Repositioning of ezetimibe for the treatment of idiopathic pulmonary fibrosis.

BACKGROUND: We previously identified ezetimibe, an inhibitor of Niemann-Pick C1-like intracellular cholesterol transporter 1 and European Medicines Agency-approved lipid-lowering agent, as a potent autophagy activator. However, its efficacy against pulmonary fibrosis has not yet been evaluated. This study aimed to determine whether ezetimibe has therapeutic potential against idiopathic pulmonary fibrosis. METHODS: Primary lung fibroblasts isolated from both humans and mice were employed for mechanistic in vitro experiments. mRNA sequencing of human lung fibroblasts and gene set enrichment analysis were performed to explore the therapeutic mechanism of ezetimibe. A bleomycin-induced pulmonary fibrosis mouse model was used to examine in vivo efficacy of the drug. Tandem fluorescent-tagged microtubule-associated protein 1 light chain 3 transgenic mice were used to measure autophagic flux. Finally, the medical records of patients with idiopathic pulmonary fibrosis from three different hospitals were reviewed retrospectively, and analyses on survival and lung function were conducted to determine the benefits of ezetimibe. RESULTS: Ezetimibe inhibited myofibroblast differentiation by restoring the mechanistic target of rapamycin complex 1-autophagy axis with fine control of intracellular cholesterol distribution. Serum response factor, a potential autophagic substrate, was identified as a primary downstream effector in this process. Similarly, ezetimibe ameliorated bleomycin-induced pulmonary fibrosis in mice by inhibiting mechanistic target of rapamycin complex 1 activity and increasing autophagic flux, as observed in mouse lung samples. Patients with idiopathic pulmonary fibrosis who regularly used ezetimibe showed decreased rates of all-cause mortality and lung function decline. CONCLUSION: Our study presents ezetimibe as a potential novel therapeutic for idiopathic pulmonary fibrosis.

Prognostic significance of tumour budding in noncolorectal gastrointestinal tract and pancreatobiliary tract: a systematic review and meta-analysis.

Tumour budding shows promise as a prognostic factor in various cancers, but its widespread application is hindered by the lack of large, validated studies and standardized criteria. This meta-analysis aims to review and examine the prognostic role of tumour budding specifically in noncolorectal gastrointestinal and pancreatobiliary tract cancers, broadening our perspective on its clinical relevance. The literature review was conducted through PubMed, Embase, and Web of Science from inception till 20 February 2023. Pooled odds ratio (OR) and hazard ratio (HR) with 95% confidence interval (CI) were calculated to assess the relation between tumour budding and clinicopathologic features, as well as overall survival. Each study was evaluated using the Newcastle-Ottawa Scale and both heterogeneity and publication bias were analysed. In this meta-analysis of 57 studies across various cancer types, multivariate HR revealed worse overall survival in oesophageal squamous cell carcinoma (HR 3.34 [95% CI 2.21-5.04]), gastric adenocarcinoma (2.03 [1.38-2.99]), pancreatic ductal adenocarcinoma (2.56 [2.02-3.25]), and biliary tract adenocarcinoma (3.11 [2.46-3.93]) with high-grade tumour budding. Additionally, high-grade tumour budding consistently correlated with adverse clinicopathological features, including lymph node metastasis, lymphovascular invasion, and distant metastasis without any observed inverse association. High heterogeneity was noted. Our study suggests that tumour budding is a valuable prognostic marker in various cancers. Nonetheless, standardized criteria tailored to specific organ types are necessary to enhance its clinical utility.

The oxidative phosphorylation inhibitor IM156 suppresses B-cell activation by regulating mitochondrial membrane potential and contributes to the mitigation of systemic lupus erythematosus.

Current treatment strategies for autoimmune diseases may not sufficiently control aberrant metabolism in B-cells. To address this concern, we investigated a biguanide derivative, IM156, as a potential regulator for B-cell metabolism in vitro and in vivo on overactive B-cells stimulated by the pro-inflammatory receptor TLR-9 agonist CpG oligodeoxynucleotide, a mimic of viral/bacterial DNA. Using RNA sequencing, we analyzed the B-cell transcriptome expression, identifying the major molecular pathways affected by IM156 in vivo. We also evaluated the anti-inflammatory effects of IM156 in lupus-prone NZB/W F1 mice. CD19+B-cells exhibited higher mitochondrial mass and mitochondrial membrane potential compared to T-cells and were more susceptible to IM156-mediated oxidative phosphorylation inhibition. In vivo, IM156 inhibited mitochondrial oxidative phosphorylation, cell cycle progression, plasmablast differentiation, and activation marker levels in CpG oligodeoxynucleotide-stimulated mouse spleen B-cells. Interestingly, IM156 treatment significantly increased overall survival, reduced glomerulonephritis and inhibited B-cell activation in the NZB/W F1 mice. Thus, our data indicated that IM156 suppressed the mitochondrial membrane potentials of activated B-cells in mice, contributing to the mitigation of lupus activity. Hence, IM156 may represent a therapeutic alternative for autoimmune disease mediated by B-cell hyperactivity.

Macrophage transcription factor TonEBP promotes systemic lupus erythematosus and kidney injury via damage-induced signaling pathways.

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by autoreactive B cells and dysregulation of many other types of immune cells including myeloid cells. Lupus nephritis (LN) is a common target organ manifestations of SLE. Tonicity-responsive enhancer-binding protein (TonEBP, also known as nuclear factor of activated T-cells 5 (NFAT5)), was initially identified as a central regulator of cellular responses to hypertonic stress and is a pleiotropic stress protein involved in a variety of immunometabolic diseases. To explore the role of TonEBP, we examined kidney biopsy samples from patients with LN. Kidney TonEBP expression was found to be elevated in these patients compared to control patients - in both kidney cells and infiltrating immune cells. Kidney TonEBP mRNA was elevated in LN and correlated with mRNAs encoding inflammatory cytokines and the degree of proteinuria. In a pristane-induced SLE model in mice, myeloid TonEBP deficiency blocked the development of SLE and LN. In macrophages, engagement of various toll-like receptors (TLRs) that respond to damage-associated molecular patterns induced TonEBP expression via stimulation of its promoter. Intracellular signaling downstream of the TLRs was dependent on TonEBP. Therefore, TonEBP can act as a transcriptional cofactor for NF-κB, and activated mTOR-IRF3/7 via protein-protein interactions. Additionally, TonEBP-deficient macrophages displayed elevated efferocytosis and animals with myeloid deficiency of TonEBP showed reduced Th1 and Th17 differentiation, consistent with macrophages defective in TLR signaling. Thus, our data show that myeloid TonEBP may be an attractive therapeutic target for SLE and LN.

Nephrin expression in human epidermal keratinocytes and its implication in poor wound closure.

Nephrin is a type-1 transmembrane protein and a component of the slit diaphragm renal-filtration barrier. It has several functions in actin remodeling and cell-cell adhesion. Nephrin is principally located in the kidney glomerulus, but several studies have reported that nephrin is found in the pancreas, brain, and placenta. However, nephrin expression and its role in human skin have not yet been reported. First, using single-cell RNA sequencing, immunohistochemistry, and immuno-electron microscopy, nephrin expression was confirmed in human-skin epidermal keratinocytes. Nephrin expression colocalized with the expression of zonula occludens-1 in keratinocytes and was closely related to keratinocyte cell density, proliferation, and migration. High glucose treatment decreased nephrin expression and compromised keratinocyte cell migration without yes-associated protein nuclear entry. This reduced cell migration under high glucose conditions was improved in nephrin-overexpressing keratinocytes. Nephrin was highly expressed on the margins of re-epithelized epidermis based on in vivo mice and ex vivo human skin wound models. The results demonstrate that nephrin is expressed in human-skin keratinocytes and functions in cell adhesion, proliferation, and migration. In conclusion, this study suggests that nephrin may have a variety of physiological roles in human skin.

The calcium-sensing receptor stabilizes podocyte function in proteinuric humans and mice.

Calcimimetic agents allosterically increase the calcium ion sensitivity of the calcium-sensing receptor (CaSR), which is expressed in the tubular system and to a lesser extent in podocytes. Activation of this receptor can reduce glomerular proteinuria and structural damage in proteinuric animal models. However, the precise role of the podocyte CaSR remains unclear. Here, a CaSR knockdown in cultured murine podocytes and a podocyte-specific CaSR knockout in BALB/c mice were generated to study its role in proteinuria and kidney function. Podocyte CaSR knockdown abolished the calcimimetic R-568 mediated calcium ion-influx, disrupted the actin cytoskeleton, and reduced cellular attachment and migration velocity. Adriamycin-induced proteinuria enhanced glomerular CaSR expression in wild-type mice. Albuminuria, podocyte foot process effacement, podocyte loss and glomerular sclerosis were significantly more pronounced in adriamycin-treated podocyte-specific CaSR knockout mice compared to wild-type littermates. Co-treatment of wild-type mice with adriamycin and the calcimimetic cinacalcet reduced proteinuria in wild-type, but not in podocyte-specific CaSR knockout mice. Additionally, four children with nephrotic syndrome, whose parents objected to glucocorticoid therapy, were treated with cinacalcet for one to 33 days. Proteinuria declined transiently by up to 96%, serum albumin increased, and edema resolved. Thus, activation of podocyte CaSR regulates key podocyte functions in vitro and reduced toxin-induced proteinuria and glomerular damage in mice. Hence, our findings suggest a potential novel role of CaSR signaling in control of glomerular disease.

Artificial Intelligence for Predicting Microsatellite Instability Based on Tumor Histomorphology: A Systematic Review.

Microsatellite instability (MSI)/defective DNA mismatch repair (dMMR) is receiving more attention as a biomarker for eligibility for immune checkpoint inhibitors in advanced diseases. However, due to high costs and resource limitations, MSI/dMMR testing is not widely performed. Some attempts are in progress to predict MSI/dMMR status through histomorphological features on H&E slides using artificial intelligence (AI) technology. In this study, the potential predictive role of this new methodology was reviewed through a systematic review. Studies up to September 2021 were searched through PubMed and Embase database searches. The design and results of each study were summarized, and the risk of bias for each study was evaluated. For colorectal cancer, AI-based systems showed excellent performance with the highest standard of 0.972; for gastric and endometrial cancers they showed a relatively low but satisfactory performance, with the highest standard of 0.81 and 0.82, respectively. However, analyzing the risk of bias, most studies were evaluated at high-risk. AI-based systems showed a high potential in predicting the MSI/dMMR status of different cancer types, and particularly of colorectal cancers. Therefore, a confirmation test should be required only for the results that are positive in the AI test.

Glomerular subepithelial microparticles - a footprint for podocyte injury.

The aim of this study was to clarify the nature and clinical significance of glomerular subepithelial microparticles (SMPs), located between the basal surface of the podocytes and the glomerular basement membrane. Ultrastructural morphology of 79 renal biopsy samples (obtained from 25 native and 54 transplanted kidneys), showing SMPs in the last 3 years, was reevaluated with regard to the podocyte changes and clinical condition of the patients. One hundred and nine SMPs were identified, with 32.9% of the samples having two or more per glomerulus. Overall, they were most frequently located in the open capillary loops (55%). However, in the native kidney samples with mesangial deposits, 64.3% of SMPs were present in the mesangium-bound areas. Each vesicle ranged from 46.9 to 87.1 nm, and vesicles were admixed with curved strands in larger SMPs. Diffuse effacement of the foot processes and condensation of the actin filaments were present in 56.0% and 62.4% of the samples, respectively. SMPs were associated with hematuria, proteinuria of ≥ 1 gm, and immune complex deposition in the patients with native kidneys, whereas they were related to hyperglycemia and elevated serum creatinine levels in the patients with renal allografts. Patients with native and transplanted kidneys most commonly presented with IgA nephropathy and allograft rejection, respectively. Finding SMPs in the renal biopsy samples is not rare and they may act as a footprint of podocyte injury caused by diverse etiologies. Considering their size, podocyte exosomes could be a possible source of SMPs.

De Novo Genotypic Heterogeneity in the UL56 Region in Cytomegalovirus-Infected Tissues: Implications for Primary Letermovir Resistance.

BACKGROUND: Letermovir, an inhibitor of unique long (UL)56-encoded cytomegalovirus (CMV)-terminase, shows prophylactic effects with low-grade adverse events in hematopoietic stem cell transplant recipients. Despite few case reports on acquired letermovir resistance, the frequency of de novo amino acid (A.A.) changes encoded by UL56 in CMV-infected tissues is unclear. METHODS: We analyzed CMV UL56 sequences between the conserved region IV and variable region I in 175 formalin-fixed, paraffin-embedded tissues obtained from 147 patients showing positive CMV immunochemical staining between November 2012 and October 2016. Nucleotides 552-1330 of the open reading frame of UL56 were amplified with 5 primers and sequenced by a dideoxy fluorescence-based cycle. RESULTS: Six (3.4%) tissues from 4 (2.7%) patients harbored A.A. substitutions. There were no known potent resistant mutations. However, we found C325Y in 2 tissues from 1 patient, along with other mutations. Four novel A.A. changes, which have not been observed in previous in vitro experiments, were identified (T244I, S301T, G312V, and M434I). Most (9 of 11, 81.8%) of the A.A. changes occurred between the codons 301 and 325 present between the conserved regions V and VI. CONCLUSIONS: The treatment difficulties associated with letermovir resistance in a clinical setting need to be verified before its widespread use.

Predictive value of mesangial C3 and C4d deposition in IgA nephropathy.

We aimed to determine the relative contribution of each complement (C3 and C4d) deposition to the progression of IgA nephropathy (IgAN). We enrolled a total of 380 patients with biopsy-confirmed IgAN. Mesangial deposition of C3(<2+ vs. ≥2+) and C4d(positive vs. negative) was evaluated by immunofluorescence staining and immunohistochemistry, respectively. Study endpoint was the composite of a 30% decline in eGFR or ESRD. The risk of reaching the primary outcome was significantly higher in patients having C3 ≥ 2+ and C4d(+) than in corresponding counterparts. Adding C3 deposition to clinical data acquired at kidney biopsy modestly increased the area under the receiver-operating characteristic curve, net reclassification improvement, and integrated discrimination improvement (IDI); adding C4d increased IDI only. In conclusion, mesangial C3 and C4d deposition was an independent risk factor for progression of IgAN. C3 showed better predictability than C4d, suggesting that lectin pathway alone has limited clinical prognostic value.

New staining method using methionyl-tRNA synthetase 1 antibody for brushing cytology of bile duct cancer.

BACKGROUND AND AIMS: Identifying malignant biliary strictures using endobiliary brushing cytology specimens is important for treatment decision-making and prognosis prediction. The sensitivity of brushing cytology specimens based on Papanicolaou (Pap) staining is low, which hampers accurate diagnosis of indeterminate strictures. Here, we assessed the diagnostic value of immunohistochemical (IHC) and immunofluorescence (IF) staining for methionyl-tRNA synthetase 1 (MARS1). METHODS: Endobiliary brushing cytology specimens were obtained during ERCP from 80 patients with an extrahepatic biliary stricture. Pap and MARS1 IF staining were performed on liquid-based cytology slides derived from these specimens. Sections of bile duct adenocarcinoma and normal bile duct tissue were obtained from 45 patients who underwent surgery for malignant biliary stricture, and MARS1 levels were evaluated by IHC staining. RESULTS: MARS1 IF staining was applied to brushing cytology specimens, and the results showed strong signals in malignant biliary structures but not in the negative for malignancy specimens. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 70.4%, 96.2%, 97.4%, 56.8%, and 78.8%, respectively, for conventional Pap staining and 98.1%, 96.1%, 98.1%, 96.2%, and 97.5%, respectively, for MARS1 IF (P < .0001). When IHC staining was used, MARS1 was detected in 45 bile duct adenocarcinoma sections but not in 15 normal bile duct sections. Moreover, MARS1 mRNA and protein levels were significantly higher in bile duct adenocarcinoma sections according to polymerase chain reaction and Western blot, respectively. CONCLUSIONS: The high sensitivity and accuracy of MARS1 IF staining enabled detection of malignancy in patients with indeterminate biliary stricture. Further prospective studies are needed to validate our findings. (Clinical trial registration number: KCT 0003285.).

Relationship between complement deposition and the Oxford classification score and their combined effects on renal outcome in immunoglobulin A nephropathy.

BACKGROUND: Complement activation has been highlighted in immunoglobulin (Ig) A nephropathy pathogenesis. However, whether the complement system can affect the downstream phenotype of IgA nephropathy remains unknown. Herein, we investigated the association of mesangial C3 deposition with the Oxford classification and their joint effects on worsening kidney function. METHODS: We investigated 453 patients with biopsy-proven IgA nephropathy. C3 deposition was defined as an immunofluorescence intensity of C3 ≥2+ within the mesangium. The subjects were classified according to the combination of C3 deposition and Oxford classification lesions. The primary endpoint was a composite of ≥30% decline in the estimated glomerular filtration rate or an increase in proteinuria ≥3.5 g/g during follow-up. RESULTS: Among the Oxford classification lesions, mesangial hypercellularity (M1), segmental glomerulosclerosis (S1) and tubulointerstitial fibrosis (T1-2) and crescentic lesion significantly correlated with C3 deposition. During a median follow-up of 33.0 months, the primary endpoint occurred more in patients with M1, S1, T1-2 and mesangial C3 deposition than in those without. In individual multivariable-adjusted Cox analyses, the presence of M1, S1, T1-2 and C3 deposition was significantly associated with higher risk of reaching primary endpoint. In the combined analyses of C3 deposition and the Oxford classification lesions, the hazard ratios for the composite outcome were significantly higher in the presence of C3/M1, C3/S1 and C3/crescent than in the presence of each lesion alone. CONCLUSIONS: Complement deposition can strengthen the significance of the Oxford classification, and the presence of both components portends a poorer prognosis in IgA nephropathy.

Renal elasticity and perfusion changes associated with fibrosis on ultrasonography in a rabbit model of obstructive uropathy.

PURPOSE: To evaluate elasticity and perfusion change associated with fibrosis in a rabbit model of unilateral ureter obstruction using shear wave elastography (SWE) and contrast-enhanced ultrasonography (CEUS). METHODS: Complete unilateral ureter obstruction by ligation was performed in the left kidney of 15 rabbits. Renal elasticity on SWE and perfusion change on CEUS at the renal cortex were measured before and after the operation. Histopathological renal fibrosis was quantified by the stained area ratio with Masson trichrome and Picrosirius red using ImageJ analysis. Renal elasticity and perfusion values were compared by the Mann-Whitney U test and Proc Mixed as a function of time. Spearman's correlation was used to analyze differences between imaging values and fibrosis. RESULTS: The duration of imaging follow-up was up to 49 days, with interval imaging performed 1-3 times. Renal elasticity values were higher in obstructed kidneys compared to contralateral kidneys (31.0 kPa vs 16.4 kPa, p < 0.001) and increased according to postoperative time (0.46 kPa/day). With respect to renal fibrosis, SWE values were positively correlated with Masson trichrome (ρ = 0.651, p < 0.001) and Picrosirius red (ρ = 0.514, p = 0.007). Among CEUS parameters, mean transit time was negatively correlated with renal fibrosis by Masson trichrome (ρ = - 0.639, p = 0.001) and Picrosirius red (ρ = - 0.625, p = 0.001). Rise time and time to peak were positively correlated with renal fibrosis. CONCLUSION: Obstructive uropathy resulted in changes to both renal elasticity and perfusion. Renal fibrosis was moderately associated with increased renal cortical stiffness and both delayed and decreased cortical perfusion. KEY POINTS: • Obstructive uropathy causes changes in elasticity and perfusion in a rabbit model. • Renal fibrosis from obstructive uropathy increases renal cortical stiffness, and both delay and decrease cortical perfusion.

Biobanking for glomerular diseases: a study design and protocol for KOrea Renal biobank NEtwoRk System TOward NExt-generation analysis (KORNERSTONE).

BACKGROUNDS: Glomerular diseases, a set of debilitating and complex disease entities, are related to mortality and morbidity. To gain insight into pathophysiology and novel treatment targets of glomerular disease, various types of biospecimens linked to deep clinical phenotyping including clinical information, digital pathology, and well-defined outcomes are required. We provide the rationale and design of the KOrea Renal biobank NEtwoRk System TOward Next-generation analysis (KORNERSTONE). METHODS: The KORNERSTONE, which has been initiated by Korea Centres for Disease Control and Prevention, is designed as a multi-centre, prospective cohort study and biobank for glomerular diseases. Clinical data, questionnaires will be collected at the time of kidney biopsy and subsequently every 1 year after kidney biopsy. All of the clinical data will be extracted from the electrical health record and automatically uploaded to the web-based database. High-quality digital pathologies are obtained and connected in the database. Various types of biospecimens are collected at baseline and during follow-up: serum, urine, buffy coat, stool, glomerular complementary DNA (cDNA), tubulointerstitial cDNA. All data and biospecimens are processed and stored in a standardised manner. The primary outcomes are mortality and end-stage renal disease. The secondary outcomes will be deterioration renal function, remission of proteinuria, cardiovascular events and quality of life. DISCUSSION: Ethical approval has been obtained from the institutional review board of each participating centre and ethics oversight committee. The KORNERSTONE is designed to deliver pioneer insights into glomerular diseases. The study design allows comprehensive, integrated and high-quality data collection on baseline laboratory findings, clinical outcomes including administrative data and digital pathologic images. This may provide various biospecimens and information to many researchers, establish the rationale for future more individualised treatment strategies for glomerular diseases. TRIAL REGISTRATION: NCT03929887 .

The Association of Glomerular Glucocorticoid Receptor Expression with Responsiveness to Corticosteroid Treatment in IgA Nephropathy.

BACKGROUND: Corticosteroids can be used to treat IgA nephropathy (IgAN). However, responsiveness to these drugs is highly variable and unpredictable. Corticosteroids act by binding glucocorticoid receptors (GCRs). Therefore, we evaluated the association between GCR expression and responsiveness to corticosteroid treatment in IgAN. METHODS: We screened 78 IgAN patients receiving steroid treatment between 2010 and 2016. Of these, 33 patients met study inclusion criteria. Glomerular GCR expression was assessed by real-time polymerase chain reaction. Complete remission (CR) and partial remission (PR) were defined as a spot urine protein-to-creatinine ratio (UPCR) of <0.3 g/g and a ≥50% reduction of proteinuria from baseline along with UPCR of ≥0.3 g/g, respectively. Disease progression was defined as a ≥30% decrease in estimated glomerular filtration rate (eGFR) from baseline. RESULTS: The mean age of study patients was 43.9 ± 11.6 years (25 males and 8 females). All 33 patients responded to steroid treatment; CR and PR occurred in 14 (42.4%) and 18 (54.5%) patients, respectively. One patient did not achieve PR, but proteinuria was decreased after treatment. There were no significant differences in baseline eGFR and proteinuria between CR and non-CR groups. GCR mRNA expression was significantly higher in the CR group compared to that in the non-CR group. Immunohistochemistry confirmed higher GCR expression in the CR group. During a median follow-up of 20.6 months, 1 (7.1%) patient in the CR group had disease progression, as compared to 8 (42.1%) patients in non-CR group (p = 0.03). CONCLUSION: This study suggests that responsiveness to corticosteroid may differ depending on the degree of glomerular GCR expression in IgAN.

Selective deletion of hepatocyte platelet-derived growth factor receptor α and development of liver fibrosis in mice.

BACKGROUND: Platelet-derived growth factor receptor α (PDGFRα) expression is increased in activated hepatic stellate cells (HSCs) in cirrhotic liver, while normal hepatocytes express PDGFRα at a negligible level. However, cancerous hepatocytes may show upregulation of PDGFRα, and hepatocellular carcinoma is preceded by chronic liver injury. The role of PDGFRα in non-cancerous hepatocytes and liver fibrosis is unclear. We hypothesized that upon liver injury, PDGFRα in insulted hepatocytes contributes to liver fibrosis by facilitating intercellular crosstalk between hepatocytes and HSCs. METHODS: Hepatocytes were isolated from normal and thioacetamide (TAA)-induced cirrhotic livers for assessment of PDGFRα expression. Conditional knock-out (KO) C57BL/6 mice, in which PDGFRα was selectively deleted in hepatocytes, were generated. Liver fibrosis was induced by injecting TAA for 8 weeks. Hep3B cells were transfected with a small interfering RNA (siRNA) (PDGFRα or control) and co-cultured with LX2 cells. RESULTS: PDGFRα expression was increased in hepatocytes from fibrotic livers compared to normal livers. Conditional PDGFRα KO mice had attenuated TAA-induced liver fibrosis with decreased HSC activation and proliferation. Immunoblot analyses revealed decreased expression of phospho-p44/42 MAPK in TAA-treated KO mice; these mice also showed almost complete suppression of the upregulation of mouse double minute 2. Although KO mice exhibited increased expression of transforming growth factor (TGF)-ß and Smad2/3, this was compensated for by increased expression of inhibitory Smad7. LX2 cells co-cultured with PDGFRα siRNA-infected Hep3B cells showed decreased PDGFRα, α smooth muscle actin, collagen α1(I), TGFß, and Smad2/3 expression. LX2/PDGFRα-deleted hepatocyte co-culture medium showed decreased PDGF-BB and PDGF-CC levels. CONCLUSIONS: Deletion of PDGFRα in hepatocytes attenuated the upregulation of PDGFRα in HSCs after TAA treatment, resulting in decreased liver fibrosis and HSC activation. This suggests that in the event of chronic liver injury, PDGFRα in hepatocytes plays an important role in liver fibrosis by affecting PDGFRα expression in HSCs.

Tubulointerstitial fibrosis can sensitize the kidney to subsequent glomerular injury.

Chronic glomerular injury is associated with eventual development of tubulointerstitial fibrosis. Here we aimed to assess whether, and how, mild chronic tubulointerstitial injury affects glomeruli. For this, we generated mice expressing different toxin receptors, one on their proximal tubular epithelial cells (diphtheria toxin receptor [DTR]) and the other only on podocytes (human CD25 [IL-2R] driven by the nephrin promoter [Nep25]), allowing serial induction of tubule-specific and glomerular (podocyte)-specific injury, respectively. Six weeks after diphtheria toxin injection, mild interstitial fibrosis was found in Nep25+/DTR+, but not in Nep25+/DTR- mice. However, atubular glomeruli and neuronal nitric oxide synthase, a mediator of tubuloglomerular feedback, were higher in Nep25+/DTR+ than in DTR- mice and these atubular glomeruli had less podocyte density as assessed by WT-1 biomarker expression. Peritubular capillary density, hypoxia-inducible factor-1 and -2, and cyclooxygenase 2 expression were similar at week six in the two groups. At week seven, all mice were given the immunotoxin LMB-2, which binds to CD25 to induce podocyte injury. Ten days later, proteinuria, podocyte injury, and glomerulosclerosis were more severe in Nep25+/DTR+ than Nep25+/DTR- mice with more severe sclerosis in the tubule-connected glomeruli. This supports the concept that even mild preexisting tubulointerstitial injury sensitizes glomeruli to subsequent podocyte-specific injury. Thus, increased atubular glomeruli and abnormal tubuloglomerular feedback significantly contribute to the crosstalk between the tubulointerstitium and glomeruli.

De novo low-dose sirolimus versus mycophenolate mofetil in combination with extended-release tacrolimus in kidney transplant recipients: a multicentre, open-label, randomized, controlled, non-inferiority trial.

BACKGROUND: Most of the previous studies reported that tacrolimus (TAC) with sirolimus (SRL) was associated with worse post-transplant outcomes in kidney transplantation, compared with TAC with mycophenolate mofetil (MMF). These might be attributable to high-dose SRL. However, outcomes using low-dose SRL with TAC for kidney transplantation are uncertain. The aim of this study was to assess the efficacy and safety of low-dose SRL with extended-release tacrolimus (ER-TAC) versus MMF with ER-TAC. METHODS: We randomly assigned 158 renal transplant patients to receive low-dose SRL or MMF in combination with ER-TAC and corticosteroid. The primary endpoint was the composite efficacy failure rate, including biopsy-proven acute rejection (BPAR), graft loss, death or loss to follow-up, within 12 months post-transplantation. This trial is registered with ClinicalTrial.gov (number NCT01680952). RESULTS: The efficacy failure rate was 6.6% in the low-dose SRL group and 13.3% in the MMF group in the intention-to-treat population (absolute difference, 6.8%; 95% confidence interval, -2.8% to 16.3%). The incidence of BPAR within 12 months post-transplantation was 5.3% in the low-dose SRL group and 13.3% in the MMF group (P = 0.09). The mean estimated glomerular filtration rate at 12 months post-transplantation was 53.2 mL/min/1.73 m2 in the low-dose SRL group and 52.4 mL/min/1.73 m2 in the MMF group (P = 0.76). The incidences of adverse events and serious adverse events were similar between groups. CONCLUSION: Low-dose SRL with ER-TAC was not inferior to MMF with ER-TAC with respect to efficacy and safety. When used for immunosuppression in kidney transplantation, low-dose SRL with ER-TAC can effectively prevent acute rejection and preserve renal function.

Glomerular IgG deposition predicts renal outcome in patients with IgA nephropathy.

Glomerular IgG deposition is frequently observed in patients with IgA nephropathy. However, the association between glomerular IgG deposition and progression of IgA nephropathy is uncertain. Six hundred and twenty-seven patients with biopsy-proven IgA nephropathy were recruited. Histological variables of the Oxford classification (Oxford-MEST) and the presence of glomerular IgG deposits were assessed. Renal progression defined as end-stage renal disease or 50% reduction in estimated glomerular filtration rate was analyzed using Kaplan-Meier methods and Cox regression analysis. Of the study population, 200 patients (31.9%) had glomerular IgG deposition on immunofluorescence staining. During a mean follow-up of 56.8±37.5 months, the rate of renal progression was significantly higher in the IgA nephropathy patients with glomerular IgG deposition compared with the IgA nephropathy patients without glomerular IgG deposition (39.8 vs 12.3 per 1000 patient-years; P<0.001). Of patients with IgG deposition, 178 (28.3%), 20 (3.2%), and 2 (0.3%) patients had mild, moderate, and marked glomerular IgG deposits, receptively. Kaplan-Meier analysis revealed that cumulative renal survival was significantly lower in IgA nephropathy patients with the higher intensity of glomerular IgG deposits (P<0.001). In addition, Cox regression analysis revealed that moderate and marked glomerular IgG deposits significantly predicted renal outcome independent of Oxford-MEST and clinical variables (HR, 2.97; 95% CI, 1.01-8.77; P=0.04). This study showed that that glomerular IgG deposition was independently associated with poor renal outcome in patient with IgA nephropathy.