Multifidus lesions: A possible pathological component in patients with low back pain after posterior lumbar surgery

There are few histological studies on multifidus after lumbar surgery, and it is not clear whether multifidus changes affect the clinical outcome after lumbar surgery. The aim of this study was to investigate the relationship between multifidus changes and clinical outcomes after lumbar surgery. Patients underwent internal fixation removal after lumbar posterior surgery were enrolled. Patients were divided into a low back pain (LBP) group (n = 15) and a non-low back pain (non-LBP) group (n = 10).The Oswestry disability index (ODI) and visual analog scale (VAS) were completed. 18 patients with lumbar fracture surgery were included as the control group. Multifidus morphological changes were observed by hematoxylin and eosin and Masson staining. The expression of TGF-β1 was observed by immunohistochemistry, immunofluorescence and Western blot. The cross-sectional area (CSA) of the multifidus in the non-LBP group and the control group were greater than those in the LBP group. TGF-β1 expression and gray value ratio in the non-LBP group and the control group were lower than those in the LBP group. The multifidus CSA and TGF-β1 expression in multifidus were strongly correlated with ODI and VAS. Patients with LBP after posterior lumbar surgery suffered from atrophy and fibrosis lesions in the multifidus, and the degree of multifidus lesions was closely related to dysfunction and pain, which might be one of the causes of LBP after posterior lumbar surgery.

Preclinical Investigations on Anti-fibrotic Potential of Long-Term Oral Therapy of Sodium Astragalosidate in Animal Models of Cardiac and Renal Fibrosis

In traditional Chinese medicine, Radix Astragali has played a vital role in treating progressive fibrotic diseases. One of its main active components, astragaloside IV, is a promising anti-fibrotic treatment despite its extremely low bioavailability. Our study aimed to optimize sodium astragalosidate (SA) by salt formation to improve solubility and oral absorption for anti-fibrotic therapy in vivo. Isoproterenol-induced myocardial fibrosis rat models and obese BKS-db mice presenting diabetic kidney fibrosis were used in this study. Daily oral administration of SA (20 mg/kg) for 14 days ameliorated cardiac fibrosis by reducing collagen accumulation and fibrosis-related inflammatory signals, including TNF-α, IL-1β, and IL-6. In db/db mice, SA (5,10, and 20 mg/kg per day for 8 weeks) dose-dependently alleviated lipid metabolism impairment and renal dysfunction when administered orally. Furthermore, Western blot and immunohistochemistry analyses demonstrated that SA treatment inhibited renal fibrosis by suppressing TGF-β1/Smads signaling. Taken together, our findings provide the oral-route medication availability of SA, which thus might offer a novel lead compound in preclinical trial-enabling studies for developing a long-term therapy to treat and prevent fibrosis.

An In-Vivo Study of Effects of Platelet-Rich Plasma on Transforming Growth Factor-β1 and Matrix Metalloprotein 9 Expression in Traumatic Ulcers with Diabetes Mellitus

OBJECTIVE

 Diabetes mellitus is not only characterized by alterations in the wound healing process but also during oral ulcer healing. The platelet-rich plasma (PRP) can be used to stimulate the healing process. This study was performed to analyze the effect of PRP on traumatic ulcers with diabetes mellitus in an animal model by analyzing the expression of transforming growth factor β1 (TGF-β1) and matrix metalloprotein 9 (MMP-9).

MATERIALS AND METHODS

 The diabetes mellitus model was developed using streptozotocin that was administrated to Rattus novergicus. The traumatic ulcer model was obtained by placing a heated tip of a ball burnisher for 5 seconds on the lower mucosa labial. Then, the traumatic ulcer was treated with PRP for 3, 5, and 7 days. The expression of TGF-β1 and MMP-9 was analyzed with indirect immunohistochemistry, and differences between each marker were analyzed with statistical analysis.

RESULTS

 All animals showed clinical oral ulceration as a yellow base during the experiment. The application of PRP showed a higher level of TGF-β1 expression than the controls for 3, 5, and 7 days (p < 0.05). In contrast, the MMP-9 expression was lower than the control for 5 and 7 days (p < 0.05).

CONCLUSION

 The PRP affected traumatic ulcers with diabetes mellitus by promoting healing through TGF-β1 expression and suppressing the MMP-9 expression. This material can serve to develop a promising topical therapy for traumatic ulcers, especially with an underlying disease such as diabetes mellitus.

Network pharmacology-based strategy for predicting therapy targets of Ecliptae Herba on breast cancer

Breast cancer is a prevalent malignancy affecting women globally, characterized by significant morbidity and mortality rates. Ecliptae Herba is a traditional herbal medicine commonly used in clinical practice, has recently been found to possess antitumor properties. In order to explore the underlying material basis and molecular mechanisms responsible for the anti-breast cancer effects of Ecliptae Herba, we used network pharmacology and experimental verification. UPLC-MS/MS was utilized to identify compounds present in Ecliptae Herba. The active components of Ecliptae Herba and its breast cancer targets were screened using public databases. Hub genes were identified using the STRING and Metascape database. The R software was utilized for visual analysis of GO and KEGG pathways. The affinity of the hub targets for the active ingredients was assessed by molecular docking analysis, which was verified by experimental assessment. A total of 178 targets were obtained from the 10 active components of Ecliptae Herba, while 3431 targets associated with breast cancer were screened. There were 144 intersecting targets between the components and the disease. Targets with a higher degree, namely EGFR and TGFB1, were identified through the hub subnetwork of PPI. GO and KEGG analyses revealed that Ecliptae Herba plays an important role in multiple cancer therapeutic mechanisms. Moreover, molecular docking results showed that the core components had good binding affinity with key targets. Finally, it was confirmed that TGF-β1 might be a potential crucial target of Ecliptae Herba in the treatment of breast cancer by cytological experiments, and the TGF-β1/Smad signaling pathway might be an important pathway for Ecliptae Herba to exert its therapeutic effects. This study elucidated the active ingredients, key targets, and molecular mechanisms of Ecliptae Herba in the treatment of breast cancer, providing a scientific foundation and therapeutic mechanism for the prevention and treatment of breast cancer with Traditional Chinese medicine.

Topical Losartan Decreases Myofibroblast Generation But Not Corneal Opacity After Surface Blast-Simulating Irregular PTK in Rabbits

Purpose

To evaluate the efficacy of topical losartan after blast injury-simulating irregular phototherapeutic keratectomy (PTK) in rabbits.

Methods

Twelve NZW rabbits underwent 100 pulse 6.5 mm diameter PTK over a metal screen to generate severe surface irregularity and inhibit epithelial basement membrane regeneration. Corneas were treated with 0.8 mg/mL losartan in balanced salt solution (BSS) or BSS 50 µL six times per day for six weeks after PTK. All corneas had slit lamp photography, with and without 1% fluorescein at two, four, and six weeks after PTK, and were analyzed using immunohistochemistry for the myofibroblast marker α-smooth muscle actin (α-SMA), keratocyte marker keratocan, mesenchymal cell marker vimentin, transforming growth factor (TGF)-β1, and collagen type IV.

Results

Topical 0.8 mg/mL losartan six times a day significantly decreased anterior stromal α-SMA intensity units compared to BSS at six weeks after anterior stromal irregularity-inducing screened PTK (P = 0.009). Central corneal opacity, however, was not significantly different between the two groups. Keratocan, vimentin, TGF-β1, or collagen type IV levels in the anterior stroma were not significantly different between the two groups.

Conclusions

Topical losartan effectively decreased myofibroblast generation after surface blast simulation irregular PTK. However, these results suggest initial masking-smoothing PTK, along with adjuvant topical losartan therapy, may be needed to decrease corneal stromal opacity after traumatic injuries that produce severe surface irregularity.

Translational Relevance

Topical losartan decreased scar-producing stromal myofibroblasts after irregular PTK over a metal screen but early smoothing of irregularity would also likely be needed to significantly decrease corneal opacity.

Study of the Urinary TGF-β1 Profile in Diabetic Nephropathy: A Single-Center Experience From India

Background Diabetic nephropathy is one of the important causes of end-stage kidney disease (ESKD). Of the various cytokines playing a role in the pathogenesis of diabetic nephropathy, transforming growth factor beta-1 (TGF-β1) is an important one. Its major role is to mediate extracellular matrix deposition. Increased renal expression of TGF-β1 is found in diabetic nephropathy and its urinary excretion can serve as a useful marker of outcomes. Material and methods A prospective observational study was conducted, which included 10 cases of diabetic nephropathy in group A with age ≥ 18 years and a urinary protein creatinine ratio (UPCR) value of > 0.5 mg/mg and 10 healthy controls in group B. Patients with active urinary tract infection, chronic kidney disease (CKD) stage Vd patients on maintenance hemodialysis, and renal transplant recipients were excluded from the study. Urinary TGF-β1 level estimation in a 24-hour urine sample, 24-hour urine protein, and other baseline laboratory investigations were done. Results In diabetic nephropathy cases (group A), the mean value of urinary TGF-β1 levels was 88.33± 12.44 ng/24 hours. In the control group (group B), the mean value of urinary TGF-β1 was 29.03 ± 3.23 ng/24 hours. Urinary TGF-β1 levels were significantly elevated in group A as compared to group B (p<0.001). There was no significant correlation between urinary TGF-β1 levels and estimated glomerular filtration rate (eGFR) (r=0.376, p= 0.285) as well as the urinary TGF-β1 levels and 24-hour urine protein levels (p = 0.334, r = 0.341) in diabetic nephropathy cases. Glycosylated hemoglobin (HbA1c) levels didn't correlate with the urinary TGF-β1 levels (r = -0.265, p = 0.46). Conclusion The urinary TGF-β1 levels were significantly elevated in diabetic nephropathy patients as compared to healthy controls. There was no significant correlation between urinary TGF-β1 levels and proteinuria, eGFR, or HbA1c levels in diabetic nephropathy patients.

An Evaluation of T-Regulatory Cells and Inflammatory Cytokines in Preeclampsia

Background Preeclampsia (PE) is a prenatal hypertension condition with unknown aetiology which is one of the leading causes of maternal morbidity and mortality, premature delivery, and foetal and neonatal mortality. T-regulatory cells (T-regs) are the specific subsets of T-lymphocytes that play a key role in the mechanisms of maternal-foetal tolerance, contributing to an effective immunological role in protecting the allogenic foetus during pregnancy and preventing pregnancy-related complications. This study evaluated the T-regs in PE and correlated the T-regs with inflammatory markers in the pathophysiology and for early diagnosis of PE. Methods After clearance from Institutional Ethics Committee, the participants were recruited from the Department of Obstetrics and Gynaecology. Three study groups were included a) normal reproductive age group women b) normal pregnant women c) PE pregnant women. 5 ml of venous blood was collected from each participant. Biochemical and haematological parameters estimation was done in Hospital's central laboratory. T-regs (CD4, CD25, FOXP3) were assessed using a flow-cytometer, and inflammatory markers (TGF-β1, IL-6, hsCRP) were assessed by ELISA and Beckman Coulter autoanalyzer in the Department of Biochemistry, AIIMS, Bhubaneswar. Results We found that the levels of CD4+CD25+ T-regs were lower in PE than in normal pregnancy, but this difference was not statistically significant (p = 0.349). The levels of CD4+FOXP3+ T-regs in PE were significantly lower compared to both normal pregnant women (p = 0.001) and normal non-pregnant women (p = 0.001). In comparison to women with PE, the levels of TGF-β1 were significantly higher in normal non-pregnant women (p = 0.020) and were higher, although not significantly so, in normal pregnant women (p = 0.994). The levels of IL-6 in women with PE were significantly higher than in normal pregnant women (p = 0.01) and normal non-pregnant women (p = 0.048). The levels of hsCRP in women with PE were significantly higher than in normal pregnant women (p = 0.045) and were higher, but not statistically significant, compared to normal non-pregnant women (p = 0.094). Conclusion The results of the study, showing a decrease in T-regs and an increase in inflammatory markers like TGF-β1, IL-6, and hsCRP levels in PE, have potential implications for the early diagnosis and management of the condition. Incorporating assessments of CD4+FOXP3+ T-regs and inflammatory markers into screening protocols, along with regular prenatal care and monitoring, can aid in the timely detection and implementation of appropriate management strategies. By intervening early, the risks associated with PE can be reduced, optimizing both maternal and fetal health.

Biomodulator of Diode Laser Irradiation on Odontoblast-Like Cells by Expression of Vascular Endothelial Growth Factor-A and Transforming Growth Factor-β1

OBJECTIVE

 This study aimed to prove that the effect of diode laser 650-nm irradiation to the expression of vascular endothelial growth factor (VEGF)-A and transforming growth factor (TGF)-β1 plays important roles in dental pulp-regulating cell proliferation, differentiation, and revascularization.

MATERIALS AND METHODS

 The research was performed by randomized posttest only control group design using Rattus norvegicus. A total of 48 samples were provided and divided into eight groups of 6 samples each with a random-sample allocation. Each group were prepared, and perforation of maxillary first molar were done. In control groups (groups 1-4), glass ionomer cement (GIC) was used to restore the teeth, while in laser groups (groups 5-8), the teeth were irradiated with diode laser 650 nm for 40 seconds before application of GIC. Half of the groups (groups 1, 2, 5, and 6) were necropsied in 7 days, and the rest (groups 3, 4, 7, and 8) were necropsied in 14 days. Immunohistochemistry (IHC) evaluation were implemented to check the expression of both VEGF-A and TGF-β1.

STATISTICAL ANALYSIS

 Both data of VEGF-A and TGF-β1 expression were analyzed using a one-way ANOVA (α = 0.05) with SPSS statistical software.

RESULTS

 The study showed that the diode laser 650-nm irradiation increased expression of VEGF-A and TGF-β1, and there was a significant difference between diode laser and control group on VEGF-A expression (p = 0.001) and TGF- β1 (p = 0.000) on days 7 and 14.

CONCLUSION

 Diode laser 650 nm with 40-second irradiation time shows increment from day 7 to day 14 reflecting increase in pulp healing by modulating VEGF-A and TGF-β1 expression since days 7 to 14.

Topical captopril: a promising treatment for secondary lymphedema

Transforming growth factor-beta 1 (TGF-β1)-mediated tissue fibrosis is an important regulator of lymphatic dysfunction in secondary lymphedema. However, TGF-β1 targeting can cause toxicity and autoimmune complications, limiting clinical utility. Angiotensin II (Ang II) modulates intracellular TGF-β1 signaling, and inhibition of Ang II production using angiotensin-converting enzyme (ACE) inhibitors, such as captopril, has antifibrotic efficacy in some pathological settings. Therefore, we analyzed the expression of ACE and Ang II in clinical lymphedema biopsy specimens from patients with unilateral breast cancer-related lymphedema (BCRL) and mouse models, and found that cutaneous ACE expression is increased in lymphedematous tissues. Furthermore, topical captopril decreases fibrosis, activation of intracellular TGF-β1 signaling pathways, inflammation, and swelling in mouse models of lymphedema. Captopril treatment also improves lymphatic function and immune cell trafficking by increasing collecting lymphatic pumping. Our results show that the renin-angiotensin system in the skin plays an important role in the regulation of fibrosis in lymphedema, and inhibition of this signaling pathway may hold merit for treating lymphedema.

Interplay of Transforming Growth Factor-Beta 1 and 3 in the Pathogenesis of Oral Submucous Fibrosis and Its Malignant Transformation: An Immunohistochemical Study

Introduction Oral submucous fibrosis (OSF) is a chronic and potentially malignant oral condition that poses a significant public health issue due to its insidious nature. Transforming growth factor-beta (TGF-β) is a key player in the pathogenesis of OSF and is responsible for fibrosis. This study aims to investigate the relationship between the expression of TGF-β1 and TGF-β3 in OSF and its malignant transformation by using immunohistochemistry. Materials and method The present study comprised of 120 formalin-fixed paraffin-embedded tissue samples, which included 20 normal oral mucosa (NOM), 80 OSF (20 each of stage 1- 4), and 20 oral squamous cell carcinoma (OSCC) (10 each of OSCC with and without OSF), and were stained for TGF-β1 and TGF-β3 by immunohistochemistry. Data were analyzed using R software version 4.1.2, GraphPad Prism 9.3.1 (GraphPad Software, San Diego, CA, USA) and Excel (Microsoft Corp., Redmond, WA). Results TGF-β1 immunoexpression was negative in NOM with no significant difference among OSF and OSCC (with or without OSF). TGF-β3 was significantly higher in OSCC (with or without OSF) than in OSF, and no significant difference was noted between OSF and NOM and between OSCC and NOM. A significant increase was seen in TGF-β3 compared to TGF-β1 in NOM, OSF (stage 1- 4), and OSCC with and without OSF. Conclusion TGF-β3 has higher immunoexpression levels than TGF-β1 in NOM, OSF, and OSCC. We speculate that quantitative or qualitative TGF- β3 may be inadequate to prevent or attenuate fibrosis in OSF patients. There is also a modicum of probability that TGF-β3 has a preventive rather than causative role in OSF pathogenesis. The role of TGF-β3 in OSF needs further clarification.

Challenges of Managing Non-rheumatic Aortic Valve Disorder in a Genetically Susceptible Woman

In this case report, we investigated the potential link between SMAD3/transforming growth factor β (TGF-β) pathway dysregulation and aortic valvular disease. We report a middle-aged female, heterozygous for the R18W novel variant of the SMAD3 gene, with a history of an aortic valve disorder and three aortic valve replacements in a span of 15 years. The patient neither has a history of congenital connective tissue disorders nor any known congenital valvular defects. The patient had genetic testing for thoracic aortic aneurysm and dissection (TAAD)/Marfan syndrome/related disorders. She was found to be heterozygous for the p.Arg18Trp (R18W) protein variant of the SMAD3 gene (chromosome position 15:67430416), coding DNA c.52 C>T. Members of the transforming growth factor β (TGF-β) family and their downstream signaling proteins, including SMAD, are important for establishing proper embryogenic development and maintaining adult tissue homeostasis. Investigating the disturbances within the TGF-β signaling pathways may provide insightful knowledge of how genetic factors can cause structural and functional valvular defects.

Celastrol Alleviates Corneal Stromal Fibrosis by Inhibiting TGF-β1/Smad2/3-YAP/TAZ Signaling After Descemet Stripping Endothelial Keratoplasty

Purpose

The purpose of this study was to investigate the effect of celastrol (CEL) on corneal stromal fibrosis after Descemet stripping endothelial keratoplasty (DSEK) and its associated mechanism.

Methods

Rabbit corneal fibroblasts (RCFs) were isolated, cultured, and identified. A CEL-loaded positive nanomedicine (CPNM) was developed to enhance corneal penetration. CCK-8 and scratch assays were performed to evaluate cytotoxicity and the effects of CEL on the migration of RCFs. The RCFs were activated by TGF-β1 with or without CEL treatment, and then the protein expression levels of TGFβRII, Smad2/3, YAP, TAZ, TEAD1, α-SMA, TGF-β1, FN, and COLI were assessed by immunofluorescence or Western blotting (WB). An in vivo DSEK model was established in New Zealand White rabbits. The corneas were stained using H&E, YAP, TAZ, TGF-β1, Smad2/3, TGFβRII, Masson, and COLI. H&E staining of the eyeball was performed to assess the tissue toxicity of CEL at 8 weeks after DSEK.

Results

In vitro CEL treatment inhibited the proliferation and migration of RCFs induced by TGF-β1. Immunofluorescence and WB showed that CEL significantly inhibited the protein expression of TGF-β1, Smad2/3, YAP, TAZ, TEAD1, α-SMA, TGF-βRII, FN, and COL1 induced by TGF-β1 in RCFs. In the rabbit DSEK model, CEL significantly reduced the levels of YAP, TAZ, TGF-β1, Smad2/3, TGFβRII, and collagen. No obvious tissue toxicity was observed in the CPNM group.

Conclusions

CEL effectively inhibited corneal stromal fibrosis after DSEK. The TGF-β1/Smad2/3-YAP/TAZ pathway may be involved in the mechanism by which CEL alleviates corneal fibrosis. The CPNM is a safe and effective treatment strategy for corneal stromal fibrosis after DSEK.

A Review on Major Pathways Leading to Peritoneal Fibrosis in Patients Receiving Continuous Peritoneal Dialysis

Peritoneal fibrosis (PF) is the most important complication of peritoneal dialysis (PD) that may arise among patients receiving continuous ambulatory peritoneal dialysis (CAPD). PF is a complex process, and many factors contribute to the formation of fibrosis. PD solutions with high glucose content, chronic inflammation, inflammatory cytokines, angiogenesis, and mesothelial to mesenchymal transition (MMT) are factors contributing to the fibrosis of the peritoneum. These factors, as well as stress-induced fibrosis, are going to be discussed further in this article. Although most experimental models are promising in preventing or delaying PD-related fibrosis, most of these recommended treatment options require further research. The lack of sufficient data from real PD patients and many inconclusive data make clinicians depend on conservative treatment. New therapeutics are indeed required for the management of patients undergoing PD to prevent the dreaded complication that may arise from continuous PD. Newer PD solutions are needed to improve survival and minimize the complication associated with PD. Recently, newer PD solutions have been shown to improve patient survival and peritoneal viability and reduce this complication that may arise as a result of continuous PD.

Evaluation of Sirtuin 1 Levels in Peripheral Blood Mononuclear Cells of Patients With Idiopathic Pulmonary Fibrosis

AIM

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disorder that is characterized by aggressive and dysbalanced wound healing. IPF is mainly a disease of the elderly and thus is likely to share common pathophysiologic mechanisms with other more age-related diseases. Emerging evidence has linked disturbance of sirtuin-1 (SIRT1) expression and activity with aging and diseases of the elderly. In the present study, we aimed to evaluate SIRT1 expression in the peripheral blood mononuclear cells (PBMCs) of patients with IPF given the lack of studies in the literature.

METHODS

We enrolled 34 IPF patients and 22 healthy volunteers (age and sex-matched). In both groups, SIRT1 levels were assessed in plasma, cell pellets of PBMCs, and supernatant from PBMCs' culture with and without the addition of 10% human serum. We also measured transforming growth factor β1 (TGF-β1) concentration in plasma from IPF patients and controls.

RESULTS

The mean (SD) age (years) of the healthy volunteers was 68.57±6.97 and of the IPF patients was 71.28±5.39 years (p>0.05). The mean SIRT1 concentration was found significantly decreased in the supernatant of PBMCs culture (without the addition of serum) in IPF subjects versus controls (1.97±0.59 ng/ml versus 2.40±0.74 ng/ml, respectively, p=0.047). No significant differences were observed between the two groups in the SIRT1 concentration of all the other materials. TGFβ1 concentration of IPF subjects was significantly increased when compared to controls (1281.38±2742.74 versus 131.11±156.06 ng/ml, respectively, p=0.032). Decreased SIRT1 levels in no-serum supernatant were predictive of IPF, after adjustment for age and sex (p=0.014, OR=0.124 [95%CI: 0.023-0.653]).

CONCLUSION

The findings of decreased concentration of SIRT1 in PBMCs supernatant and increased concentration of TGFβ1 in plasma in IPF patients versus controls provide important insights into the role of SIRT1 in IPF and could serve as a tool for the diagnosis and evaluation of patients with IPF.

Loss of LRRC33-Dependent TGFβ1 Activation Enhances Antitumor Immunity and Checkpoint Blockade Therapy

TGFβ has multiple roles and gene products (TGFβ1, -β2, and -β3), which make global targeting of TGFβ undesirable. Expression of TGFβ requires association with milieu molecules, which localize TGFβ to the surface of specific cells or extracellular matrices. Here, we found that LRRC33 was specifically associated with TGFβ1, not TGFβ2 and TGFβ3, and was required for surface display and activation of TGFβ1 on tumor-infiltrating myeloid cells. Loss of LRRC33-dependent TGFβ1 activation slowed tumor growth and metastasis by enhancing innate and adaptive antitumor immunity in multiple mouse syngeneic tumor models. LRRC33 loss resulted in a more immunogenic microenvironment, with decreased myeloid-derived suppressor cells, more active CD8+ T and NK cells, and more skewing toward tumor-suppressive M1 macrophages. LRRC33 loss and PD-1 blockade synergized in controlling B16.F10 tumor growth. Our results demonstrate the importance of LRRC33 in tumor biology and highlight the therapeutic potential of dual blockade of the LRRC33/TGFβ1 axis and PD-1/PD-L1 in cancer immunotherapy.

Hepatitis B and Hepatitis C Virus Infection Promote Liver Fibrogenesis through a TGF-β1-Induced OCT4/Nanog Pathway

Hepatitis B virus (HBV)/hepatitis C virus (HCV) coinfection accelerates liver fibrosis progression compared with HBV or HCV monoinfection. Octamer binding transcription factor 4 (OCT4) and Nanog are direct targets of the profibrogenic TGF-β1 signaling cascade. We leveraged a coculture model to monitor the effects of HBV and HCV coinfection on fibrogenesis in both sodium taurocholate cotransporting polypeptide-transfected Huh7.5.1 hepatoma cells and LX2 hepatic stellate cells (HSCs). We used CRISPR-Cas9 to knock out OCT4 and Nanog to evaluate their effects on HBV-, HCV-, or TGF-β1-induced liver fibrogenesis. HBV/HCV coinfection and HBx, HBV preS2, HCV Core, and HCV NS2/3 overexpression increased TGF-β1 mRNA levels in sodium taurocholate cotransporting polypeptide-Huh7.5.1 cells compared with controls. HBV/HCV coinfection further enhanced profibrogenic gene expression relative to HBV or HCV monoinfection. Coculture of HBV and HCV monoinfected or HBV/HCV coinfected hepatocytes with LX2 cells significantly increased profibrotic gene expression and LX2 cell invasion and migration. OCT4 and Nanog guide RNA independently suppressed HBV-, HCV-, HBV/HCV-, and TGF-β1-induced α-SMA, TIMP-1, and Col1A1 expression and reduced Huh7.5.1, LX2, primary hepatocyte, and primary human HSC migratory capacity. OCT4/Nanog protein expression also correlated positively with fibrosis stage in liver biopsies from patients with chronic HBV or HCV infection. In conclusion, HBV and HCV independently and cooperatively promote liver fibrogenesis through a TGF-β1-induced OCT4/Nanog-dependent pathway.

Integrin/TGF-β1 inhibitor GLPG-0187 blocks SARS-CoV-2 Delta and Omicron pseudovirus infection of airway epithelial cells which could attenuate disease severity

As COVID-19 continues to pose major risk for vulnerable populations including the elderly, immunocompromised, patients with cancer, and those with contraindications to vaccination, novel treatment strategies are urgently needed. SARS-CoV-2 infects target cells via RGD-binding integrins either independently or as a co-receptor with surface receptor angiotensin-converting enzyme 2 (ACE2). We used pan-integrin inhibitor GLPG-0187 to demonstrate blockade of SARS-CoV-2 pseudovirus infection of target cells. Omicron pseudovirus infected normal human small airway epithelial (HSAE) cells significantly less than D614G or Delta variant pseudovirus, and GLPG-0187 effectively blocked SARS-CoV-2 pseudovirus infection in a dose-dependent manner across multiple viral variants. GLPG-0187 inhibited Omicron and Delta pseudovirus infection of HSAE cells more significantly than other variants. Pre-treatment of HSAE cells with MEK inhibitor (MEKi) VS-6766 enhanced inhibition of pseudovirus infection by GLPG-0187. Because integrins activate TGF-β signaling, we compared plasma levels of active and total TGF-β in COVID-19+ patients. Plasma TGF-β1 levels correlated with age, race, and number of medications upon presentation with COVID-19, but not with sex. Total plasma TGF-β1 levels correlated with activated TGF-β1 levels. In our preclinical studies, Omicron infects lower airway lung cells less efficiently than other COVID-19 variants. Moreover, inhibition of integrin signaling prevents SARS-CoV-2 Delta and Omicron pseudovirus infectivity, and may mitigate COVID-19 severity through decreased TGF-β1 activation. This therapeutic strategy may be further explored through clinical testing in vulnerable and unvaccinated populations.

Circular RNA Plasmacytoma Variant Translocation 1 (CircPVT1) knockdown ameliorates hypoxia-induced bladder fibrosis by regulating the miR-203/Suppressor of Cytokine Signaling 3 (SOCS3) signaling axis

The effects of circular RNAs (circRNAs) on bladder outlet obstruction (BOO)-induced hypertrophy and fibrogenesis in rats and hypoxia-induced bladder smooth muscle cell (BSMC) fibrosis remain unclear. This study aimed to determine the regulatory role of circRNAs in the phenotypic changes in BSMCs in BOO-induced rats.circRNAmicroarray and real-time PCR were used to explore differentiated expressed circRNAs. Bioinformatics analyses and dual-luciferase reporter were performed to identify the targets for circRNA PVT1 (circPVT1). BOO was performed to establish a bladder fibrosis animal model. The circPVT1 and suppressor of cytokine signaling 3 (SOCS3) expression levels were upregulated (p = 0.0061 and 0.0328, respectively), whereas the microRNA-203a (miR-203) level was downregulated in rats with bladder remodeling (p=0.0085). Bioinformatics analyses and dual-luciferase reporter assay results confirmed that circPVT1 sponges miR-203 and that the latter targets the 3'-untranslated region of SOCS3. Additionally, circPVT1 knockdown alleviated BOO-induced bladder hypertrophy and fibrogenesis. Furthermore, hypoxia was induced in BSMCs to establish a cell model of bladder fibrosis. Hypoxia induction in BSMCs resulted in upregulated circPVT1 and SOCS3 levels (p = 0.0052) and downregulated miR-203 levels. Transfection with circPVT1 and SOCS3 shRNA ameliorated hypoxia-induced transforming growth factor-β (TGF-β1), TGFβR1, α-smooth muscle actin, fibrotic growth factor, extracellular matrix subtypes, BSMC proliferation, and apoptosis-associated cell injury, whereas co-transfection with miR-203 inhibitor counteracted the effect of circPVT1 shRNA on these phenotypes.These findings revealed a novel circRNA regulator of BOO-associated bladder wall remodeling and hypoxia-induced phenotypic changes in BMSCs by targeting the miR-203-SOCS3 signaling axis.

Plumbagin attenuates traumatic tracheal stenosis in rats and inhibits lung fibroblast proliferation and differentiation via TGF-β1/Smad and Akt/mTOR pathways

Traumatic tracheal stenosis (TS) is a serious respiratory disease characterized by hyperplasia of airway granulation. Plumbagin (PLB) is a natural naphthoquinone component with anti-fibrotic properties. This research aimed to explore the roles of PLB in alleviating TS and the underlying mechanisms. For in vitro studies, lung fibroblasts (IMR-90 cells), with/without PLB treatment or TGF-β1 induction, were used. The viability and proliferation of IMR-90 cells were examined by CCK-8 and EdU incorporation assays. The differentiation of IMR-90 cells was assessed by detecting the mRNA and protein expression levels of collagen (COL)-1 and alpha-smooth muscle actin (α-SMA). Besides, immunofluorescence assay was conducted to evaluate the localization of α-SMA in TGF-β1-induced IMR-90 cells. Moreover, the combination of PLB with/without TβRI (SB-431,542), PI3K/Akt (Ly294002) or mTOR (rapamycin) inhibitor was pretreated on IMR-90 cells after TGF-β1 induction. For in vivo studies, a rat model of TS was established. The pathological features and severity of TS were determined by hematoxylin and eosin staining. The protein levels of TGF-β1/Smad and Akt/mTOR pathways were detected for both in vitro and in vivo models. PLB effectively inhibited the proliferation and differentiation of TGF-β1-induced IMR-90 cells, and suppressed TGF-β1/Smad and Akt/mTOR signaling pathways both in vivo and in vitro. Furthermore, PLB reduced the degree of TS in rats. Taken together, our results indicate that PLB regulates lung fibroblast activity and attenuates TS in rats by inhibiting TGF-β1/Smad and Akt/mTOR signaling pathways. In conclusion, this study implies that PLB may serve as a promising therapeutic compound for TS.

Harnessing the Role of HDAC6 in Idiopathic Pulmonary Fibrosis: Design, Synthesis, Structural Analysis, and Biological Evaluation of Potent Inhibitors

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease characterized by a progressive-fibrosing phenotype. IPF has been associated with aberrant HDAC activities confirmed by our immunohistochemistry studies on HDAC6 overexpression in IPF lung tissues. We herein developed a series of novel hHDAC6 inhibitors, having low inhibitory potency over hHDAC1 and hHDAC8, as potential pharmacological tools for IPF treatment. Their inhibitory potency was combined with low in vitro and in vivo toxicity. Structural analysis of 6h and structure-activity relationship studies contributed to the optimization of the binding mode of the new molecules. The best-performing analogues were tested for their efficacy in inhibiting fibrotic sphere formation and cell viability, proving their capability in reverting the IPF phenotype. The efficacy of analogue 6h was also determined in a validated human lung model of TGF-β1-dependent fibrogenesis. The results highlighted in this manuscript may pave the way for the identification of first-in-class molecules for the treatment of IPF.

Interleukin-18 promotes the antitumor ability of natural killer cells in colorectal cancer via the miR-574-3p/TGF-β1 axis

Interleukin (IL)-18 has a clear antitumor effect; however, its mechanisms of action are not understood in patients with colorectal cancer (CRC). Here, we investigated the potential mechanism of IL-18 in CRC. The results showed that IL-18 treatment alone had no effect on HCT116 cells apoptosis, whereas IL-18 in the presence of natural killer (NK) cells resulted in apoptosis and inhibition of cells proliferation in vitro. Profiling of miRNA expression following coculture with NK cells and treatment with IL-18 resulted in significant downregulation of miR-574-3p expression and upregulated expression of the target gene transforming growth factor beta 1 (TGF-β1). miR-574-3p binds to TGF-β1, and miR-574-3p overexpression increased the proliferation and decreased the apoptotic rate of HCT116 cells in NK cells coculture with IL-18 treatment; overexpression of TGF-β1 restored the effect of miR-574-3p overexpression. The miRNA profile of HCT116 undergoes significant alteration before and after coculturing with NK cells and treatment with IL-18. IL-18 alone did not affect HCT116 cells apoptosis but did promote the antitumor ability of NK cells in coculture with HCT116 cells via the miR-574-3p/TGF-β1 axis. Our study suggested that IL-18 can be a new potential target for cancer immunotherapy for CRC.

Correlations between the polymorphism of +869T/C in TGF-β1 and rheumatoid arthritis

OBJECTIVE

To explore the correlations between the polymorphism of the gene first exon +869T/C in transforming growth factor-β1 (TGF-β1) and rheumatoid arthritis (RA).

METHODS

The patient group included 150 RA patients at the Department of Rheumatology in the First Affiliated Hospital of Chengdu Medical College between March 2014 and May 2017 and 150 healthy cases as the control group. The polymorphism was analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and relationships between RA patients and genotypes were analyzed using logistic regression.

RESULTS

The genotype frequency distribution and the genotype frequency of +869T/C locus was statistically different between two groups (P<0.05). Compared to the control group, the genotype frequency of +869 CC in the inpatient group was significantly lower (17.3% vs 32.7%), while the genotype frequency of +869 TT increased significantly (29.3% vs 20.7%). The T allele frequency in inpatient group was significantly higher than that in control group (57.83% vs 48.82%), while the C allele frequency in control group was significantly higher than that in inpatient group (51.18% vs 42.17%).

CONCLUSION

The polymorphism of the gene first exon +869T/C in TGF-β1 significantly correlated with RA and CC genotype might be the susceptible gene of RA.

Anti-fibrotic role and mechanism of Periplaneta americana extracts in CCl4-induced hepatic fibrosis in rats

Hepatic fibrosis is resulted from sustained wound-healing responses to various harmful stimuli, including viral infection, drug toxicity, alcohol, and autoimmune hepatopathy, and it has recently attracted the attention of an increasing number of researchers and clinical workers. The aims of this study were to examine the anti-fibrotic effects of extracts of Periplaneta americana (EPA) on CCl4-induced hepatic fibrosis in rats, to preliminary determine the anti-fibrotic efficacy of EPA, and to identify a potential and effective therapeutic agent to attenuate hepatic fibrosis. In this study, we routinely detected liver functional indices, such as alanine aminotransferase (ALT), aspartate transaminase (AST), and albumin (Alb). We also measured hepatic fibrosis-related serum markers, including hyaluronic acid (HA), laminin (LN), type III procollagen (PC III), and type IV collagen (IV-C) via radioimmunoassay. Moreover, we examined histological activity and fibrosis stage via light microscopy after hematoxylin and eosin and Masson staining. Furthermore, we detected the expressions of nuclear factor-kappa B (NF-κB), alpha-smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1), and tissue inhibitor of metalloprotease-1 (TIMP-1) in rat liver tissues by immunohistochemical staining. We found that EPA, whose main components are viscous sugar amino acids, can reduce the levels hepatic fibrosis-related factors, including HA, LN, PC III, and IV-C, improve liver function, attenuate, or reverse pathological damage associated with hepatic fibrosis, and thus inhibit the progression of hepatic fibrosis. The mechanism of EPA action may be related to the inhibition of TGF-β1, NF-κB, and α-SMA expressions and the reduction of TIMP-1 levels in the liver to reduce the accumulation of extracellular matrix (ECM) components, thereby blocking the relevant signaling pathways and preventing inflammatory responses to attenuate or reverse hepatic fibrosis. EPA may thus be used as a potentially effective therapeutic agent for the treatment of hepatic fibrosis.

New methodologies to accurately assess circulating active transforming growth factor-β1 levels: implications for evaluating heart failure and the impact of left ventricular assist devices

Transforming growth factor-β1 (TGF-β1) has been used as a biomarker in disorders associated with pathologic fibrosis. However, plasma TGF-β1 assessment is confounded by the significant variation in reported normal values, likely reflecting variable release of the large pool of platelet TGF-β1 after blood drawing. Moreover, current assays measure only total TGF-β1, which is dominated by the latent form of TGF-β1 rather than the biologically active form. To address these challenges, we developed methodologies to prevent ex vivo release of TGF-β1 and to quantify active TGF-β1. We then used these techniques to measure TGF-β1 in healthy controls and patients with heart failure (HF) before and after insertion of left ventricular assist devices (LVAD). Total plasma TGF-β1 was 1.0 ± 0.60 ng/mL in controls and 3.76 ± 1.55 ng/mL in subjects with HF (P < 0.001), rising to 5.2 ± 2.3 ng/mL following LVAD placement (P = 0.006). These results were paralleled by the active TGF-β1 values; controls had 3-16 pg/mL active TGF-β1, whereas levels were 2.7-fold higher in patients with HF before, and 4.2-fold higher after, LVAD implantation. Total TGF-β1 correlated with levels of the platelet-derived protein thrombospondin-1 (r = 0.87; P < 0.001), suggesting that plasma TGF-β1 may serve as a surrogate indicator of in vivo platelet activation. von Willebrand factor high molecular weight multimers correlated inversely with TGF-β1 levels (r = -0.63; P = 0.023), suggesting a role for shear forces in loss of these multimers and platelet activation. In conclusion, accurate assessment of circulating TGF-β1 may provide a valuable biomarker for in vivo platelet activation and thrombotic disorders.

c-Fos mediates α1, 2-fucosyltransferase 1 and Lewis y expression in response to TGF-β1 in ovarian cancer

FUT1 is a key rate-limiting enzyme in the synthesis of Lewis y, a membrane-associated carbohydrate antigen. The aberrant upregulation of FUT1 and Lewis y antigen is related to proliferation, invasion and prognosis in malignant epithelial tumors. A c-Fos/activator protein-1 (AP-1) binding site was found in the FUT1 promoter. However, the mechanisms of transcriptional regulation of FUT1 remain poorly understood. TGF-β1 is positively correlated to Lewis y. In the present study, we investigated the molecular mechanism of FUT1 gene expression in response to TGF-β1. We demonstrated that c-Fos was highly expressed in 77.50% of ovarian epithelial carcinoma cases and was significantly correlated with Lewis y. Using luciferase activity and chromatin immunoprecipitation (ChIP) assay, we further revealed that c-Fos interacted with the FUT1 promoter in ovarian cancer cells and transcriptional capacity of the heterodimer formed by c-Fos and c-Jun was stronger than that of the c-Fos or c-Jun homodimers. Then, we demonstrated that TGF-β1 induced dose-dependent c-Fos expression, which was involved in TGF-β1-induced ovarian cancer cell proliferation. In addition, inhibition of MAPK activation or TGF-β1 receptor by pharmacological agents prevented TGF-β1-induced c-Fos and Lewis y expression. Silencing of c-Fos prevented TGF-β1-induced Lewis y expression. Collectively, the results of these studies demonstrated that TGF-β1 regulated FUT1 and Lewis y expression by activating the MAPK/c-Fos pathway.

Bile duct ligation-induced biliary hyperplasia, hepatic injury, and fibrosis are reduced in mast cell-deficient KitW-sh mice

Activated mast cells (MCs) release histamine (HA) and MCs infiltrate the liver following bile duct ligation (BDL), increasing intrahepatic bile duct mass (IBDM) and fibrosis. We evaluated the effects of BDL in MC-deficient (Kit^W-sh ) mice. Wild-type (WT) and Kit^W-sh mice were subjected to sham or BDL for up to 7 days and Kit^W-sh mice were injected with cultured mast cells or 1× phosphate-buffered saline (PBS) before collecting serum, liver, and cholangiocytes. Liver damage was assessed by hematoxylin and eosin and alanine aminotransferase levels. IBDM was detected by cytokeratin-19 expression and proliferation by Ki-67 immunohistochemistry (IHC). Fibrosis was detected by IHC, hydroxyproline content, and by qPCR for fibrotic markers. Hepatic stellate cell (HSC) activation and transforming growth factor-beta 1 (TGF-β1) expression/secretion were evaluated. Histidine decarboxylase (HDC) and histamine receptor (HR) expression were detected by qPCR and HA secretion by enzymatic immunoassay. To evaluate vascular cells, von Willebrand factor (vWF) and vascular endothelial growth factor (VEGF)-C expression were measured. In vitro, cultured HSCs were stimulated with cholangiocyte supernatants and alpha-smooth muscle actin levels were measured. BDL-induced liver damage was reduced in BDL Kit^W-sh mice, whereas injection of MCs did not mimic BDL-induced damage. In BDL Kit^W-sh mice, IBDM, proliferation, HSC activation/fibrosis, and TGF-β1 expression/secretion were decreased. The HDC/HA/HR axis was ablated in sham and BDL Kit^W-sh mice. vWF and VEGF-C expression decreased in BDL Kit^W-sh mice. In Kit^W-sh mice injected with MCs, IBDM, proliferation, fibrosis, and vascular cell activation increased. Stimulation with cholangiocyte supernatants from BDL WT or Kit^W-sh mice injected with MCs increased HSC activation, which decreased with supernatants from BDL Kit^W-sh mice.

CONCLUSION

MCs promote hyperplasia, fibrosis, and vascular cell activation. Knockout of MCs decreases BDL-induced damage. Modulation of MCs may be important in developing therapeutics for cholangiopathies. (Hepatology 2017;65:1991-2004).

[Therapeutic effect of baicalin in treatment of renal interstitial fibrosis in rats with unliateral ureteral obstruction and related mechanisms]

OBJECTIVE

To investigate the therapeutic effect of baicalin at different doses administered for different periods of time in the treatment of renal interstitial fibrosis in rats with unliateral ureteral obstruction (UUO) and related mechanisms.

METHODS

Sixty-four Sprague-Dawley rats were randomly divided into sham-operation, model, low-dose baicalin, and high-dose baicalin groups, and each group was further randomly divided into 7-day and 14-day groups (n=8 each). Left ureteral ligation was used to establish the rat model of UUO. Hematoxylin and eosin staining was used to observe the pathological changes in the kidney. ELISA was used to measure the serum levels of transforming growth factor-β1 (TGF-β1), Notch1, and Jagged1. Immunohistochemistry was used to measure the expression of TGF-β1 and Notch1. The Pearson correlation analysis was used for correlation analysis.

RESULTS

Hematoxylin and eosin staining showed inflammatory cell infiltration and edema in renal interstitium, tubular dilation and structure disorder, degeneration and necrosis of renal tubular epithelial cells, and a basically normal structure of the glomeruli on days 7 and 14 in the model group, and these lesions were alleviated in the low- and high-dose baicalin groups. Compared with the sham-operation group, the model group had a significantly higher serum level of TGF-β1 and a significantly higher number of TGF-β1-positive cells in renal tissues on days 7 and 14 (P<0.05). Compared with the model group at the same time points, the high- and low-dose baicalin groups had a significantly lower serum level of TGF-β1 and a significantly lower number of TGF-β1-positive cells in renal tissues on days 7 and 14 (P<0.05). The serum level of Jagged1 showed no significant differences between any two groups on days 7 and 14 (P>0.05). The serum level of TGF-β1 was positively correlated with that of Notch1 (r=0.650, P<0.01), and the serum level of Notch1 was positively correlated with that of Jagged1 (r=0.727, P<0.01). TGF-β1 level in renal tissues was also positively correlated with the number of Notch1-positive cells (r=0.743, P<0.01).

CONCLUSIONS

Baicalin can alleviate renal interstitial fibrosis in UUO rats, probably by inhibiting Notch1 signaling pathway and the expression of TGF-β1.

The anti-oxidative transcription factor Nuclear factor E2 related factor-2 (Nrf2) counteracts TGF-β1 mediated growth inhibition of pancreatic ductal epithelial cells -Nrf2 as determinant of pro-tumorigenic functions of TGF-β1

BACKGROUND

Nuclear factor E2 related factor-2 (Nrf2) is an oxidative stress inducible transcription factor being essential in regulating cell homeostasis. Thus, acute induction of Nrf2 in epithelial cells exposed to inflammation confers protection from oxidative cell damage and mutagenesis supporting an anti-tumorigenic role for Nrf2. However, pancreatic ductal adenocarcinoma (PDAC) is characterized by persistent Nrf2 activity conferring therapy resistance which points to a pro-tumorigenic role of Nrf2. A similar dichotomous role in tumorigenesis is described for the Transforming Growth Factor-beta 1 (TGF-β1). The present study therefore aimed at elucidating whether the switch of Nrf2 function towards a tumor promoting one relates to the modulation of TGF-β1 induced cell responses and whether this might occur early in PDAC development.

METHODS

In situ analysis comprised immunohistochemical stainings of activated (phosphorylated) Nrf2 and Ki67 in pancreatic tissues containing normal ducts and pancreatic intraepithelial neoplasia (PanINs). In vitro, Nrf2 levels in benign (H6c7-pBp), premalignant (H6c7-kras) and malignant (Colo357) pancreatic ductal epithelial cells were modulated by Nrf2 specific siRNA or Nrf2 overexpression. Then, the effect of Nrf2 alone and in combination with TGF-β1 on cell growth and survival was investigated by cell counting, Ki67 staining and apoptosis assays. The underlying cell signaling was investigated by western blotting. Statistical analysis was performed by Shapiro-Wilk test for normal distribution. Parametric data were analyzed by one-way ANOVA, while non-parametric data were analyzed by Kruskal-Wallis one-way ANOVA on ranks.

RESULTS

Significantly elevated expression of activated Nrf2 and Ki67 could be detected in PanINs but not in normal pancreatic ductal epithelium. While the effect of Nrf2 on basal cell growth of H6c7-pBp, H6c7-kras and Colo357 cells was minor, it clearly attenuated the growth inhibiting effects of TGF-β1 in all cell lines. This enhanced Nrf2-mediated cell survival was predominantly based on an enhanced proliferative activity. Accordingly, expression of p21 expression along with expression of phospho-p38 and phospho-Smad3 was diminished whereas Erk-phosphorylation was enhanced under these conditions.

CONCLUSIONS

Overall, our data demonstrate that Nrf2 being elevated in early precursor lesions counteracts the growth inhibiting function of TGF-β1 already in benign and premalignant pancreatic ductal epithelial cells. This could represent one fundamental mechanism underlying the functional switch of both- TGF-β1 and Nrf2 - which may manifest already in early stages of PDAC development.

Transforming growth factor-β1-mediated cardiac fibrosis: potential role in HIV and HIV/antiretroviral therapy-linked cardiovascular disease

HIV infection elevates the incidence of cardiovascular disease (CVD) independent of traditional risk factors. Autopsy series document cardiac inflammation and endomyocardial fibrosis in the HIV+ treatment naïve, and gadolinium enhancement magnetic resonance imaging has identified prominent myocardial fibrosis in the majority of HIV+ individuals despite use of suppressive antiretroviral therapies (ART). The extent of such disease may correlate with specific ART regimens. For example, HIV-infected patients receiving ritonavir (RTV)-boosted protease inhibitors have the highest prevalence of CVD, and RTV-exposed rodents exhibit cardiac dysfunction coupled with cardiac and vascular fibrosis, independent of RTV-mediated lipid alterations. We recently showed that platelet transforming growth factor (TGF)-β1 is a key contributor to cardiac fibrosis in murine models. We hypothesize that in the HIV+/ART naïve, cardiac fibrosis is a consequence of proinflammatory cytokine and/or ART-linked platelet activation with release of TGF-β1. Resultant TGF-β1/Smad signaling would promote collagen synthesis and organ fibrosis. We document these changes in a pilot immunohistochemical evaluation of cardiac tissue from two ART-naive pediatric AIDS patients. In terms of ART, we showed that RTV inhibits immunoproteasome degradation of TRAF6, a nuclear adapter signaling molecule critical to the regulation of proinflammatory cytokine signaling pathways involved in osteoclast differentiation and accelerated osteoporosis. We now present a model illustrating how RTV could similarly amplify TGF-β1 signaling in the promotion of cardiac fibrosis and accelerated CVD. Supportive clinical data correlate RTV use with elevation of NT-proBNP, a biomarker for CVD. We discuss potential interventions involving intrinsic modulators of inflammation and collagen degradation, including carbon monoxide-based therapeutics.

Cigarette smoke mediates epigenetic repression of miR-217 during esophageal adenocarcinogenesis

Although microRNAs (miRs) have been implicated in the pathogenesis of various human malignancies, limited information is available regarding mechanisms by which these noncoding RNAs contribute to initiation and progression of tobacco-induced esophageal cancers. In this study, array and quantitative reverse transcriptase-PCR techniques were used to examine miR expression in immortalized esophageal epithelia (IEE) and esophageal adenocarcinoma (EAC) cells cultured in normal media with or without cigarette smoke condensate (CSC). Under relevant exposure conditions, CSC significantly decreased miR-217 expression in these cells. Endogenous levels of miR-217 expression in cultured EAC cells (EACC)/primary EACs were significantly lower than those observed in IEE/ paired normal esophageal tissues. RNA crosslink immunoprecipitation, quantitative reverse transcriptase-PCR (qRT-PCR) and immunoblot experiments demonstrated direct interaction of miR-217 with kallikrein 7 (KLK7), encoding a putative oncogene not previously implicated in EAC. Repression of miR-217 correlated with increased levels of KLK7 in primary EACs, particularly those from smokers. Chromatin and methylated DNA immunoprecipitation experiments demonstrated that CSC-mediated repression of miR-217 coincided with DNMT3b-dependent hypermethylation and decreased occupancy of nuclear factor 1 within the miR-217 genomic locus. Deoxyazacytidine induced miR-217 expression and downregulated KLK7 in EACC; deoxyazacytidine also attenuated CSC-mediated miR-217 repression and upregulation of KLK7 in IEE and EACC. Overexpression of miR-217 significantly decreased, whereas overexpression of KLK7 increased proliferation, invasion and tumorigenicity of EACC. Collectively, these data demonstrate that epigenetic repression of miR-217 contributes to the pathogenesis of EAC via upregulation of KLK7 and suggest that restoration of miR-217 expression may be a novel treatment strategy for these malignancies.

TGF-β1 induces epigenetic silence of TIP30 to promote tumor metastasis in esophageal carcinoma

TGF-β1, a potent EMT (epithelial-mesenchymal transition) inducer present in the tumor microenvironment, is involved in the metastasis and progression of various carcinomas, including esophageal squamous cell carcinoma (ESCC). TIP30 (30kDa HIV-1 Tat interacting protein) is a putative tumor metastasis suppressor. Here, we found TIP30 was decreased in cells undergoing EMT induced by TGF-β1, an occurrence that was related to promoter hypermethylation. TGF-β1 induced TIP30 hypermethylation via increasing DNMT1 and DNMT3A expression, which could be restored by TGF-β antibodies. In our in vitro and in vivo studies, we showed that silence of TIP30 led to EMT, enhanced migrative and invasive abilities of ESCC cells, promoted tumor metastasis in xenografted mice; alternatively, overexpression of TIP30 inhibited TGF-β1-induced EMT, and metastatic abilities of ESCC cells. Mechanically, TIP30 silencing induced the nuclear translocation and transcriptional activation of β-catenin in an AKT-dependent manner, which further resulted in the initiation of EMT. Consistently, TIP30 was frequently methylated and downregulated in ESCC patients. Loss of TIP30 correlated with nuclear β-catenin and aberrant E-cadherin expression. TIP30 was a powerful marker in predicting the prognosis of ESCC. Taken together, our results suggest a novel and critical role of TIP30 involved in TGF-β1-induced activation of AKT/β-catenin signaling and ESCC metastasis.

MiR-429 inhibits cells growth and invasion and regulates EMT-related marker genes by targeting Onecut2 in colorectal carcinoma

The 5-year survival rate for colorectal cancer is approximately 55 % because of its invasion and metastasis. The epithelial-mesenchymal transition (EMT) is one of the well-defined processes during the invasion and distant metastasis of primary epithelial tumors. miR-429, a member of the miR-200 family of microRNAs, was previously shown to inhibit the expression of transcriptional repressors ZEB1/delta EF1 and SIP1/ZEB2, and regulate EMT. In this study, we showed that miR-429 was significantly downregulated in colorectal carcinoma (CRC) tissues and cell lines. We found that miR-429 inhibited the proliferation and growth of CRC cells in vitro and in vivo, suggesting that miR-429 could play a role in CRC tumorigenesis. We also showed that downregulation of miR-429 may contribute to carcinogenesis and the initiation of EMT of CRC by targeting Onecut2. Further researches indicated that miR-429 inhibited the cells migration and invasion and reversed TGF-β-induced EMT changes in SW620 and SW480 cells. miR-429 could reverse the change of EMT-related markers genes induced by TGF-β1, such as E-cadherin, CTNNA1, CTNNB1, TFN, CD44, MMP2, Vimentin, Slug, Snail, and ZEB2 by targeting Onecut2. Taken together, our data showed that transcript factor Onecut2 is involved in the EMT, migration and invasion of CRC cells; miR-429 inhibits the initiation of EMT and regulated expression of EMT-related markers by targeting Onecut2; and miR-429 or Onecut2 is the important therapy target for CRC.

Hepatocyte growth factor inhibits TGF-β1-induced myofibroblast differentiation in tendon fibroblasts: role of AMPK signaling pathway

The transforming growth factor-β1 (TGF-β1)-induced myofibroblastic differentiation in tendon fibroblasts was thought to be one of the most important features of scar fibrosis formation, which is associated with occurrence of re-rupture. Previously, we reported that hepatocyte growth factor (HGF) inhibited TGF-β1-induced myofibroblast differentiation and extracellular matrix deposition in the Achilles tendon of rats. Here, we investigated the potential molecular mechanisms underlying the inhibitory effect of HGF on TGF-β1-induced myofibroblast differentiation. We found that treatment with HGF (10, 20, and 40 ng/ml) increased phosphorylation of adenosine monophosphate kinase (AMPK) and acetyl-CoA carboxylase (ACC) in tendon fibroblasts. Pharmacological inhibition of the AMPK signaling pathway using compound C, a specific blocker of AMPK signaling, remarkably attenuated the inhibitory effect of HGF on TGF-β1-induced myofibroblastic differentiation in tendon fibroblasts. Moreover, small interfering RNA (siRNA)-mediated knockdown of AMPKα1 subunit decreased the inhibitory effect of HGF on TGF-β1-induced myofibroblastic differentiation in tendon fibroblasts. Finally, overexpression of constitutively active AMPKα1, which led to constitutive activation of the AMPK signaling pathway in tendon fibroblasts, mimicked the inhibitory effect of HGF on the TGF-β1-induced myofibroblastic differentiation. Our study therefore suggests that HGF inhibits TGF-β1-induced myofibroblastic differentiation via an AMPK signaling pathway-dependent manner in tendon fibroblasts.

Involvement of p300/CBP and epigenetic histone acetylation in TGF-β1-mediated gene transcription in mesangial cells

Transforming growth factor-β1 (TGF-β1)-induced expression of plasminogen activator inhibitor-1 (PAI-1) and p21 in renal mesangial cells (MCs) plays a major role in glomerulosclerosis and hypertrophy, key events in the pathogenesis of diabetic nephropathy. However, the involvement of histone acetyl transferases (HATs) and histone deacetylases (HDACs) that regulate epigenetic histone lysine acetylation, and their interaction with TGF-β1-responsive transcription factors, are not clear. We evaluated the roles of histone acetylation, specific HATs, and HDACs in TGF-β1-induced gene expression in rat mesangial cells (RMCs) and in glomeruli from diabetic mice. Overexpression of HATs CREB binding protein (CBP) or p300, but not p300/CBP-activating factor, significantly enhanced TGF-β1-induced PAI-1 and p21 mRNA levels as well as transactivation of their promoters in RMCs. Conversely, they were significantly attenuated by HAT domain mutants of CBP and p300 or overexpression of HDAC-1 and HDAC-5. Chromatin immunoprecipitation assays showed that TGF-β1 treatment led to a time-dependent enrichment of histone H3-lysine9/14-acetylation (H3K9/14Ac) and p300/CBP occupancies around Smad and Sp1 binding sites at the PAI-1 and p21 promoters. TGF-β1 also enhanced the interaction of p300 with Smad2/3 and Sp1 and increased Smad2/3 acetylation. High glucose-treated RMCs exhibited increased PAI-1 and p21 levels, and promoter H3K9/14Ac, which were blocked by TGF-β1 antibodies. Furthermore, increased PAI-1 and p21 expression was associated with elevated promoter H3K9/14Ac levels in glomeruli from diabetic mice. Thus TGF-β1-induced PAI-1 and p21 expression involves interaction of p300/CBP with Smads and Sp1, and increased promoter access via p300/CBP-induced H3K9/14Ac. This in turn can augment glomerular dysfunction linked to diabetic nephropathy.

Investigating the role of substrate stiffness in the persistence of valvular interstitial cell activation

During heart valve remodeling and in many disease states, valvular interstitial cells (VICs) shift to an activated myofibroblast phenotype characterized by enhanced synthetic and contractile activity. Pronounced alpha smooth muscle actin (αSMA)-positive stress fibers, the hallmark of activated myofibroblasts, are also observed in VICs cultured on stiff substrates especially in the presence of transforming growth factor-beta1 (TGF-β1), however, the detailed relationship between stiffness and VIC phenotype has not been explored. The goal of this study was to characterize VIC activation as a function of substrate stiffness over a wide range of stiffness levels including that of diseased valves (stiff), normal valves (compliant), and hydrogels for heart valve tissue engineering (very soft). VICs obtained from porcine aortic valves were cultured on stiff tissue culture plastic to activate them, then, cultured on collagen-coated polyacrylamide substrates of predefined stiffness in a high-throughput culture system to assess the persistence of activation. Metrics extracted from regression analysis demonstrate that relative to a compliant substrate, stiff substrates result in higher cell numbers, more pronounced expression of αSMA-positive stress fibers, and larger spread area which is in qualitative agreement with previous studies. Our data also indicate that VICs require a much lower substrate stiffness level to "deactivate" them than previously thought. The high sensitivity of VICs to substrate stiffness demonstrates the importance of the mechanical properties of materials used for valve repair or for engineering valve tissue.

TGF-β1 → SMAD/p53/USF2 → PAI-1 transcriptional axis in ureteral obstruction-induced renal fibrosis

Chronic kidney disease constitutes an increasing medical burden affecting 26 million people in the United States alone. Diabetes, hypertension, ischemia, acute injury, and urological obstruction contribute to renal fibrosis, a common pathological hallmark of chronic kidney disease. Regardless of etiology, elevated TGF-β1 levels are causatively linked to the activation of profibrotic signaling pathways initiated by angiotensin, glucose, and oxidative stress. Unilateral ureteral obstruction (UUO) is a useful and accessible model to identify mechanisms underlying the progression of renal fibrosis. Plasminogen activator inhibitor-1 (PAI-1), a major effector and downstream target of TGF-β1 in the progression of several clinically important fibrotic disorders, is highly up-regulated in UUO and causatively linked to disease severity. SMAD and non-SMAD pathways (pp60(c-src), epidermal growth factor receptor [EGFR], mitogen-activated protein kinase, p53) are required for PAI-1 induction by TGF-β1. SMAD2/3, pp60(c-src), EGFR, and p53 activation are each increased in the obstructed kidney. This review summarizes the molecular basis and translational significance of TGF-β1-stimulated PAI-1 expression in the progression of kidney disease induced by ureteral obstruction. Mechanisms discussed here appear to be operative in other renal fibrotic disorders and are relevant to the global issue of tissue fibrosis, regardless of organ site.

Dispersal state of multiwalled carbon nanotubes elicits profibrogenic cellular responses that correlate with fibrogenesis biomarkers and fibrosis in the murine lung

We developed a dispersal method for multiwalled carbon nanotubes (MWCNTs) that allows quantitative assessment of dispersion on profibrogenic responses in tissue culture cells and in mouse lung. We demonstrate that the dispersal of as-prepared (AP), purified (PD), and carboxylated (COOH) MWCNTs by bovine serum albumin (BSA) and dipalmitoylphosphatidylcholine (DPPC) influences TGF-β1, PDGF-AA, and IL-1β production in vitro and in vivo. These biomarkers were chosen based on their synergy in promoting fibrogenesis and cellular communication in the epithelial-mesenchymal cell trophic unit in the lung. The effect of dispersal was most noticeable in AP- and PD-MWCNTs, which are more hydrophobic and unstable in aqueous buffers than hydrophilic COOH-MWCNTs. Well-dispersed AP- and PD-MWCNTs were readily taken up by BEAS-2B, THP-1 cells, and alveolar macrophages (AM) and induced more prominent TGF-β1 and IL-1β production in vitro and TGF-β1, IL-1β, and PDGF-AA production in vivo than nondispersed tubes. Moreover, there was good agreement between the profibrogenic responses in vitro and in vivo as well as the ability of dispersed tubes to generate granulomatous inflammation and fibrosis in airways. Tube dispersal also elicited more robust IL-1β production in THP-1 cells. While COOH-MWCNTs were poorly taken up in BEAS-2B and induced little TGF-β1 production, they were bioprocessed by AM and induced less prominent collagen deposition at sites of nongranulomatous inflammation in the alveolar region. Taken together, these results indicate that the dispersal state of MWCNTs affects profibrogenic cellular responses that correlate with the extent of pulmonary fibrosis and are of potential use to predict pulmonary toxicity.

Identification of common mechanisms between endometriosis and ovarian cancer

PURPOSE

To determine common molecular markers between endometriosis and ovarian cancer.

METHODS

Patients included women who underwent laparoscopic excision of ovarian endometriotic lesions (n = 7), healthy non-pregnant women with normal pelvises, who underwent excision of normal peritoneum (n = 7). Two epithelial ovarian cancer (EOC) cell lines were also utilized. Expression of transforming growth factor (TGF)-β1, cyclooxygenase (COX)-2, vascular endothelial growth factor (VEGF), estrogen receptor (ER)-1α, progesterone receptor (PR), androgen receptor (AR), and aromatase was evaluated by real-time RT-PCR.

RESULTS

Endometriosis and EOC cells manifested significantly higher mRNA levels of TGF-β1, COX-2, VEGF, ER-1α, AR, and aromatase, while they expressed significantly lower mRNA levels of PR.

CONCLUSIONS

Increased TGF-β1, COX-2, VEGF, ER-1α, AR, and aromatase and decreased PR in endometriotic as well as EOC cells suggests a potential association between these two disease processes. This association is important, as it may reveal common mechanisms for both diseases.

TGF-β1 stimulates mouse macrophages to express APRIL through Smad and p38MAPK/CREB pathways

A proliferation-inducing ligand (APRIL), a new TNF family member, supports B-cell survival and tumor cell proliferation. APRIL is secreted as a soluble protein by macrophages, dendritic cells and activated T cells. However, factors involved in regulation of APRIL expression are as yet unknown. In this study, we investigated the effect of TGF-β1 on APRIL expression in P388D1, a mouse macrophage cell line. TGF-β1 induced APRIL mRNA expression in a time- and dose-dependent manner. One nanogram per milliliter of TGF-β1 was optimal and APRIL transcripts appeared as early as 3 h after stimulation. Based on our studies, which included overexpression of Smad3, DN-Smad3, and sh-Smad3, we found that Smad3 mediates APRIL transcription at least partially. Further, experiments using inhibitors revealed that p38MAPK and CREB are also involved in TGF-β1-induced APRIL expression. These results suggest that TGF-β1, through Smad3 and p38MAPK/CREB signaling pathways, stimulates APRIL expression in macrophages.

Elevated transforming growth factor-beta 1 (TGF-β1) levels in human fracture healing

INTRODUCTION

Transforming growth factor-beta 1(TGF-β1) is a regulatory protein, involved in bone fracture healing. Circulating TGF-β1 levels have been reported to be a predictor of delayed bone healing and non-union, suggesting active relationship between tissue and circulating TGF-β1 in fracture healing. The purpose of this study was to analyse TGF-β1 local and serum concentrations in fracture healing to further contribute to the understanding of molecular regulation of fracture healing.

PATIENTS AND METHODS

Serum samples of 113 patients with long bone fractures were collected over a period of 6 months following a standardised time schedule. TGF-β1 serum concentrations were measured using ELISA. Patients were assigned to 2 groups: Group 1 contained 103 patients with physiological healing. Group 2 contained 10 patients with impaired healing. Patients in both groups were matched. One patient of the group 2 had to be excluded because of missing match partner. In addition, fracture haematoma from 11 patients of group 1 was obtained to analyse local TGF-β1 concentrations. 33 volunteers donated serum which served as control.

RESULTS

TGF-β1 serum concentrations increased during the early healing period and were significantly higher in patients with physiological healing compared to controls (P=0.04). Thereafter, it decreased continuously between weeks 2 and 8 and fell again after week 8. TGF-β1 serum concentrations in patients with physiological healing were significantly higher at week 24 compared to controls (P=0.05). In non-unions, serum concentrations differed significantly from those of controls at week 6 (P=0.01). No significant difference in between patients with physiological and impaired fracture healing was observed. Fracture haematoma contained significantly higher TGF-β1 concentrations than peripheral serum of the patients (P=0.017).

CONCLUSION

Elevated levels of TGF-β1 in haematoma and in serum after bone fracture especially during the entire healing process indicate its importance for fracture healing.

SLIT/ROBO1 signaling suppresses mammary branching morphogenesis by limiting basal cell number

In the field of breast biology, there is a growing appreciation for the "gatekeeping function" of basal cells during development and disease processes yet mechanisms regulating the generation of these cells are poorly understood. Here, we report that the proliferation of basal cells is controlled by SLIT/ROBO1 signaling and that production of these cells regulates outgrowth of mammary branches. We identify the negative regulator TGF-β1 upstream of Robo1 and show that it induces Robo1 expression specifically in the basal layer, functioning together with SLIT2 to restrict branch formation. Loss of SLIT/ROBO1 signaling in this layer alone results in precocious branching due to a surplus of basal cells. SLIT2 limits basal cell proliferation by inhibiting canonical WNT signaling, increasing the cytoplasmic and membrane pools of β-catenin at the expense of its nuclear pool. Together, our studies provide mechanistic insight into how specification of basal cell number influences branching morphogenesis.

Genetic deficiency of aldose reductase counteracts the development of diabetic nephropathy in C57BL/6 mice

AIMS/HYPOTHESIS

The aim of the study was to investigate the effects of genetic deficiency of aldose reductase in mice on the development of key endpoints of diabetic nephropathy.

METHODS

A line of Ar (also known as Akr1b3)-knockout (KO) mice, a line of Ar-bitransgenic mice and control C57BL/6 mice were used in the study. The KO and bitransgenic mice were deficient for Ar in the renal glomeruli and all other tissues, with the exception of, in the bitransgenic mice, a human AR cDNA knockin-transgene that directed collecting-tubule epithelial-cell-specific AR expression. Diabetes was induced in 8-week-old male mice with streptozotocin. Mice were further maintained for 17 weeks then killed. A number of serum and urinary variables were determined for these 25-week-old mice. Periodic acid-Schiff staining, western blots, immunohistochemistry and protein kinase C (PKC) activity assays were performed for histological analyses, and to determine the levels of collagen IV and TGF-β1 and PKC activities in renal cortical tissues.

RESULTS

Diabetes-induced extracellular matrix accumulation and collagen IV overproduction were completely prevented in diabetic Ar-KO and bitransgenic mice. Ar deficiency also completely or partially prevented diabetes-induced activation of renal cortical PKC, TGF-β1 and glomerular hypertrophy. Loss of Ar results in a 43% reduction in urine albumin excretion in the diabetic Ar-KO mice and a 48% reduction in the diabetic bitransgenic mice (p < 0.01).

CONCLUSIONS/INTERPRETATION

Genetic deficiency of Ar significantly ameliorated development of key endpoints linked with early diabetic nephropathy in vivo. Robust and specific inhibition of aldose reductase might be an effective strategy for the prevention and treatment of diabetic nephropathy.

Epithelial to mesenchymal transition of mesothelial cells in tuberculous pleurisy

PURPOSE

Tuberculous pleurisy is the most frequent extrapulmonary manifestation of tuberculosis. In spite of adequate treatment, pleural fibrosis is a common complication, but the mechanism has not been elucidated. This study is to determine whether epithelial to mesenchymal transition (EMT) of mesothelial cells occurs in tuberculous pleurisy.

MATERIALS AND METHODS

Normal pleural mesothelial cells, isolated from irrigation fluids during operations for primary spontaneous pneumothorax, were characterized by immunofluorescence and reverse transcription polymerase chain reaction (RT-PCR). These cells were treated in vitro with various cytokines, which were produced in the effluents of tuberculous pleurisy. The isolated cells from the effluents of tuberculous pleurisy were analyzed by immunofluorescence and RT-PCR analysis.

RESULTS

The isolated cells from the irrigation fluid of primary spontaneous pneumothorax had epithelial characteristics. These cells, with transforming growth factor-β1 and/or interleukin-1β treatment, underwent phenotypic transition from epithelial to mesenchymal cells, with the loss of epithelial morphology and reduction in cytokeratin and E-cadherin expression. Effluent analysis from tuberculous pleurisy using immunofluorescence and RT-PCR demonstrated two phenotypes that showed mesenchymal characteristics and both epithelial & mesencymal characteristics.

CONCLUSION

Our results suggest that pleural mesothelial cells in tuberculous pleurisy have been implicated in pleural fibrosis through EMT.

Expression of TGF-β1 in the blood during fracture repair in an estrogen-deficient rat model

OBJECTIVES

Previous studies have reported that osteoporosis due to estrogen deficiency influences fracture healing. Transforming growth factor (TGF-b) has been found to be involved in fracture healing via the regulation of the differentiation and activation of osteoblasts and osteoclasts. The current study aimed to determine the effects of estrogen on the expression of TGF-β1 during fracture healing in ovariectomized rats.

METHODS

Thirty female Sprague-Dawley rats weighing 200-250 g were assigned to: (i) a sham-operated group that was given a normal saline; (ii) an ovariectomized control group that was given a normal saline; or (iii) an ovariectomized + estrogen (100 mg/kg/day) group that was treated with conjugated equine estrogen. The right femur of all rats was fractured, and a Kirschner wire was inserted six weeks post-ovariectomy. Treatment with estrogen was given for another six weeks post-fracture. At the end of the study, blood samples were taken, and the right femur was harvested and subjected to biomechanical strength testing.

RESULTS

The percentage change in the plasma TGF-β1 level before treatment was significantly lower in the ovariectomized control and estrogen groups when compared with the sham group (p<0.001). After six weeks of treatment, the percentage change in the plasma TGF-β1 level in the estrogen group was significantly higher compared with the level in the ovariectomized control group (p = 0.001). The mean ultimate force was significantly increased in the ovariectomized rats treated with estrogen when compared with the ovariectomized control group (p = 0.02).

CONCLUSION

These data suggest that treatment with conjugated equine estrogen enhanced the strength of the healed bone in estrogen-deficient rats by most likely inducing the expression of TGF-β1.

LMP1 regulates periodontal ligament progenitor cell proliferation and differentiation

LMP1 is an intracellular scaffold protein that contains a PDZ domain and three LIM domains. LMP1 has multiple functions including regulating mesenchymal stem cell (MSC) osteogenesis. Gene delivery of LMP1 induces bone formation in vivo in heterotopic and orthotopic sites. However, little is known about the physiological function and gene regulatory mechanisms of LMP1 in MSCs at the molecular level. Periodontal ligament (PDL) cells are a unique progenitor cell population that can differentiate into multiple cell types, including osteoblasts, adipocytes, or chondrocytes. This study sought to determine the physiological function and gene regulatory mechanisms of LMP1 in PDL cells at the molecular level. We show that LMP1 is upregulated in early stage of PDL cell osteogenic differentiation. Stable gene knockdown of LMP1 by shRNA inhibits DNA synthesis and corresponding cell proliferation in PDL cells, and further leads to decreased mineralization in vitro. Overexpression of LMP1 increases cell proliferation, and PDZ and ww-interacting domains are not sufficient to mediate this effect. Further, we found that in PDL cells, LMP1 is a downstream target gene of TGF-beta1 that is an early signal critical in preosteoblast proliferation and differentiation. TGF-beta1 stimulates PDL cell proliferation, however, this effect is compromised when LMP1 is knocked down. We further identified that the activation of TAK1-JNK/p38 kinase cascade is involved in the LMP1 gene regulation by TGF-beta1. We conclude that LMP1 is a downstream gene of TGF-beta1, involved in PDL cell proliferation. Our findings advance the understanding of the physiological function of LMP1 and define a regulatory mechanism of LMP1 in PDL progenitor cells and other MSCs.

Hepatitis C virus regulates transforming growth factor beta1 production through the generation of reactive oxygen species in a nuclear factor kappaB-dependent manner

BACKGROUND & AIMS

The generation of oxidative stress and transforming growth factor beta1 (TGF-beta1) production play important roles in liver fibrogenesis. We have previously shown that hepatitis C virus (HCV) increases hepatocyte TGF-beta1 expression. However, the mechanisms by which this induction occurs have not been well studied. We explored the possibility that HCV infection regulates TGF-beta1 expression through the generation of reactive oxygen species (ROS), which act through > or =1 of the p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and nuclear factor kappaB (NFkappaB) signaling pathways to induce TGF-beta1 expression.

METHODS

We used small molecule inhibitors and short interfering RNAs to knock down these pathways to study the mechanism by which HCV regulates TGF-beta1 production in the infectious JFH1 model.

RESULTS

We demonstrated that HCV induces ROS and TGF-beta1 expression. We further found that JFH1 induces the phosphorylation of p38MAPK, JNK, ERK, and NFkappaB. We also found that HCV-mediated TGF-beta1 enhancement occurs through a ROS-induced and p38 MAPK, JNK, ERK1/2, NFkappaB-dependent pathway.

CONCLUSIONS

These findings provide further evidence to support the hypothesis that HCV enhances hepatic fibrosis progression through the generation of ROS and induction of TGF-beta1. Strategies to limit the viral induction of oxidative stress appear to be warranted to inhibit fibrogenesis.

Comparison of liver regeneration after a splenectomy and splenic artery ligation in a dimethylnitrosamine-induced cirrhotic rat model

AIM

A splenectomy and splenic artery ligation accelerate liver regeneration and improve liver function after a hepatectomy. However, there are no studies that directly compared the effects of a splenectomy and splenic artery ligation. In the present study, we compared the effects of a splenectomy and splenic artery ligation in cirrhotic rats.

METHODS

Dimethylnitrosamine (DMN) was administered intraperitoneally for 4 weeks to induce cirrhosis. The rats were divided into three groups: sham operation (CT group), splenic artery ligation (SAL group) and splenectomy (SP group). Liver functions [alanine aminotransferase (ALT) and total bilirubin (T. Bil)], plasma TGF-beta1, histopathological changes, extent of liver fibrosis (fibrotic rate) and regeneration [Ki-67 labelling index(LI)] were investigated in each group.

RESULTS

ALT and T. Bil levels were significantly lower in the SP group than the CT and SAL groups. TGF-beta1 levels were significantly lower in the SP group than in the CT and SAL groups. The fibrotic rate was significantly lower in the SP group than in the CT and SAL groups. The Ki-67 labelling index was significantly higher in the SP group than in the CT and SAL groups.

DISCUSSION

A splenectomy significantly improved liver regeneration with reduction of plasma TGF-beta1 levels compared with splenic artery ligation in DMN-treated cirrhotic rats.

Mesenchymal cell fate and phenotypes in the pathogenesis of emphysema

Emphysema is characterized by the destruction of alveolar parenchymal tissue and the concordant loss of lung epithelial cells, endothelial cells, and interstitial mesenchymal cells. Key features in the pathobiology of emphysema include inflammation, alveolar epithelial cell injury/apoptosis, and excessive activation of extracellular matrix (ECM) proteases. Mesenchymal cells are versatile connective tissue cells that are critical effectors of wound-repair. The excessive loss of connective tissue and the destruction of alveolar septae in emphysema suggest that the mesenchymal cell reparative response to epithelial injury is impaired. Yet, the mechanisms regulating mesenchymal cell (dys)function in emphysema remain poorly understood. We propose that mesenchymal cell fate, modulated by transforming growth factor beta-1 (TGF-beta1) and the balance of ECM proteases and antiproteases, is a critical determinant of the emphysema phenotype. We examine emphysema in the context of wound-repair responses, with a focus on the regulation of mesenchymal cell fate and phenotype. We discuss the emerging evidence supporting that genetic factors, inflammation and environmental factors, including cigarette smoke itself, collectively impair mesenchymal cell survival and function, thus contributing to the pathogenesis of emphysema.