Prostaglandin F2alpha receptor (FP receptor) agonists are potent adipose differentiation inhibitors for primary culture of adipocyte precursors in defined medium

Simultaneous Effects of a Selective EP2 Agonist, Omidenepag, and a Rho-Associated Coiled-Coil Containing Protein Kinase Inhibitor, Ripasudil, on Human Orbital Fibroblasts

Purpose: To assess the combined effects of omidenepag (OMD), a selective EP2 agonist, and ripasudil (Rip), an inhibitor of rho-associated coiled-coil containing protein kinases, on the human orbital adipose tissue, two-dimensional (2D) or three-dimensional (3D) cultures of human orbital fibroblasts (HOFs) were employed. Methods: Cellular metabolic functions (2D), physical (3D), lipid staining (3D), and quantitative polymerase chain reaction for adipogenesis-related genes, PPARγ and AP2, and extracellular matrix (ECM) molecules, including collagen (COL)1, 4, and 6, and fibronectin (FN) (3D) were evaluated in the presence of OMD (100 nM) and/or Rip (10 μM). Results: Real-time metabolic analyses revealed that the adipogenic differentiation (DIF+) with OMD significantly shifted an energetic state toward energetic, whereas DIF+ with Rip significantly shifted that toward quiescent. In the case of both drugs upon DIF+, the metabolic effect of OMD was predominant. DIF+ induced enlargement and stiffed 3D spheroid with increased lipid staining and mRNA expression of adipogenesis-related genes, COL4 and COL6, and decreased the expression of COL1. In the presence of OMD and/or Rip to DIF+, (1) the sizes were further increased by Rip and the stiffness was significantly decreased by OMD or Rip and (2) COL4 or AP2 expression was substantially increased by OMD or Rip, respectively. Conclusion: The results presented herein indicate that the metabolic effects of OMD and Rip exerted opposing effects and the effects of OMD toward Ap2 and ECM expressions were distinct from those of Rip, but the effects of OMD toward the physical aspects and adipogenesis of the 3D cultured HOFs were similar to the effects of Rip.

In Vivo Effects of Prostaglandin Analogues Application by Topical Drops or Retrobulbar Injections on the Orbital Fat of a Rat Model

PURPOSE

To assess the in vivo effects of bimatoprost 0.03% (Lumigan®) on the orbital fat in a rat model.

METHODS

Twenty rats were randomly divided into two groups: bimatoprost was administrated to the right eye by topical drops (group 1) or retrobulbar injection (group 2), and saline was administrated to the left eye by similar administration routes (controls). Four weeks later, all rats were sedated and euthanized, both orbits exenterated, and thin sections through the intraconal orbital fat were obtained.

RESULTS

Average adipocyte cell count was significantly lower in the bimatoprost treated orbits (drops or retrobulbar injection, 29.5 vs. 67.5 cells per slide in the control globes, p=0.046). Fat cells were not detected in 9/20 (45%) bimatoprost treated orbits     .

CONCLUSIONS

Orbits treated with bimatoprost by drops or retrobulbar injection demonstrated significant decrease in adipocytes cell count compared with controls. Bimatoprost could be an effective treatment for inactive thyroid eye disease.

Do Prostaglandin Analogue Lash Lengtheners Cause Eyelid Fat and Volume Loss?

BACKGROUND

Prostaglandin analogues (PGAs; a first-line antiglaucoma treatment) have been remarketed as popular eyelash-lengthening serums due to their lash-lengthening and lash-thickening side effects. Periorbital volume loss is now a well-established side effect of topical PGAs used to treat glaucoma (prostaglandin-associated periorbitopathy) but has not, to date, been listed as a potential side effect of lash-lengthening serums containing PGAs.

OBJECTIVES

The aim of this study was to identify whether periorbital fat/volume loss is seen in users of PGA lash lengtheners.

METHODS

This investigation comprised a case report and an informal randomized controlled study comparing "before-and-after" color photographs displayed on the websites of manufacturers of PGA-containing lash lengtheners (PGALLs) (ie, containing bimatoprost, norbimatoprost, isopropyl cloprostenate, dechloro-dihydroxy-difluoro-ethylcloprostenolamide, or methylamido-dihydro-noralfaprostal) vs 2 control groups: non-PGALLs (NPGALL) and false eyelashes (FLs). Expert and layperson blinded graders used a purpose-designed grading system to identify subtle signs of periorbital fat/volume loss over time.

RESULTS

A 35-year-old female developed thin, wrinkled, darker skin, and periorbital hollowing after 10 months of treatment with Lash Boost (Rodan & Fields, San Francisco, CA), containing isopropyl cloprostenate, which reversed 6 months after discontinuation. Fifteen "before-and-after" pairs of photographs (PGALL, n = 10; NPGALL, n = 3; FL, n = 2) were graded by 5 graders (3 expert, 2 layperson). Mean grading score was 8.2 (of 19) in the PGALL group, 2.3 in the NPGALL group, and 3.2 in the FL group. PGALL scores were significantly higher than scores in the NPGALL (P < 0.001) and FL (P = 0.017) groups.

CONCLUSIONS

Review of commercial "before-and-after" photographs suggests that PGALL users develop changes compatible with prostaglandin-associated periorbitopathy. Consumers must be aware of the possibility of periorbital volume loss prior to commencing treatment with PGALLs. Often the customer-facing product ingredient list contains no mention of PGAs.

LEVEL OF EVIDENCE: 4

The Prostaglandin E2 Pathway and Breast Cancer Stem Cells: Evidence of Increased Signaling and Potential Targeting

Culprits of cancer development, metastasis, and drug resistance, cancer stem cells (CSCs) are characterized by specific markers, active developmental signaling pathways, metabolic plasticity, increased motility, invasiveness, and epithelial-mesenchymal transition. In breast cancer, these cells are often more prominent in aggressive disease, are amplified in drug-resistant tumors, and contribute to recurrence. For breast cancer, two distinct CSC populations exist and are typically defined by CD44+/CD24- cell surface marker expression or increased aldehyde dehydrogenase (ALDH) activity. These CSC populations share many of the same properties but also exhibit signaling pathways that are more active in CD44+/CD24- or ALDH+ populations. Understanding these CSC populations and their shared or specific signaling pathways may lead to the development of novel therapeutic strategies that will improve breast cancer patient outcomes. Herein, we review the current evidence and assess published patient tumor datasets of sorted breast CSC populations for evidence of heightened prostaglandin E2 (PGE₂) signaling and activity in these breast CSC populations. PGE₂ is a biologically active lipid mediator and in cancer PGE₂ promotes tumor progression and poor patient prognosis. Overall, the data suggests that PGE₂ signaling is important in propagating breast CSCs by enhancing inherent tumor-initiating capacities. Development of anti-PGE₂ signaling therapeutics may be beneficial in inhibiting tumor growth and limiting breast CSC populations.

Reactivities of a Prostanoid EP2 Agonist, Omidenepag, Are Useful for Distinguishing between 3D Spheroids of Human Orbital Fibroblasts without or with Graves' Orbitopathy

Background. To obtain new insights into the activation of the thyroid-stimulating hormone (TSH) and insulin-like growth factor 1 (IGF-1) receptors in human orbital fibroblasts (n-HOFs), the effects of the prostanoid EP2 agonist, omidenepag (OMD), and a rho-associated coiled-coil-containing protein kinase (ROCK) inhibitor, ripasudil (Rip) were evaluated using three-dimension (3D) n-HOFs spheroids in the absence and presence of the recombinant human TSH receptor antibodies, M22 and IGF-1. Methods. The effects of 100 nM OMD or 10 μM Rip on the physical properties, size, stiffness, and mRNA expression of several extracellular matrix (ECM) molecules, their regulator, inflammatory cytokines, and endoplasmic reticulum (ER) stress-related factors were examined and compared among 3D spheroids of n-HOFs, M22-/IGF-1-activated n-HOFs and GO-related human orbital fibroblasts (GHOFs). Results. The physical properties and mRNA expressions of several genes of the 3D n-HOFs spheroids were significantly and diversely modulated by the presence of OMD or Rip. The OMD-induced effects on M22-/IGF-1-activated n-HOFs were similar to the effects caused by GHOHs, but quite different from those of n-HOFs. Conclusions. The findings presented herein indicate that the changes induced by OMD may be useful in distinguishing between n-HOFs and GHOFs.

ROCK inhibitors modulate the physical properties and adipogenesis of 3D spheroids of human orbital fibroblasts in different manners

To elucidate the pharmacological effects of Rho-associated coiled-coil containing protein kinase inhibitors (ROCK-is), ripasudil (Rip), Y27632, and KD025, on human orbital fatty tissue, the human orbital fibroblasts (HOFs) were three-dimensional (3D) cultured for 12 days. The effects of ROCK-is on the physical properties of the 3D-cultured HOF spheroids, including their sizes and physical stiffness, their adipogenesis by lipid staining, and the mRNA expression of adipogenesis-related genes, PPARγ and AP2, and extracellular matrix (ECM) including collagen (COL) 1, 4, and 6, and fibronectin were analyzed. A significant increase in the sizes, physical stiffness, lipid staining, and mRNA expression of adipogenesis-related genes, COL4 and COL6, and a decrease in COL1 expression were observed with adipogenesis (DIF+). In the presence of ROCK-is, such DIF+-induced effects were differently modulated as follows: (1) the sizes were not affected or significantly enhanced by Rip, Y27632, or KD025, (2) the physical stiffness was significantly decreased in Rip and Y27632, but was substantially increased in KD025, (3) the lipid staining was further enhanced or significantly suppressed by Rip, Y27632, or KD025, and both PPARγ and AP2 expression were significantly downregulated or upregulated by KD025 or Rip, and (4) Rip upregulated the expression of COL4, Y27632 upregulated the expression of COL1, COL4, and COL6, and KD025 upregulated the expression of COL1 and COL4. This study indicates that ROCK-is significantly and differently modulate physical properties of the 3D HOF spheroids as well as their adipogenesis.

Addition of ROCK inhibitors to prostaglandin derivative (PG) synergistically affects adipogenesis of the 3D spheroids of human orbital fibroblasts (HOFs)

To study the additive effects of Rho-associated coiled-coil containing protein kinase inhibitors, ripasudil (Rip) to bimatoprost acid (BIM-A) on orbital adipose tissue, three-dimensional (3D) cultures of human orbital fibroblasts (HOFs) were prepared and the physical properties including the 3D spheroid size and stiffness, lipid staining by BODIPY and the mRNA expression of adipogenesis-related genes, PPARγ and AP2, and extracellular matrix (ECM) including collagen (COL)1, 4 and 6, and fibronectin (FN) were analyzed. Adipogenesis (DIF+) induced (1) enlargement and increasing stiffness of the 3D HOFs spheroid, (2) increased lipid staining, the expression of adipogenesis-related gene expressions, and (3) the down-regulation of COL1 and FN and up-regulation of COL4 and COL6. In the presence of BIM-A, (1) such DIF+-induced changes in 3D spheroid size and stiffness were significantly inhibited or enhanced, respectively, (2) the lipid staining and its related gene expressions were significantly down-regulated, and (3) the expression of COL1 and COL6 were up-regulated. By the addition of Rip to BIM-A, the above BIM-A-induced effects were all inhibited, except for the up-regulation of COL6 and FN expression, that is, enlarging and decreasing stiffness, enhancement of lipid staining and its related gene expression, and down-regulation of COL1 expression. Our present study indicates that Rip significantly suppressed BIM-A-induced effects toward 3D HOFs spheroids.

Revisiting the Safety of Prostaglandin Analog Eyelash Growth Products

BACKGROUND

The FDA approved bimatoprost ophthalmic solution 0.03% for treatment of eyelash hypotrichosis in 2008. Consumer concern persists regarding potential side effects of this product.

OBJECTIVE

To identify gaps in the safety information associated with the use of prostaglandin eyelash growth products.

MATERIALS AND METHODS

Literature searches were performed using PubMed, Embase, and Nexis Uni databases without restriction to publication date, language, or study setting.

RESULTS

The literature pertaining to bimatoprost for treatment of eyelash hypotrichosis is dominated by industry-sponsored clinical trials. Study design choices create gaps in our understanding of the clinical safety of these products.

CONCLUSION

Because of study design choice, clinical trials of bimatoprost for eyelash growth may have systematically underreported the incidence of drug application discomfort and prostaglandin-associated periorbitopathy. The risk of increased iris pigmentation remains inadequately investigated. Consequently, there is an ongoing need to educate and monitor patients who choose to use these products.

ROCK inhibitors enhance the production of large lipid-enriched 3D organoids of 3T3-L1 cells

Since the recent discovery of prostaglandin-associated peri-orbitopathy, a great deal of interest has developed concerning the side effects of anti-glaucoma medications toward periocular fatty tissue, especially their adipogenesis. Two- or three-dimension (2D or 3D) cultures of the 3T3-L1 cells were employed to elucidate the effects of the Rho-associated coiled-coil containing protein kinase inhibitor (ROCK-i) the anti-glaucoma drug, Ripasudil, and other ROCK-i, such as Y27632 on adipogenesis. Ultrastructure by electron microscopy and physical stiffness measurements by a micro-squeezer demonstrated the 3D organoids had essentially matured during the 7-day culture. The effects of ROCK-i on 3D organoid sizes, lipid staining, the mRNA expression of adipogenesis related genes, Pparγ, Cebpa and Leptin, and extracellular matrix (ECM) including collagen (COL) 1, 4 and 6, and fibronectin, and physical stiffness were then conducted. Upon adipogenesis, the sizes, lipid staining and mRNA expressions of adipogenesis related genes, Col 4 and Col 6 were dramatically increased, and were further enhanced by ROCK-i. Micro-squeezer analysis demonstrated that adipogenesis resulted in a marked less stiffed 3D organoid and this was further enhanced by ROCK-i. Our present study indicates that ROCK-i significantly enhanced the production of large lipid-enriched 3T3-L1 3D organoids.

Prostaglandin F2α in vitro can affect basic inflammatory parameters of mesenchymal stem cells and slight modulating some of their immunomodulatory properties

In the last decade, mesenchymal stem cells (MSCs) have been gaining attention due their ability to influence the function of other cells as well as modulate the inflammatory response. This occurs via their immunomodulatory functions,  acting through direct cell-cell interaction or by releasing a broad spectrum of bioactive factors such as cytokines and growth factors. In addition, prostaglandins are arachidonic acid metabolites that play a key role in the generation and modulation of the inflammatory response. Among the bioactive prostaglandins, PGF_2α is able to stimulate cell proliferation as well as act to inhibit progenitor cell differentiation, but no information about this prostaglandin's action on the immunoregulatory function of MSCs has been reported. In this study we evaluate important aspects of the influence of PGF_2α analog (17-phenyl-trinor PGF_2α), which is a potent prostaglandin FP receptor agonist, on some mechanisms that control the main functions of MSCs. C3H10T1/2, a mesenchymal stem cell linage, was stimulated with PGF_2α under inflammatory conditions trigged by LPS in order to investigate PGF_2α inflammatory parameters as well as its ability to immunoregulate macrophages and lymphocytes. PGF_2α has the ability to increase proliferation tax without altering the cell viability of LPS-stimulated MSCs, while also diminishing the phosphorylation of NFκB transcription factor leading to attenuation of IL-1β and GM-CSF production. Additionally, MSC-s conditioned media from cells stimulated with PGF_2α was able to increase the lymphocytes' IL-10 production. Overall, this study implied that PGF_2α are able to modify some properties of MSCs.

Changes in Prostaglandin-associated Periorbital Syndrome After Switch from Conventional Prostaglandin F2α Treatment to Omidenepag Isopropyl in 11 Consecutive Patients

PURPOSE

We evaluated the recovery of patients with PAPS for whom the treatment regimen switched from conventional prostaglandin F2α analogues to a new selective prostaglandin-EP2 agonist: omidenepag isopropyl.

PATIENTS AND METHODS

From November 2018 to July 2019, we prospectively evaluated 11 patients who had been using conventional PGF2α drugs. Digital photographs of the patients were taken before the start of omidenepag isopropyl therapy and ~3 and 6 months after. Three independent observers used the photographs to judged recovery according to the 5 signs of PAPS: deepening of the upper eyelid sulcus (DUES), flattening of the lower eyelid bags, upper eyelid ptosis, ciliary hypertrichosis, and periorbital skin hyperpigmentation.

RESULTS

The mean age of patients was 61, and 7 patients were female. The original PGF2α drugs were bimatoprost, latanoprost, travoprost, and tafluprost. The mean duration of PGF2α treatment was 65 months. PAPS signs were evaluated in 10 patients after 3 months and in all 11 patients after 6 months: After 3 and 6 months, DUES improved in 3 and 3 patients, respectively; flattening of the lower eyelid bags improved in 1 and 2 patients, respectively; upper eyelid ptosis did not improve in any patients; ciliary hypertrichosis improved in 0 and 2 patients, respectively; and eyelid pigmentation improved in 2 and 8 patients, respectively. The 3 patients who showed improvement in DUES at 6 months had all previously used bimatoprost.

CONCLUSIONS

Some PAPS signs improved after patients started taking omidenepag isopropyl. Our findings will be useful for patients taking antiglaucoma eye drops.

One-Year Follow-Up Study of Changes in Prostaglandin-Associated Periorbital Syndrome After Switch From Conventional Prostaglandin F2alfa to Omidenepag Isopropyl

Background

Cosmetic problems induced by conventional prostaglandin F2α (PGF2α) analogs are common. We prospectively evaluated the improvement of patients with prostaglandin-associated periorbital syndrome (PAPS) for whom the treatment regimen was switched from conventional PGF2α analogs to a new selective prostaglandin-EP2 agonist (i.e., omidenepag isopropyl).

Methods

We finally evaluated 12 patients with follow-up for one year who changed the therapy from conventional PGF2α drugs to omidenepag isopropyl. Digital facial images of the patients were captured prior to the initiation of therapy with omidenepag isopropyl and after approximately three, six, and 12 months. Three independent observers judged the recovery according to the five signs of PAPS - deepening of the upper eyelid sulcus (DUES), flattening of the lower eyelid bags, upper eyelid ptosis, ciliary hypertrichosis, and periorbital skin hyperpigmentation - by comparing images at baseline and each month.

Results

The mean age of patients (eight females; four males) was 61 years. The original PGF2α drugs were bimatoprost (N = 7), latanoprost (N = 3), travoprost (N = 1), and tafluprost (N = 1). The mean duration of treatment with PGF2α was 61 months. PAPS signs were evaluated in 11 patients after three months and in all 12 patients after six and 12 months. After three, six, and 12 months, DUES improved in five, six, and six patients, respectively; flattening of the lower eyelid bags improved in two, two, and three patients, respectively; upper eyelid ptosis improved in zero, one, and two patients, respectively; ciliary hypertrichosis improved in zero, one, and zero patients, respectively; and eyelid pigmentation improved in one, five, and three patients, respectively. Recovery of DUES was the most observed sign at ≤50%, whereas the recovery of ciliary hypertrichosis was the least sign at ≤8% at 12 months. All patients with improved DUES at one year had been receiving bimatoprost or travoprost.

Conclusions

Some PAPS signs improved after the administration of omidenepag isopropyl for one year. Our findings are useful for patients suffering from cosmetic problems induced by conventional PGF2α analogs.

Identification and characterization of adipose surface epitopes

Adipose tissue is a central regulator of metabolism and an important pharmacological target to treat the metabolic consequences of obesity, such as insulin resistance and dyslipidemia. Among the various cellular compartments, the adipocyte cell surface is especially appealing as a drug target as it contains various proteins that when activated or inhibited promote adipocyte health, change its endocrine function and eventually maintain or restore whole-body insulin sensitivity. In addition, cell surface proteins are readily accessible by various drug classes. However, targeting individual cell surface proteins in adipocytes has been difficult due to important functions of these proteins outside adipose tissue, raising various safety concerns. Thus, one of the biggest challenges is the lack of adipose selective surface proteins and/or targeting reagents. Here, we discuss several receptor families with an important function in adipogenesis and mature adipocytes to highlight the complexity at the cell surface and illustrate the problems with identifying adipose selective proteins. We then discuss that, while no unique adipocyte surface protein might exist, how splicing, posttranslational modifications as well as protein/protein interactions can create enormous diversity at the cell surface that vastly expands the space of potentially unique epitopes and how these selective epitopes can be identified and targeted.

Shortening of Interpupillary Distance after Instillation of Topical Prostaglandin Analog Eye Drops

PURPOSE

To investigate changes in the interpupillary distance (IPD) after continual instillation of topical prostaglandin analogs (PGAs) in glaucoma patients as an objective indicator of prostaglandin-associated periorbitopathy (PAP).

DESIGN

Retrospective, comparative case series.

METHODS

A total of 152 institutional patients with glaucoma were enrolled in this study. Inclusion criteria were visual acuities exceeding 10/20 bilaterally and no intraocular surgery during observation. Intervention/observation procedures: First-time bilateral instillation of bimatoprost, travoprost, latanoprost, or tafluprost and IPDs measured by automatic refractometry. IPDs, intraocular pressures (IOPs), and refractive errors were measured before and after continual drug administration (treatment, 2-24 months).

MAIN OUTCOME MEASUREMENTS

Post-treatment changes in IPDs. A total of 61 untreated patients served as controls.

RESULTS

The IPDs shortened significantly (P < 0.001) after treatment (-0.80 ± 2.1 mm); the IPDs of control subjects remained unchanged (0.05 ± 0.96 mm; P = 0.69). The IPD change after bimatoprost instillation (-2.20 ± 0.97 mm) was significantly (P < 0.001) greater than with other PGAs (-0.65 ± 2.09 mm). The IOPs decreased significantly (P < 0.001) (-3.7 ± 4.3 mm Hg); the refractive errors did not change significantly (P < 0.099) (-0.07 ± 0.69 diopter) post-treatment. The percentages of subjects with 2-mm or greater decreases in IPD after bimatoprost, travoprost, latanoprost, or tafluprost were 85.7%, 20.0%, 18.2%, and 17.2%, respectively, and with 3-mm or greater decreases in IPD 35.7%, 12.0%, 14.5%, and 12.1%, respectively. The specificities were 93.4% and 100% in the control group, respectively, with IPD threshold changes of 2 and 3 mm or more, respectively.

CONCLUSIONS

The IPD decreased significantly after topical PGAs within 24 months. The effect was significantly greater with bimatoprost than with other PGAs. The noninvasive, immediate automatic refractometry measurement may be an objective numerical indicator of PAP.

Decreased orbital fat and enophthalmos due to bimatoprost: Quantitative analysis using magnetic resonance imaging

We quantitatively determined the relation between the decrease in orbital fat and enophthalmos due to bimatoprost using magnetic resonance imaging (MRI). Nine orbits in nine patients were treated unilaterally with bimatoprost for glaucoma or ocular hypertension. The contralateral orbits were used as controls. The volumes of the orbital tissues and the enophthalmos were measured using MRI. The mean volumes on the treated and untreated sides were, respectively, 14.6 ± 2.1 and 17.0 ± 4.3 cm³ for orbital fat (P = 0.04) and 3.4 ± 0.5 and 3.3 ± 0.5 cm³ for total extraocular muscles (P = 0.85). The mean enophthalmos values were 14.7 ± 2.5 and 16.0 ± 2.3 mm on the treated and untreated sides, respectively (P = 0.002). The data acquired by quantitatively measuring the volumes of orbital fat and enophthalmos on MRI showed that each might be reduced by bimatoprost administration. The enophthalmos could be caused by the bimatoprost-induced decrease in orbital fat.

Treatment with bimatoprost for exophthalmos in patients with inactive thyroid-associated ophthalmopathy

Purpose

This study was performed to observe changes prospectively in exophthalmos and orbital fat in patients with inactive thyroid-associated ophthalmopathy (TAO) treated with bimatoprost.

Methods

In this 12-month single-treatment pilot observational study, 13 patients with inactive-phase TAO were administered bimatoprost to treat exophthalmos due to TAO. Exophthalmos values and orbital tissue volumes were measured on MRI by technicians in a masked fashion.

Results

Nine orbits of nine patients (eight women, one man) were treated with bimatoprost for 12 months. Mean exophthalmos values before and after treatment were 21.7±2.2 and 21.7±2.0 mm, respectively. The mean value after 12 months of treatment was not significantly different from before treatment (P=0.82). Mean orbital fat volume before and after 12 months of treatment was 17.2±2.5 and 17.0±3.0 cm³, respectively. The corresponding total extraocular muscle volume was 4.0±0.7 and 3.8±0.9 cm³, respectively. Mean volume in each tissue type after 12 months of treatment was not significantly different from before treatment (orbital fat, P=0.70; extraocular muscles, P=0.32).

Conclusion

Topical bimatoprost treatment did not reduce exophthalmos or orbital fat in this cohort of patients with inactive TAO.

Prostacyclin: A major prostaglandin in the regulation of adipose tissue development

Prostaglandins (PGs) belong to the group lipid mediators and can act as local hormones. They contain 20 carbon atoms, including a 5-carbon ring, and are biosynthesized from membrane phospholipid derived arachidonic acid through the arachidonate cyclooxygenase (COX) pathway with the help of various terminal synthase enzymes. Prostacyclin (prostaglandin I₂ ) is one of the major prostanoids produced with the help of prostacyclin synthase (prostaglandin I₂ synthase) enzyme and rapidly hydrolyzed into 6-keto-PGF_1α in biological fluids. Obesity indicates an excess of body adiposity, which is globally considered as one of the major health disasters responsible for developing complex pathological situations in the human body. Adipose tissues can produce various PGs, and thus, the level and the molecular activity of these endogenously synthesized PGs are considered critical for the development of obesity. In this regard, the involvement of prostacyclin in adipogenesis has been studied in the last few decades. The current review, along with the background of other related PGs, presents the several molecular aspects of endogenous prostaglandin I₂ in adipose tissue development. Especially, the regulation of life cycle of adipocytes, impact on terminal differentiation, activity through prostacyclin receptor (IP), autocrine-paracrine manner, thermogenic adipose tissue remodeling and some future experimental aspects of prostacyclin have been focused upon in this study. This discussion might assist to develop new drug molecules acting on the signaling pathways of prostacyclin and devise therapeutic strategies for treating obesity.

Alterations of protein glycosylation in embryonic stem cells during adipogenesis

The understanding of adipose tissue development is crucial for the treatment of obesity-related diseases. Adipogenesis has been extensively investigated at the gene and protein levels in recent years. However, the alterations in protein glycosylation during this process remains unknown, particularly that of parthenogenetic embryonic stem cells (pESCs), a type of ESCs with low immunogenicity and no ethical concerns regarding their use. Protein glycosylation markedly affects cell growth and development, cell-to-cell communication, tumour growth and metastasis. In the present study, the adipogenic potentials of J1 ESCs and pESCs were first compared and the results demonstrated that pESCs had lower adipogenic potential compared with J1 ESCs. Lectin microarray was then used to screen the alteration of protein glycosylation during adipogenesis. The results revealed that protein modification of GlcNAc and α-1-2-fucosylation increased, whereas α-1-6‑fucosylation, α-2-6-sialylation and α-1-6-mannosylation decreased in J1 ESCs and pESCs during this process. In addition, α-1-3-mannosylation decreased only in pESCs. Lectin histochemistry and quantitative polymerase chain reaction of glycosyltransferase confirmed the results obtained by lectin microarray. Therefore, protein glycosylation of ESCs was significantly altered during adipogenesis, indicating that protein glycosylation analysis is not only helpful for studying the mechanism of adipogenesis, but may also be used as a marker to monitor adipogenic development.

Effects of pre-surgical administration of prostaglandin analogs on the outcome of trabeculectomy

For primary open angle glaucoma (POAG), laser treatment or surgery is used when the target intraocular pressure (IOP) cannot be achieved by pharmacological agents, such as prostaglandin (PG) analogs; these drugs also have varied effects. We retrospectively reviewed the medical records of 74 POAG patients (74 eyes) whose IOP was inadequately controlled by PG analogs (bimatoprost [13 eyes], latanoprost [34 eyes], tafluprost [11 eyes], and travoprost [16 eyes]) and underwent primary trabeculectomy. The proportion of patients with no recurrent IOP elevation within 24 months post-trabeculectomy was significantly (P < 0.001) lower in the bimatoprost group (31.3%) than in the latanoprost (83.2%), tafluprost (45.5%), or travoprost groups (65.6%). Deepening of the upper eyelid sulcus (DUES) was observed before trabeculectomy in 18 of 74 eyes (24.3%) treated with bimatoprost (9 eyes; 50.0%), latanoprost (3 eyes; 16.7%), tafluprost (1 eye; 5.5%) and travoprost (5 eyes; 27.8%). The proportion of patients with no recurrent IOP elevation up to 24 months post-trabeculectomy was significantly (P < 0.0001) lower in the DUES(+) group (34.7%) than in the DUES(-) group (74.3%). Multivariate stepwise logistic regression analysis, with no recurrent IOP elevation used as dependent variable, and bimatoprost, latanoprost, travoprost, tafluprost, β-blocker, carbonic anhydrase inhibitor, brimonidine, gender, age, preoperative IOP, mean deviation, duration of PG analog use before surgery, and the number of ophthalmic solutions used as independent variables, identified only bimatoprost as a significant independent factor (P = 0.0368). Thus, the outcome of trabeculectomy varied depending on the PG analog used preoperatively, and bimatoprost use was associated with a high risk of recurrent IOP elevation up to 2 years post-trabeculectomy. This may indicate that the incidence of DUES differed with the PG analog used. Patients with glaucoma who are treated with bimatoprost should be monitored for DUES, and when these patients undergo trabeculectomy, the postoperative course of IOP should be followed carefully.

In Vivo Effects of Retrobulbar Bimatoprost Injection on Orbital Fat

PURPOSE

Recent publications have reported the adverse effects of prostaglandin analogues on the periocular tissues. These medications may cause periorbital lipodystrophy, enophthalmos, and deepening of the superior sulcus deformity. While these effects may have adverse consequences for some patients, the atrophy of the periorbital fat may have a useful role in diseases that lead to orbital and periorbital fat hypertrophy such as thyroid eye disease. In this pilot study, the authors investigated the effects of retrobulbar bimatoprost injection on the intraocular pressure and orbital fat in a rat animal model.

METHODS

Three rats were sedated and intraocular pressure was measured. A 0.1 ml aliquot of bimatoprost was injected into the right orbit of all rats. In the left orbit, 0.1 ml of phosphate-buffered saline was injected as a control. Three weeks later, all rats were sedated and intraocular pressure was measured before euthanizing. Routine histologic staining was performed and thin sections through the intraconal orbital fat were obtained. Density of intraconal adipocytes was measured and adipocyte heterogeneity was determined using a computer image analysis algorithm.

RESULTS

The specimens injected with bimatoprost demonstrated atrophy of orbital fat with significantly increased adipocyte density (p = 0.009) and heterogeneity (p = 0.008) when compared with control. Intraocular pressure was not significantly decreased at 3 weeks after injection of retrobulbar bimatoprost.

CONCLUSIONS

In this pilot study, orbital injection of bimatoprost demonstrated atrophy of intraconal adipocytes when compared with control orbits injected with saline. The orbits injected with bimatoprost were noted to have smaller, more heterogeneous adipocytes that were densely packed in the intraconal space. The study limitations include the small sample size, which limited the ability for us to make conclusions about the effect on intraocular pressure. Nevertheless, the findings presented suggest that retrobulbar bimatoprost may present a nonsurgical alternative to induce atrophy of the orbital fat without inducing inflammation or hypotony.

Prostaglandin-Associated Periorbital Lipodystrophy in Cosmetic Eyelid Surgery: A Novel Cause of Facial Asymmetry

A 70-year-old woman presented to our practice with profound ptosis of the left upper eyelid and notable asymmetry of the periocular area. On examination, she was noted to have significant atrophy of the periocular tissues on the left side, with lower eyelid retraction. These features were present but less severe on the right side. Upon further questioning, she stated that she had cataract surgery on the left side that was complicated by a high intraocular pressure and required subsequent secondary surgery. She had taken a prostaglandin eyedrop for many months after her cataract surgery to keep the eye pressure low. Recently, a newly recognized adverse effect of prostaglandin eyedrops has been described in the ophthalmic literature in which patients develop periorbital lipodystrophy. This case emphasizes that this may occur unilaterally in patients taking the eyedrop in only one eye, and should be recognized prior to considering functional and aesthetic surgery of the periocular area.

Expression of genes related to prostaglandin synthesis or signaling in human subcutaneous and omental adipose tissue: depot differences and modulation by adipogenesis

OBJECTIVES

(1) To examine depot-specific PGE2 and PGF2α release and mRNA expression of enzymes or receptors involved in PG synthesis or signaling in human adipose tissues; (2) to identify changes in expression of these transcripts through preadipocyte differentiation; and (3) to examine associations between adipose tissue mRNA expression of these transcripts and adiposity measurements.

METHODS

Fat samples were obtained surgically in women. PGE2 and PGF2α release by preadipocytes and adipose tissue explants was measured. Expression levels of mRNA coding for enzymes or receptors involved in PG synthesis or signaling were measured by RT-PCR.

RESULTS

Cultured preadipocytes and explants from omental fat released more PGE2 and PGF2α than those from the subcutaneous depot and the corresponding transcripts showed consistent depot differences. Following preadipocyte differentiation, expression of PLA2G16 and PTGER3 mRNA was significantly increased whereas COX-1, COX-2, PTGIS, and PTGES mRNA abundance were decreased in both compartments (P ≤ 0.01 for all). Transcripts that were stimulated during adipogenesis were those that correlated best with adiposity measurements.

CONCLUSION

Cells from the omental fat compartment release more PGE2 and PGF2α than those from the subcutaneous depot. Obesity modulates expression of PG-synthesizing enzymes and PG receptors which likely occurs through adipogenesis-induced changes in expression of these transcripts.

Incidence of deepening of the upper eyelid sulcus in prostaglandin-associated periorbitopathy with a latanoprost ophthalmic solution

PURPOSE

Among some local side effects of prostaglandin-associated periorbitopathy (PAP), deepening of the upper eyelid sulcus (DUES) is the most prominent clinical feature, and is one of the most significant adverse cosmetic events. Here, we prospectively investigated the incidence of DUES in Japanese open-angle glaucoma patients initially treated with latanoprost (Xalatan 0.005%) ophthalmic solution.

METHODS

This was an open-label prospective study. Facial photographs and subjective reports of the recognition of DUES were obtained at the beginning of latanoprost treatment and at 2, 4, and 6 months thereafter. Intraocular pressure (IOP) was measured at three consecutive visits before and after treatment with latanoprost. The incidence of DUES was evaluated objectively by three blinded investigators who compared the series of photographs.

RESULTS

A total of 52 eyes of 52 newly diagnosed open-angle glaucoma Japanese patients (28 males, 24 females) were evaluated. The objective rate of DUES was 1/52 (2%; 95% CI 0.05 to 10.7%) at 2 months, 2/52 (4%; 95% CI 0.5 to 13.9%) at 4 months, and 3/52 (6%; 95% CI 1.2 to 16.9%) at 6 months. During this period, no patient self-reported an occurrence of DUES. Mean IOPs before and after treatment were 16.5±2.9 and 13.8±3.0 mm Hg, respectively. Latanoprost reduced the IOP significantly (P<0.0001, paired t-test).

CONCLUSIONS

Latanoprost caused DUES rarely and had a robust IOP-lowering effect in Japanese glaucoma patients.

Incidence of deepening of the upper eyelid sulcus after topical use of travoprost ophthalmic solution in Japanese

PURPOSE

To investigate the incidence of deepening of the upper eyelid sulcus (DUES) with topical use of travoprost in Japanese glaucoma patients.

PATIENTS AND METHODS

This prospective study enrolled 32 primary open-angle glaucoma Japanese patients who had been treated topically with travoprost unilaterally for 6 months at baseline, and started treatment in both eyes. The patients were observed during outpatient visits at 2, 4, and 6 months. At every visit, the photographs of both eyes and forehead were displayed randomly and the presence of DUES was diagnosed when 3 examiners unanimously rated the case as positive. The patients were also asked if they noticed any subjective symptom of DUES. Sex, refraction, and intraocular pressure (IOP) were evaluated as potential risk factors.

RESULTS

DUES was identified objectively in 34% (11/32) of the patients after 2 months of treatment, and in 53% (17/32) after 4 and 6 months of treatment. The incidence was significantly higher in older patients (P<0.05), but not related to sex, refraction, pretreatment and posttreatment IOP, and IOP reduction. Finally, 41% (7/17) of patients with objectively diagnosed DUES noticed the presence of DUES by themselves. No patient dropped out of the study because of DUES.

CONCLUSIONS

DUES is a common side effect of topical travoprost treatment in Japanese glaucoma patients.

Topical prostaglandin analogue drugs inhibit adipocyte differentiation

Purpose

To investigate the effects of topical prostaglandin analogue drugs on the differentiation of adipocytes.

Methods

Differentiation of 3T3-L1 preadipocytes was induced with isobutylmethylxanthine, dexamethasone, and insulin. 3T3-L1 cells were exposed to 0.008, 0.08, 0.2 µM of latanoprost and travoprost. Reverse transcription polymerase chain reaction for mRNA expression of lipoprotein lipase and peroxisome proliferator-activated receptor γ 2 (PPARγ2), and glycerol-3-phosphate dehydrogenase (G3PDH) assays were performed to examine the effects on early and late differentiation, respectively. Also, glycerol assays were done to evaluate the effect of prostaglandin analogues on lipolysis after differentiation.

Results

Both prostaglandin analogues inhibited differentiation of preadipocytes. Topical prostaglandin analogues significantly decreased G3PDH activity, a marker of late differentiation. However, topical prostaglandin analogues did not change mRNA expressions of lipoprotein lipase and PPARγ2, markers of early differentiation. The activities of the early markers of differentiation were not changed significantly before and after growth arrest. Compared to latanoprost, travoprost decreased G3PDH activity more significantly (p < 0.05). Both prostaglandin analogues did not affect the lipolysis of differentiated adipocytes (p > 0.05).

Conclusions

Prostaglandin analogues display an inhibitory effect on the differentiation of adipocytes when the cells start to differentiate especially in the late stage of differentiation. Thus, commercial topical prostaglandin analogues may decrease the fat contents of eyelids.

Prostaglandin (PG) F2 alpha synthesis in human subcutaneous and omental adipose tissue: modulation by inflammatory cytokines and role of the human aldose reductase AKR1B1

INTRODUCTION

PGF2α may be involved in the regulation of adipose tissue function.

OBJECTIVES

1) To examine PGF2α release by primary preadipocytes, mature adipocytes and whole tissue explants from the subcutaneous and omental fat compartments; 2) To assess which PGF synthase is the most relevant in human adipose tissue.

METHODS

Fat samples were obtained by surgery in women. PGF2α release by preadipocytes, adipocytes and explants under stimulation by TNF-α, IL-1β or both was measured. Messenger RNA expression levels of AKR1B1 and AKR1C3 were measured by RT-PCR in whole adipose tissue and cytokine-treated preadipocytes. The effect of AKR1B1 inhibitor ponalrestat on PGF2α synthesis was investigated.

RESULTS

PGF2α release was significantly induced in response to cytokines compared to control in omental (p = 0.01) and to a lesser extent in subcutaneous preadipocytes (p = 0.02). Messenger RNA of COX-2 was significantly higher in omental compared to subcutaneous preadipocytes in response to combined TNF-α and IL-1β (p = 0.01). Inflammatory cytokines increased AKR1B1 mRNA expression and protein levels (p≤0.05), but failed to increase expression levels of AKR1C3 in cultured preadipocytes. Accordingly, ponalrestat blunted PGF2α synthesis by preadipocytes in basal and stimulated conditions (p≤0.05). Women with the highest PGF2α release by omental adipocytes had a higher BMI (p = 0.05), waist circumference (p≤0.05) and HOMAir index (p≤0.005) as well as higher mRNA expression of AKR1B1 in omental (p<0.10) and subcutaneous (p≤0.05) adipose tissue compared to women with low omental adipocytes PGF2α release. Positive correlations were observed between mRNA expression of AKR1B1 in both compartments and BMI, waist circumference as well as HOMAir index (p≤0.05 for all).

CONCLUSION

PGF2α release by omental mature adipocytes is increased in abdominally obese women. Moreover, COX-2 expression and PGF2α release is particularly responsive to inflammatory stimulation in omental preadipocytes. Yet, blockade of PGF synthase AKR1B1 inhibits most of the PGF2α release.

Ocular surface cytotoxicity and safety evaluation of tafluprost, a recently developed anti-glaucoma prostaglandin analog

In vitro cytotoxicity of tafluprost, which is the most recently developed anti-glaucoma prostaglandin (PG) analog, in ocular surface cells is addressed in comparison with other PG analogs. Irrespective of cell lines and models, the cytotoxicity of anti-glaucoma PG eyedrops was primarily related to the concentration of benzalkonium chloride (BAK) contained in the eyedrops as a preservative. Accordingly, preservative-free tafluprost was apparently less cytotoxic than BAK-preserved PG analogs. Furthermore, our study for cytotoxicity assays on ocular cells, conducted by comprehensive investigations covering a variety of concentrations and treatment times, which is termed the cell viability score (CVS) system, demonstrated that 0.001% BAK-preserved tafluprost was not cytotoxic, and suggested that tafluprost may even reduce the cytotoxic effect of BAK. It has been reported that adverse reactions associated with tafluprost in healthy human volunteers and patients with glaucoma include conjunctival hyperemia, eyelid pigmentation, eyelash bristles, and deepening of upper eyelid sulcus. Nonetheless, most clinical studies have demonstrated that not only preservative-free tafluprost but also BAK-preserved tafluprost is well tolerated and safe in patients with glaucoma and ocular hypertension.

Incidence of deepening of the upper eyelid sulcus on treatment with a tafluprost ophthalmic solution

PURPOSE

Deepening of the upper eyelid sulcus (DUES), one symptom of prostaglandin-associated periorbitopathy, was recently found to be an additional side effect of prostaglandin-related ophthalmic solutions. Here, we prospectively investigated the incidence and factors associated with DUES in Japanese open-angle glaucoma patients initially treated with benzalkonium chloride (BAK)-preserved tafluprost (TAF).

METHODS

In this open-label prospective study instilling TAF in one eye, mean deviation (MD) and intraocular pressure (IOP) were measured, and facial photographs and subjective reports of DUES were obtained at intervals over 6 months. Three ophthalmologists independently assessed the photographs of DUES and reached consensus. Relationships between demographic and ocular/systemic factors (age, sex, MD, refraction and IOP reduction) and DUES occurrence were evaluated.

RESULTS

Forty-three eyes of 43 glaucoma patients (24 men and 19 women) were evaluated. Mean IOP before treatment was 16.6 ± 2.7 and after treatment, 14.1 ± 2.3 mmHg (P < 0.001). The objective rate of DUES was 9 % (4/43) at 2 months, 14 % (6/43) at 4 months and 14 % (6/43) at 6 months. During this period, only one patient self-reported an occurrence of DUES. No significant association was found between DUES occurrence and any of the demographic, ocular, or systemic factors.

CONCLUSIONS

Physicians should inform patients about DUES as a minor side effect when prescribing TAF for IOP control.

Effects of prostaglandin F(2α) on adipocyte biology relevant to graves' orbitopathy

BACKGROUND

In Graves' orbitopathy (GO), increased proliferation, excess adipogenesis, and hyaluronan overproduction produce GO exophthalmos. Enophthalmos occurs in some glaucoma patients treated with Bimatoprost (prostaglandin F2α, PGF2α) eye drops. We hypothesized that enophthalmos is secondary to reductions in orbital tissue proliferation, adipogenesis, and/or increased lipolysis. We aimed to determine which of these is affected by PGF2α by using the 3T3-L1 murine preadipocyte cell line and primary human orbital fibroblasts (OFs) from GO patients (n=5) and non-GO (n=5).

METHODS

3T3-L1 cells and orbital OFs were cultured alone or with PGF2α (all experiments used 10(-8) to 10(-6) M) and counted on days 1/2/3 or 5, respectively; cell cycle analysis (flow cytometry) was applied. Adipogenesis (in the presence/absence of PGF2α) was evaluated (day 7 or 15 for 3T3-L1 and primary cells, respectively) morphologically by Oil Red O staining and quantitative polymerase chain reaction measurement of adipogenesis markers (glycerol-3-phosphate dehydrogenase and lipoprotein lipase, respectively). For lipolysis, in vitro-differentiated 3T3-L1 or mature orbital adipocytes were incubated with norepinephrine and PGF2α and free glycerol was assayed. Appropriate statistical tests were applied.

RESULTS

The population doubling time of 3T3-L1 was 27.3±1.4 hours-significantly increased by dimethyl sulfoxide 0.02% to 44.6±4.8 hours (p=0.007) and further significantly increased (p=0.049 compared with dimethyl sulfoxide) by 10(-8) M PGF2α to 93.6±19.0 hours, indicating reduced proliferation, which was caused by prolongation of G2/M. GO OFs proliferated significantly more rapidly than non-GO (population doubling time 5.36±0.34 or 6.63±0.35 days, respectively, p=0.035), but the proliferation of both was significantly reduced (dose dependent from 10(-8) M) by PGF2α, again with prolongation of G2/M. Adipogenesis in 3T3-L1 cells was minimally affected by PGF2α when assessed morphologically, but the drug significantly reduced transcripts of the glycerol-3-phosphate dehydrogenase differentiation marker. GO OFs displayed significantly higher adipogenic potential than non-GO, but in both populations, adipogenesis, evaluated by all 3 methods, was significantly reduced (dose dependent from 10(-8) M) by PGF2α. There was no effect of PGF2α on basal or norepinephrine-induced lipolysis, in 3T3-L1 or human OFs, either GO or non-GO.

CONCLUSIONS

The results demonstrate that PGF2α significantly reduces proliferation and adipogenesis and that human OFs are more sensitive to its effects than 3T3-L1. Consequently, PGF2α could be effective in the treatment of GO.

Incidence of deepening of upper eyelid sulcus after topical use of tafluprost ophthalmic solution in Japanese patients

PURPOSE

To investigate the incidence of deepening of upper eyelid sulcus (DUES) with topical use of tafluprost in Japanese glaucoma patients.

METHODS

This study was a prospective, open-label, non-controlled case series conducted at a single center. Thirty-six primary open-angle glaucoma Japanese patients who had no history of surgery were enrolled. The patients were prescribed 0.0015% topical tafluprost once daily to one eye that had the more severe visual field disorder, and observed during outpatient visits before and at 30, 60, and 90 days after starting treatment. At every visit, three examiners judged the presence of DUES unanimously by facial photographs including eyebrows and lower eyelids. The primary outcome variable was the incidence of DUES at the end of day 90 in the study as assessed by observer-masked facial photography. The patients were also asked if they noticed any subjective symptom of DUES. Gender, refraction, and intraocular pressure were evaluated as potential risk factors.

RESULTS

Thirty-two patients completed this clinical trial. DUES were identified objectively in 19% (6/32) of the patients after 90 days of treatment. The incidence was not related to gender, refraction, baseline or post-treatment intraocular pressure, or intraocular pressure reduction. Finally, 17% (1/6) of patients with objectively diagnosed DUES noticed the presence of DUES by themselves. No patient dropped out of the study because of DUES.

CONCLUSION

Similar to other prostaglandin analogs, topical use of tafluprost ophthalmic solution is associated with DUES as a local adverse reaction.

Anandamide-derived prostamide F2α negatively regulates adipogenesis

Lipid mediators variedly affect adipocyte differentiation. Anandamide stimulates adipogenesis via CB1 receptors and peroxisome proliferator-activated receptor γ. Anandamide may be converted by PTGS2 (COX2) and prostaglandin F synthases, such as prostamide/prostaglandin F synthase, to prostaglandin F2α ethanolamide (PGF2αEA), of which bimatoprost is a potent synthetic analog. PGF2αEA/bimatoprost act via prostaglandin F2αFP receptor/FP alt4 splicing variant heterodimers. We investigated whether prostamide signaling occurs in preadipocytes and controls adipogenesis. Exposure of mouse 3T3-L1 or human preadipocytes to PGF2αEA/bimatoprost during early differentiation inhibits adipogenesis. PGF2αEA is produced from anandamide in preadipocytes and much less so in differentiating adipocytes, which express much less PTGS2, FP, and its alt4 splicing variant. Selective antagonism of PGF2αEA receptors counteracts prostamide effects on adipogenesis, as does inhibition of ERK1/2 phosphorylation. Selective inhibition of PGF2αEA versus prostaglandin F2α biosynthesis accelerates adipogenesis. PGF2αEA levels are reduced in the white adipose tissue of high fat diet-fed mice where there is a high requirement for new adipocytes. Prostamides also inhibit zebrafish larval adipogenesis in vivo. We propose that prostamide signaling in preadipocytes is a novel anandamide-derived antiadipogenic mechanism.

The beneficial role of vitamin D in obesity: possible genetic and cell signaling mechanisms

The prevalence rates of overweight and obesity are considered an important public issue in the United States, and both of these conditions are increasing among both children and adults. There is evidence of aberrations in the vitamin D-endocrine system in obese subjects. Vitamin D deficiency is highly prevalent in patients with obesity, and many studies have demonstrated the significant effect of calcitriol on adipocytes. Genetic studies have provided an opportunity to determine which proteins link vitamin D to obesity pathology, including the vitamin D receptor, toll-like receptors, the renin-angiotensin system, apolipoprotein E, vascular endothelial growth factor, and poly (ADP-ribose) polymerase-1. Vitamin D also exerts its effect on obesity through cell-signaling mechanisms, including matrix metalloproteinases, mitogen-activated protein kinase pathways, the reduced form of nicotinamide adenine dinucleotide phosphate, prostaglandins, reactive oxygen species, and nitric oxide synthase.

In conclusion, vitamin D may have a role in obesity. The best form of vitamin D for use in the obese individuals is calcitriol because it is the active form of the vitamin D₃ metabolite, its receptors are present in adipocytes, and modulates inflammatory cytokine expression.

Prostaglandins as PPARγ Modulators in Adipogenesis

Adipocytes and fat cells play critical roles in the regulation of energy homeostasis. Adipogenesis (adipocyte differentiation) is regulated via a complex process including coordinated changes in hormone sensitivity and gene expression. PPARγ is a ligand-dependent transcription factor and important in adipogenesis, as it enhances the expression of numerous adipogenic and lipogenic genes in adipocytes. Prostaglandins (PGs), which are lipid mediators, are associated with the regulation of PPARγ function in adipocytes. Prostacyclin promotes the differentiation of adipocyte-precursor cells to adipose cells via activation of the expression of C/EBPβ and δ. These proteins are important transcription factors in the activation of the early phase of adipogenesis, and they activate the expression of PPARγ, which event precedes the maturation of adipocytes. PGE₂ and PGF_2α strongly suppress the early phase of adipocyte differentiation by enhancing their own production via receptor-mediated elevation of the expression of cycloxygenase-2, and they also suppress the function of PPARγ. In contrast, PGD₂ and its non-enzymatic metabolite, Δ¹²-PGJ₂, activate the middle-late phase of adipocyte differentiation through both DP2 receptors and PPARγ. This paper focuses on potential roles of PGs as PPARγ modulators in adipogenesis and regulators of obesity.

Recovery from deepening of the upper eyelid sulcus after switching from bimatoprost to latanoprost

PURPOSE

Although useful for reducing intraocular pressure (IOP), bimatoprost (BIM) can cause deepening of the upper eyelid sulcus (DUES), one of the symptoms of prostaglandin-associated periorbitopathy (PAP). We investigated recovery from BIM-induced DUES after switching treatment to latanoprost (LAT).

DESIGN

Prospective, observer-masked, open-label study.

METHODS

Twenty-five Japanese patients suffering from primary open-angle glaucoma treated with LAT in both eyes for longer than 6 months and requiring further IOP reduction were prospectively enrolled in the study. During the first 6 months after the switch to BIM, 15 of the 25 patients (60 %) developed DUES. Among these patients, 13 were switched back to LAT and re-examined for DUES at 2-month intervals for an additional 6 months.

RESULTS

Two months after the switch back to LAT, for 11 of the 13 patients (85 %) the DUES symptoms had either decreased or disappeared, and this was maintained for at least 6 months. During this time, 6 of 8 patients (75 %) subjectively positive for DUES self-reported a decrease in DUES.

CONCLUSIONS

Although DUES is a frequent side effect of treatment with BIM, switching to LAT may reverse the condition for most patients.

Depressed levels of prostaglandin F2α in mice lacking Akr1b7 increase basal adiposity and predispose to diet-induced obesity

Negative regulators of white adipose tissue (WAT) expansion are poorly documented in vivo. Prostaglandin F(2α) (PGF(2α)) is a potent antiadipogenic factor in cultured preadipocytes, but evidence for its involvement in physiological context is lacking. We previously reported that Akr1b7, an aldo-keto reductase enriched in adipose stromal vascular fraction but absent from mature adipocytes, has antiadipogenic properties possibly supported by PGF(2α) synthase activity. To test whether lack of Akr1b7 could influence WAT homeostasis in vivo, we generated Akr1b7(-/-) mice in 129/Sv background. Akr1b7(-/-) mice displayed excessive basal adiposity resulting from adipocyte hyperplasia/hypertrophy and exhibited greater sensitivity to diet-induced obesity. Following adipose enlargement and irrespective of the diet, they developed liver steatosis and progressive insulin resistance. Akr1b7 loss was associated with decreased PGF(2α) WAT contents. Cloprostenol (PGF(2α) agonist) administration to Akr1b7(-/-) mice normalized WAT expansion by affecting both de novo adipocyte differentiation and size. Treatment of 3T3-L1 adipocytes and Akr1b7(-/-) mice with cloprostenol suggested that decreased adipocyte size resulted from inhibition of lipogenic gene expression. Hence, Akr1b7 is a major regulator of WAT development through at least two PGF(2α)-dependent mechanisms: inhibition of adipogenesis and lipogenesis. These findings provide molecular rationale to explore the status of aldo-keto reductases in dysregulations of adipose tissue homeostasis.

In vitro study of antiadipogenic profile of latanoprost, travoprost, bimatoprost, and tafluprost in human orbital preadiopocytes

PURPOSE

To investigate the effect of prostaglandin F2α (PGF2α), latanoprost, travoprost, bimatoprost, and tafluprost on human orbital preadipocyte differentiation and intracellular lipid storage, and to reveal the potential mechanisms by which topical prostaglandin analogs induce orbital fat volume reduction and cause deep superior sulcus syndrome.

METHODS

Human orbital adipose precursors were treated in vitro for 24 h (day 1) with PGF2α, latanoprost, travoprost, bimatoprost, and tafluprost in their commercial formulations (1:100 dilution). Expressions of adipogenic transcription factor, peroxisome proliferator-activated receptor-gamma (PPARγ), and CCAAT-enhancer-binding protein α (C/EBPα) were determined by real-time reverse transcription-polymerase chain reaction (RT-PCR) at day 7. At 14 days, cells were stained with oil red O, intracellular lipid accumulation was evaluated by lipid absorbance, and adipocyte expression marker [Lipoprotein lipase (LPL)] was determined by real-time RT-PCR.

RESULTS

Our results showed that PGF2α and topical prostaglandin analogs down-regulated the expression of PPARγ and C/EBPα, and inhibited accumulation of intra-cytoplasmic lipid droplets and expression of LPL compared with the untreated control. Comparison between the 4 drugs showed that latanoprost had the weakest antiadipogenic effect, and bimatoprost induced the most significant reduction of adipogenesis.

CONCLUSION

Latanoprost, travoprost, bimatoprost, and tafluprost inhibited human preadipocyte differentiation and intracellular lipid accumulation. Morphologic and metabolic changes in orbital adipocytes caused by PGF2α analogs are a possible pathophysiologic explanation of superior eyelid deepening in patients with glaucoma.

International Union of Basic and Clinical Pharmacology. LXXXIII: classification of prostanoid receptors, updating 15 years of progress

It is now more than 15 years since the molecular structures of the major prostanoid receptors were elucidated. Since then, substantial progress has been achieved with respect to distribution and function, signal transduction mechanisms, and the design of agonists and antagonists (http://www.iuphar-db.org/DATABASE/FamilyIntroductionForward?familyId=58). This review systematically details these advances. More recent developments in prostanoid receptor research are included. The DP(2) receptor, also termed CRTH2, has little structural resemblance to DP(1) and other receptors described in the original prostanoid receptor classification. DP(2) receptors are more closely related to chemoattractant receptors. Prostanoid receptors have also been found to heterodimerize with other prostanoid receptor subtypes and nonprostanoids. This may extend signal transduction pathways and create new ligand recognition sites: prostacyclin/thromboxane A(2) heterodimeric receptors for 8-epi-prostaglandin E(2), wild-type/alternative (alt4) heterodimers for the prostaglandin FP receptor for bimatoprost and the prostamides. It is anticipated that the 15 years of research progress described herein will lead to novel therapeutic entities.

Changes to upper eyelid orbital fat from use of topical bimatoprost, travoprost, and latanoprost

PURPOSE

To confirm the possible mechanism by which topical prostaglandin antiglaucoma drugs cause a deep superior sulcus.

METHODS

Among patients who used bimatoprost (Lumigan), latanoprost (Xalatan), or travoprost (Travatan) and who developed a deep upper lid sulcus, 18 eyes of 11 patients (mean age, 58.2 ± 8.9 years) were studied. Seven patients were binocular users of one of the eye drops and four were monocular users. Preaponeurotic orbital fat was obtained, and the mean adipocyte density compared.

RESULTS

In the four monocular users, mean adipocyte density of treated eyes was 1758.21 ± 158.15 cells/mm(2), and that of untreated eyes was 1258.73 ± 127.54 cells/mm(2). This difference was statistically significant (P = 0.04), suggesting that the adipocytes were atrophied in the treated eyes. The mean adipocyte density of the bimatoprost group was 2073.35 ± 184.89 cells/mm(2), that of the travoprost group was 1623.46 ± 218.99 cells/mm(2), and that of the latanoprost group was 1468.20 ± 113.44 cells/mm(2). The densities of the bimatoprost and travoprost groups, but not of the latanoprost group (P = 0.75), were significantly different from that of the untreated group (P < 0.001).

CONCLUSIONS

Fat atrophy can be considered a mechanism of upper eyelid sulcus deepening in patients using topical prostaglandin analogs.

Prostaglandin F(2alpha) suppresses early phase of adipogenesis, but is not associated with osteoblastogenesis in mouse mesenchymal stem cells

In this study, we investigated the roles of prostaglandin (PG) F(2alpha) in the differentiation of mouse ST2 mesenchymal stem cells (MSC) into adipocytes and osteoblasts. PGF(2alpha) was not produced in the undifferentiated ST2 MSC, but its highest level of production was detected at 3h after the initiation of adipogenesis and then quickly decreased. On the contrary, apparent PGF(2alpha) production was not detected during the osteoblastogenesis of ST2 MSC. The PGF(2alpha) production pattern during adipogenesis well resembled the expression profiles of aldo-keto reductase (AKR) 1B3, which acted as the PGF(2alpha) synthase, and cyclooxygenase-2 genes; but the pattern showed a slight delay compared with these profiles. The siRNA for AKR1B3, but not that for AKR1B8 or 1B10, decreased PGF(2alpha) production and enhanced the expression of adipogenic genes, but did not affect the mRNA levels of osteoblastogenic genes, during the adipogenesis of ST2 MSC. The FP receptor was expressed during adipogenesis of ST2 MSC, and its agonist or antagonist suppressed or enhanced, respectively, the lipid accumulation and the adipogenic gene expression; but this receptor was not associated with the osteoblastogenesis. These results indicate that AKR1B3-mediated PGF(2alpha) suppressed the early phase of adipogenesis through FP receptors, but did not affect osteoblastogenesis in ST2 MSC. Therefore, PGF(2alpha) suppressed the progression of early phase adipogenesis after determination of the cell fate that causes MSC to differentiate into adipocytes.

Aldo-keto reductase 1C3 expression in MCF-7 cells reveals roles in steroid hormone and prostaglandin metabolism that may explain its over-expression in breast cancer

Aldo-keto reductase (AKR) 1C3 (type 5 17beta-hydroxysteroid dehydrogenase and prostaglandin F synthase), may stimulate proliferation via steroid hormone and prostaglandin (PG) metabolism in the breast. Purified recombinant AKR1C3 reduces PGD(2) to 9alpha,11beta-PGF(2), Delta(4)-androstenedione to testosterone, progesterone to 20alpha-hydroxyprogesterone, and to a lesser extent, estrone to 17beta-estradiol. We established MCF-7 cells that stably express AKR1C3 (MCF-7-AKR1C3 cells) to model its over-expression in breast cancer. AKR1C3 expression increased steroid conversion by MCF-7 cells, leading to a pro-estrogenic state. Unexpectedly, estrone was reduced fastest by MCF-7-AKR1C3 cells when compared to other substrates at 0.1muM. MCF-7-AKR1C3 cells proliferated three times faster than parental cells in response to estrone and 17beta-estradiol. AKR1C3 therefore represents a potential target for attenuating estrogen receptor alpha induced proliferation. MCF-7-AKR1C3 cells also reduced PGD(2), limiting its dehydration to form PGJ(2) products. The AKR1C3 product was confirmed as 9alpha,11beta-PGF(2) and quantified with a stereospecific stable isotope dilution liquid chromatography-mass spectrometry method. This method will allow the examination of the role of AKR1C3 in endogenous prostaglandin formation in response to inflammatory stimuli. Expression of AKR1C3 reduced the anti-proliferative effects of PGD(2) on MCF-7 cells, suggesting that AKR1C3 limits peroxisome proliferator activated receptor gamma (PPARgamma) signaling by reducing formation of 15-deoxy-Delta(12,14)-PGJ(2) (15dPGJ(2)).

Suppression of adipocyte differentiation by aldo-keto reductase 1B3 acting as prostaglandin F2alpha synthase

Prostaglandin (PG) F(2alpha) suppresses adipocyte differentiation by inhibiting the function of peroxisome proliferator-activated receptor gamma. However, PGF(2alpha) synthase (PGFS) in adipocytes remains to be identified. Here, we studied the expression of members of the aldo-keto reductase (AKR) 1B family acting as PGFS during adipogenesis of mouse 3T3-L1 cells. AKR1B3 mRNA was expressed in preadipocytes, and its level increased about 4-fold at day 1 after initiation of adipocyte differentiation, and then quickly decreased the following day to a level lower than that in the preadipocytes. In contrast, the mRNA levels of Akr1b8 and 1b10 were clearly lower than that level of Akr1b3 in preadipocytes and remained unchanged during adipogenesis. The transient increase in Akr1b3 during adipogenesis was also observed by Western blot analysis. The mRNA for the FP receptor, which is selective for PGF(2alpha), was also expressed in preadipocytes. Its level increased about 2-fold within 1 h after the initiation of adipocyte differentiation and was maintained at almost the same level throughout adipocyte differentiation. The small interfering RNA for Akr1b3, but not for Akr1b8 or 1b10, suppressed PGF(2alpha) production and enhanced the expression of adipogenic genes such as peroxisome proliferator-activated receptor gamma, fatty acid-binding protein 4 (aP2), and stearoyl-CoA desaturase. Moreover, an FP receptor agonist, Fluprostenol, suppressed the expression of those adipogenic genes in 3T3-L1 cells; whereas an FP receptor antagonist, AL-8810, efficiently inhibited the suppression of adipogenesis caused by the endogenous PGF(2alpha). These results indicate that AKR1B3 acts as the PGFS in adipocytes and that AKR1B3-produced PGF(2alpha) suppressed adipocyte differentiation by acting through FP receptors.

Periorbital changes associated with topical bimatoprost

PURPOSE

To describe periorbital changes induced by chronic topical therapy with daily bimatoprost 0.03% (Lumigan, Allergan Inc., Irvine, CA, U.S.A.).

METHODS

A clinical investigation of 5 nonconsecutive patients with unilateral glaucoma treated daily with topical bimatoprost 0.03% for up to 4 years prior to presentation.

RESULTS

In eyes treated with bimatoprost 0.03% the authors noted periorbital fat atrophy, deepening of the upper eyelid sulcus, relative enophthalmos, loss of the lower eyelid fullness, and involution of dermatochalasis compared with the fellow untreated eye. By inspecting old photographs the authors confirmed that these unilateral changes were not present prior to starting bimatoprost. In addition, these changes were partially reversible after discontinuation of the medication, whenever that was possible. In 2 cases imaging studies confirmed the clinical impression that these findings were not related to primary orbital pathology.

CONCLUSIONS

Physicians and patients should be aware of the potential of bimatoprost 0.03% to produce periorbital changes.

The granulin-epithelin precursor is a steroid-regulated growth factor in endometrial cancer

OBJECTIVES

The majority of endometrial cancers arise as a result of estrogen stimulation, the molecular targets of which remain incompletely defined. We hypothesize that the granulin-epithelin precursor (GEP) may be one such target. In this study, we examined the frequency of GEP and estrogen receptor (ER) co-expression in human endometrial cancers. Once we established the co-expression of GEP with the estrogen receptor we examined the potential estrogen regulation of GEP expression, as well as the functional significance of GEP expression in vitro.

METHODS

Double immunofluorescence and confocal microscopy were used to compare GEP and ER expression among 41 endometrial cancers. The effects of estradiol and tamoxifen treatment on GEP expression in two endometrial cancer cell lines, KLE and HEC-1-A, were assessed through reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis. The antiproliferative effect of GEP silencing by short hairpin (sh)RNA, was evaluated in HEC-1-A cells using an MTT assay.

RESULTS

GEP co-expression with ER was observed in 63% of the cancers examined. A two- to fivefold increase in GEP expression with estradiol and/or tamoxifen treatment was observed in KLE cells. Silencing of GEP in HEC-1-A cells using shRNA resulted in a decrease in proliferation among transfected cells.

CONCLUSIONS

Co-expression of GEP and ER in endometrial cancer cells, and the regulation of GEP by estrogen, suggests a role for GEP in steroid-mediated endometrial cancer cell growth. Further characterization of GEP as a steroid-mediated growth factor in these cells may broaden our understanding of endometrial cancer biology and also provide guidance in the development of novel therapeutic targets.

Regulation of adipocyte differentiation and function by polyunsaturated fatty acids

A diet enriched in PUFAs, in particular of the n-3 family, decreases adipose tissue mass and suppresses development of obesity in rodents. Although several nuclear hormone receptors are identified as PUFA targets, the precise molecular mechanisms underlying the effects of PUFAs still remain to be elucidated. Here we review research aimed at elucidating molecular mechanisms governing the effects of PUFAs on the differentiation and function of white fat cells. This review focuses on dietary PUFAs as signaling molecules, with special emphasis on agonistic and antagonistic effects on transcription factors currently implicated as key players in adipocyte differentiation and function, including peroxisome proliferator activated receptors (PPARs) (alpha, beta and gamma), sterol regulatory element binding proteins (SREBPs) and liver X receptors (LXRs). We review evidence that dietary n-3 PUFAs decrease adipose tissue mass and suppress the development of obesity in rodents by targeting a set of key regulatory transcription factors involved in both adipogensis and lipid homeostasis in mature adipocytes. The same set of factors are targeted by PUFAs of the n-6 family, but the cellular/physiological responses are dependent on the experimental setting as n-6 PUFAs may exert either an anti- or a proadipogenic effect. Feeding status and hormonal background may therefore be of particular importance in determining the physiological effects of PUFAs of the n-6 family.

Adipocyte differentiation of multipotent cells established from human adipose tissue

In this study multipotent adipose-derived stem cells isolated from human adipose tissue (hMADS cells) were shown to differentiate into adipose cells in serum-free, chemically defined medium. During the differentiation process, hMADS cells exhibited a gene expression pattern similar to that described for rodent clonal preadipocytes and human primary preadipocytes. Differentiated cells displayed the key features of human adipocytes, i.e., expression of specific molecular markers, lipolytic response to agonists of beta-adrenoreceptors (beta2-AR agonist > beta1-AR agonist >> beta3-AR agonist) and to the atrial natriuretic peptide, insulin-stimulated glucose transport, and secretion of leptin and adiponectin. hMADS cells were able to respond to drugs as inhibition of adipocyte differentiation was observed in the presence of prostaglandin F2alpha, tumour necrosis factor-alpha, and nordihydroguaiaretic acid, a natural polyhydroxyphenolic antioxidant. Thus, for the first time, human adipose cells with normal karyotype and indefinite life span have been established. They represent a novel and valuable tool for studies of fat tissue development and metabolism.