NLRP3 deficiency protects against acetaminophen‑induced liver injury by inhibiting hepatocyte pyroptosis

Acetaminophen (APAP) overdose is the primary cause of drug‑induced acute liver failure in numerous Western countries. NLR family pyrin domain containing 3 (NLRP3) inflammasome activation serves a pivotal role in the pathogenesis of various forms of acute liver injury. However, the cellular source for NLRP3 induction and its involvement during APAP‑induced hepatotoxicity have not been thoroughly investigated. In the present study, hematoxylin and eosin staining was performed to assess histopathological changes of liver tissue. Immunohistochemistry staining(NLRP3, Caspase‑1, IL‑1β, GSDMD and Caspase‑3), western blotting (NLRP3, Caspase‑1, IL‑1β, GSDMD and Caspase‑3) and RT‑qPCR (NLRP3, Caspase‑1 and IL‑1β) were performed to assess the expression of NLRP3/GSDMD signaling pathway. TUNEL staining was performed to assess apoptosis of liver tissue. The serum expression levels of inflammatory factors (IL‑6, IL‑18, IL‑1β and TNF‑α) were assessed using ELISA and inflammation of liver tissue was assessed using immunohistochemistry (Ly6G and CD68) and RT‑qPCR (TNF‑α, Il‑6, Mcp‑1, Cxcl‑1, Cxcl‑2). A Cell Counting Kit‑8 was performed to assess cell viability and apoptosis. Protein and gene expression were analyzed by western blotting (PCNA, CCND1) and RT‑qPCR (CyclinA2, CyclinD1 and CyclinE1). Through investigation of an APAP‑induced acute liver injury model (AILI), the present study demonstrated that APAP overdose induced activation of NLRP3 and cleavage of gasdermin D (GSDMD) in hepatocytes, both in vivo and in vitro. Additionally, mice with hepatocyte‑specific knockout of Nlrp3 exhibited reduced liver injury and lower mortality following APAP intervention, accompanied by decreased infiltration of inflammatory cells and attenuated inflammatory response. Furthermore, pharmacological blockade of NLRP3/GSDMD signaling using MCC950 or disulfiram significantly ameliorated liver injury and reduced hepatocyte death. Notably, hepatocyte Nlrp3 deficiency promoted liver recovery by enhancing hepatocyte proliferation. Collectively, the present study demonstrated that inhibition of the NLRP3 inflammasome protects against APAP‑induced acute liver injury by reducing hepatocyte pyroptosis and suggests that targeting NLRP3 may hold therapeutic potential for treating AILI.

Ferroptosis in organ ischemia-reperfusion injuries: recent advancements and strategies

Ferroptosis is a newly discovered type of regulated cell death participated in multiple diseases. Different from other classical cell death programs such as necrosis and apoptosis, ferroptosis involving iron-catalyzed lipid peroxidation is characterized by Fe2+ accumulation and mitochondria alterations. The phenomenon of oxidative stress following organ ischemia-reperfusion (I/R) has recently garnered attention for its connection to the onset of ferroptosis and subsequent reperfusion injuries. This article provides a comprehensive overview underlying the mechanisms of ferroptosis, with a further focus on the latest research progress regarding interference with ferroptotic pathways in organ I/R injuries, such as intestine, lung, heart, kidney, liver, and brain. Understanding the links between ferroptosis and I/R injury may inform potential therapeutic strategies and targeted agents.

AQP5 deficiency promotes the senescence of lens epithelial cells through mitochondrial dysfunction

Cataract is lens opacity, which is a common blinding eye disease worldwide. Aquaporin 5 (AQP5) is expressed in the human and mouse lenses. This study aimed to investigate the underlying mechanisms of AQP5 in the senescence of lens epithelial cells (LECs). Primary LECs were isolated and cultured from Aqp5+/+ and Aqp5-/- mice. Western blot or immunofluorescence staining of p16, Ki67, MitoSOX, JC-1 and phalloidin was used in the experiments to evaluate the changes in the primary LECs. The primary Aqp5-/- LECs showed increased p16 expression and mitochondrial reactive oxygen species, decreased mitochondrial membrane potential and activity, and cytoskeletal disorders. When the cells were pretreated with Mito-TEMPO, the Aqp5-/- mice showed decreased p16 expression, reduced mitochondrial dysfunction and cytoskeletal disorders. Our results revealed that AQP5 deficiency promotes the senescence of primary LECs through mitochondrial dysfunction. This provides a new perspective for the treatment of cataracts by regulating AQP5 expression.

Regulation of Axon Guidance by Slit2 and Netrin-1 Signaling in the Lacrimal Gland of Aqp5 Knockout Mice

Purpose

Dry eye disease (DED) is multifactorial and associated with nerve abnormalities. We explored an Aquaporin 5 (AQP5)-deficiency-induced JunB activation mechanism, which causes abnormal lacrimal gland (LG) nerve distribution through Slit2 upregulation and Netrin-1 repression.

Methods

Aqp5 knockout (Aqp5-/-) and wild-type (Aqp5+/+) mice were studied. LGs were permeabilized and stained with neuronal class III β-tubulin, tyrosine hydroxylase (TH), vasoactive intestinal peptide (VIP), and calcitonin gene-related peptide (CGRP). Whole-mount images were acquired through tissue clearing and 3D fluorescence imaging. Mouse primary trigeminal ganglion (TG) neurons were treated with LG extracts and Netrin-1/Slit2 neutralizing antibody. Transcription factor (TF) prediction and chromatin immunoprecipitation-polymerase chain reaction (ChIP-PCR) experiments verified the JunB binding and regulatory effect on Netrin-1 and Slit2.

Results

Three-dimensional tissue and section immunofluorescence showed reduced LG nerves in Aqp5-/- mice, with sympathetic and sensory nerves significantly decreased. Netrin-1 was reduced and Slit2 increased in Aqp5-/- mice LGs. Aqp5+/+ mice LG tissue extracts (TEs) promoted Aqp5-/- TG neurons axon growth, but Netrin-1 neutralizing antibody (NAb) could inhibit that promotion. Aqp5-/- mice LG TEs inhibited Aqp5+/+ TG axon growth, but Slit2 NAb alleviated that inhibition. Furthermore, JunB, a Netrin-1 and Slit2 TF, could bind them and regulate their expression. SR11302, meanwhile, reversed the Netrin-1 and Slit2 shifts caused by AQP5 deficiency.

Conclusions

AQP5 deficiency causes LG nerve abnormalities. Persistent JunB activation, the common denominator for Netrin-1 suppression and Slit2 induction, was found in Aqp5-/- mice LG epithelial cells. This affected sensory and sympathetic nerve fibers' distribution in LGs. Our findings provide insights into preventing, reversing, and treating DED.

Aquaporin 5 in the eye: Expression, function, and roles in ocular diseases

As a water channel protein, aquaporin 5 (AQP5) is essential for the maintenance of the normal physiological functions of ocular tissues. This review provides an overview of the expression and function of AQP5 in the eye and discusses their role in related eye diseases. Although AQP5 plays a vital role in ocular functions, such as maintaining corneal and lens transparency, regulating water movement, and maintaining homeostasis, some of its functions in ocular tissues are still unclear. Based on the key role of AQP5 in eye function, this review suggests that in the future, eye diseases may be treated by regulating the expression of aquaporin.

TNF-α/IL-1β-licensed hADSCs alleviate cholestatic liver injury and fibrosis in mice via COX-2/PGE2 pathway

BACKGROUND

Adipose tissue-derived stem cell (ADSC) transplantation has been shown to be effective for the management of severe liver disorders. Preactivation of ADSCs enhanced their therapeutic efficacy. However, these effects have not yet been examined in relation to cholestatic liver injury.

METHODS

In the present study, a cholestatic liver injury model was established by bile duct ligation (BDL) in male C57BL/6 mice. Human ADSCs (hADSCs) with or without tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β) pretreatment were administrated into the mice via tail vein injections. The efficacy of hADSCs on BDL-induced liver injury was assessed by histological staining, real-time quantitative PCR (RT-qPCR), Western blot, and enzyme-linked immune sorbent assay (ELISA). In vitro, the effects of hADSC conditioned medium on the activation of hepatic stellate cells (HSCs) were investigated. Small interfering RNA (siRNA) was used to knock down cyclooxygenase-2 (COX-2) in hADSCs.

RESULTS

TNF-α/IL-1β preconditioning could downregulate immunogenic gene expression and enhance the engraftment efficiency of hADSCs. Compared to control hADSCs (C-hADSCs), TNF-α/IL-1β-pretreated hADSCs (P-hADSCs) significantly alleviated BDL-induced liver injury, as demonstrated by reduced hepatic cell death, attenuated infiltration of Ly6G + neutrophils, and decreased expression of pro-inflammatory cytokines TNF-α, IL-1β, C-X-C motif chemokine ligand 1 (CXCL1), and C-X-C motif chemokine ligand 2 (CXCL2). Moreover, P-hADSCs significantly delayed the development of BDL-induced liver fibrosis. In vitro, conditioned medium from P-hADSCs significantly inhibited HSC activation compared to that from C-hADSCs. Mechanistically, TNF-α/IL-1β upregulated COX-2 expression and increased prostaglandin E2 (PGE2) secretion. The blockage of COX-2 by siRNA transfection reversed the benefits of P-hADSCs for PGE2 production, HSC activation, and liver fibrosis progression.

CONCLUSION

In conclusion, our results suggest that TNF-α/IL-1β pretreatment enhances the efficacy of hADSCs in mice with cholestatic liver injury, partially through the COX-2/PGE2 pathway.

The Role of the NLRP3 Inflammasome and Programmed Cell Death in Acute Liver Injury

Acute liver injury (ALI) is a globally important public health issue that, when severe, rapidly progresses to acute liver failure, seriously compromising the life safety of patients. The pathogenesis of ALI is defined by massive cell death in the liver, which triggers a cascade of immune responses. Studies have shown that the aberrant activation of the nod-like receptor protein 3 (NLRP3) inflammasome plays an important role in various types of ALI and that the activation of the NLRP3 inflammasome causes various types of programmed cell death (PCD), and these cell death effectors can in turn regulate NLRP3 inflammasome activation. This indicates that NLRP3 inflammasome activation is inextricably linked to PCD. In this review, we summarize the role of NLRP3 inflammasome activation and PCD in various types of ALI (APAP, liver ischemia reperfusion, CCl₄, alcohol, Con A, and LPS/D-GalN induced ALI) and analyze the underlying mechanisms to provide references for future relevant studies.

Loss of aquaporin 5 contributes to the corneal epithelial pathogenesis via Wnt/β-catenin pathway

AQP5 plays a crucial role in maintaining corneal transparency and the barrier function of the cornea. Here, we found that in the corneas of Aqp5-/- mice at older than 6 months, loss of AQP5 significantly increased corneal neovascularization, inflammatory cell infiltration, and corneal haze. The results of immunofluorescence staining showed that upregulation of K1, K10, and K14, and downregulation of K12 and Pax6 were detected in Aqp5-/- cornea and primary corneal epithelial cells. Loss of AQP5 aggravated wound-induced corneal neovascularization, inflammation, and haze. mRNA sequencing, western blotting, and qRT-PCR showed that Wnt2 and Wnt6 were significantly decreased in Aqp5-/- corneas and primary corneal epithelial cells, accompanied by decreased aggregation in the cytoplasm and nucleus of β-catenin. IIIC3 significantly suppressed corneal neovascularization, inflammation, haze, and maintained corneal transparent epithelial in Aqp5-/- corneas. We also found that pre-stimulated Aqp5-/- primary corneal epithelial cells with IIIC3 caused the decreased expression of K1, K10, and K14, the increased expression of K12, Pax6, and increased aggregation in the cytoplasm and nucleus of β-catenin. These findings revealed that AQP5 may regulate corneal epithelial homeostasis and function through the Wnt/β-catenin signaling pathway. Together, we uncovered a possible role of AQP5 in determining corneal epithelial cell fate and providing a potential therapeutic target for corneal epithelial dysfunction.

Aquaporin5 Deficiency Aggravates ROS/NLRP3 Inflammasome-Mediated Pyroptosis in the Lacrimal Glands

Purpose

The pathogenesis of the lacrimal glands (LGs) is facilitated by inflammation mediated by the NACHT, LRR, and NLRP3 inflammasomes in dry eye disease. This research aimed to explore the protective effects of Aquaporin 5 (AQP5) on LGs by inhibiting reactive oxygen species (ROS) and the NLRP3 inflammasome.

Methods

AQP5 knockout (AQP5-/-) mice were used to evaluate pathological changes in LGs. ROS generation was detected with a dichlorodihydro-fluorescein diacetate assay. Lipid metabolism was assessed by Oil Red O staining. The reversal of the mitochondrial membrane potential was detected using a JC-1 fluorescent probe kit. The effect of AQP5 on NLRP3/caspase-1/Gasdermin-D (GSDMD)-mediated pyroptosis was examined using pharmacological treatment of N-acetyl L-cysteine or MCC950.

Results

AQP5 loss significantly increased ROS generation, lipid metabolism disorders, TUNEL-positive cells, and reversal of the mitochondrial membrane potential in the AQP5-/- LGs. NLRP3 upregulation, increased caspase-1 and GSDMD activity, and enhanced IL-1β release were detected in the AQP5-/- mouse LGs and primary LG epithelial cells. MCC950 significantly suppressed NLRP3 inflammasome-related pyroptosis induced by AQP5 deficiency in LGs and primary LG epithelial cells. Furthermore, we discovered that prestimulating the AQP5-/- primary LG epithelial cells with N-acetyl L-cysteine decreased NLRP3 expression, caspase-1 and GSDMD activity levels, and IL-1β release.

Conclusions

Our results revealed that AQP5 loss promoted NLRP3 inflammasome activation through ROS generation. Inhibiting the ROS or NLRP3 inflammasome significantly alleviated the damage and pyroptosis of AQP5-deficient LG epithelial cells, which could provide new insights into dry eye disease.

Efficacy and Safety of Mesenchymal Stromal Cells Therapy for COVID-19 Infection: A Systematic Review and Meta-analysis

BACKGROUND

Coronavirus disease 2019 (COVID-19) is an infectious respiratory disease prevalent worldwide with a high mortality rate, and there is currently no specific medicine to treat patients.

OBJECTIVE

We aimed to assess the safety and efficacy of stem cell therapy for COVID-19 by providing references for subsequent clinical treatments and trials.

METHOD

We systematically searched PubMed, Embase, Cochrane, and Web of Science, using the following keywords: "stem cell" or "stromal cell" and "COVID-19." Controlled clinical trials published in English until 24th August 2021 were included. We followed the PRISMA guidelines and used Cochrane Collaboration's tool for assessing the risk of bias. We analysed the data using a fixed-effect model.

RESULTS

We identified 1779 studies, out of which eight were eligible and included in this study. Eight relevant studies consisted of 156 patients treated with stem cells and 144 controls (300 individuals in total). There were no SAEs associated with stem cell therapy in all six studies, and no significant differences in AEs (p = 0.09, I² = 40%, OR = 0.53, 95% CI: 0.26 to 1.09) between the experimental group and control group were observed. Moreover, the meta-analysis found that stem cell therapy effectively reduced the high mortality rate of COVID-19 (14/156 vs. 43/144; p<0.0001, I2 = 0%, OR=0.18, 95% CI: 0.08 to 0.41).

CONCLUSION

This study suggests that MSCs therapy for COVID-19 has shown some promising results in safety and efficacy. It effectively reduces the high mortality rate of COVID-19 and does not increase the incidence of adverse events.

Collagen-binding fibroblast growth factor ameliorates liver fibrosis in murine bile duct ligation injury

Cholestatic liver injury, characterized by liver fibrosis, has increasingly become a global health problem, with no effective treatment available. Hepatic stellate cells (HSCs) differentiate into myofibroblasts, leading to excessive deposition of the extracellular matrix (ECM), which is a feature of liver fibrosis. Basic fibroblast growth factor (bFGF) has proven antifibrotic effects in chronic liver disease; however, the lack of an effective delivery system to the injury site reduces its therapeutic efficacy. The aim of this study was to assess the therapeutic effect of collagen-binding bFGF (CBD-bFGF) for the treatment of liver fibrosis in a murine bile duct ligation (BDL) model. We found that CBD-bFGF treatment significantly alleviated liver injury in the early phase of BDL injury, and was associated with decreased necroptotic cell death and inflammatory response. Moreover, CBD-bFGF had enhanced therapeutic effects for liver fibrosis on day 7 after surgery compared to those obtained with native bFGF treatment. In vitro, CBD-bFGF treatment notably inhibited TGF-β1-induced LX-2 cell activation, migration, and contraction compared with native bFGF. In conclusion, CBD-bFGF may be a promising treatment for hepatic fibrosis.

The NLRP3 Activation in Infiltrating Macrophages Contributes to Corneal Fibrosis by Inducing TGF-β1 Expression in the Corneal Epithelium

Purpose

To explore the effect and mechanism of NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasomes on corneal fibrosis.

Methods

The wild-type, NLRP3 knockout (KO), and myeloid cell-specific NLRP3 KO (NLRP3 Lyz-KO) C57 mice were used to establish a corneal scarring model. NLRP3 inhibitor, IL-1β neutralizing antibody, and an IL-1R antagonist were used to investigate the role of NLRP3 and IL-1β in corneal fibrosis. The expression of the NLRP3 signaling pathway related proteins, alpha-smooth muscle actin, TGF-β was determined by quantitative real-time polymerase chain reaction, Western blotting, and immunofluorescence staining. Flow cytometry was used to detect the infiltration of macrophages during corneal fibrosis.

Results

The components of the NLRP3 inflammasomes were elevated and activated during corneal scarring. Additionally, genetic or chemical-mediated blocking of NLRP3 as well as IL-1β significantly alleviated corneal fibrosis. Moreover, neutrophil (CD45⁺Ly6G⁺) and macrophage (CD45⁺ F4/80⁺) accumulation increased in the cornea during the progression of corneal fibrosis. Intriguingly, the increased concentrations of NLRP3 and IL-1β were prominently colocalized with the infiltrating F4/80⁺ macrophages. Expectedly, NLRP3 Lyz-KO mice exhibited a marked decrease in their corneal fibrosis symptoms. Mechanistically, the activation of IL-1β or macrophage NLRP3 stimulated the expression of TGF-β1 in the corneal epithelial cells, whereas an NLRP3 deficiency decreased its expression in the corneal epithelium.

Conclusions

These observations revealed that the NLRP3 inflammasome activation in infiltrating macrophages contributes to corneal fibrosis by regulating corneal epithelial TGF-β1 expression. Targeting the NLRP3 inflammasome might be a promising strategy for the treatment of corneal scarring.

Corneal Epithelium-Derived Netrin-1 Alleviates Dry Eye Disease via Regulating Dendritic Cell Activation

Purpose

To investigate the expression of corneal epithelium-derived netrin-1 (NTN-1) and its immunoregulatory function in dry eye disease (DED) using a DED mouse model.

Methods

We generated DED mouse models with desiccating stress under scopolamine treatment. RNA sequencing was performed to identify differentially expressed genes (DEGs) in the corneal epithelium of DED mice. NTN-1 expression was analyzed via real-time PCR, immunofluorescence staining, and immunoblotting. The DED mice were then treated with recombinant NTN-1 or neutralizing antibodies to investigate the severity of the disease, dendritic cell (DC) activation, and inflammatory cytokine expression.

Results

A total of 347 DEGs (292 upregulated and 55 downregulated) were identified in the corneal epithelium of DED mice: corneal epithelium-derived NTN-1 expression was significantly decreased in DED mice compared to that in control mice. Topical recombinant NTN-1 application alleviated the severity of the disease, accompanied by restoration of tear secretion and goblet cell density. In addition, NTN-1 decreased the number of DCs, inhibited the activation of the DCs and Th17 cells, and reduced the expression of inflammatory factors in DED mice. In contrast, blocking endogenous NTN-1 activity with an anti-NTN-1 antibody aggravated the disease, enhanced DC activation, and upregulated the inflammatory factors in the conjunctivae of DED mice.

Conclusions

We identified decreased NTN-1 expression in the corneal epithelium of DED mice. Our findings elucidate the role of NTN-1 in alleviating DED and impeding DC activation, thereby indicating its therapeutic potential in suppressing ocular inflammation in DED.

Copolymer micelle-administered melatonin ameliorates hyperosmolarity-induced ocular surface damage through regulating PINK1 mediated mitophagy

PURPOSE

To investigate the role and mechanism of melatonin-loaded polymer polyvinyl caprolactam-polyvinyl acetate-polyethyleneglycol graft copolymer (PVCL-PVA-PEG) micelles (Mel-Mic) in dry eye disease (DED).

METHODS

In vitro, the apoptosis and reactive oxygen species (ROS) generation in HCECs were analyzed by immunostaining and flow cytometry (FCM). The effect of Mel-Mic on autophagy and mitophagy was evaluated by immunostaining and western blots. PINK1 knockdown was analyzed by small interfering RNA (siRNA). In vivo, sodium fluorescein staining, tear secretion test, and periodic acid-schiff (PAS) staining were used to determine whether Mel-Mic can alleviate the severity of DED. Small molecule antagonists were pretreated to investigate whether melatonin type 1 and/or 2 receptors (MT1/MT2) mediate the effects of Mel-Mic.

RESULTS

Mel-Mic improved the solubility and biological activities of Mel in aqueous solutions. Treatment with Mel-Mic decreased the apoptosis of HCECs exposed to hyperosmotic medium, accompanied by downregulation of cleaved Caspase-3 and upregulation of Bcl-2. In addition, Mel-Mic application suppressed ROS overproduction, rescued mitochondrial function, and decreased the level of oxidative stress associated biomarkers (COX-2 and 4-HNE) in HCECs. Interestingly, HCECs treated with Mel-Mic exhibited increased levels of mitophagy markers (PINK1, PARKIN, Beclin 1 and LC3B) and restored impaired mitophagic flux under hyperosmolarity. While PINK1 knock down largely abolished its protective effects. In vivo, compared to vehicle group, topical Mel-Mic solution treated mice showed significantly improved clinical parameters, increased tear production and decreased goblet cells loss in a dose-dependent manner. Also, TEM assay revealed increased autophagosome number in the corneal epithelium of Mel-Mic group. Moreover, luzindole, a non-selective MT1/MT2 antagonist, but not 4-P-PDOT, a selective MT2 antagonist, blocked the protective effect of Mel-Mic.

CONCLUSIONS

Our findings demonstrated that Mel-Mic ameliorates hyperosmolarity induced ocular surface damage via PINK1 mediated mitophagy and may represent an effective treatment for DED possibly through acting MT1 receptor.

Micelles based on polyvinylpyrrolidone VA64: A potential nanoplatform for the ocular delivery of apocynin

Purpose of this work was to determine the feasibility of a nano-ophthalmic solution consisting of the nanocarrier polyvinylpyrrolidone VA64 (VA64) and encapsulated apocynin (APO) as treatment for ocular inflammatory diseases. Results showed the solution, termed APO-VA64 ophthalmic solution, could be fabricated via a simple process. This solution was clear, colorless, and possessed valuable characteristics, such as small micelle size (14.12 ± 1.24 nm), narrow micelle size distribution, and high APO encapsulation efficiency. Encapsulated APO was also found to have high aqueous solubility and in vitro release and antioxidant activities. APO-VA64 ophthalmic solution showed good ocular tolerance and demonstrated improved corneal permeation ability in mouse eyes. In an in vivo mice model, topically administered APO-VA64 ophthalmic solution was found to be significantly more effective against benzalkonium chloride-induced ocular damage than APO, VA64, and a mix of APO and VA64. Blockage of high mobility group box 1 signaling and its related proinflammatory cytokines were involved in this therapeutic effect. In conclusion, these in vitro and in vivo findings demonstrate that VA64 micelles are a potential nanoplatform for ocular drug delivery, and that the nanoformulation APO-VA64 ophthalmic solution may be a promising candidate for the efficacious treatment of ocular inflammatory diseases.

Pterostilbene alleviates liver ischemia/reperfusion injury via PINK1-mediated mitophagy

Hepatic ischemia/reperfusion (I/R) injury contributes to morbidity and mortality during liver resection or transplantation, with limited effective treatments available. Here, we investigated the potential benefits and underlying mechanisms of pterostilbene (Pt), a natural component of blueberries and grapes, in preventing hepatic I/R injury. Male C57BL/6 mice subjected to partial warm hepatic I/R and human hepatocyte cell line L02 cells exposed to anoxia/reoxygenation (A/R) were used as in vivo and in vitro models, respectively. Our findings showed that pretreatment with Pt ameliorated hepatic I/R injury by improving liver histology, decreasing hepatocyte apoptosis, and reducing plasma ALT and AST levels. Likewise, cell apoptosis, mitochondrial membrane dysfunction, and mitochondrial ROS overproduction in L02 cells triggered by the A/R challenge in vitro were reduced due to Pt administration. Mechanistically, Pt treatment efficiently enhanced mitophagy and upregulated PINK1, Parkin, and LC3B expression. Notably, the protective effect of Pt was largely abrogated after cells were transfected with PINK1 siRNA. Moreover, Pt pretreatment promoted hepatocyte proliferation and liver regeneration in the late phase of hepatic I/R. In conclusion, our findings provide evidence that Pt exerts hepatoprotective effects in hepatic I/R injury by upregulating PINK1-mediated mitophagy.

Lacrimal gland homeostasis is maintained by the AQP5 pathway by attenuating endoplasmic reticulum stress inflammation in the lacrimal gland of AQP5 knockout mice

Purpose

AQP5^-/- mice spontaneously exhibit dry eye symptoms. The purpose of this study was to assess the endoplasmic reticulum (ER) stress-mediated inflammation generated by a deficiency of aquaporin 5 (AQP5) in the lacrimal gland.

Methods

Hematoxylin and eosin (H&E) staining, Oil Red O staining, and transmission electron microscopy (TEM) analysis were performed to identify structural changes in lacrimal gland epithelial cells because of AQP5 deficiency. Corneal epithelial defects were assessed with sodium fluorescein staining. The expression profiles of mRNA and proteins were determined by quantitative real-time reverse transcription PCR (qRT-PCR) and western blot. Mice in the quercetin group were injected intraperitoneally with 40 mg/kg of quercetin, and the control group was injected with an equal volume of dimethyl sulfoxide (DMSO) for 4 weeks.

Results

Aqueous tear secretion fell at about 50% in 1- and 6-month-old AQP5^-/- mice compared with that of AQP5^+/+ mice. TEM showed that the ER structure was damaged. ER stress was significantly increased in the lacrimal gland of AQP5^-/- mice. Lipid droplets accumulated in the matrix and acinar cells, and changes occurred in the lipid metabolism and gene expression levels for PPARα, CPT1α, and CPT2 in the AQP5^-/- mice. Immune cell infiltration and increases in the gene expression levels of the chemokines CXCL1, CXCL2, and CCL5 were found in the lacrimal gland of AQP5^-/- mice. Quercetin partially reversed ER stress levels, inflammation, and lipid accumulation, and it inhibited tear secretion.

Conclusions

The study data indicated that a deficiency of AQP5 induced pathophysiological changes and functional decompensation of the lacrimal gland. Quercetin may improve the inflammation in the lacrimal glands of AQP5^-/- mice by regulating the ER stress levels.

Aquaporin 5 Facilitates Corneal Epithelial Wound Healing and Nerve Regeneration by Reactivating Akt Signaling Pathway

Aquaporins (AQPs) are normally expressed in the corneal epithelium. The aim of this study was to determine whether AQP5 played a role in corneal epithelial wound healing. AQP5 knockout (AQP5^-/-) mice were constructed using CRISPR/Cas9 technology. A corneal wound healing model was performed using epithelial debridement on corneas. The time to corneal epithelial and nerve regeneration was significantly delayed in the AQP5^-/- mice. Reduced Ki-67-positive cells and nerve growth factor (NGF) expression were confirmed in the AQP5^-/- mice during healing. The epithelial and nerve regeneration rates were significantly promoted in the AQP5^-/- mice by treatment with NGF, which was accompanied by recovered levels of phosphorylated Akt. NGF treatment also improved the recovery of corneal nerve fiber density and sensitivity in the AQP5^-/- mice. However, the promotion of NGF induced corneal epithelial and nerve regeneration rates, and Akt reactivation was reversed by Akt inhibitor. The significant impairment of corneal wound healing in the AQP5^-/- mice resulted from distinct defects in corneal epithelial cell proliferation and nerve regeneration. The results provided evidence for the involvement of aquaporin in cell proliferation and suggested that AQP5 induction could be a potential therapy for accelerating the resurfacing of corneal defects.

Improved bioavailability and anticancer efficacy of Hesperetin on breast cancer via a self-assembled rebaudioside A nanomicelles system

Hesperetin (HSP) has excellent biological activities with poor water solubility which limits its clinical development. In this study, we successfully prepared a novel, self-assembled micelle based on Rebaudioside A (RA) for oral delivery of HSP with improved bioavailability and therapeutic effects. We found that RA and HSP could be formylated into nanomicelles with particle sizes of 4.541 nm ± 0.048 nm. HSP was readily encapsulated into RA micelles and this improved its water solubility (to 12.74 mg/mL ± 0.28 mg/mL). The MTT results showed that RA-HSP enhanced the cytotoxicity, the clonal formation inhibitory activity, and cell migration inhibitory activity of HSP in human breast cancer MDA-MB-231 cells. The mechanism results showed that RA-HSP induced cell apoptosis by inducing the production of reactive oxygen species (ROS), destroying the mitochondrial membrane potential (MMP), and inhibiting the PI3K/Akt signaling pathway. Moreover, RA-HSP enhanced the anticancer activity, increased the oral bioavailability and tissue distribution of HSP in vivo. Moreover, the mechanism studies in vivo found that HSP inhibited PI3K/Akt signaling pathway with low side effects. These findings indicate that RA micelle formulations have great potential in oral drug delivery systems for the delivery of hydrophobic drugs.

In vivo Confocal Microscopic Evaluation of Corneal Dendritic Cell Density and Subbasal Nerve Parameters in Dry Eye Patients: A Systematic Review and Meta-analysis

Purpose: To conduct a systematic review and meta-analysis of the available research on evaluating changes in corneal dendritic cell density (CDCD) and the main subbasal nerve parameters (SNPs) on the ocular surface and assessing the diagnostic performance of in vivo confocal microscopy in patients with dry eye disease. Methods: A computerized systematic review of literature published in PUBMED, EMBASE, Web of Science, Scopus, and the Cochrane Central Register of Controlled Trials until May 8, 2020 was performed. All statistical analyses were conducted in RevMan V.5.3 software. The weighted mean differences (WMDs) and standardized mean differences (SMDs) with 95% confidence intervals (CI) between dry eye patients and healthy subjects were presented as results. Results: A total of 11 studies with 755 participants were recruited, and 931 eyes were included in this meta-analysis. However, not all studies reported both CDCD and SNPs. CDCD in the central cornea was higher (WMD = 51.06, 95% CI = 39.42-62.71), while corneal nerve fiber density (CNFD) and corneal nerve fiber length (CNFL) were lower (WMD = -7.96, 95% CI = -12.12 to -3.81; SMD = -2.30, 95%CI = -3.26 to -1.35) in dry eye patients in comparison with the corresponding values in healthy controls (all p < 0.00001). Conclusion: Taken together, while CNFD and CNFL were lower in dry eye patients, central CDCD showed a significant increase in these patients in comparison with the corresponding values in healthy controls.

AQP5 regulates vimentin expression via miR-124-3p.1 to protect lens transparency

The pathogenesis of congenital cataract (CC), a major disease associated with blindness in infants, is complex and diverse. Aquaporin 5 (AQP5) represents an essential membrane water channel. In the present study, whole exome sequencing revealed a novel heterozygous missense mutation of AQP5 (c.152 T > C, p. L51P) in the four generations of the autosomal dominant CC (adCC) family. By constructing a mouse model of AQP5 knockout (KO) using the CRISPR/Cas9 technology, we observed that the lens of AQP5-KO mice showed mild opacity at approximately six months of age. miR-124-3p.1 expression was identified to be downregulated in the lens of AQP5-KO mice as evidenced by qRT-PCR analysis. A dual luciferase reporter assay confirmed that vimentin was a target gene of miR-124-3p.1. Organ-cultured AQP5-KO mouse lenses were showed increased opacity compared to those of WT mice, and vimentin expression was upregulated as determined by RT-PCR, western blotting, and immunofluorescence staining. After miR-124-3p.1 agomir was added, the lens opacity in WT mice and AQP5-KO mice decreased, accompanied by the downregulation of vimentin. AQP5-L51P increased vimentin expression of in human lens epithelial cells. Therefore, a missense mutation in AQP5 (c.152 T > C, p. L51P) was associated with adCC, and AQP5 could participate in the maintenance of lens transparency by regulating vimentin expression via miR-124-3p.1.

Novel poly (ADP-ribose) polymerases inhibitor DHC-1 exhibits in vitro and in vivo anticancer activity on BRCA-deficient pancreatic cancer cells

Poly (ADP-ribose) polymerases (PARPs) play a key role in DNA repair. In this study we designed a novel small-molecular compound, (E)-2-(2,3-dibromo-4,5-dimethoxybenzylidene)hydrazine-1-carbothioamide (DHC-1), which was a potent and selective PARP-1 inhibitor. DHC-1 selectively inhibited PARP-1 activity with an IC₅₀ value of 41.12 ± 13.28 nM. Cytotoxicity results showed that DHC-1 selectively inhibited the proliferation of BRCA1-deficient breast cancer HCC-1937 and BRCA2-deficient pancreatic cancer Capan-1 cells. Mechanism studies found that DHC-1 stabilized PARP-1-DNA complexes and inhibited PAR formation in BRCA2^-/- Capan-1 cells. Further experiments found that DHC-1 induced DNA double-strand damage in BRCA2^-/- Capan-1 cells, which was demonstrated by accumulation of γ-H2AX foci. Flow cytometry experiments revealed that DHC-1 induced G2/M phase arrest and activate mitochondrial-induced apoptotic pathways. Interestingly, we also found that DHC-1 enhanced cell proliferation inhibitory effect of oxaliplatin (OXA). The further in vivo nude mouse studies showed that DHC-1 inhibited the growth of Capan-1 xenografts and showed a similar mechanism to that in vitro. Collectively, our results demonstrate that DHC-1 may be an excellent candidate for treatment of BRCA-deficient pancreatic cancers.

Expression Profiles of CircRNA and mRNA in Lacrimal Glands of AQP5-/- Mice With Primary Dry Eye

Purpose: This work aimed to identify differentially expressed circular RNAs (circRNAs) and elucidate their potential function in aquaporin 5 (AQP5) knockout (AQP5^–/–) mice with the primary dry eye phenotype.

Methods: A slit lamp examination was performed on AQP5^–/– mice to assess corneal epithelial defects using fluorescein sodium staining. Hematoxylin–eosin staining and transmission electron microscopy analysis were performed to identify structural changes in lacrimal gland epithelial cells due to AQP5 deficiency. The expression profiles of circRNA and messenger RNA (mRNA) were determined by a microarray analysis. The selected circRNA was verified by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to predict the biological functions and the potential pathways of parental genes involved in lacrimal gland epithelial cell changes. According to the bioinformatics analysis of identified circRNAs, we predicted a circRNA–miRNA–mRNA network of phagosomes.

Results: The AQP5^–/– mice spontaneously exhibit dry eye symptoms, wherein the AQP5 deficiency changes the structure of lacrimal gland epithelial cells. The analysis revealed that, compared to AQP5^+/+ mice, 30 circRNAs in the lacrimal glands of AQP5^–/– mice were differentially expressed (fold change ≥ 2.0, p < 0.05). Nine upregulated circRNAs were identified using qRT-PCR, and nine upregulated validated circRNAs, 40 altered microRNAs (miRNAs), and nine upregulated mRNAs were identified through a network analysis. The KEGG analysis showed that these nine target genes were expressed in phagosomes.

Conclusion: The AQP5^–/– mice have primary and stable dry eye phenotypes from birth. We identified differently expressed circRNAs in the lacrimal glands of AQP5^–/– and AQP5^+/+ mice, predicting a circRNA–miRNA–mRNA network of phagosomes. CircRNA likely plays an important role in lacrimal gland epithelial cell pathogenesis. Therefore, it is reasonable to use circRNA as a potential therapeutic agent for the treatment of dry eyes.

Netrin-1 promotes diabetic corneal wound healing through molecular mechanisms mediated via the adenosine 2B receptor

Netrins are secreted chemoattractants with the roles in axon guidance, cell migration and epithelial plasticity. In the present study, we investigated the roles of netrin-1 in the regulation of corneal epithelial wound healing, inflammation response and nerve fiber regeneration in diabetic mice and cultured corneal epithelial cells. In diabetic mice, the expression of netrin-1 was decreased when compared with that of normal mice. Furthermore, high glucose blocked the wounding-induced up-regulation of netrin-1 expression in corneal epithelial cells. Exogenous netrin-1 promoted the corneal epithelial wound healing in diabetic mice, and facilitated the proliferation and migration by reactivating the phosphorylation of ERK and EGFR in high-glucose treated corneal epithelial cells. Moreover, netrin-1 decreased the neutrophil infiltration and promoted M2 macrophage transition, accompanied with the attenuated expression of pro-inflammatory factors in diabetic mouse corneal epithelium. The promotions of netrin-1 on corneal epithelial wound healing and inflammation resolution were mediated at least through the adenosine 2B receptor. In addition, netrin-1 promoted the regeneration of corneal nerve fibers that was impaired in diabetic mice. Taken together, netrin-1 regulates corneal epithelial wound healing, inflammation response and nerve fiber regeneration in diabetic mice, indicating the potential application for the therapy of diabetic keratopathy.

Resolvin D1 promotes corneal epithelial wound healing and restoration of mechanical sensation in diabetic mice

PURPOSE

To investigate the effect and mechanism of proresolving lipid mediator resolvin D1 (RvD1) on the corneal epithelium and the restoration of mechanical sensation in diabetic mice.

METHODS

Type 1 diabetes was induced in mice with intraperitoneal streptozocin injections. The healthy and diabetic mice underwent removal of the central corneal epithelium, and then 100 ng/ml RvD1 or its formyl peptide receptor 2 (FPR2) antagonist WRW4 was used to treat the diabetic mice. Regeneration of the corneal epithelium and nerves was observed with sodium fluorescein staining and whole-mount anti-β3-tubulin fluorescence staining. The inflammatory response level was measured with hematoxylin and eosin staining (inflammatory cell infiltration), enzyme-linked immunosorbent assay (tumor necrosis factor alpha and interleukin-1 beta content), myeloperoxidase activity, and fluorescence staining (macrophage content). The reactive oxygen species (ROS) and glutathione (GSH) levels were examined with incubation with fluorescent probes, and oxidative stress-related protein expression levels were evaluated with fluorescence staining and western blotting.

RESULTS

Topical application of RvD1 promoted regeneration of the corneal epithelium in diabetic mice, accompanied by the reactivation of signaling and inflammation resolution related to regeneration of the epithelium. Furthermore, RvD1 directly attenuated the accumulation of ROS and nicotinamide adenine dinucleotide phosphate oxidase 2/4 expression, while RvD1 enhanced GSH synthesis and reactivated the Nrf2-ARE signaling pathway that was impaired in the corneal epithelium in the diabetic mice. More interestingly, topical application of RvD1 promoted regeneration of corneal nerves and completely restored impaired mechanical sensitivity of the cornea in diabetic mice. In addition, the promotion of corneal epithelial wound healing by RvD1 in diabetic mice was abolished by its FPR2 antagonist WRW4.

CONCLUSIONS

Topical application of RvD1 promotes corneal epithelial wound healing and the restoration of mechanical sensation in diabetic mice, which may be related to the lipid mediator's regulation of inflammation resolution, the reactivation of regenerative signaling in the epithelium, and the attenuation of oxidative stress.

Epithelium-derived miR-204 inhibits corneal neovascularization

MicroRNA-204 (miR-204) is highly expressed in cornea, here we explored the role and mechanism of miR-204 in corneal neovascularization (CNV). Mouse CNV was induced by intrastromal placement of suture in BALB/c mice with the subconjunctival injection of miR-204 agomir or negative control. Human primary limbal epithelial cells (LECs) and immortalized microvascular endothelial cells (HMECs) were used to evaluate the expression changes and anti-angiogenic effects of miR-204 under biomechanical stress (BS). The expression and localization of miR-204, vascular endothelial growth factor (VEGF) and their receptors were detected by quantitative real-time PCR, in situ hybridization, immunohistochemistry and Western blot. The results showed that miR-204 expression was mainly localized in epithelium and down-expressed in vascularized cornea. Subconjunctival injection of miR-204 agomir inhibited CNV and reduced the expression of VEGF and VEGF receptor 2. Similarly, miR-204 overexpression attenuated the increased expression of VEGF by biomechanical stress in LECs, and suppressed the proliferation, migration, and tube formation of HMECs. These novel findings indicate that epithelium-derived miR-204 inhibits suture-induced CNV through regulating VEGF and VEGF receptor 2.

Corneal Epithelium-Derived Neurotrophic Factors Promote Nerve Regeneration

Purpose

To explore the neurotrophic factor expression in corneal epithelium and evaluate their effects on the trigeminal ganglion (TG) neurite outgrowth and corneal nerve regeneration in mice.

Methods

The expression of neurotrophic factors was compared among the intact, regenerating, and regenerated mouse corneal epithelium. Mouse primary TG neurons were treated with the conditioned medium of mouse corneal epithelial cells. Nerve growth factor (NGF) neutralizing antibody and glial cell-derived neurotrophic factor (GDNF) neutralizing antibody were used to evaluate their roles in mouse corneal nerve regeneration and TG neurite outgrowth. The promoting effects of NGF and GDNF for the corneal nerve regeneration were further evaluated in the diabetic mice.

Results

The expression of NGF and GDNF showed significant up-regulation in regenerating corneal epithelium and return to the preinjury levels in the regenerated epithelium, which was consistent with the progress of corneal subbasal nerve regeneration. The conditioned medium of corneal epithelial cells promoted the TG neurite outgrowth with extended branching and elongation. Furthermore, the blockage of either NGF or GDNF significantly impaired the promotion of the neurite outgrowth by the conditioned medium or the corneal nerve regeneration in normal mice. Moreover, the expression of NGF and GDNF was attenuated in the diabetic regenerating corneal epithelium as compared to that in normal mice, while exogenous NGF or GDNF supplement promoted the corneal epithelial and nerve regeneration in diabetic mice.

Conclusions

Corneal epithelium expresses multiple neurotrophic factors, among which NGF and GDNF may play an important role in the corneal nerve regeneration.

Mesenchymal Stem Cells Promote Diabetic Corneal Epithelial Wound Healing Through TSG-6-Dependent Stem Cell Activation and Macrophage Switch

Purpose

To explore the role and mechanism of bone marrow-derived mesenchymal stem cells (BM-MSCs) in corneal epithelial wound healing in type 1 diabetic mice.

Methods

Diabetic mice were treated with subconjunctival injections of BM-MSCs or recombinant tumor necrosis factor-α-stimulated gene/protein-6 (TSG-6). The corneal epithelial wound healing rate was examined by fluorescein staining. The mRNA and protein expression levels of TSG-6 were measured by quantitative RT-PCR and Western blot. The infiltrations of leukocytes and macrophages were analyzed by flow cytometry and immunofluoresence staining. The effect of TSG-6 was further evaluated in cultured limbal epithelial stem/progenitor cells, macrophages, and diabetic mice by short hairpin RNA (shRNA) knockdown.

Results

Local MSC transplantation significantly promoted diabetic corneal epithelial wound healing, accompanied by elevated corneal TSG-6 expression, increased corneal epithelial cell proliferation, and attenuated inflammatory response. Moreover, in cultured human limbal epithelial stem/progenitor cells, TSG-6 enhanced the colony-forming efficiency, stimulated mitogenic proliferation, and upregulated the expression level of ΔNp63. Furthermore, in diabetic mouse cornea and in vitro macrophage culture, TSG-6 alleviated leukocyte infiltration and promoted the polarization of recruited macrophages to anti-inflammatory M2 phenotypes with increased phagocytotic capacity. In addition, the promotion of epithelial stem/progenitor cell activation and macrophage polarization by MSC transplantation was largely abrogated by shRNA knockdown of TSG-6.

Conclusions

This study provided the first evidence of TSG-6 secreted by MSCs promoting corneal epithelial wound healing in diabetic mice through activating corneal epithelial stem/progenitor cells and accelerating M2 macrophage polarization.

Mesenchymal stem cell-conditioned medium promotes MDA-MB-231 cell migration and inhibits A549 cell migration by regulating insulin receptor and human epidermal growth factor receptor 3 phosphorylation

Various in vitro and in vivo studies have linked mesenchymal stem cells (MSCs) with cancer, but little is known about the effect of MSCs on tumor progression. The present study aimed to analyze the role of the MSCs from different tissues, consisting of human bone marrow, adipose and the umbilical cord tissues, and the heterogeneity of tumors in tumor progression. By collecting the culture supernatants of MSCs as MSC-conditioned media (CMs), the present study found that MSC-CM produces no significant effect on the proliferation of MDA-MB-231 and A549 tumor cells. The migration of MDA-MB-231 cells was enhanced upon incubation with MSC-CM, while that of A549 cells was inhibited. Furthermore, the phosphorylation of insulin receptors (IRs) was upregulated in MSC-CM-treated MDA-MB-231 cells, while in MSC-CM-treated A549 cells, the phosphorylation of human epidermal growth factor receptor 3 (Her3) was downregulated. Taken together, the findings suggest that the phosphorylation of IR and Her3 may contribute to the discrepant effects of MSC-CM on the migration of the 2 cell lines.

Ciliary neurotrophic factor promotes the activation of corneal epithelial stem/progenitor cells and accelerates corneal epithelial wound healing

Ciliary neurotrophic factor (CNTF), a well-known neuroprotective cytokine, has been found to play an important role in neurogenesis and functional regulations of neural stem cells. As one of the most innervated tissue, however, the role of CNTF in cornea epithelium remains unclear. This study was to explore the roles and mechanisms of CNTF in the activation of corneal epithelial stem/progenitor cells and wound healing of both normal and diabetic mouse corneal epithelium. In mice subjecting to mechanical removal of corneal epithelium, the corneal epithelial stem/progenitor cell activation and wound healing were promoted by exogenous CNTF application, while delayed by CNTF neutralizing antibody. In cultured corneal epithelial stem/progenitor cells, CNTF enhanced the colony-forming efficiency, stimulated the mitogenic proliferation, and upregulated the expression levels of corneal epithelial stem/progenitor cell-associated transcription factors. Furthermore, the promotion of CNTF on the corneal epithelial stem/progenitor cell activation and wound healing was mediated by the activation of STAT3. Moreover, in diabetic mice, the content of CNTF in corneal epithelium decreased significantly when compared with that of normal mice, and the supplement of CNTF promoted the diabetic corneal epithelial wound healing, accompanied with the advanced activation of corneal epithelial stem/progenitor cells and the regeneration of corneal nerve fibers. Thus, the capability of expanding corneal epithelial stem/progenitor cells and promoting corneal epithelial wound healing and nerve regeneration indicates the potential application of CNTF in ameliorating limbal stem cell deficiency and treating diabetic keratopathy.

Substance P promotes diabetic corneal epithelial wound healing through molecular mechanisms mediated via the neurokinin-1 receptor

Substance P (SP) is a neuropeptide, predominantly released from sensory nerve fibers, with a potentially protective role in diabetic corneal epithelial wound healing. However, the molecular mechanism remains unclear. We investigated the protective mechanism of SP against hyperglycemia-induced corneal epithelial wound healing defects, using type 1 diabetic mice and high glucose-treated corneal epithelial cells. Hyperglycemia induced delayed corneal epithelial wound healing, accompanied by attenuated corneal sensation, mitochondrial dysfunction, and impairments of Akt, epidermal growth factor receptor (EGFR), and Sirt1 activation, as well as decreased reactive oxygen species (ROS) scavenging capacity. However, SP application promoted epithelial wound healing, recovery of corneal sensation, improvement of mitochondrial function, and reactivation of Akt, EGFR, and Sirt1, as well as increased ROS scavenging capacity, in both diabetic mouse corneal epithelium and high glucose-treated corneal epithelial cells. The promotion of SP on diabetic corneal epithelial healing was completely abolished by a neurokinin-1 (NK-1) receptor antagonist. Moreover, the subconjunctival injection of NK-1 receptor antagonist also caused diabetic corneal pathological changes in normal mice. In conclusion, the results suggest that SP-NK-1 receptor signaling plays a critical role in the maintenance of corneal epithelium homeostasis, and that SP signaling through the NK-1 receptor contributes to the promotion of diabetic corneal epithelial wound healing by rescued activation of Akt, EGFR, and Sirt1, improvement of mitochondrial function, and increased ROS scavenging capacity.

Inductive differentiation of conjunctival goblet cells by γ-secretase inhibitor and construction of recombinant conjunctival epithelium

γ-secretase inhibitor has been shown to promote intestinal goblet cell differentiation. We now demonstrated that the in vitro addition of γ-secretase inhibitor in the culture of human conjunctival epithelial cells significantly promoted the differentiation of conjunctival goblet cells with typical droplet-like phenotype, positive periodic acid-Schiff and goblet cell-specific Muc5Ac, cytokeratin 7 and Helix pomatia agglutinin lectin staining. Moreover, topical application of γ-secretase inhibitor promoted the differentiation of mouse conjunctival goblet cells in vivo. Furthermore, the expression of Notch target gene HES-1 was down-regulated during the differentiation of conjunctival goblet cells. In addition, we found that the recombinant conjunctival epithelium on amniotic membrane showed less goblet cell density and abnormal location when compared with normal conjunctival epithelium, which were improved by the addition of γ-secretase inhibitor in the final induction.

Development and evaluation of a trehalose-contained solution formula to preserve hUC-MSCs at 4°C

Human mesenchymal stem cells (hMSCs) hold great promise in cell therapy and regenerative medicine. Various preclinical and clinical trials have been carried out to illustrate the therapeutic potential of these cells. However, one major challenge for manufacturing clinical grade hMSCs is the requisition of current good manufacturing practice (cGMP) grade practices in cell isolation, processing, storage, and distribution. Development of non-toxic and animal serum-free preservation medium is critical for storage and distribution of mesenchymal stem cells (MSCs). In this study, we developed a solution formula that could preserve MSCs at 4°C for up to 3 weeks. In the solution, trehalose is a key ingredient for maintaining survival of MSCs. Among the concentrations investigated, 40 mM trehalose showed the best outcome with the viability maintained more than 92.7 ± 1.5% for 7 days. Cells preserved in the solution formula for 3 weeks still remained about 70% viability, and produced results similar to those of freshly harvested hMSCs in terms of growth kinetics, expression profile of cell surface antigens, and differentiation potential. In summary, storage of MSCs in the medium makes it far easier for transporting the cells from processing units to clinical sites.

P5-13-13: The Role of Topoisomerase IIa in Predicting Sensitivity to Anthracyclines in Breast Cancer Patients: A Meta-Analysis of Published Literatures

Topoisomerase IIα is not only a proliferation marker of tumor cells but also a target for anthracycline-based chemotherapy. Both in vitro and in vivo studies have shown that there was a relationship between topo IIα and chemosensitivity to anthracyclines, but the predictive role of topo IIα is still controversial in breast cancer patients. A meta-analysis based on published studies was performed with the aim of obtaining an accurate evaluation of the association between topo IIα and sensitivity to anthracycline-based chemotherapy. A total of 13 eligible studies including 2,633 cases and 2,118 controls were identified. Topo IIα was associated with sensitivity to anthracyclines in locally advanced breast cancer patients who received neoadjuvant chemotherapy (RR = 1.93, 95%CI: 1.27−2.94, P=0.002; RR =1.98, 95%CI: 1.37−2.86, P&lt;0.001). In early breast cancer patients who received anthracycline-based adjuvant chemotherapy compared with non-taxane-based polychemotherapy, amplification(HR = 0.64, 95%CI: 0.49−0.83, P=0.001; HR = 0.59, 95% CI: 0.35−1.01, P=0.056) or deletion (HR = 0.82, 95%CI: 0.67−1.00, P=0.051; HR =0.58, 95%CI: 0.35−0.97, P=0.036) of topo IIα was significantly associated with better RFS and OS. The subgroup analysis in the early breast cancer patients indicated that taxane could be an interference for evaluation of the predictive role of topo IIα. In summary, the present meta-analysis suggests that topo IIα is a predictive factor for breast cancer patients who received anthracycline-based chemotherapy. Larger and well-designed prospective studies are required to further evaluate the predictive role of topo IIα in clinical practice.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-13-13.

Diffusion-Weighted MRI in Predicting the Efficacy of Neoadjuvant Chemotherapy of Breast Cancer

Objective: To approach the apparent diffusion coefficient(ADC) obtained on diffusion weighted imaging (DWI) in predicting the response of breast cancer to neoadjuvant chemotherapy.Methods: 53 locally advanced breast cancer patients participated in this prospective study on neoadjuvant chemotherapy. All patients were treated with weekly neoadjuvant paclitaxel plus carboplatin for 4 cycles. DWI and ADC value were examined before chemotherapy(the first time point), after the first and the forth cycle of chemotherapy(the second and the third time point). Patients were categorized as high responders if their ADC at the second time point were higher by 2 times the standard deviation than the mean pre-chemotherapy ADC, and otherwise the patients were considered as low responders. Logistic regression was conducted to examine the independent factors predictive of clinical complete response(CR) and pathologic complete response(pCR).Results: CR was documented in 13 patients (24.5%); partial response in 36 patients (67.9%); stable disease in 4 patients (7.5%) and no patient had progressive disease. 11 patients(20.8%) have achieved pCR. There was a strong positive correlation between the percentage changes in ADC value at the third time points and the degree of the tumor reduction. A significant increase in ADC value was observed at the second time point compared with the first time point (1.104±0.117×10-3mm2/s, 1.220±0.158×10-3mm2/s, P&lt;0.001), while the decrease of the longest diameter of the tumors measured by physical examination, ultrasound or MRI or the tumor volumn measured by MRI were not (P&gt;0.05). Logistic regression revealed that percentage changes of ADC value at the second time point were significantly associated with CR(P=0.022, hazard ratio[HR] =1.08, 95% confidence interval[CI]: 1.01∼1.16) and pCR(P=0.022, HR =1.11, 95%CI: 1.02∼1.21). The AUC value of the receiver operating characteristic curve were 0.721(95%CI: 0.512∼0.931, P=0.017) and 0.775(95%CI: 0.598∼0.952, P=0.005) in the two diagnostic tests for CR and pCR, and the sensitivity and specificity were 76.9%, 63.6% and 77.5%, 90.5%, respectively. According to categorizing system described above, 10 patients(18.9%) were considered as high responders and 43 patients(81.1%) low responders. 7 patients(70%) of the high responders have achieved clinical CR and pCR while for the low responders there were only 6 patients(14.0%) and 4 patients (9.3%) proven to have CR and pCR. The difference have both reached statistical significance(P=0.001, P&lt;0.001). Logistic regression confirmed that the categorizing system was independently predictive of CR(P=0.006, HR=42.26, 95%CI: 2.86∼624.08) and pCR(P=0.013, HR=25.19, 95%CI: 2.00∼318.91). Taking this categorizing system as a dignostic test, the sensitivity and specificity were 53.8% and 92.5% for CR and 63.6% and 92.9% for pCR, respectively.Conclusions: The change of ADC value obtained on DWI after the first cycle of neoadjuvant chemotherapy occured prior to the morphologic changes of the tumor and at this time ADC value could to some extent predict the efficacy of neoadjuvant chemotherapy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4025.

Estrogen Receptor Expression: Possible Predictor of Pathological Complete Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer Patients

BackgroundEstrogen receptor(ER) status has been found to correlate inversely to pathologic complete response (pCR) rates of neoadjuvant chemotherapy(NAC) of breast cancer. However, not all ER-positive breast cancer respond equally to NAC. The present study aimed to determine the relationship between different ER expression level with pCR in locally advanced breast cancer(LABC) patients who have received NAC.MethodsA retrospective study of 332 female unilateral LABC patients undergoing NAC was performed. All patients were confirmed as invasive breast cancer before treated with NAC, including VE (vinorelbine, epirubicin), CEF (cyclophosphamide, epirubicin, fluorouracil) and PCb regimen (paclitaxel, carboplatin). All patients underwent radical surgery and pCR was defined as the absence of invasive breast cancer in both breast and axillary lymph nodes. ER status were checked using the established immunohistochemical(IHC) method and defined as negative, weakly positive(1+), medium positive(2+) and strongly positive(3+). Binary logistic regression was performed to determine the independent predictors of pCR.ResultsER negativity, 1+, 2+ and 3+ were found in 156, 108, 37 and 31 patients, of which 42(26.9%), 21(19.4%), 3(8.1%) and 1 patients(3.2%) have achieved pCR. Binary logistic regression showed that different ER expression level(P=0.021) and HER2 status(P=0.007, hazard ratio[HR] =2.557, 95% confidence interval[CI]: 1.297∼5.038) were significantly associated with the pCR rates. pCR was much more likely to occur in patients with ER-negative(P=0.024, HR =13.119, 95% CI: 1.402∼122.774) or ER 1+(P=0.025, HR=12.928, 95% CI: 1.388∼120.390) tumors than those with ER 3+ tumors.ConclusionER weekly positive patients also gain considerable benefit from NAC, which is probably less effective in ER strongly positive patients in terms of pCR.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1104.

Genetic Contribution of GADD45A to Susceptibility to Sporadic and Non-BRCA1/2 Familial Breast Cancers: A Systemic Evaluation in Chinese Populations

GADD45A is a candidate breast cancer susceptibility gene because its product participates in DNA repair and it is a downstream gene of p53 and BRCA1, both of which are breast cancer susceptibility genes. The genetic contribution of GADD45A to sporadic and familial breast cancer is still ambiguous. We screened germline mutation of GADD45A in 185 non-BRCA1/2 familial breast cancer patients, but no deleterious mutation was found. Seven single-nucleotide-polymorphisms were identified in a sub-sample. Five common variants (minor allele frequency (MAF)&gt;10%) were genotyped for association analyses to scrutinize the relationship between breast cancer and polymorphisms in GADD45A in two independent population sets. In the first case-control study, a comparison of genotype frequencies between sporadic breast cancer patients and controls indicated the CT/TT-genotypes of +1506C&gt;T and CG/CC-genotypes of +3204G&gt;C were associated with decreased breast cancer risk (adjusted odds ratio (OR), 0.77; 95% confidence interval (CI), 0.62-0.96; and adjusted OR, 0.71; 95%CI, 0.57-0.88, respectively) compared with their wild-type homozygotes. A common hyplotype CGTCC was also associated with reduced risk (P=1.0×10-4). In a second familial breast cancer patient-based case-control study, although +1506C&gt;T and +3204G&gt;C failed to be validated, the haplotype CGTCC showed a borderline significance. Notably, the combined P-values were robust for +3204G&gt;C (P=3.1×10-4) and CGTCC (P=1.6×10-5). Moreover, CGTCC was correlated with a higher GADD45A expression in normal breast tissues. In conclusion, although germline mutation of GADD45A is not common in familial breast cancer patients, polymorphisms/haplotypes in GADD45A contribute to breast cancer risk, at least to sporadic breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5163.