at one of the mechanisms by which the GAP portion of ExoS (ExoS-GAP) mediates cellular toxicity. METHODS: The effects of ExoS-GAP on CFTR trafficking were studied in CFBE41o- Kir 2.2 and MDCK cell lines stably expressing CFTR using a transient transfection system. RESULTS: Transient transfection of ExoS-GAP increased the total and surface protein levels of mature wild type CFTR in epithelial cells stably expressing wild type (WT) CFTR. The effect of ExoS-GAP was specific to CFTR in bronchial epithelial cells since it did not affect the total protein levels of Na(+)/K(+)ATPase, another membrane protein. A point mutation in the ExoS GAP domain (R146K), known to disrupt its catalytic GAP activity, abolished the effect of ExoS-GAP on WT CFTR. Lysosomal inhibition studies with Bafilomycin A1 indicate that ExoS-GAP decreased lysosomal degradation of the mature WT CFTR with concomitant increase in the total levels of mature WT CFTR. However, ExoS-GAP did not increase the total protein levels of ∆F508CFTR. CONCLUSION: The GAP portion of the PA TTST ExoS increases the total and surface levels of wild type CFTR in vitro mammalian cell system. The effect of ExoS-GAP on WT CFTR total protein levels provides new insight into understanding the virulent pathophysiology of PA infections.

MicroRNA-mediated attenuation of branched-chain amino acid catabolism promotes ferroptosis in chronic kidney disease.

Chronic kidney disease can develop from kidney injury incident to chemotherapy with cisplatin, which complicates the prognosis of cancer patients. MicroRNAs regulate gene expression by pairing with specific sets of messenger RNAs. Therefore, elucidating direct physical interactions between microRNAs and their target messenger RNAs can help decipher crucial biological processes associated with cisplatin-induced kidney injury. Through intermolecular ligation and transcriptome-wide sequencing, we here identify direct pairs of microRNAs and their target messenger RNAs in the kidney of male mice injured by cisplatin. We find that a group of cisplatin-induced microRNAs can target select messenger RNAs that affect the mitochondrial metabolic pathways in the injured kidney. Specifically, a cisplatin-induced microRNA, miR-429-3p, suppresses the pathway that catabolizes branched-chain amino acids in the proximal tubule, leading to cell death dependent on lipid peroxidation, called ferroptosis. Identification of miRNA-429-3p-mediated ferroptosis stimulation suggests therapeutic potential for modulating the branched-chain amino acid pathway in ameliorating cisplatin-induced kidney injury.

Assessing the preventive effect of immediate lymphatic reconstruction on the upper extremity lymphedema.

Background: An immediate lymphatic reconstruction (ILR) combining axillary reverse lymphatic mapping (ARLM) and lymphovenous anastomosis (LVA) has been gradually in the spotlight as a novel surgical technique to prevent lymphedema. In this study, we investigate the preventive effect of ILR for the risk of upper extremity lymphedema. We will compare the incidence of postoperative lymphedema between the ILR treatment group and the no-try or failure group during the same period with analysis of the effects of different variables. Methods: In this retrospective cohort study, we analyzed 213 patients who had undergone mastectomy for node-positive unilateral breast cancer in our institution between November 1, 2019 and February 28, 2021. To assess the effect of preventive ILR, we divided the patients into a treatment group (n=30) and a control group (n=183). Univariate and multivariate Cox proportional hazards regression models were used to evaluate the association between ILR and lymphedema occurrence. Results: Of the 30 patients who were attempted, we successfully performed ILRs in 26 patients (86.7%). During a mean follow-up of 14 months, one patient (3.8%) was confirmed to have upper extremity lymphedema in the treatment group, whereas 14 out of 183 patients (7.7%) were diagnosed in the control group. In multivariate analysis, ILR success showed a borderline significant decrease in risk of lymphedema [hazard ratio (HR) =0.174; 95% confidence interval (CI): 0.022-1.374; P=0.097]. Conclusions: Our results suggested that ILR may be a promising surgical treatment to prevent postoperative lymphedema. There is a need for larger studies with longer follow-up to confirm the findings obtained in our study.