Targeting Borrelia burgdorferi HtpG with a berserker molecule, a strategy for anti-microbial development.

Conventional antimicrobial discovery relies on targeting essential enzymes in pathogenic organisms, contributing to a paucity of new antibiotics to address resistant strains. Here, by targeting a non-essential enzyme, Borrelia burgdorferi HtpG, to deliver lethal payloads, we expand what can be considered druggable within any pathogen. We synthesized HS-291, an HtpG inhibitor tethered to the photoactive toxin verteporfin. Reactive oxygen species, generated by light, enables HS-291 to sterilize Borrelia cultures by causing oxidation of HtpG, and a discrete subset of proteins in proximity to the chaperone. This caused irreversible nucleoid collapse and membrane blebbing. Tethering verteporfin to the HtpG inhibitor was essential, since free verteporfin was not retained by Borrelia in contrast to HS-291. For this reason, we liken HS-291 to a berserker, wreaking havoc upon the pathogen's biology once selectively absorbed and activated. This strategy expands the druggable pathogenic genome and offsets antibiotic resistance by targeting non-essential proteins.

Drug screen identifies verteporfin as a regulator of lipid metabolism in macrophage foam cells.

Arterial macrophage foam cells are filled with cholesterol ester (CE) stored in cytosolic lipid droplets (LDs). Foam cells are central players in progression of atherosclerosis as regulators of lipid metabolism and inflammation, two major driving forces of atherosclerosis development. Thus, foam cells are considered plausible targets for intervention in atherosclerosis. However, a compound that directly regulates the lipid metabolism of LDs in the arterial foam cells has not yet been identified. In this study, we screened compounds that inhibit macrophage foam cell formation using a library of 2697 FDA-approved drugs. From the foam cells generated via loading of human oxidized low-density lipoprotein (oxLDL), we found 21 and 6 compounds that reduced and enhanced accumulations of lipids respectively. Among them, verteporfin most significantly reduced oxLDL-induced foam cell formation whereas it did not display a significant impact on foam cell formation induced by fatty acid. Mechanistically our data demonstrate that verteporfin acts via inhibition of oxLDL association with macrophages, reducing accumulation of CE. Interestingly, while other drugs that reduced foam cell formation did not have impact on pre-existing foam cells, verteporfin treatment significantly reduced their total lipids, CE, and pro-inflammatory gene expression. Together, our study identifies verteporfin as a novel regulator of foam cell lipid metabolism and inflammation and a potential compound for intervention in atherosclerosis.

Hippo/YAP1 inhibition by verteporfin attenuates osteophyte formation in a mouse surgical osteoarthritis model.

Osteophyte is an outgrowth of cartilage formed at the margins of the affected joint through endochondral ossification-like processes, and is one of the most common radiographic features of osteoarthritis (OA) that has been used to define the stage of disease. Osteophyte has been regarded to adapt the joint to the altered biomechanics of OA patients, limits joint movement and represent a source of joint pain, however, the mechanism of osteophyte formation, the morphology characteristics and biomechanical properties of osteophyte cells are remained unclear. In the present study, we isolated osteophyte cells and chondrocytes from late-stage OA patients who underwent total knee replacement surgeries, by applying Atomic Force Microscopy (AFM), we identified osteophyte cells were in irregular shape with dendrites, shrunk cell body, smooth surface and high elastic modulus (23.3 ± 5.4 kPa) when compared with chondrocytes (6.5 ± 1.8 kPa). In addition, osteophyte cells showed higher proliferation ability and colony formation capacity than chondrocytes. Mechanistically, we identified YAP1, the core transcriptional factor of Hippo signaling pathway, was highly expressed in osteophyte cell both at protein and RNA levels. Inactivation of Hippo/YAP1 signaling pathway by Verteporfin is sufficient to inhibit osteophyte cell proliferation in vitro and attenuate osteophyte formation in vivo. In conclusion, the morphology characteristic and biomechanical property of osteophyte cells at single cell level are quite different from chondrocytes, although we could not exclude other regulatory mechanisms, our findings suggested that Hippo/YAP1 is of great importance for osteophyte formation.

Regulation of Hippo/YAP signaling pathway ameliorates cochlear hair cell injury by regulating ferroptosis.

Cisplatin, which is effective for the treatment of solid tumors, also can induce cochlear hair cell damage. Therefore, this study was intended to explore how Hippo/YAP signaling pathway affects the cochlear hair cell injury by regulating ferroptosis. After cisplatin induction, or LAT1-IN-1 (YAP activator) and verteporfin (YAP inhibitor) treatment or transfection, the viability of HEI-OC1 cells was detected by cell counting kit-8 (CCK-8) assay. The iron level and the levels of oxidative stress markers (ROS, MDA and 4-HNE) were analyzed by iron assay kit, reactive oxygen species (ROS), malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) assay kits, respectively. The expression of ferritin light chain (FTL) in HEI-OC1 cells was detected by immunofluorescence and protein expressions of yes associated protein (YAP,) phosphorylated YAP (p-YAP), transferrin receptor (TFRC), glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long-chain family member 4 (ACSL4) and solute carrier family 7 member 11 (SLC7A11) in HEI-OC1 cells were detected by western blot. The transcription of FTL and TFRC by YAP1 was verified by dual-luciferase reporter assay. The transfection efficiency of small interfering RNA (si-RNA) specific to FTL (siRNA-FTL) and TFRC (siRNA-TFRC) was confirmed by reverse transcription­quantitative polymerase chain reaction (RT­qPCR). As a result, cisplatin inhibited the viability of HEI-OC1 cells by increasing free Fe2+ level and decreasing FTL level. LAT1-IN-1 promoted the viability of cisplatin-induced HEI-OC1 cells by suppressing oxidative stress level, free Fe2+ level, ferroptosis and increasing FTL level, while the effect of verteporfin was the opposite. YAP1 transcriptionally regulated the expression of FTL and TFRC. Inhibition of FTL suppressed the viability of cisplatin-induced HEI-OC1 cells by increasing oxidative stress level, free Fe2+ level, ferroptosis and decreasing FTL level, while the effect of TFRC inhibition was the opposite. In conclusion, YAP1 ameliorated cochlear hair cell injury by upregulating FTL and TFRC to suppress ferroptosis.

YAP1 silencing attenuated lung injury/fibrosis but worsened diaphragmatic function by regulating oxidative stress and inflammation response in mice.

Oxidative stress is a crucial mechanism in the pathophysiology of lung injury/fibrosis and diaphragmatic dysfunction. Yes-associated protein 1 (YAP1) is a key oxidative stress response regulator. However, how lung injury/fibrosis and the subsequent YAP1 silencing treatment affect diaphragmatic function remains largely uncharacterized. In this study, mice models of acute lipopolysaccharide (LPS) and paraquat exposure were used to establish acute lung injury and chronic pulmonary fibrosis. AT2 and C2C12 cells were co-cultured under LPS and paraquat challenge. YAP1 was interfered with shRNA given in vivo and verteporfin administration in vitro. Pulmonary histology, contractile properties, and cross-sectional areas (CSAs) of the diaphragm and gastrocnemius were evaluated. Histological and biochemical analyses were performed for targeted biomarker determination. We found that LPS and paraquat caused significant lung injury/fibrosis and significantly reduced the diaphragmatic-specific force and CSAs compared with the control. YAP1 silencing alleviated inflammatory cell infiltration or collagen deposition in the lungs yet worsened the already impaired diaphragmatic function by increasing inflammatory cytokines (IL-6 and TNF-α), mitochondrial reactive oxidative species (ROS) emission, protein degradation (Murf-1, atrogin-1, and calpain), and decreasing antioxidant capabilities (superoxide dismutase 2 and glutathione peroxidase). No significant improvements were observed in diaphragmatic function by transient YAP1 knockdown in the gastrocnemius. In vitro, LPS- or paraquat-caused cytotoxicity in AT2 cells was mostly alleviated by verteporfin in a concentration that was 20-fold higher than that in C2C12 cells (20 and 1 µg/mL, respectively). Finally, 0.5 µg/mL of verteporfin significantly ameliorated hydrogen peroxide-induced proteolytic activity and antioxidant enzyme suppression in C2C12 cells, whereas 2 µg/mL of verteporfin deteriorated the same. Collectively, lung injury/fibrosis adversely affects the diaphragm. YAP1 inhibition alleviates lung injury/fibrosis but worsens diaphragmatic function potentially by enhancing inflammatory cytokines and ROS-mediated protein degradation. This disparity might be attributed to differences in susceptibility to YAP1 inhibition between muscles and the lungs.

YAP, a novel target regulates F-actin rearrangement-associated CAFs transformation and promotes colorectal cancer cell progression.

Colorectal cancer (CRC) progression is strongly influenced by the tumor microenvironment (TME) in which cancer-associated fibroblasts (CAFs) are the major components influencing CRC growth and progression. The present study aimed to investigate the effect of YAP on F-actin arrangement in CAF transformation and the possibility of using YAP as a target for inhibiting CRC growth and progression. Conditioned media were collected from direct interaction between CRC cells and fibroblasts. CAF markers were investigated by flow cytometry, western blot analysis, and immunofluorescence assay in CM-treated fibroblasts. Promoting the CRC progression of conditioned media was determined in CRC cells by using MTT assay, fluorescence assay, wound healing assay, transwell migration assay, and tubulogenesis. The results showed that the conditioned media induced the expression of CAF markers associated with the central rearrangement of F-actin in colon fibroblasts, upregulating and promoting the nuclear translocation of YAP. The conditioned media also significantly promoted the proliferation, migration, invasion, and angiogenesis of CRC cells. Interestingly, Verteporfin, a YAP inhibitor during cocultivation, abolished the conversion of CAFs and inhibited proliferation, migration, invasion, and angiogenesis in CRC cells. Moreover, bioinformatics analysis was employed to determine the potential role of YAP as a prognostic marker in CRC patients from databases. The results suggested that YAP has higher expression in CRC patients and is associated with a poor prognosis. In conclusion, these findings demonstrate that YAP-related F-actin rearrangement may be a potential new target of combination therapy with a focus on targeting TME.

Verteporfin ameliorates fibrotic aspects of Dupuytren's disease nodular fibroblasts irrespective the activation state of the cells.

Dupuytren's disease is a chronic, progressive fibroproliferative condition of the hand fascia which results in digital contraction. So far, treatments do not directly interfere with the (myo)fibroblasts that are responsible for the formation of the collagen-rich cords and its contraction. Here we investigated whether verteporfin (VP) is able to inhibit the activation and subsequent differentiation of DD nodular fibroblasts into myofibroblasts. Fibroblasts were isolated from nodules of 7 Dupuytren patients. Cells are treated (1) for 48 h with 5 ng/ml transforming growth factor ß1 (TGF-ß1) followed by 48 h with/without 250 nM VP in the absence of TGF-ß1, or treated (2) for 48 h with TGF-ß1 followed by 48 h with/without VP in the presence of TGF-ß1. mRNA levels were measured by means of Real-Time PCR, and proteins were visualized by means of Western blotting and/or immunofluorescence. Quantitative data were statistically analyzed with GraphPad Prism using the paired t-test. We found that fibroblasts activated for 48 h with TGF-ß1 show a decrease in mRNA levels of COL1A1, COL3A1, COL4A1, PLOD2, FN1EDA, CCN2 and SERPINE1 when exposed for another 48 h with VP, whereas no decrease is seen for ACTA2, YAP1, SMAD2 and SMAD3 mRNA levels. Cells exposed for an additional 48 h with TGF-ß1, but now in the presence of VP, are not further activated anymore, whereas in the absence of VP the cells continue to differentiate into myofibroblasts. Collagen type I, fibronectin-extra domain A, α-smooth muscle actin, YAP1, Smad2 and Smad3 protein levels were attenuated by both VP treatments. We conclude that VP has strong anti-fibrotic properties: it is able to halt the differentiation of fibroblasts into myofibroblasts, and is also able to reverse the activation status of fibroblasts. The decreased protein levels of YAP1, Smad2 and Smad3 in the presence of VP explain in part the strong anti-fibrotic properties of VP. Verteporfin is clinically used as a photosensitizer for photodynamic therapy to eliminate abnormal blood vessels in the eye to attenuate macular degeneration. The antifibrotic properties of VP do not rely on photo-activation, as we used the molecule in its non-photoinduced state.

Sestrin2 attenuates renal damage by regulating Hippo pathway in diabetic nephropathy.

Glomerular mesangial cell proliferation and extracellular matrix accumulation contribute to the progression of diabetic nephropathy (DN). As a conserved stress-inducible protein, sestrin2 (Sesn2) plays critical role in the regulation of oxidative stress, inflammation, autophagy, metabolism, and endoplasmic reticulum stress. In this study, we investigated the role of Sesn2 on renal damage in diabetic kidney using transgenic mice overexpressing Sesn2 and the effect of Sesn2 on mesangial cell proliferation and extracellular matrix accumulation in diabetic conditions and the possible molecular mechanisms involved. Sesn2 overexpression improved renal function and decreased glomerular hypertrophy, albuminuria, mesangial expansion, extracellular matrix accumulation, and TGF-ß1 expression, as well as oxidative stress in diabetic mice. In vitro experiments, using human mesangial cells (HMCs), revealed that Sesn2 overexpression inhibited high glucose (HG)-induced proliferation, fibronectin and collagen IV production, and ROS generation. Meanwhile, Sesn2 overexpression restored phosphorylation levels of Lats1 and YAP and inhibited TEAD1 expression. Inhibition of Lats1 accelerated HG-induced proliferation and expression of fibronectin and collagen IV. Verteporfin, an inhibitor of YAP, suppressed HG-induced proliferation and expression of fibronectin and collagen IV. However, Sesn2 overexpression reversed Lats1 deficiency-induced Lats1 and YAP phosphorylation, nuclear expression levels of YAP and TEAD1, and proliferation and fibronectin and collagen IV expressions in HMCs exposed to HG. In addition, antioxidant NAC or tempol treatment promoted phosphorylation of Lats1 and YAP and inhibited TEAD1 expression, proliferation, and fibronectin and collagen IV accumulation in HG-treated HMCs. Taken together, Sesn2 overexpression inhibited mesangial cell proliferation and fibrosis via regulating Hippo pathway in diabetic nephropathy. Induction of Sesn2 may be a potential therapeutic target in diabetic nephropathy.

Verteporfin synergizes the efficacy of anti-PD-1 in cholangiocarcinoma.

BACKGROUND: Cholangiocarcinoma (CCA) is one of the primary hepatobiliary malignant neoplasms with only 10% of 5-year survival rate. Promising immunotherapy with the blockade of immune checkpoints has no clear benefit in CCA. The inhibition of YAP1 signaling by verteporfin has shown encouraging results by inhibiting cell proliferation and inducing apoptosis. This study aimed to evaluate the potential benefit of the combination of verteporfin and anti-programmed cell death 1 (PD-1) in CCA mouse model. METHODS: We assessed the cytotoxicity of verteporfin in human CCA cell lines in vitro, including both intrahepatic CCA and extrahepatic CCA cells. We examined the in vitro effect of verteporfin on cell proliferation, apoptosis, and stemness. We evaluated the in vivo efficacy of verteporfin, anti-PD-1, and a combination of both in subcutaneous CCA mouse model. RESULTS: Our study showed that verteporfin reduced tumor cell growth and enhanced apoptosis of human CCA tumor cells in vitro in a dose-dependent fashion. Nevertheless, verteporfin impaired stemness evidenced by reduced spheroid formation and colony formation, decreased numbers of cells with aldehyde dehydrogenase activity and positive cancer stem cell markers (all P < 0.05). The combination of verteporfin and anti-PD-1 reduced tumor burden in CCA subcutaneous SB1 tumor model compared to either agent alone. CONCLUSIONS: Verteporfin exhibits antitumor effects in both intrahepatic and extrahepatic CCA cell lines and the combination with anti-PD-1 inhibited tumor growth.

Verteporfin is a substrate-selective γ-secretase inhibitor that binds the amyloid precursor protein transmembrane domain.

This work reports substrate-selective inhibition of a protease with broad substrate specificity based on direct binding of a small-molecule inhibitor to the substrate. The target for these studies was γ-secretase protease, which cleaves dozens of different single-span membrane protein substrates, including both the C99 domain of the human amyloid precursor protein and the Notch receptor. Substrate-specific inhibition of C99 cleavage is desirable to reduce production of the amyloid-ß polypeptide without inhibiting Notch cleavage, a major source of toxicity associated with broad specificity γ-secretase inhibitors. In order to identify a C99-selective inhibitors of the human γ-secretase, we conducted an NMR-based screen of FDA-approved drugs against C99 in model membranes. From this screen, we identified the small-molecule verteporfin with these properties. We observed that verteporfin formed a direct 1:1 complex with C99, with a KD of 15-47 µM (depending on the membrane mimetic used), and that it did not bind the transmembrane domain of the Notch-1 receptor. Biochemical assays showed that direct binding of verteporfin to C99 inhibits γ-secretase cleavage of C99 with IC50 values in the range of 15-164 µM, while Notch-1 cleavage was inhibited only at higher concentrations, and likely via a mechanism that does not involve binding to Notch-1. This work documents a robust NMR-based approach to discovery of small-molecule binders to single-span membrane proteins and confirmed that it is possible to inhibit γ-secretase in a substrate-specific manner.

Targeted inhibition of YAP/TAZ alters the biological behaviours of keloid fibroblasts.

Abnormal activation of fibroblasts plays a crucial role in keloid development. However, the mechanism of fibroblast activation remains to be determined. YAP/TAZ are key molecules in the Hippo signalling pathway that promote cell proliferation and inhibit apoptosis. Here, we show that keloid fibroblasts have higher levels of YAP/TAZ mRNA and proteins on primary culture. Targeted knockdown of endogenous YAP or TAZ significantly inhibited cell proliferation, reduced cell migration, induced cell apoptosis and down-regulated collagen1a1 production by keloid fibroblasts. Moreover, we demonstrate that verteporfin, an inhibitor of YAP/TAZ, has similar but stronger inhibitory effects on fibroblasts compared to YAP/TAZ knockdown. Our study provides evidence that YAP/TAZ may be involved in the pathogenesis of keloids. Targeted inhibition of YAP/TAZ could change the biological behaviours of fibroblasts and can potentially be used as therapy for keloids.

The Antiasthma Medication Ciclesonide Suppresses Breast Cancer Stem Cells through Inhibition of the Glucocorticoid Receptor Signaling-Dependent YAP Pathway.

Ciclesonide is an FDA-approved glucocorticoid used to treat asthma and allergic rhinitis. However, whether it has anticancer and anti-cancer stem cell (CSC) effects is unknown. This study focused on investigating the effect of ciclesonide on breast cancer and CSCs and determining its underlying mechanism. Here, we showed that ciclesonide inhibits breast cancer and CSC formation. Similar glucocorticoids-dexamethasone and prednisone-did not inhibit CSC formation. Ciclesonide-induced glucocorticoid receptor (GR) degradation was dependent on ubiquitination. We showed via GR small interfering RNA (siRNA) that GR plays an important role in CSC formation. We showed via western blot and immunofluorescence assays that ciclesonide reduces the nuclear level of GR. The GR antagonist RU-486 also inhibited CSC formation. Ciclesonide reduced the protein level of the Hippo transducer Yes-associated protein (YAP). GR siRNA induced a decrease in YAP protein expression and inhibited mammosphere formation. The YAP inhibitor verteporfin inhibited CSC formation and transcription of the connective tissue growth factor and cysteine-rich protein 61 genes. The GR/YAP1 pathway regulated breast CSC formation. We showed that the GR/YAP signaling pathway regulates breast CSC formation and revealed a new approach for targeting GR and YAP to inhibit CSC formation.

Intractable Ocular Diseases and Treatment Progress.

In recent years, with the aging of the population and the frequent use of electronic devices, many eye diseases have shown a linear upward trend, such as dry eye disease, glaucoma, cataract, age-related macular degeneration, and diabetic retinopathy. These diseases are often chronic and difficult to cure. Based on the structure and barrier of the human eye, this review describes the pathogenesis and treatments of several intractable eye diseases and summarizes the advanced ocular drug delivery systems to provide new treatment ideas for these diseases. Finally, we also look forward to the prospect of RNAi therapy in the treatment of eye diseases.

Collagen Complexity Spatially Defines Microregions of Total Tissue Pressure in Pancreatic Cancer.

The poor efficacy of systemic cancer therapeutics in pancreatic ductal adenocarcinoma (PDAC) is partly attributed to deposition of collagen and hyaluronan, leading to interstitial hypertension collapsing blood and lymphatic vessels, limiting drug delivery. The intrinsic micro-regional interactions between hyaluronic acid (HA), collagen and the spatial origins of mechanical stresses that close off blood vessels was investigated here. Multiple localized pressure measurements were analyzed with spatially-matched histochemical images of HA, collagen and vessel perfusion. HA is known to swell, fitting a linear elastic model with total tissue pressure (TTP) increasing above interstitial fluid pressure (IFP) directly with collagen content. However, local TTP appears to originate from collagen area fraction, as well as increased its entropy and fractal dimension, and morphologically appears to be maximized when HA regions are encapsulated by collagen. TTP was inversely correlated with vascular patency and verteporfin uptake, suggesting interstitial hypertension results in vascular compression and decreased molecular delivery in PDAC. Collagenase injection led to acute decreases in total tissue pressure and increased drug perfusion. Large microscopic variations in collagen distributions within PDAC leads to microregional TPP values that vary on the hundred micron distance scale, causing micro-heterogeneous limitations in molecular perfusion, and narrows viable treatment regimes for systemically delivered therapeutics.