Growth Factor System Research Articles

Insulin-like growth factor system components expressed at the conceptus-maternal interface during the establishment of equine pregnancy.

In many species, the insulin-like growth factors (IGF1 and IGF2), their receptors and IGF binding proteins play important roles in preparing the endometrium for implantation, and regulating conceptus growth and development. To determine whether the IGF system may contribute to conceptus-maternal interaction during equine pre-implantation development, we evaluated mRNA expression for IGF system components in conceptuses, and endometrium recovered from pregnant and cycling mares, on days 7, 14, 21 and 28 after ovulation. We also investigated expression of IGF1, IGF2 and their receptors 6 and 11 days after transfer of day 8 embryos to synchronous (day 8) or asynchronous (day 3) recipient mares. Expression of IGF1 and IGF2, IGF1R, IGF2R, INSR and IGFBPs 1, 2, 4 and 5 was evident in endometrium and conceptus membranes during days 7–28. Endometrial IGF2, INSR, IGFBP1 and IGFBP2 expression increased between days 7 and 28 of pregnancy. In conceptus membranes, expression of all IGF system components increased with developmental stage. Immunohistochemistry revealed strong expression of IGF1, IGF2 and IGF1R in both endometrium and conceptus membranes, whereas INSR was highly expressed in endometrium but barely detectable in the conceptus. Finally, a negatively asynchronous uterine environment retarded IGF1, IGF2 and INSR expression in the conceptus, whereas in the endometrium only INSR expression was altered by asynchrony. The presence of IGFs, their receptors and IGFBPs in the endometrium and conceptus during early equine pregnancy, and down-regulation in the conceptus following asynchronous embryo transfer, suggest a role in conceptus-maternal communication during the preparation for implantation.

Regulation of Signaling from the Epidermal Growth Factor Family.

The epidermal growth factor (EGF) system has allowed chemists, biologists, and clinicians to improve our understanding of cell production and cancer therapy. The discovery of EGF led to the recognition of cell surface receptors capable of controlling the proliferation and survival of cells. The detailed structures of the EGF-like ligand and the responses of their receptors (EGFR-family) has revealed the conformational and aggregation changes whereby ligands activate the intracellular kinase domains. Biophysical analysis has revealed the preformed clustering of different EGFR-family members and the processes which occur on ligand binding. Understanding these receptor activation processes and the consequential cytoplasmic signaling has allowed the development of inhibitors which are revolutionizing cancer therapy. This Review describes the recent progress in our understanding of the activation of the EGFR-family, the effects of signaling from the EGFR-family on cell proliferation, and the targeting of the EGFR-family in cancer treatment.

The Insulin-like Growth Factor System and Colorectal Cancer.

Insulin-like growth factors (IGFs) are peptides which exert mitogenic, endocrine and cytokine activities. Together with their receptors, binding proteins and associated molecules, they participate in numerous pathophysiological processes, including cancer development. Colorectal cancer (CRC) is a disease with high incidence and mortality rates worldwide, whose etiology usually represents a combination of the environmental and genetic factors. IGFs are most often increased in CRC, enabling excessive autocrine/paracrine stimulation of the cell growth. Overexpression or increased activation/accessibility of IGF receptors is a coinciding step which transmits IGF-related signals. A number of molecules and biochemical mechanisms exert modulatory effects shaping the final outcome of the IGF-stimulated processes, frequently leading to neoplastic transformation in the case of irreparable disbalance. The IGF system and related molecules and pathways which participate in the development of CRC are the focus of this review.

Rectangular multivariate normal prediction regions for setting reference regions in laboratory medicine

ABSTRACT Reference intervals are among the most widely used medical decision-making tools and are invaluable in the interpretation of laboratory results of patients. Moreover, when multiple biochemical analytes are measured on each patient, a multivariate reference region (MRR) is needed. Such regions are more desirable than separate univariate reference intervals since the latter disregard the cross-correlations among variables. Traditionally, assuming multivariate normality, MRRs have been constructed as ellipsoidal regions, which cannot detect componentwise extreme values. Consequently, MRRs are rarely used in actual practice. In order to address the above drawback of ellipsoidal reference regions, we propose a procedure to construct rectangular MRRs under multivariate normality. The rectangular MRR is computed using a prediction region criterion. However, since the population correlations are unknown, a parametric bootstrap approach is employed for computing the required prediction factor. Also addressed in this study is the computation of mixed reference intervals, which include both two-sided and one-sided prediction limits, simultaneously. Numerical results show that the parametric bootstrap procedure is quite accurate, with estimated coverage probabilities very close to the nominal level. Moreover, the expected volumes of the proposed rectangular regions are substantially smaller than the expected volumes obtained from Bonferroni simultaneous prediction intervals. We also explore the computation of covariate-dependent MRRs in a multivariate regression setting. Finally, we discuss real-life applications of the proposed methods, including the computation of reference ranges for the assessment of kidney function and for components of the insulin-like growth factor system in adults.

Central FGF21 production regulates memory but not peripheral metabolism.

SUMMARYFibroblast growth factor 21 (FGF21) is a liver-derived endocrine hormone that functions to regulate energy homeostasis and macronutrient intake. Recently, FGF21 was reported to be produced and secreted from hypothalamic tanycytes, to regulate peripheral lipid metabolism; however, rigorous investigation of FGF21 expression in the brain has yet to be accomplished. Using a mouse model that drives CRE recombinase in FGF21-expressing cells, we demonstrate that FGF21 is not expressed in the hypothalamus, but instead is produced from the retrosplenial cortex (RSC), an essential brain region for spatial learning and memory. Furthermore, we find that central FGF21 produced in the RSC enhances spatial memory but does not regulate energy homeostasis or sugar intake. Finally, our data demonstrate that administration of FGF21 prolongs the duration of long-term potentiation in the hippocampus and enhances activation of hippocampal neurons. Thus, endogenous and pharmacological FGF21 appear to function in the hippocampus to enhance spatial memory.

Leptin Promotes Primordial Follicle Activation by Regulating Ovarian Insulin-like Growth Factor System in Chicken.

Leptin and insulin-like growth factor 1 (IGF-1) regulate follicle development and reproduction in vertebrates. This study investigated the role played by leptin and IGF-1 in primordial follicle activation in the ovary of 7-day-old chicks. Different doses of leptin were intraperitoneally administrated to female layer chicks, and further analyses were performed. While leptin administration did not affect hepatic leptin receptor (LEPR), growth hormone receptor (GHR), or IGF-1, the lower dose of leptin significantly increased the messenger RNA (mRNA) expression of IGF-1, IGF-1 receptor, and IGF-binding protein (IGFBP)-2 and attenuated anti-Müllerian hormone (AMH) gene expression in the ovary. Furthermore, the ovaries of the same age chicks were challenged with leptin and/or IGF-1 in vitro. Leptin at a lower dose increased the mRNA expression of IGF-1, LEPR, and leptin; 100 ng/mL leptin and 10 ng/mL IGF-1 alone or combined with leptin reduced IGFBP-2 mRNA expression. AMH gene expression was also reduced by all doses except 10 ng/mL leptin. Histological studies showed that a lower dose of leptin injection induced the primordial follicle growth in the ovary in vivo, and the number of primordial follicles was higher in all leptin treatments over control in vitro. Moreover, the luciferase assay revealed that leptin enhanced IGF-1 promoter activity in LEPR-expressing CHO-K1 cells. Collectively, these results indicate that leptin directly affects the IGF-1/IGFBP system and promotes primordial follicular growth in the ovary of early posthatch chicks. In addition, the follicular development by leptin-induced IGF-1 is, at least in part, caused by the suppression of AMH in the ovary.

Circulating insulin-like growth factor system adaptations in hibernating brown bears indicate increased tissue IGF availability.

Brown bears conserve muscle and bone mass during 6 mo of inactive hibernation. The molecular mechanisms underlying hibernation physiology may have translational relevance for human therapeutics. We hypothesize that protective mechanisms involve increased tissue availability of insulin-like growth factors (IGFs). In subadult Scandinavian brown bears, we observed that mean plasma IGF-1 and IGF-2 levels during hibernation were reduced to 36 ± 10% and 56 ± 15%, respectively, compared with the active state (n = 12). Western ligand blotting identified IGF-binding protein (IGFBP)-3 as the major IGFBP in the active state, whereas IGFBP-2 was codominant during hibernation. Acid labile subunit (ALS) levels in hibernation were reduced to 41±16% compared with the active state (n = 6). Analysis of available grizzly bear RNA sequencing data revealed unaltered liver mRNA IGF-1, IGFBP-2, and IGFBP-3 levels, whereas ALS levels were significantly reduced during hibernation (n = 6). Reduced ALS synthesis and circulating levels during hibernation should prompt a shift from ternary IGF/IGFBP/ALS to smaller binary IGF/IGFBP complexes, thereby increasing IGF tissue availability. Indeed, size-exclusion chromatography of bear plasma demonstrated a shift to lower molecular weight IGF-containing complexes in the hibernating versus the active state. Furthermore, we note that the major IGF-2 mRNA isoform expressed in livers in both Scandinavian brown bears and grizzly bears was an alternative splice variant in which Ser29 is replaced with a tetrapeptide possessing a positively charged Arg residue. Homology modeling of the bear IGF-2/IGFBP-2 complex showed the tetrapeptide in proximity to the heparin-binding domain involved in bone-specific targeting of this complex. In conclusion, this study provides data which suggest that increased IGF tissue availability combined with tissue-specific targeting contribute to tissue preservation in hibernating bears.NEW & NOTEWORTHY Brown bears shift from circulating ternary IGF/IGFBP/ALS complexes in the active state to binary IGF/IGFBP complexes during hibernation, indicating increased tissue IGF-bioactivity. Furthermore, brown bears use a splice variant of IGF-2, suggesting increased bone-specific targeting of IGF anabolic signaling.

Growth Factor and Cytokine Delivery Systems for Wound Healing.

Skin wound healing is a highly coordinated process involving multiple tissue-resident and recruited cell types. Cells within the wound microenvironment respond to key secreted factors such as pro-proliferative growth factors and immunomodulatory cytokines to repair the skin and promptly restore its essential barrier role. Therefore, recombinant growth factors and cytokines are promising therapeutics for skin wounds, in particular for large acute wounds such as burns, or wounds associated with underlying pathologies such as nonhealing chronic and diabetic wounds. However, translation of growth factors and cytokines into clinically effective treatments has been limited. Short half-life, poor stability, rapid diffusion, uncontrolled signaling, and systemic side effects are currently the key challenges to developing efficient growth factor- and cytokine-based therapies. To overcome these limitations, novel delivery systems have been developed to improve the regenerative potential of recombinant growth factors and cytokines. In this review, we discuss biomaterial and protein engineering strategies used to optimize the delivery of growth factor and cytokine therapeutics for skin wound treatment.

Insulin-like growth factor 1 and its binding protein-2 in tumor and peritumoral tissues as important factors involved in recurrence of soft tissue sarcomas in older men.

e23556 Background: The system of insulin-like growth factors (IGF) is involved in the pathogenesis of many malignant tumors. At the same time, the specificity of this system in recurrent soft tissue sarcomas is unknown. The purpose of this study was to analyze the IGF system in tumors and their peritumoral areas in men with recurrent soft tissue sarcomas. Methods: The study included 26 men aged 57.8±6.2 years with primary (n = 12, group 1, controls) and recurrent (n = 14, group 2, main group) soft tissue sarcoma of the extremities, T2bN0M0. Grade 1 tumors were diagnosed in 6 patients of group 1 and in 7 patients of group 2, while the other patients had G3 or G4 tumors. 95% of tumors were liposarcomas. All patients of group 2 had previously underwent surgical and radiation treatment for primary sarcomas and their relapses (up to 2 episodes), with the last surgery more than 1 year ago. Levels of the IGF system components were determined in tumor (T) and peritumoral (PT) tissues by ELISA, and ratios of IGF(T)/IGF(PT) were calculated. Results: Levels of the IGF system components in patients of group 1 were similar in T and PT. In group 2, levels of IGF1 and IGFВР2 in T were respectively 2.2 and 1.6 times (p < 0.05) lower than in PT, but did not differ significantly from the levels in group 1. The IGF1(T)/IGF1(PT) ratio in patients of group 2 was 1.8 times (p < 0.05) lower than in group 1. PT levels of IGF2 in group 2 depended on the tumor grade: they were 1.5 times (p < 0.05) higher in G1 than in G3-G4, while no such dependence was observed in T. Conclusions: The levels of the IGF system components in recurrent soft tissue sarcomas in older men had some peculiarities. Unlike primary sarcomas with similar levels of the studied components of the IGF system in tumors and in peritumoral tissues, recurrent tumors contained less IGF1 and IGFBP2 than the corresponding peritumoral areas. The levels of IGF2 in the peritumoral tissues of recurrent tumors depended on the tumor grade.

An interaction between growth hormone/insulin-like growth factor-1 and vitamin D in children with short stature

There are disorders in the growth hormone (GH)/growth factors system in a significant part of patients with short stature; first of all, this concerns such diseases as growth hormone deficiency, where there is a sharp decrease in GH, insulin-like growth factor-1 (IGF-1). The association between vitamin D and GH/growth factor system remains unclear. It was found that vitamin D is able to increase IGF-1 level in healthy individuals. Linear growth is accelerated after treatment of vitamin D deficiency in children, which may indicate the linking role of vitamin D between the proliferative cells of the growth plate cartilage and GH/growth factor system.Research objective: to determine 25-hydroxyvitamin D level in blood plasma in children with short stature, depending on the state of GH/IGF-1 system.Materials and methods. Study included 101 children with short stature: 33 children with partial somatotropic insufficiency (group 1); 44 children with complete somatotropic insufficiency (group 2); 24 children with syndrome of biologically inactive GH (group 3). Patients in groups 1 and 2 had a confirmed GH deficiency and a decrease or sharp decrease in of IGF-1 level; patients in group 3 had a normal stimulated release of GH against the background of a reduced IGF-1 level. GH, IGF-1, 25-hydroxyvitamin D, thyroid-stimulating hormone, and free thyroxine were determined in all children.Results. The average level of vitamin D in three groups corresponded to the vitamin deficiency according to international standards and was 52.24 ± 5.99 nmol/l in patients with partial somatotropic insufficiency, 67.6 ± 5.35 nmol/l in patients with complete somatotropic insufficiency and 58, ± 7.91 nmol/l in patients with syndrome of biologically inactive GH. A direct correlation was found between vitamin D and background GH level, stimulated GH level in children with both partial and complete somatotropic insufficiency. A direct correlation between vitamin D and IGF-1 level in this group of patients was also detected.Conclusions. It is advisable to determine the serum 25(OH)D in all children with short stature. Vitamin D levels should be taken into account in insulin/clonidine diagnostic tests in order to obtain a realistic indication of stimulated GH and IGF-1 levels.

Pleiotropic Effects of IGF1 on the Oocyte.

A woman’s endocrine system plays a crucial role in orchestrating cellular interactions throughout her life. The growth hormone (GH) and insulin-like growth factor (IGF) system appears to impact crucial reproductive events and cell types of the ovary, such as granulosa cells, theca cells, and oocytes. Further, IGF1 is a cornerstone during embryonic development and influences predominantly developing and pre-antral follicles. In this commentary, we will emphasize the pleiotropic effects of IGF1 on physiological processes inside the egg. Herein, we will provide a brief overview on IGF1 related cell signal transduction pathways during the maturation and aging of oocytes. We aim to elucidate from a molecular and biochemical point of view if IGF1 in women with metabolic imbalances such as obesity or diabetes could be used in clinics as a novel, reliable estimator for the developmental competence of an oocyte.

Cranial Dysmorphology in the Palatine, Vomer, and Pterygoid Plates of Fgfr2mice

The fibroblast growth factor and receptor system (FGF/FGFR) regulates cell proliferation and differentiation for various tissue types in the body – including osseous tissue. Mutations in the FGFR2 gene are associated with craniosynostosis, leading to alterations of the shape of bones in the head and face. We have previously demonstrated premature fusion of the spheno‐septal synchondrosis in Fgfr2C342Y/+ mice, a model for Crouzon syndrome. Here, we further describe the specific morphology of individual bones as a result of the Fgfr2C342Y/+ mutation.We used microCT scans of mutant and wild‐type littermates at two developmental stages (adult and postnatal day 14) to create 3D virtual reconstructions of the skull in the program 3DSlicer. After transforming each scan to a uniform, orthogonal orientation, we collected coordinate data for 38 fixed craniometric landmarks to estimate the shape of the cranium. We used the geomorphpackage in R to perform a Procrustes superimposition and principal components analysis (PCA). We used the resulting shape coordinates in a two‐way Procrustes ANOVA to test the effects of Age and Genotype. In addition, we isolated key cranial elements (palatine, vomer, and pterygoid plates of the sphenoid) to compare between genotype groups at the P14 stage using a mesh‐to‐mesh comparison. This allowed us to test our expectation that fusion of the spheno‐septal synchondrosis has a greater impact on the vomer than on the palatines or pterygoid plates.Our morphometric analysis and two‐way Procrustes ANOVA confirmed previous reports of statistically significant cranial shape differences between wild‐type and Fgfr2 mutants at both timepoints. Vomer shape was significantly altered in the mutant P14 cranium when compared to other key cranial elements (palatine, and sphenoidal pterygoid plates), suggesting that fusion of the spheno‐septal synchondrosis has a greater impact on the vomer compared to the other bones in the skull. Our mesh‐to‐mesh comparison showed that the vomer is both dorso‐ventrally and rostro‐caudally compressed in mutants relative to wild‐type mice at this early stage. Additionally, the palato‐sphenoid suture appears prematurely fused in the mutants.This study provides insight into the skeletal phenotypic mechanisms that characterize diseases involving mutations of the FGFR2 gene, such as Crouzon syndrome. The dysmorphology of individual bones affect other osseous structures due to morphological integration within the skull. Elucidating the underlying mechanisms of the phenotypic expression of FGFR2 syndromes supports further translational research.

Role of the insulin-like growth factor system in bone health and military relevance during military training

Introduction: Bone is in a constant state of remodelling to remove old or damaged bone and form new bone. This process of bone resorption and formation is ‘coupled’ to preserve bone size, structure, and mass. Several physiological challenges—typical of military training and employment—can disturb bone metabolism including high levels of physical activity and energy and sleep restriction. Accumulation of damaged bone during exercise stimulates targeted remodelling, a process where the resorption of damaged bone can cause pores in the cortical bone and eventually stress fracture.

IGF-dependent dynamic modulation of a protease cleavage site in the intrinsically disordered linker domain of human IGFBP2.

Functional regulation via conformational dynamics is well known in structured proteins but less well characterized in intrinsically disordered proteins and their complexes. Using NMR spectroscopy, we have identified a dynamic regulatory mechanism in the human insulin-like growth factor (IGF) system involving the central, intrinsically disordered linker domain of human IGF-binding protein-2 (hIGFBP2). The bioavailability of IGFs is regulated by the proteolysis of IGF-binding proteins. In the case of hIGFBP2, the linker domain (L-hIGFBP2) retains its intrinsic disorder upon binding IGF-1, but its dynamics are significantly altered, both in the IGF binding region and distantly located protease cleavage sites. The increase in flexibility of the linker domain upon IGF-1 binding may explain the IGF-dependent modulation of proteolysis of IGFBP2 in this domain. As IGF homeostasis is important for cell growth and function, and its dysregulation is a key contributor to several cancers, our findings open up new avenues for the design of IGFBP analogs inhibiting IGF-dependent tumors.

Fibroblast Growth Factor 9 as a Potential Biomarker for Schizophrenia

Preclinical and clinical studies have suggested that fibroblast growth factor (FGF) system contributed to the onset and development of schizophrenia (SCZ). However, there was no strong clinical evidence to link an individual FGF with SCZ. In this study, we aim to measure blood FGF9 levels in the patients with SCZ with and/or without medication, and test whether FGF9 has a potential to be a biomarker for SCZ. We recruited 130 patients with SCZ and 111 healthy individuals, and the ELISA and qRT-PCR assays were used to measure serum FGF9 levels in the participants. ELISA assay demonstrated that serum FGF9 protein levels were dramatically reduced in first-episode, drug-free patients, but not in chronically medicated patients when compared to healthy control subjects. Further analysis showed that treatment of the first-episode, drug-free SCZ patients with antipsychotics for 8 weeks significantly increased the serum FGF9 levels. In addition, we found that blood FGF9 mRNA levels were significantly lower in first-onset SCZ patients than controls. Under the receiver operating characteristic curve, the optimal cutoff values for FGF9 protein level as an indicator for diagnosis of drug-free SCZ patients was projected to be 166.4 pg/ml, which yielded a sensitivity of 0.955 and specificity of 0.86, and the area under the curve was 0.973 (95% CI, 0.954-0.993). Furthermore, FGF9 had good performance to discriminate between drug-free SCZ patients and chronically medicated patients, the optimal cutoff value for FGF9 concentration was projected to be 165.035 pg/ml with a sensitivity of 0.86 and specificity of 0.919, and the AUC was 0.968 (95% CI, 0.944, 0.991). Taken together, our results for the first time demonstrated the dysregulation of FGF9 in SCZ, and FGF9 has the potential to be served as a biomarker for SCZ.

Obesity, Diabetes, and Cancer: The Role of the Insulin/IGF Axis; Mechanisms and Clinical Implications

This biomolecules Special Issue includes original research articles and reviews focusing on recent advances in the biology of the insulin-like growth factor (IGF) system [...].

The Origination of Growth Hormone/Insulin-Like Growth Factor System: A Story From Ancient Basal Chordate Amphioxus.

The growth hormone/insulin-like growth factor (GH/IGF) system, also called the pituitary-liver axis, has a somatotrophic role in the body. Although the GH/IGF system has always been regarded as a vertebrate-specific endocrine system, its actual origin remained unknown for a long time. The basal chordate, amphioxus, occupies an evolutionary position between vertebrates and invertebrates. Impressively, most of the members of the GH/IGF system are present in the amphioxus. The GH-like molecule in the amphioxus is mainly expressed in Hatschek’s pit. It functions similarly to vertebrate GH and has a GH receptor-like binding partner. The amphioxus IGF-like peptide shows mitogenic activity and an expression pattern resembling that of vertebrate IGF-I. The receptor of IGF-like peptide and IGF binding protein (IGFBP) have also been demonstrated to exist in the amphioxus. These results reveal the origin of the gene families in the GH/IGF system, providing strong evidence that this system emerged in the amphioxus.

Liver and muscle-specific effects of phoenixin-20 on the insulin-like growth factor system mRNAs in zebrafish

ObjectivePhoenixin-20 (Pnx-20) is a bioactive peptide with endocrine-like actions in vertebrates. Recent studies suggest Pnx-20 promotes growth hormone/insulin-like growth factors (Gh/Igf) axis, an important endocrine regulator of growth in mammals and fish. DesignIn this research, we determined whether Pnx-20 affects the different members of the Igf family, its binding proteins and receptors (Igf-system) in zebrafish liver and muscle. ResultsIn vivo administration of Pnx-20 downregulated igfs, igf receptors (igfrs) and igf binding protein (igfbp) 5 mRNA expression in the liver of male and female zebrafish at both 1 and 6 h post-intraperitoneal (IP) injection. Interestingly, this effect occurred at a relatively earlier timepoint in female zebrafish suggesting sex-specific differences in Pnx-20 action. Besides, either 6 or 24 h in vitro incubations with Pnx-20 downregulated the expression of all igfs, igfrs and igfbp5 mRNAs (except igf2a) analyzed in a zebrafish liver cell (ZFL) line. Moreover, siRNA-mediated knockdown of Pnx-20 upregulated all Igf-system mRNAs analyzed in ZFL cells. Together, these results (both in vivo and in vitro) revealed a general suppressive action for both endogenous and exogenous Pnx-20 on the hepatic Igf-system of zebrafish. In contrast, a general sex-specific upregulation of the Igf-system mRNAs analyzed was found in the muscle of Pnx-20 injected fish. Future research should explore the sex- and time-differences observed in the present study. ConclusionsCollectively, this research shows that Pnx-20 is a tissue-specific regulator of the liver (suppressor) and muscle (stimulant) Igf signaling in both male and female zebrafish.

Early Abnormal Placentation and Evidence of Vascular Endothelial Growth Factor System Dysregulation at the Feto-Maternal Interface After Periconceptional Alcohol Consumption.

Adequate placentation, placental tissue remodeling and vascularization is essential for the success of gestation and optimal fetal growth. Recently, it was suggested that abnormal placenta induced by maternal alcohol consumption may participate in fetal growth restriction and relevant clinical manifestations of the Fetal Alcohol Spectrum Disorders (FASD). Particularly, periconceptional alcohol consumption up to early gestation can alter placentation and angiogenesis that persists in pregnancy beyond the exposure period. Experimental evidence suggests that abnormal placenta following maternal alcohol intake is associated with insufficient vascularization and defective trophoblast development, growth and function in early gestation. Accumulated data indicate that impaired vascular endothelial growth factor (VEGF) system, including their downstream effectors, the nitric oxide (NO) and metalloproteinases (MMPs), is a pivotal spatio-temporal altered mechanism underlying the early placental vascular alterations induced by maternal alcohol consumption. In this review we propose that the periconceptional alcohol intake up to early organogenesis (first trimester) alters the VEGF-NO-MMPs system in trophoblastic-decidual tissues, generating imbalances in the trophoblastic proliferation/apoptosis, insufficient trophoblastic development, differentiation and migration, deficient labyrinthine vascularization, and uncompleted remodelation and transformation of decidual spiral arterioles. Consequently, abnormal placenta with insufficiency blood perfusion, vasoconstriction and reduced labyrinthine blood exchange can be generated. Herein, we review emerging knowledge of abnormal placenta linked to pregnancy complications and FASD produced by gestational alcohol ingestion and provide evidence of the early abnormal placental angiogenesis-vascularization and growth associated to decidual-trophoblastic dysregulation of VEGF system after periconceptional alcohol consumption up to mid-gestation, in a mouse model.

Chitosan-dipotassium orthophosphate lyophilizate: a novel in situ thermogel carrier system of allogeneic platelet lysate growth factors

The clinical success of platelet-rich plasma (PRP) is constrained by its limited mechanical strength, rapid disintegration by lytic enzymes, and the consequent short-term release of bioactive growth factors (GFs). Recently, attempts to formulate PRP and other hemoderivatives, such as platelet lysate (PL) have been underway. The current study aimed to formulate allogeneic freeze-dried human platelet lysate (HPL) onto lyophilized chitosan - dipotassium hydrogen orthophosphate (CS/DHO) thermo-sensitive scaffolds. A systemic approach was employed to optimize freeze-drying (FD) procedures targeting predefined critical quality attributes (CQAs). Thermal behavior, vibrational spectroscopy, morphological and moisture content analyses were used to detect possible protein destabilization during formulation and suboptimal cake properties. The effect of CS/DHO concentrations on thermo-responsiveness and release kinetics were investigated. Finally, six-months stability and cytotoxicity studies were carried out. An optimized lyophilizate was attainable with residual moisture of less than 5% and thermoresponsive to 33 °C in less than 3 min. HPL proteins were sustainedly released over five days in a pH-sensitive manner. The stability study indicated plausible physical and biochemical stability. Cell viability testing supported the cytocompatibility of the system. Finally, the lyophilizate variant of CS/DHO thermogel overcomes limited storage stability previously posed as a challenge in freshly prepared thermogels. The developed system overcomes the drawbacks of currently used PRP treatment and provides a novel GF-rich scaffold for wound repair.