Heat Shock Protein 47 Expression Research Articles

Downregulation of heat shock protein 47 caused lysosomal dysfunction leading to excessive chondrocyte apoptosis

Heat shock protein 47 (HSP47) is a collagen-specific chaperone present in several regions of the endoplasmic reticulum and cytoplasm. Elevated HSP47 expression in cells causes various cancers and fibrotic disorders. However, the consequences of HSP47 downregulation leading to chondrocyte death, as well as the underlying pathways, remain largely unclear. This study presents the first experimental evidence of the localization of HSP47 on lysosomes. Additionally, it successfully designed and generated shRNA HSP47 target sequences to suppress the expression of HSP47 in ATDC5 chondrocytes using lentiviral vectors. By employing a chondrocyte model that has undergone stable downregulation of HSP47, we observed that HSP47 downregulation in chondrocytes, disturbs the acidic homeostatic environment of chondrocyte lysosomes, causes hydrolytic enzyme activity dysregulation, impairs the lysosome-mediated autophagy-lysosome pathway, and causes abnormal expression of lysosomal morphology, number, and functional effector proteins. This implies the significance of the presence of HSP47 in maintaining proper lysosomal function. Significantly, the inhibitor CA-074 Me, which can restore the dysfunction of lysosomes, successfully reversed the negative effects of HSP47 on the autophagy-lysosomal pathway and partially reduced the occurrence of excessive cell death in chondrocytes. This suggests that maintaining proper lysosomal function is crucial for preventing HSP47-induced apoptosis in chondrocytes. The existence of HSP47 is crucial for preserving optimal lysosomal function and autophagic flux, while also inhibiting excessive apoptosis in ATDC5 chondrocytes.

HSP47 in human diseases: Navigating pathophysiology, diagnosis and therapy.

Heat shock protein 47 (HSP47) is a chaperone protein responsible for regulating collagen maturation and transport, directly impacting collagen synthesis levels. Aberrant HSP47 expression or malfunction has been associated with collagen-related disorders, most notably fibrosis. Recent reports have uncovered new functions of HSP47 in various cellular processes. Hsp47 dysregulation in these alternative roles has been linked to various diseases, such as cancer, autoimmune and neurodegenerative disorders, thereby highlighting its potential as both a diagnostic biomarker and a therapeutic target. In this review, we discuss the pathophysiological roles of HSP47 in human diseases, its potential as a diagnostic tool, clinical screening techniques and its role as a target for therapeutic interventions.

Overexpression of heat shock protein 47 is associated with increased proliferation and metastasis in gastric cancer

Here, we investigated that the heat shock protein 47 (HSP47) plays a crucial role in the progression of gastric cancer (GC). We analyzed HSP47 gene expression in GC cell lines and patient tissues. The HSP47 mRNA and protein expression levels were significantly higher in GC cell lines and tumor tissues compared to normal gastric mucosa. Using siRNA to silence the expression of HSP47 in GC cells resulted in a significant reduction in their proliferation, wound healing, migration, and invasion capacities. Additionally, we also showed that the mRNA expression of matrix metallopeptidase-7 (MMP-7), a metastasis-promoting gene, was significantly reduced in HSP47 siRNA-transfected GC cells. We confirmed that the HSP47 promoter region was methylated in the SNU-216 GC cell line expressing low levels of HSP47 and in most non-cancerous gastric tissues. It means that the expression of HSP47 is regulated by epigenetic regulatory mechanisms. These findings suggest that targeting HSP47, potentially through its promoter methylation, could be a useful new therapeutic strategy for treating GC.

Targeting HSP47 for cancer treatment.

Heat shock protein 47 (HSP47) serves as an endoplasmic reticulum residing collagen-specific chaperone and plays an important role in collagen biosynthesis and structural assembly. HSP47 is encoded by the SERPINH1 gene, which is located on chromosome 11q13.5, one of the most frequently amplified regions in human cancers. The expression of HSP47 is regulated by multiple cellular factors, including cytokines, transcription factors, microRNAs, and circular RNAs. HSP47 is frequently upregulated in a variety of cancers and plays an important role in tumor progression. HSP47 promotes tumor stemness, angiogenesis, growth, epithelial-mesenchymal transition, and metastatic capacity. HSP47 also regulates the efficacy of tumor therapies, such as chemotherapy, radiotherapy, and immunotherapy. Inhibition of HSP47 expression has antitumor effects, suggesting that targeting HSP47 is a feasible strategy for cancer treatment. In this review, we highlight the function and expression of regulatory mechanisms of HSP47 in cancer progression and point out the potential development of therapeutic strategies in targeting HSP47 in the future.

HSP47 Increases the Expression of Type I Collagen in Fibroblasts through IRE1α Activation, XBP1 Splicing, and Nuclear Translocation of β-Catenin.

Heat shock protein 47 (HSP47), also known as SERPINH1, functions as a collagen-specific molecular chaperone protein essential for the formation and stabilization of the collagen triple helix. Here, we delved into the regulatory pathways governed by HSP47, shedding light on collagen homeostasis. Our investigation revealed a significant reduction in HSP47 mRNA levels in the skin tissue of older mice as compared to their younger counterparts. The augmented expression of HSP47 employing lentivirus infection in fibroblasts resulted in an increased secretion of type I collagen. Intriguingly, the elevated expression of HSP47 in fibroblasts correlated with increased protein and mRNA levels of type I collagen. The exposure of fibroblasts to IRE1α RNase inhibitors resulted in the reduced manifestation of HSP47-induced type I collagen secretion and expression. Notably, HSP47-overexpressing fibroblasts exhibited increased XBP1 mRNA splicing. The overexpression of HSP47 or spliced XBP1 facilitated the nuclear translocation of β-catenin and transactivated a reporter harboring TCF binding sites on the promoter. Furthermore, the overexpression of HSP47 or spliced XBP1 or the augmentation of nuclear β-catenin through Wnt3a induced the expression of type I collagen. Our findings substantiate that HSP47 enhances type I collagen expression and secretion in fibroblasts by orchestrating a mechanism that involves an increase in nuclear β-catenin through IRE1α activation and XBP1 splicing. This study therefore presents potential avenues for an anti-skin-aging strategy targeting HSP47-mediated processes.

HSP47: A Therapeutic Target in Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterized by a progressive decline in lung function and poor prognosis. The deposition of the extracellular matrix (ECM) by myofibroblasts contributes to the stiffening of lung tissue and impaired oxygen exchange in IPF. Type I collagen is the major ECM component and predominant collagen protein deposited in chronic fibrosis, suggesting that type I collagen could be a target of drugs for fibrosis treatment. Heat shock protein 47 (HSP47), encoded by the serpin peptidase inhibitor clade H, member 1 gene, is a stress-inducible collagen-binding protein. It is an endoplasmic reticulum-resident molecular chaperone essential for the correct folding of procollagen. HSP47 expression is increased in cellular and animal models of pulmonary fibrosis and correlates with pathological manifestations in human interstitial lung diseases. Various factors affect HSP47 expression directly or indirectly in pulmonary fibrosis models. Overall, understanding the relationship between HSP47 expression and pulmonary fibrosis may contribute to the development of novel therapeutic strategies.

Overexpression of heat-shock protein 47 impacts survival of patients with oral squamous cell carcinoma.

The expression of heat-shock protein 47 (HSP47) has been linked to collagen synthesis control and implicated in fibrotic disorders, but more recent studies have demonstrated its role in solid tumors. In this study, we explored the prognostic impact of HSP47 in oral squamous cell carcinomas (OSCC) and determined the in vitro effects of its loss-of-function on viability, proliferation, migration, invasion, and resistance to cisplatin of OSCC cells. The HSP47 expression in tumor samples was assessed by immunohistochemistry in two independent cohorts totaling 339 patients with OSCC, and protein levels were associated with clinicopathological features and survival outcomes. The OSCC cell lines HSC3 and SCC9 were transduced with lentivirus expressing short hairpin RNA to stably silence HSP47 and used in assays to measure cellular viability, proliferation, migration, and invasion. HSP47 was overexpressed in OSCC samples, and its overexpression was significantly and independently associated with poor disease-specific survival and shortened disease-free survival in both OSCC cohorts. The knockdown of HSP47 showed no effects on cell viability or cisplatin sensitivity, but impaired significantly proliferation, migration, and invasion of OSCC cells, with stronger effects on SCC9 cells. Our results show a significant prognostic impact of HSP47 overexpression in OSCC and reveal that HSP47 inhibition impairs the proliferation, migration, and invasion of OSCC cells. HSP47 may represent a potential therapeutic target for OSCC.

Heat shock protein 47 promotes cell migration and invasion through AKT signal in non-small cell lung cancer.

Lung cancer is one of the most lethal malignancies, with the highest number of cases and deaths. Non-small cell lung cancer (NSCLC) is the most ordinary type of pathology in lung cancer. Meanwhile, various researchers have reported that heat shock protein 47 (HSP47) plays a vital regulatory role in cancer. However, the role of HSP47 in NSCLC is not clear. Consequently, the current study set out to investigate the role of HSP47 in the pathogenesis of NSCLC. First, we evaluated the expression patterns of HSP47 in NSCLC cell lines related to human normal lung epithelial cells, and HSP47 was found to be highly expressed in NSCLC cell lines. In addition, inhibiting the expression of HSP47 brought about marked repression in cell proliferation, migration and invasion in PC-9 cells. On the contrary, cell proliferation, migration and invasion were all elevated after over-expression of HSP47. Mechanistical experimentation further illustrated that protein kinase B (AKT) signal was repressed after inhibition of HSP47, and the influence of sh-HSP47 on cell proliferation, migration and invasion was countered by epidermal growth factor. Lastly, in-vivo animal models demonstrated that inhibition of HSP47 repressed cell tumorigenesis and AKT signal. Collectively, our findings illustrated that HSP47 was highly expressed in NSCLC cell lines, whereas inhibition of HSP47 repressed cell migration and invasion by diminishing the AKT signal. Inhibition of HSP47 also exhibited strong therapeutic effects on NSCLC in vivo.

MiR-29b Regulates TGF-β1-Induced Epithelial-Mesenchymal Transition by Inhibiting Heat Shock Protein 47 Expression in Airway Epithelial Cells.

Tissue remodeling contributes to ongoing inflammation and refractoriness of chronic rhinosinusitis (CRS). During this process, epithelial-mesenchymal transition (EMT) plays an important role in dysregulated remodeling and both microRNA (miR)-29b and heat shock protein 47 (HSP47) may be engaged in the pathophysiology of CRS. This study aimed to determine the role of miR-29b and HSP47 in modulating transforming growth factor (TGF)-β1-induced EMT and migration in airway epithelial cells. Expression levels of miR-29b, HSP47, E-cadherin, α-smooth muscle actin (α-SMA), vimentin and fibronectin were assessed through real-time PCR, Western blotting, and immunofluorescence staining. Small interfering RNA (siRNA) targeted against miR-29b and HSP47 were transfected to regulate the expression of EMT-related markers. Cell migration was evaluated with wound scratch and transwell migration assay. miR-29b mimic significantly inhibited the expression of HSP47 and TGF-β1-induced EMT-related markers in A549 cells. However, the miR-29b inhibitor more greatly induced the expression of them. HSP47 knockout suppressed TGF-β1-induced EMT marker levels. Functional studies indicated that TGF-β1-induced EMT was regulated by miR-29b and HSP47 in A549 cells. These findings were further verified in primary nasal epithelial cells. miR-29b modulated TGF-β1-induced EMT-related markers and migration via HSP47 expression modulation in A549 and primary nasal epithelial cells. These results suggested the importance of miR-29b and HSP47 in pathologic tissue remodeling progression in CRS.

High glucose induces HSP47 expression and promotes the secretion of inflammatory factors through the IRE1α/XBP1/HIF-1α pathway in retinal Müller cells.

Diabetic retinopathy, a common complication of diabetes, is the leading cause of blindness globally. Müller cells are key players in diabetes-associated retinal inflammation and dysfunction. However, the pathological changes of Müller cells in response to high glucose (HG) and the underlying mechanism remain unclear. The aim of the present study was to investigate the key role of heat shock protein 47 (HSP47) in HG-induced unfolded protein and inflammatory responses. Primary mouse Müller cells were starved in serum-free DMEM overnight and then treated with HG (30 mM) for 0, 6, 12 or 24 h. It was observed that HG (30 mM) significantly induced the protein expression of HSP47, inositol-requiring transmembrane kinase and endonuclease-1α (IRE1α) and spliced X-box-binding protein 1 (XBP1s) in primary mouse Müller cells compared with the untreated group. In addition, the immunoprecipitation results revealed that HSP47 directly interacted with IRE1α, and this interaction was significantly enhanced by HG exposure for 12 or 24 h compared with the untreated group. Furthermore, small interfering RNA-mediated silencing of HSP47 significantly suppressed HG-induced activation of the IRE1α/XBP1s/hypoxia inducible factor-1 subunit α (HIF-1α) pathway and upregulation of the mRNA expression levels of the inflammatory cytokines vascular endothelial growth factor, platelet-derived growth factor subunit B, inducible nitric oxide synthase and angiopoietin-2 in Müller cells. Furthermore, overexpression of IRE1α or HIF-1α partially attenuated HSP47-siRNA-mediated inhibition of inflammatory cytokine expression in Müller cells. Collectively, these results indicated that HG may induce HSP47 expression and promote the inflammatory response through enhancing the interaction between HSP47 and IRE1α, and activating the IRE1α/XBP1s/HIF-1α pathway in retinal Müller cells.

Heat shock protein 47 confers chemoresistance on pancreatic cancer cells by interacting with calreticulin and IRE1α.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most chemoresistant cancers. An understanding of the molecular mechanism by which PDAC cells have a high chemoresistant potential is important for improvement of the poor prognosis of patients with PDAC. Here we show for the first time that disruption of heat shock protein 47 (HSP47) enhances the efficacy of the therapeutic agent gemcitabine for PDAC cells and that the efficacy is suppressed by reconstituting HSP47 expression. HSP47 interacts with calreticulin (CALR) and the unfolded protein response transducer IRE1α in PDAC cells. Ablation of HSP47 promotes both the interaction of CALR with sarcoplasmic/endoplasmic reticulum Ca2+‐ATPase 2 and interaction of IRE1α with inositol 1,4,5‐triphosphate receptor, which generates a condition in which an increase in intracellular Ca2+ level is prone to be induced by oxidative stimuli. Disruption of HSP47 enhances NADPH oxidase‐induced generation of intracellular reactive oxygen species (ROS) and subsequent increase in intracellular Ca2+ level in PDAC cells after treatment with gemcitabine, resulting in the death of PDAC cells by activation of the Ca2+/caspases axis. Ablation of HSP47 promotes gemcitabine‐induced suppression of tumor growth in PDAC cell‐bearing mice. Overall, these results indicated that HSP47 confers chemoresistance on PDAC cells and suggested that disruption of HSP47 may improve the efficacy of chemotherapy for patients with PDAC.

Molecular and Histological Evidence Detailing Clinically Observed Skin Improvement Following Cryolipolysis.

BackgroundIn addition to body contouring, there is anecdotal and clinical evidence of reduced laxity caused by skin tightening after cryolipolysis. However, it has not been established how cryolipolysis triggers dermal changes. ObjectivesThe aim of this study was to investigate the fundamental mechanisms behind clinically observed dermal changes by molecular and immunohistochemistry (IHC) analytical methods.MethodsThis feasibility study involved 7 subjects who received cryolipolysis treatment. Tissue samples were harvested from 3 days to 5 weeks after treatment. RNA-sequencing examined differential gene expression of major collagens. RNA in situ hybridization (RNA-ISH) investigated the distribution of 1 of the gene markers for collagen type I (COL1A1). IHC for procollagen type I, heat shock protein 47 (HSP47), transforming growth factor β (TGF-β), and tropoelastin was performed and quantified.ResultsGene expression analysis highlighted a gradual upregulation of collagen mRNA genes. RNA-ISH confirmed upregulation of COL1A1 mRNA and showed a homogeneous distribution through the dermis. IHC showed increases in protein expression. Quantification revealed a 3.62-fold increase of procollagen type I (P < 0.0071), a 2.91-fold increase of TGF-β (P < 0.041), a 1.54-fold increase of HSP47 (P < 0.007), and a 1.57-fold increase of tropoelastin (P < 0.39) compared with untreated areas.ConclusionsThis study revealed significant induction of molecular and protein markers of type I collagen, which supports neocollagenesis and may play an essential role in clinically relevant skin improvement. A dermal remodeling process driven by increased TGF-β and higher expression of HSP47 was observed. Overall, these data provide the first evidence of dermal remodeling and clarify the mechanism by which cryolipolysis may induce skin improvement.Level of Evidence: 4

Preoperative heat shock protein 47 levels identify colorectal cancer patients with lymph node metastasis and poor prognosis.

Accumulating evidence suggests that overexpression of heat shock protein 47 (HSP47) increases cancer progression, and that HSP47 level in the tumor-associated stroma may serve as a diagnostic marker in various cancers. The present study aimed to evaluate whether HSP47 gene expression in colorectal cancer (CRC) tissues could be used to identify lymph node (LN) metastasis status preoperatively in patients with CRC. To do so, HSP47 gene expression was determined and its association with the clinicopathological characteristics of patients with CRC was analyzed. A total of 139 surgical specimens from patients with CRC and 36 patients with benign colonic disease undergoing surgery at Mie University Hospital were analyzed. HSP47 gene expression was determined by reverse transcription quantitative PCR using Power SYBR Green PCR methods. Expression level of HSP47 was significantly higher in CRC tissues compared with normal tissue from patients with benign colonic disease. Furthermore, high HSP47 expression was significantly associated with tumor progression, including high T stage, lymph node metastasis and venous invasion, and high TNM stage. High HSP47 expression may therefore serve as a novel predictive biomarker for determining patients with CRC and LN metastasis. According to Kaplan-Meier analysis, patients with high HSP47 expression level had significantly poorer overall survival than those with low HSP47 expression level. Furthermore, multivariate analyses identified HSP47 expression as an independent predictive marker for LN metastasis and poor overall survival in patients with CRC. In summary, the present study demonstrated that HSP47 expression may be considered as a novel biomarker for predicting LN metastasis status and prognosis in patients with CRC.

Decreased Expression of Heat Shock Protein 47 Is Associated with T-2 Toxin and Low Selenium-Induced Matrix Degradation in Cartilages of Kashin-Beck Disease.

Recent evidence suggests a role of type II collagen in Kashin-Beck disease (KBD) degeneration. We aimed to assess the abnormal expression of heat shock protein 47 (HSP47) which is associated with a decrease in type II collagen and an increase in cartilage degradation in KBD. Hand phalange cartilages were collected from KBD and healthy children. Rats were administered with T-2 toxin under the selenium (Se)-deficient diet. ATDC5 cells were seeded on bone matrix gelatin to construct engineered cartilaginous tissue. C28/I2 and ATDC5 cells and engineered tissue were exposed to different concentrations of T-2 toxin with or without Se. Cartilage degeneration was determined through histological evaluation. The distribution and expression of type II collagen and HSP47 were investigated through immunohistochemistry, western blotting, and real-time PCR. KBD cartilages showed increased chondronecrosis and extracellular matrix degradation in deep zone with decreased type II collagen and HSP47 expression. The low-Se + T-2 toxin animal group showed a significantly lower type II collagen expression along with decreased HSP47 expression. Decreased type II collagen and HSP47 in C28/I2 and ATDC5 cells induced by T-2 toxin showed a dose-dependent manner. Hyaline-like cartilage with zonal layers was developed in engineered cartilaginous tissues, with decreased type II collagen and HSP47 expression found in T-2 toxin-treated group. Se-supplementation partially antagonized the inhibitory effects of T-2 toxin in chondrocytes and cartilages. HSP47 plays a role in the degenerative changes of KBD and associated with T-2 toxin-induced decreased type II collagen expression, further promoting matrix degradation.

Therapeutic effect of 1,25(OH)2-VitaminD3 on fibrosis and angiogenesis of peritoneum induced by chlorhexidine

The biological activity of vitamin D, which mediated by the vitamin D receptor, is widespread throughout the body. The present study aimed to define whether 1,25-dihydroxy vitamin D3 (1,25-(OH)2D3) can protect against the progression of peritoneum fibrosis (PF) through its impact on the expression of connective tissue growth factor (CTGF) and heat shock protein 47 (HSP47) in vivo and in vitro. The male Sprague-Dawley (SD) rats of PF were induced by daily intraperitoneally injection of chlorhexidine gluconate (CG) for 4 wks. PF Rats were also treated with calcitriol (i.p. 6 ng/100g*d) from initiation of the CG. In calcitriol rats, the ultrafiltration and the ratio of dialysate urea nitrogen to blood urea nitrogen were improved (P < 0.05), pathological changes and peritoneal thickness were milder than that of the PF group. Calcitriol ameliorated high glucose-induced HSP47 expression in peritoneal mesothelial cells via CTGF down-regulation both at the mRNA level and protein level. Furthermore, calcitriol prevented angiogenic mediators of fibrosis by reduced the expression of CD34 and vascular endothelial growth factor (VEGF). The present study demonstrated that 1,25-(OH)2D3 intervention had a partially protective effect on peritoneum fibrosis, which might inhibit CTGF/HSP47 and CD34/VEGF in the peritoneum tissues.

Expression of Collagen (Types I, III, and V), HSP47, MMP-2, and TIMP-1 in Retrobulbar Adipose Tissue of Patients with Thyroid-Associated Orbitopathy.

Objective This study aimed to investigate the expression of collagen (types I, III, and V), heat shock protein 47 (HSP47), matrix metalloproteinase-2 (MMP-2), and tissue inhibitors of metalloproteinase-1 (TIMP-1) in the retrobulbar adipose tissues of patients with thyroid-associated orbitopathy (TAO). Materials and Methods The retrobulbar adipose tissues were collected from 4 TAO patients undergoing orbital decompression and 4 ocular enucleation patients with atrophic eyeball caused by ocular trauma between May 2019 and September 2019. Masson staining was performed to analyze the differences in collagen expression and degree of histologic fibrosis in each sample. The protein expressions of collagen (types I, III, and V), HSP47, MMP-2, and TIMP-1 were determined by western blotting. The data of western blotting were analyzed using SPSS version 17.0, with independent t-tests. Results The results of Masson staining showed that the expression of collagen fibers in the TAO group was significantly higher than that in the control group, and the fibers were diffuse and irregular in distribution. The expression level of collagen (types I, III, and V), HSP47, MMP-2, and TIMP-1 in the TAO group were significantly higher than that in the control group (P < 0.05). Conclusion The proliferation and fibrosis of retrobulbar adipose tissue in TAO patients might be related to the increased expression of collagen (types I, III, and V) and HSP47 and decreased degradation of extracellular matrix.

Heat shock protein 47 promotes tumor survival and therapy resistance by modulating AKT signaling via PHLPP1 in colorectal cancer.

Objective: Heat shock protein 47 (HSP47) is a collagen-specific molecular chaperone that facilitates collagen maturation. Its role in cancer remains largely unknown. In this study, we investigated the roles of HSP47 in colorectal cancer (CRC) and therapy resistance.Methods: Expression of HSP47 in CRC tissues was examined (1) in paired human CRC/adjacent normal tissues, using real time quantitative reverse transcription polymerase chain reaction (qRT-PCR), The Cancer Genome Atlas (TCGA) database, and 22 independent microarray databases (curated CRC). In vitro studies on several CRC cell lines (HCT116, RKO and CCL228) with modulated HSP47 expression were conducted to assess cell viability and apoptosis (TUNEL assay and caspase-3/-7) during exposure to chemotherapy. AKT signaling and co-immunoprecipitation studies were performed to examine HSP47 and PHLPP1 interaction. In vivo studies using tumor xenografts were conducted to assess the effects of HSP47 modulation on tumor growth and therapy response.Results: HSP47 was upregulated in CRC and was associated with poor prognosis in individuals with CRC. In vitro, HSP47 overexpression supported the survival of CRC cells, whereas its knockdown sensitized cells to 5-fluorouracil (5-FU). HSP47 promoted survival by inhibiting apoptosis, enhancing AKT phosphorylation, and decreasing expression of the AKT-specific phosphatase PHLPP1 when cells were exposed to chemotherapy. These effects were partly results of the interaction between HSP47 and PHLPP1, which decreased PHLPP1 stability and led to more persistent AKT activity. In vivo, HSP47 supported tumor growth despite 5-FU treatment.Conclusions: HSP47 supports the growth of CRC tumors and suppresses the efficacy of chemotherapy via modulation of AKT signaling.

Heat shock protein 47 (HSP47) binds to discoidin domain–containing receptor 2 (DDR2) and regulates its protein stability

Cell-collagen interactions are crucial for cell migration and invasion during cancer development and progression. Heat shock protein 47 (HSP47) is an endoplasmic reticulum-resident molecular chaperone that facilitates collagen maturation and deposition. It has been previously shown that HSP47 expression in cancer cells is crucial for cancer invasiveness. However, exogenous collagen cannot rescue cell invasion in HSP47-silenced cancer cells, suggesting that other HSP47 targets contribute to cancer cell invasion. Here, we show that HSP47 expression is required for the stability and cell-surface expression of discoidin domain-containing receptor 2 (DDR2) in breast cancer tissues. HSP47 silencing reduced DDR2 protein stability, accompanied by suppressed cell migration and invasion. Co-immunoprecipitation results revealed that HSP47 binds to the DDR2 ectodomain. Using a photoconvertible technique and total internal reflection fluorescence microscopy, we further demonstrate that HSP47 expression significantly sustains the membrane localization of the DDR2 protein. These results suggest that binding of HSP47 to DDR2 increases DDR2 stability and regulates its membrane dynamics and thereby enhances cancer cell migration and invasion. Given that DDR2 has a crucial role in the epithelial-to-mesenchymal transition and cancer progression, targeting the HSP47-DDR2 interaction might be a potential strategy for inhibiting DDR2-dependent cancer progression.

Roles of transforming growth factor - β1 and heat shock protein 47 in progression of Schistosoma japonicum-induced hepatic fibrosis

To investigate the dynamic expression of transforming growth factor-β1 (TGF-β1) and heat shock protein 47 (HSP47) and explore their roles in the progression of hepatic fibrosis induced by Schistosoma japonicum infection. Fifty female mice of the ICR strain were randomly divided into the infection group and the normal control group, of 25 mice in each group. Each mouse in the infection group was infected with 20 ± 1 cercariae of S. japonicum via the abdominal skin, while uninfected animals served as normal control. Five mice were sacrificed 4, 6, 8, 10 and 12 weeks post-infection and liver tissues were sampled. Serum HSP47 and TGF-β1 was determined using enzyme-linked immunosorbent assay (ELISA), and the pathological changes of liver specimens were observed with hematoxylin & eosin (HE) staining. In addition, the synthesis of alpha 1 chain of type I collagen (COL1A1) was measured using Masson staining, and the mRNA expression of TGF-β1, HSP47 and COL1A1 was determined using real-time fluorescent quantitative PCR (qPCR) assay. During the period of S. japonicum-induced hepatic fibrosis, the serum HSP47 and TGF-β1 levels and the mRNA expression of TGF - β1, HSP47 and COL1A1 gradually increased with the progression of hepatic fibrosis. The serum levels of HSP47 and TGF-β1 were (179.26 ± 29.87) pg/mL and (22.37 ± 5.21) ng/mL 6 weeks post-infection, respectively, which were significantly greater than those [(150.29 ± 34.91) pg/mL and (18.54 ± 7.78) ng/mL, respectively] in the normal control group (both P values < 0.05). In addition, the mRNA expression of HSP47, COL1A1 and TGF-β1 was (0.86 ± 0.04), (1.17 ± 0.06) and (0.64 ± 0.13) in mouse liver specimens, which was significantly higher than that (0.23 ± 0.03, 0.20 ± 0.02 and 0.38 ± 0.02) in the normal control group (all P values < 0.01). The expression of TGF-β1 and HSP47 during the period of S. japonicum-induced hepatic fibrosis is consistent with the progression of the hepatic fibrosis, and exhibits the same tendency with type I collagen expression. HSP47 is a novel promising diagnosis marker and therapeutic target for S. japonicum-induced hepatic fibrosis.

Ocular instillation of vitamin A–coupled liposomes containing HSP47 siRNA ameliorates dry eye syndrome in chronic GVHD

AbstractChronic graft-versus-host disease (GVHD) profoundly affects the quality of life of long-term survivors of allogeneic hematopoietic stem cell transplantation (SCT). The eyes are frequently involved, and dry eye syndrome is the most common manifestation of ocular chronic GVHD. We explored the role of heat shock protein 47 (HSP47) in ocular GVHD and developed a novel antifibrotic topical therapy using vitamin A–coupled liposomes containing HSP47 small interfering RNA (siRNA) against HSP47 (VA-lip HSP47). In a mouse model of chronic GVHD, infiltration of HSP47+ fibroblasts and massive fibrosis surrounding the lacrimal ducts were observed after allogeneic SCT, leading to impaired tear secretion. After ocular instillation, VA-lip HSP47 was distributed to the lacrimal glands, knocked down HSP47 expression in fibroblasts, reduced collagen deposition, and restored tear secretion after allogeneic SCT. Ocular instillation of VA-lip HSP47 also ameliorated established lacrimal gland fibrosis and dry eye syndrome. VA-lip HSP47 eye drops are a promising prophylactic and therapeutic option against dry eye syndrome in chronic GVHD.