Roles of TGFβ and FGF signals during growth and differentiation of mouse lens epithelial cell in vitro

Human intermediate prostate cancer stem cells contribute to the initiation and development of prostate adenocarcinoma

BACKGROUND

Intermediate cells are present in the early stages of human prostate development and adenocarcinoma. While primary cells isolated from benign human prostate tissues or tumors exhibit an intermediate phenotype in vitro, they cannot form tumors in vivo unless genetically modified. It is unclear about the stem cell properties and tumorigenicity of intermediate cells.

METHODS

We developed a customized medium to culture primary human intermediate prostate cells, which were transplanted into male immunodeficient NCG mice to examine tumorigenicity in vivo. We treated the cells with different concentrations of dihydrotestosterone (DHT) and enzalutamide in vitro and surgically castrated the mice after cell transplantation in vivo. Immunostaining, qRT-PCR, RNA sequencing, and western blotting were performed to characterize the cells in tissues and 2D and 3D cultures.

RESULTS

We found intermediate cells expressing AR+PSA+CK8+CK5+ in the luminal compartment of human prostate adenocarcinoma by immunostaining. We cultured the primary intermediate cells in vitro, which expressed luminal (AR+PSA+CK8+CK18+), basal (CK5+P63+), intermediate (IVL+), and stem cell (CK4+CK13+PSCA+SOX2+) markers. These cells resisted castration in vitro by upregulating the expression of AR, PSA, and proliferation markers KI67 and PCNA. The intermediate cells had high tumorigenicity in vivo, forming tumors in immunodeficient NCG mice in a month without any genetic modification or co-transplantation with embryonic urogenital sinus mesenchyme (UGSM) cells. We named these cells human castration-resistant intermediate prostate cancer stem cells or CriPCSCs and defined the xenograft model as patient primary cell-derived xenograft (PrDX). Human CriPCSCs resisted castration in vitro and in vivo by upregulating AR expression. Furthermore, human CriPCSCs differentiated into amplifying adenocarcinoma cells of luminal phenotype in PrDX tumors in vivo, which can dedifferentiate into CriPCSCs in vitro.

CONCLUSIONS

Our study identified and established methods for culturing human CriPCSCs, which had high tumorigenicity in vivo without any genetic modification or UGSM co-transplantation. Human CriPCSCs differentiated into amplifying adenocarcinoma cells of luminal phenotype in the fast-growing tumors in vivo, which hold the potential to dedifferentiate into intermediate stem cells. These cells resisted castration by upregulating AR expression. The human CriPCSC and PrDX methods hold significant potential for advancing prostate cancer research and precision medicine.

The significance of growth shells in development of symmetry, transparency, and refraction of the human lens

Human visual function depends on the biological lens, a biconvex optical element formed by coordinated, synchronous generation of growth shells produced from ordered cells at the lens equator, the distal edge of the epithelium. Growth shells are comprised of straight (St) and S-shaped (SSh) lens fibers organized in highly symmetric, sinusoidal pattern which optimizes both the refractile, transparent structure and the unique microcirculation that regulates hydration and nutrition over the lifetime of an individual. The fiber cells are characterized by diversity in composition and age. All fiber cells remain interconnected in their growth shells throughout the life of the adult lens. As an optical element, cellular differentiation is constrained by the physical properties of light and its special development accounts for its characteristic symmetry, gradient of refractive index (GRIN), short range transparent order (SRO), and functional longevity. The complex sinusoidal structure is the basis for the lens microcirculation required for the establishment and maintenance of image formation.

Two-dimensional vascularized liver organoid on extracellular matrix with defined stiffness for modeling fibrotic and normal tissues

Antifibrotic drug screening requires evaluating the inhibitory effects of drug candidates on fibrotic cells while minimizing any adverse effects on normal cells. It is challenging to create organ-specific vascularized organoids that accurately model fibrotic and normal tissues for drug screening. Our previous studies have established methods for culturing primary microvessels and epithelial cells from adult tissues. In this proof-of-concept study, we used rats as a model organism to create a two-dimensional vascularized liver organoid model that comprised primary microvessels, epithelia, and stellate cells from adult livers. To provide appropriate substrates for cell culture, we engineered ECMs with defined stiffness to mimic the different stages of fibrotic tissues and normal tissues. We examined the effects of two TGFβ signaling inhibitors, A83-01 and pirfenidone, on the vascularized liver organoids on the stiff and soft ECMs. We found that A83-01 inhibited fibrotic markers while promoting epithelial genes of hepatocytes and cholangiocytes. However, it inhibited microvascular genes on soft ECM, indicating a detrimental effect on normal tissues. Furthermore, A83-01 significantly promoted the expression of markers of stem cells and cancers, increasing the potential risk of it being a carcinogen. In contrast, pirfenidone, an FDA-approved compound for antifibrotic treatments, did not significantly affect all the genes examined on soft ECM. Although pirfenidone had minor effects on most genes, it did reduce the expression of collagens, the major components of fibrotic tissues. These results explain why pirfenidone can slow fibrosis progression with minor side effects in clinical trials. In conclusion, our study presents a method for creating vascularized liver organoids that can accurately mimic fibrotic and normal tissues for drug screening. Our findings provide valuable insights into the potential risks and benefits of using A83-01 and pirfenidone as antifibrotic drugs. This method can be applied to other organs to create organ-specific vascularized organoids for drug development.

FGF-2 Differentially Regulates Lens Epithelial Cell Behaviour during TGF-β-Induced EMT

Fibroblast growth factor (FGF) and transforming growth factor-beta (TGF-β) can regulate and/or dysregulate lens epithelial cell (LEC) behaviour, including proliferation, fibre differentiation, and epithelial–mesenchymal transition (EMT). Earlier studies have investigated the crosstalk between FGF and TGF-β in dictating lens cell fate, that appears to be dose dependent. Here, we tested the hypothesis that a fibre-differentiating dose of FGF differentially regulates the behaviour of lens epithelial cells undergoing TGF-β-induced EMT. Postnatal 21-day-old rat lens epithelial explants were treated with a fibre-differentiating dose of FGF-2 (200 ng/mL) and/or TGF-β2 (50 pg/mL) over a 7-day culture period. We compared central LECs (CLECs) and peripheral LECs (PLECs) using immunolabelling for changes in markers for EMT (α-SMA), lens fibre differentiation (β-crystallin), epithelial cell adhesion (β-catenin), and the cytoskeleton (alpha-tropomyosin), as well as Smad2/3- and MAPK/ERK1/2-signalling. Lens epithelial explants cotreated with FGF-2 and TGF-β2 exhibited a differential response, with CLECs undergoing EMT while PLECs favoured more of a lens fibre differentiation response, compared to the TGF-β-only-treated explants where all cells in the explants underwent EMT. The CLECs cotreated with FGF and TGF-β immunolabelled for α-SMA, with minimal β-crystallin, whereas the PLECs demonstrated strong β-crystallin reactivity and little α-SMA. Interestingly, compared to the TGF-β-only-treated explants, α-SMA was significantly decreased in the CLECs cotreated with FGF/TGF-β. Smad-dependent and independent signalling was increased in the FGF-2/TGF-β2 co-treated CLECs, that had a heightened number of cells with nuclear localisation of Smad2/3 compared to the PLECs, that in contrast had more pronounced ERK1/2-signalling over Smad2/3 activation. The current study has confirmed that FGF-2 is influential in differentially regulating the behaviour of LECs during TGF-β-induced EMT, leading to a heterogenous cell population, typical of that observed in the development of post-surgical, posterior capsular opacification (PCO). This highlights the cooperative relationship between FGF and TGF-β leading to lens pathology, providing a different perspective when considering preventative measures for controlling PCO.

Capsulotomy opening diameter outcomes in aphakic eyes after primary congenital cataract removal and its association

Aim

To observe the change of capsulotomy opening diameter (COD) in aphakic eyes after primary congenital cataract removal and investigate its influencing factors.

Methods

Ocular parameters, including corneal diameter (CD), axial length (AL), anterior and posterior COD (ACOD, PCOD), and age at surgery were recorded at primary congenital cataract removal and secondary intraocular lens implantation. The concentrations of 15 kinds of cytokines in aqueous humor samples collected at the primary surgery were detected. The change (Δ) of COD between two surgeries were described, and its association was analyzed.

Results

Fifty eyes from 33 patients with congenital cataract who underwent primary and secondary surgery were enrolled. The changes in ACOD and PCOD were not statistically significant on the whole. ΔACOD was positively correlated with ΔCD and the concentrations of PDGF-AA, VEGF and TGF-β1. The concentration of FGF-2 and the interval between two surgeries showed negative correlations with ΔACOD and ΔPCOD.

Conclusion

COD in aphakic eyes kept changing after primary surgery. The positive correlation between ΔACOD and ΔCD manifested the enlargement of ACOD was influenced by lateral eye growth. Meanwhile, ΔACOD was also associated with cytokines, indicating postoperative inflammation promoted the ACOD constriction.

Methodologies to unlock the molecular expression and cellular structure of ocular lens epithelial cells

The transparent ocular lens in the anterior chamber of the eye is responsible for fine focusing of light onto the retina. The lens is entirely cellular with bulk of the tissue composed of fiber cells, and the anterior hemisphere of the lens is covered by a monolayer of epithelial cells. Lens epithelial cells are important for maintaining fiber cell homeostasis and for continual growth of the lens tissue throughout life. Cataracts, defined as any opacity in the lens, remain the leading cause of blindness in the world. Following cataract surgery, lens epithelial cells can undergo a process of epithelial-to-mesenchymal transition (EMT), leading to secondary cataracts due to posterior capsular opacification (PCO). Since the epithelial cells make up only a small fraction of the lens, specialized techniques are required to study lens epithelial cell biology and pathology. Studies using native lens epithelial cells often require pooling of samples to obtain enough cells to make sufficient samples for traditional molecular biology techniques. Here, we provide detailed protocols that enable the study of native mouse lens epithelial cells, including immunostaining of the native lens epithelium in flat mounts, extraction of RNA and proteins from pairs of lens epithelial monolayers, and isolation of lens epithelial cells for primary culture. These protocols will enable researchers to gain better insight on representative molecular expression and cellular structure of lens epithelial cells. We also provide comparative data between native, primary culture, and immortalized lens epithelial cells and discuss the advantages and disadvantages of each technique presented.

Expansion of mouse castration-resistant intermediate prostate stem cells in vitro

Background

Most castration-resistant prostate cancers (CRPCs) have a luminal phenotype with high androgen receptor (AR) and prostate-specific antigen (PSA) expression. Currently, it is difficult to culture castration-resistant luminal cells with AR and PSA expression.

Methods

We formulated a custom-made medium and isolated primary cells from the prostate of adult wild-type (WT) and TRAMP mice. The cells were characterized by immunofluorescence staining, transcriptomic analysis, and qRT-PCR verification. Their self-renewal and differentiation potential in vitro and in vivo were examined. We treated the cells with androgen deprivation and enzalutamide and performed immunofluorescence staining and western blotting to analyze their expression of AR and PSA.

Results

We isolated a novel type of castration-resistant intermediate prostate stem cells (CRIPSCs) from adult WT and TRAMP mice. The mouse CRIPSCs proliferated rapidly in two-dimensional (2D) culture dishes and can be cultured for more than six months. The mouse CRIPSCs expressed luminal markers (AR, PSA, and Dsg4), basal markers (CK5 and p63), Psca, and the intermediate cell marker (Ivl). Transcriptomic analysis showed that the mouse CRIPSCs had upregulated signaling pathways related to cancer development and drug resistance. In the long-term culture, TRAMP CRIPSCs had higher expression of the genes related to stem cells and cancers than WT mice. Both WT and TRAMP CRIPSCs formed organoids in Matrigel. WT CRIPSCs did not form prostate tissues when transplanted in vivo without urogenital sinus mesenchyme (UGM) cells. In contrast, TRAMP CRIPSCs formed prostate ducts in NOG mice without UGM  cells and differentiated into luminal, basal, and neuroendocrine cells. Androgens regulated AR translocation between the nucleus and cytoplasm in the mouse CRIPSCs. Treatment of androgen deprivation  (ADT) and enzalutamide reduced AR expression in WT and TRAMP CRIPSCs; however, this treatment promoted PSA expression in TRAMP, while not WT CRIPSCs, similar to the clinical observations of CRPC.

Conclusions

Our study established a method for isolating and expanding mouse CRIPSCs in 2D culture dishes. Mouse CRIPSCs had markers of basal and luminal cells, including AR and PSA, and can differentiate into prostate organoids and tissues. TRAMP CRIPSCs had elevated PSA expression upon ADT and enzalutamide treatment. Our method can be translated into clinical settings for CRPC precision medicine.

The local wound environment is a key determinant of the outcome of TGFβ signaling on the fibrotic response of CD44+ leader cells in an ex vivo post-cataract-surgery model

The cytokine transforming growth factor beta (TGFβ) has a role in regulating the normal and pathological response to wound healing, yet how it shifts from a pro-repair to a pro-fibrotic function within the wound environment is still unclear. Using a clinically relevant ex vivo post-cataract surgery model that mimics the lens fibrotic disease posterior capsule opacification (PCO), we investigated the influence of two distinct wound environments on shaping the TGFβ-mediated injury response of CD44⁺ vimentin-rich leader cells. The substantial fibrotic response of this cell population occurred within a rigid wound environment under the control of endogenous TGFβ. However, TGFβ was dispensable for the role of leader cells in wound healing on the endogenous basement membrane wound environment, where repair occurs in the absence of a major fibrotic outcome. A difference between leader cell function in these distinct environments was their cell surface expression of the latent TGFβ activator, αvβ3 integrin. This receptor is exclusively found on this CD44⁺ cell population when they localize to the leading edge of the rigid wound environment. Providing exogenous TGFβ to bypass any differences in the ability of the leader cells to sustain activation of TGFβ in different environments revealed their inherent ability to induce pro-fibrotic reactions on the basement membrane wound environment. Furthermore, exposure of the leader cells in the rigid wound environment to TGFβ led to an accelerated fibrotic response including the earlier appearance of pro-collagen + cells, alpha smooth muscle actin (αSMA)+ myofibroblasts, and increased fibrotic matrix production. Collectively, these findings show the influence of the local wound environment on the extent and severity of TGFβ-induced fibrotic responses. These findings have important implications for understanding the development of the lens fibrotic disease PCO in response to cataract surgery wounding.

Aberrant TGF-β1 signaling activation by MAF underlies pathological lens growth in high myopia

High myopia is a leading cause of blindness worldwide. Myopia progression may lead to pathological changes of lens and affect the outcome of lens surgery, but the underlying mechanism remains unclear. Here, we find an increased lens size in highly myopic eyes associated with up-regulation of β/γ-crystallin expressions. Similar findings are replicated in two independent mouse models of high myopia. Mechanistic studies show that the transcription factor MAF plays an essential role in up-regulating β/γ-crystallins in high myopia, by direct activation of the crystallin gene promoters and by activation of TGF-β1-Smad signaling. Our results establish lens morphological and molecular changes as a characteristic feature of high myopia, and point to the dysregulation of the MAF-TGF-β1-crystallin axis as an underlying mechanism, providing an insight for therapeutic interventions.

High myopia is associated with lens changes, but the underlying mechanisms are unclear. Here, the authors show increased equatorial diameter of the lens in subjects affected by high myopia, and find that these changes are associated with an increase in crystallin expression driven by the transcription factor MAF and TGF-β1 signaling.

Bleomycin induces epithelial-to-mesenchymal transition via bFGF/PI3K/ESRP1 signaling in pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal and chronic disease with a high rate of infection and mortality; however, its etiology and pathogenesis remain unclear. Studies have revealed that epithelial–mesenchymal transition (EMT) is a crucial cellular event in IPF. Here, we identified that the pulmonary fibrosis inducer bleomycin simultaneously increased the expression of bFGF and TGF-β1 and inhibited epithelial-specific regulatory protein (ESRP1) expression in vivo and in vitro. In addition, in vitro experiments showed that bFGF and TGF-β1 down-regulated the expression of ESRP1 and that silencing ESRP1 promoted EMT in A549 cells. Notably, we determined that bFGF activates PI3K/Akt signaling, and treatment with the PI3K/Akt inhibitor LY294002 inhibited bleomycin-induced cell morphology changes and EMT. In addition, the effects of LY294002 on bleomycin-induced EMT were inhibited by ESRP1 silencing in A549 cells. Taken together, these findings suggest that bleomycin induced EMT through down-regulating ESRP1 by simultaneously increasing bFGF and TGF-β1 in pulmonary fibrosis. Additionally, our findings indicated that bFGF inhibits ESRP1 by activating PI3K/Akt signaling.

Long-term myofibroblast persistence in the capsular bag contributes to the late spontaneous in-the-bag intraocular lens dislocation

Late spontaneous in-the-bag intraocular lens (IOL) dislocation is a complication presenting 6 months or later after cataract surgery. We aimed to characterize the cells in the lens capsules (LCs) of 18 patients with spontaneous late in-the-bag IOL dislocation. Patients' average age was 82.6 ± 1.5 years (range 72-98), and most of them had pseudoexfoliation syndrome (PEX). Cells from the LCs were positive for myofibroblast (αSMA), proliferation (Ki-67, PCNA), early lens development/lens progenitor (SOX2, PAX6), chemokine receptor (CXCR4), and transmembrane (N-cadherin) markers, while negative for epithelial (E-cadherin) marker. Moreover, the cells produced abundant fibronectin, type I and type V collagen in the nearby extracellular matrix (ECM). During ex vivo cultivation of dislocated IOL-LCs in toto, the cells proliferated and likely migrated onto the IOL's anterior side. EdU proliferation assay confirmed the proliferation potential of the myofibroblasts (MFBs) in dislocated IOL-LCs. Primary cultured lens epithelial cells/MFBs isolated from the LC of dislocated IOLs could induce collagen matrix contraction and continuously proliferated, migrated, and induced ECM remodeling. Taken together, this indicates that long-lived MFBs of dislocated IOLs might contribute to the pathogenic mechanisms in late in-the-bag IOL dislocation.

Differentiation Induction of Human Stem Cells for Corneal Epithelial Regeneration

Deficiency of corneal epithelium causes vision impairment or blindness in severe cases. Transplantation of corneal epithelial cells is an effective treatment but the availability of the tissue source for those cells is inadequate. Stem cells can be induced to differentiate to corneal epithelial cells and used in the treatment. Multipotent stem cells (mesenchymal stem cells) and pluripotent stem cells (embryonic stem cells and induced pluripotent stem cells) are promising cells to address the problem. Various protocols have been developed to induce differentiation of the stem cells into corneal epithelial cells. The feasibility and efficacy of both human stem cells and animal stem cells have been investigated for corneal epithelium regeneration. However, some physiological aspects of animal stem cells are different from those of human stem cells, the protocols suited for animal stem cells might not be suitable for human stem cells. Therefore, in this review, only the investigations of corneal epithelial differentiation of human stem cells are taken into account. The available protocols for inducing the differentiation of human stem cells into corneal epithelial cells are gathered and compared. Also, the pathways involving in the differentiation are provided to elucidate the relevant mechanisms.

Abnormal Fractional Amplitude of Low-Frequency Fluctuation Changes in Patients with Monocular Blindness: A Functional Magnetic Resonance Imaging (MRI) Study

BACKGROUND We used fractional amplitude of low-frequency fluctuation (fALFF) technology to investigate spontaneous cerebral activity in patients with monocular blindness (MB) and in healthy controls (HCs). MATERIAL AND METHODS Thirty MB patient and 15 HCs were included in this study. All subjects were scanned by resting-state functional magnetic resonance imaging (rs-fMRI). The independent sample t test and chi-squared test were applied to analyze demographics of MB patients and HCs. The 2-sample t test and receiver operating characteristic (ROC) curves were applied to identify the difference in average fALFF values between MB patients and HCs. Pearson's correlation analysis was applied to explore the relationship between the average fALFF values of brain areas and clinical behavior in the MB group. RESULTS MB patients had lower fALFF values in the left anterior cingulate and higher fALFF values in the left precuneus and right and left inferior parietal lobes than in HCs. Moreover, the mean fALFF values of MB patients in the left anterior cingulate had negative correlations with the anxiety scale score (r=-0.825, P<0.001) and the depression scale score (r=-0.871, P<0.001). CONCLUSIONS Our study found that MB patients had abnormal spontaneous activities in the visual and vision-related regions. The finding of abnormal neuronal activity helps to reveal the underlying neuropathologic mechanisms of vision loss.

Connexin 50-R205G Mutation Perturbs Lens Epithelial Cell Proliferation and Differentiation

Purpose

To investigate the underlying mechanisms for how the mouse Cx50-R205G point mutation, a homologue of the human Cx50-R198W mutation that is linked to cataract-microcornea syndrome, affects proper lens growth and fiber cell differentiation to lead to severe lens phenotypes.

Methods

EdU labeling, immunostaining, confocal imaging analysis, and primary lens epithelial cell culture were performed to characterize the lens epithelial cell (LEC) proliferation and fiber cell differentiation in wild-type and Cx50-R205G mutant lenses in vivo and in vitro.

Results

The Cx50-R205G mutation severely disrupts the lens size and transparency. Heterozygous and homozygous Cx50-R205G mutant and Cx50 knockout lenses all show decreased central epithelium proliferation while only the homozygous Cx50-R205G mutant lenses display obviously decreased proliferating LECs in the germinative zone of neonatal lenses. Cultured Cx50-R205G lens epithelial cells reveal predominantly reduced Cx50 gap junction staining but no change of the endoplasmic reticulum stress marker BiP. The heterozygous Cx50-R205G lens fibers show moderately disrupted Cx50 and Cx46 gap junctions while the homozygous Cx50-R205G lens fibers have drastically reduced Cx50 and Cx46 gap junctions with severely altered fiber cell shape in vivo.

Conclusions

The Cx50-R205G mutation inhibits both central and equatorial lens epithelial cell proliferation to cause small lenses. This mutation also disrupts the assembly and functions of both Cx50 and Cx46 gap junctions in lens fibers to alter fiber cell differentiation and shape to lead to severe lens phenotypes.

Engineering Tissues without the Use of a Synthetic Scaffold: A Twenty-Year History of the Self-Assembly Method

Twenty years ago, Dr. François A. Auger, the founder of the Laboratory of Experimental Organogenesis (LOEX), introduced the self-assembly technique. This innovative technique relies on the ability of dermal fibroblasts to produce and assemble their own extracellular matrix, differing from all other tissue-engineering techniques that use preformed synthetic scaffolds. Nevertheless, the use of the self-assembly technique was limited for a long time due to its main drawbacks: time and cost. Recent scientific breakthroughs have addressed these limitations. New protocol modifications that aim at increasing the rate of extracellular matrix formation have been proposed to reduce the production costs and laboratory handling time of engineered tissues. Moreover, the introduction of vascularization strategies in vitro permits the formation of capillary-like networks within reconstructed tissues. These optimization strategies enable the large-scale production of inexpensive native-like substitutes using the self-assembly technique. These substitutes can be used to reconstruct three-dimensional models free of exogenous materials for clinical and fundamental applications.