Effect of obesity and glycemic control on serum lipocalins and insulin-like growth factor axis in type 2 diabetic patients

A comprehensive review and in silico analysis of the role of survivin (BIRC5) in hepatocellular carcinoma hallmarks: A step toward precision

Hepatocellular carcinoma (HCC) is a complex malignancy driven by the dysregulation of multiple cellular pathways. Survivin, a key member of the inhibitor of apoptosis (IAP) family, plays a central role in HCC tumorigenesis and progression. Despite significant research, a comprehensive understanding of the contributions of survivin to the hallmarks of cancer, its molecular network, and its potential as a therapeutic target remains incomplete. In this review, we integrated bioinformatics analysis with an extensive literature review to provide deeper insights into the role of survivin in HCC. Using bioinformatics tools such as the Human Protein Atlas, GEPIA, STRING, TIMER, and Metascape, we analyzed survivin expression and its functional associations and identified the top 20 coexpressed genes in HCC. These include TK1, SPC25, SGO2, PTTG1, PRR11, PLK1, NCAPH, KPNA2, KIF2C, KIF11, HJURP, GTSE1, FOXM1, CEP55, CENPA, CDCA3, CDC45, CCNB2, CCNB1 and CTD-2510F5.4. Our findings also revealed significant protein-protein interactions among these genes, which were enriched in pathways associated with the FOXM1 oncogenic signaling cascade, and biological processes such as cell cycle regulation, mitotic checkpoints, and diseases such as liver neoplasms. We also discussed the involvement of survivin in key oncogenic pathways, including the PI3K/AKT, WNT/β-catenin, Hippo, and JAK/STAT3 pathways, and its role in modulating cell cycle checkpoints, apoptosis, and autophagy. Furthermore, we explored its interactions with the tumor microenvironment, particularly its impact on immune modulation through myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages, and natural killer cell function in HCC. Additionally, we highlighted its involvement in alkylglycerone phosphate synthase (AGPS)-mediated lipid reprogramming and identified important gaps in the survivin network that warrant further investigation. This review also examined the role of survivin in cancer stemness, inflammation, and virally mediated hepatocarcinogenesis. We evaluated its potential as a diagnostic, prognostic, predictive, and pharmacodynamic biomarker in HCC, emphasizing its relevance in precision medicine. Finally, we summarized emerging survivin-targeted therapeutics and ongoing clinical trials, underscoring the need for novel strategies to effectively target survivin in HCC.

Macrophage polarization in hepatocellular carcinoma: a lncRNA-centric perspective on tumor progression and metastasis

Hepatocellular carcinoma (HCC) represents a multifaceted and aggressive cancer frequently associated with chronic inflammation and immune cell activation. The pathogenesis of HCC is influenced by a variety of factors such as long non-coding RNAs (lncRNAs). LncRNAs, a significant class of non-coding RNAs, contribute to the intricate nature of the transcriptome and are extensively distributed across various tissues and cell types in mammals. In HCC, these transcripts are crucial not only for deepening our molecular understanding but also for advancing clinical outcomes, as they serve as both oncogenes and tumor suppressors by dysregulating essential genes and signaling pathways. Additionally, macrophage polarization is crucial in HCC tumor progression. The study explores the role of lncRNAs in hepatocellular carcinoma (HCC) and elucidates the specific molecular mechanisms by which key lncRNAs such as HULC and MALAT1 regulate macrophage polarization in the tumor microenvironment. These lncRNAs modulate cytokine profiles and influence immune regulators including IL-10 and TGF-β, steering macrophages toward an M2-like, pro-tumor phenotype that fosters aggressive tumor characteristics and progression. Mechanistically, these transcripts interact with epigenetic modifiers like EZH2 to alter histone modifications and chromatin accessibility, while also stabilizing mRNAs that encode inflammatory mediators, thereby reinforcing an immunosuppressive response. The clinical implications of these findings are substantial. The detection of such lncRNAs in patient samples offers a minimally invasive diagnostic avenue, while their pivotal role in complex immune cell behavior positions them as promising prognostic biomarkers. Moreover, targeting these lncRNAs may lead to innovative therapeutic strategies aimed at disrupting tumor-supportive inflammatory cascades and restoring an effective antitumor immune response. Understanding the intricate interplay between lncRNA-mediated epigenetic regulation and macrophage polarization not only refines our grasp of HCC progression but also opens new pathways for interventions designed to improve patient outcomes.

LincRNA-miR interactions in hepatocellular carcinoma: comprehensive review and in silico analysis: a step toward ncRNA precision

The most prevalent form of primary liver cancer and one of the chief drivers of cancer-related mortality globally is hepatocellular carcinoma (HCC). Imminent evidence has indicated that non-coding RNAs (ncRNAs) play an integral part in the development and propagation of HCC. RNA stabilization, transcription regulation, chromatin and genomic architecture remodeling, enhancer-associated activity, and other varied properties set long intergenic ncRNA (lincRNA) genes apart from messenger RNA (mRNA)-encoding genes. Through a variety of processes, lincRNAs may generally be used to fine-tune the transcription of nearby genes with exceptional tissue specificity, underscoring our quickly developing knowledge of the non-coding genome. Through their binding with divergent cell targets, some HCC-related ncRNAs have been demonstrated to exhibit abnormal expression, contribute to malignant growth, evade apoptosis, and have invasive potential. Therefore, a better comprehension of lincRNA dysregulation might offer novel perspectives on the pathophysiology of HCC as well as innovative instruments for the early detection and management of HCC. In the present review, we provide an overview of the increasing relevance of lincRNAs as a major contributor to the pathophysiology of HCC, emphasizing their influence on signaling pathways implicated in the development, progression, and response to treatment of tumors. In addition, we go over the new approaches that target lincRNAs for HCC treatment as well as the possible therapeutic uses of lincRNAs as prognostic and diagnostic biomarkers for HCC.

Association of the estimated glucose disposal rate with and mortality risk in patients with atherosclerotic cardiovascular disease: A cohort study from the NHANES 1999-2018

AIM

To investigate the association between estimated glucose disposal rate (eGDR) and mortality risk among patients with atherosclerotic cardiovascular disease (ASCVD).

METHODS

NHANES (1999-2018) data were analyzed using weighted Cox regression and restricted cubic splines (RCS) to assess the association between eGDR and mortality. Improvement in predictive performance was evaluated. Subgroup, mediation, and sensitivity analyses were conducted.

RESULTS

Among 4,425 ASCVD patients (67.40 % ≥60 years, 44.66 % female), 1,815 deaths (35.62 %) and 751 CVD deaths (18.48 %) occurred over 7.7 years. Compared to the highest quartile, the lowest eGDR quartile had HRs of 2.13 and 2.06 for CVD and all-cause mortality, respectively. RCS demonstrated linearity (P-nonlinear > 0.05). Addition of eGDR improved the predictive performance for both CVD and all-cause mortality (P < 0.001), whereas other insulin resistance indicators did not yield comparable improvements. Diabetes status modified its association with CVD mortality (P-interaction = 0.029). Neutrophil-to-lymphocyte ratio and estimated pulse wave velocity were key mediators.

CONCLUSIONS

Lower eGDR was associated with increased mortality risk in ASCVD, particularly among patients without diabetes. eGDR enhances mortality prediction, supporting its role as a prognostic marker in ASCVD.

Comprehensive review and in silico analysis of the role of noncoding RNAs in retinoblastoma: A step-toward ncRNA precision

Noncoding RNAs (ncRNAs) have greatly revolutionized our understanding of gene regulation and its main role in oncogenesis, particularly in retinoblastoma (RB), the most prevalent type of intraocular malignancy in children. Despite recent significant therapeutic advances, the prognosis for RB remains unclear owing to late diagnosis and resistance to conventional treatments. This review comprehensively explores the multiple roles of ncRNAs-microRNAs (miRNAs), long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), and PIWI-interacting RNAs (piRNAs)-in RB pathogenesis. miRNA dysregulation serves as the initial cascade for modulating cell proliferation, apoptosis, and metastasis. Similarly, lncRNAs demonstrate dual behavior, functioning either as oncogenic drivers or tumor suppressors by interacting with several molecular targets and interacting with different signaling pathways, such as the PI3K/Akt and Wnt/β-catenin pathways. Additionally, circRNAs, owing to their persistent stability and unique ability to act as miRNA sponge main binding sites, affect various normal physiological processes, influencing tumor progression and chemoresistance. Emerging data also highlight the intricate crosstalk between piRNAs and other ncRNAs in retinal homeostasis and oncogenesis, with promising future implications for their utility as diagnostic biomarkers in liquid biopsy types. This comprehensive review consolidates the latest knowledge on the molecular mechanisms of noncoding RNAs (ncRNAs) in retinoblastoma (RB), along with in silico analysis of ncRNA-gene interactions, providing a guide for precision medical approaches. However, future research should aim to utilize ncRNAs as a vital clinical tool to improve the early diagnosis, prognosis, and targeted treatment of RB.

Association of glycemic variability with short and long-term mortality among critically ill patients with heart failure: Analysis of the MIMIC-IV database

OBJECTIVE

High glycemic variability (GV) often indicates a poor prognosis. Our aim is to investigate the relationship between GV and short and long-term mortality in critically ill heart failure (HF) patients.

METHODS

We extracted data from the Medical Information Mart for Intensive Care IV database. The risks of in-hospital and 1-year mortality were calculated using Logistic and COX regression. In addition, mediation analysis was used to investigate the indirect effect of ventricular arrhythmias (VA) on in-hospital mortality.

RESULTS

Among 8,980 critically ill HF patients, the multifactorial regression analysis showed that high GV was associated with an increased risk of in-hospital and 1-year mortality (OR 1.69, 95 % CI 1.47-1.93; HR 1.12, 95 % CI 1.02-1.22). The Kaplan-Meier survival curve and restricted cubic spline plot also emphasized this association. Furthermore, the impact of GV on in-hospital mortality was partially mediated by VA (4.98%). And the increased risk of 1-year mortality associated with high GV was more significant in person with diabetes (p for interaction =0.018).

CONCLUSION

Our Study indicates that high GV may be an independent risk factor for short and long-term mortality in critically ill HF patients. Maintaining the stability of blood glucose can reduce adverse outcomes in critically ill HF patients.

Comprehensive insights and In silico analysis into the emerging role of LincRNAs in lung diseases pathogenesis; a step toward ncRNA precision

Long non-coding RNAs (lncRNAs) have emerged as essential regulators of gene expression, significantly influencing various biological processes. Approximately half of all lncRNAs are classified as long intergenic non-coding RNAs (lincRNAs), which are situated among coding genes. Recent studies have documented the role of lincRNAs in the pathogenesis of lung diseases, including lung cancer, pulmonary fibrosis, and pulmonary arterial hypertension. These lincRNAs can modulate gene expression through various mechanisms, including epigenetic modifications, transcriptional regulation, and post-transcriptional regulation. By functioning as competing endogenous RNAs (ceRNAs), lincRNAs can affect the activity of microRNAs (miRNAs) and their corresponding target genes. This review delves into the intricate mechanisms by which lincRNAs contribute to the development and progression of various lung diseases. Furthermore, it discusses the potential of lincRNAs as therapeutic targets.

B Lymphocyte-A Prognostic Indicator in Post-Acute Pancreatitis Diabetes Mellitus

OBJECTIVE

To determine the value of lymphocyte subsets and granulocyte/monocyte surface markers in predicting the risk of post-acute pancreatitis diabetes (PPDM-A).

METHODS

This study included 308 in patients with acute pancreatitis (AP). The markers of granulocytes and monocytes and lymphocyte subsets were detected by flow cytometry, and the fluorescence intensity, absolute count and percentage were obtained. Based on the occurrence of diabetes after AP, patients were divided into two groups: PPDM-A and PPNG-A (post-acute pancreatitis with normal glucose). Correlations between granulocyte and monocyte surface markers and lymphocyte subsets were analyzed. Binary logistic regression was used to analyze the potential influencing factors of PPDM-A.

METHODS

Compared with patients with PPNG-A, patients with PPDM-A tend to be younger (p < 0.001) and have a higher proportion of fatty liver, recurrent pancreatitis, and hyperlipidemic pancreatitis. The results of linear regression showed that B% was negatively correlated with MFI of HLA-DR on monocytes (R2 = 0.145, p < 0.001), B% was positively correlated with CD10-NEUT% (R2 = 0.291, p < 0.001), and MFI of HLA-DR on monocytes was negatively correlated with CD10-NEUT% (R2 = 0.457, p < 0.001). Multivariate logistic regression analysis revealed that age, serous effusion, fatty liver, recurrent pancreatitis, and B% were independent risk factors for the occurrence of PPDM-A.

CONCLUSION

Our study has first confirmed the correlation between PPDM-A and lymphocyte subsets and CD10-NEUT%. Furthermore we indicated that age, fatty liver, serous effusion, recurrent AP, and B% were independent risk factors for PPDM-A. The mechanism of granulocyte and monocyte surface markers and B lymphocytes on PPDM-A is worthy of study. This would help clarify the pathogenesis of PPDM-A at the cellular level and potentially provide new strategies for immunotherapy and even disease prevention.

Evaluation Between Serum Concentrations of Lipocalin-2 and Metabolic Syndrome and its Components in Korean-Chinese and Han-Chinese Individuals from Yanbian Area

Objectives: To investigate the association between the blood concentration of lipocalin-2 (LCN2) in local multiethnic residents and the increased risk for the development of metabolic syndrome (MS) in the Yanbian Korean Autonomous Prefecture population. Methods: A total of 2078 subjects with (study group) or without (control group) MS (1217 Korean-Chinese and 861 Han-Chinese subjects) were included in this study. MS subjects were divided into five groups according to ethnicity and MS components. They were assessed for smoking history, drinking history, past medical history, general demographic characteristics, and LCN2 concentrations. Results: LCN2 concentrations were higher in all ethnic MS groups than in the control group, and the highest concentrations were detected in Han-Chinese subjects with dyslipidemia. Moreover, LCN2 concentrations were significantly higher in Korean-Chinese individuals with all MS components than in the control group. Logistic regression analyses were conducted. In the unadjusted models, Korean-Chinese and Han-Chinese individuals with high LCN2 concentrations both faced a risk of MS with odds ratios (ORs) of 2.339 (95% confidence interval [CI]: 1.632-3.352) and 1.523 (95% CI: 1.101-2. 108), respectively. After the adjustment, the risk only remained in Korean-Chinese individuals, with an OR of 1.818 (95% CI: 1.031-3.207). Conclusion: Elevated circulating LCN2 was associated with the increased incidence of MS, and the effect in Korean-Chinese individuals was stronger than that in Han-Chinese individuals.

The impact of insulin resistance and glycaemic control on insulin-like growth factor-1 in patients with type 2 diabetes: a cross-sectional study

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a multifaceted metabolic disorder. Over the past decade, the potential role of Growth Hormone (GH) and Insulin-like Growth Factor-1 (IGF-1) in the pathogenesis and progression of T2DM has garnered scientific interest. These hormones, while interrelated, exert differential effects on glucose homeostasis; GH elevates blood glucose levels, whereas IGF-1 sustains insulin secretion and augments insulin sensitivity.

OBJECTIVE

The study aimed to investigate the impact of insulin resistance and glycaemic control on IGF-1 levels and to assess other risk factors influencing IGF-1 in T2DM.

METHODS

A cross-sectional study was conducted at the National Diabetes Centre, Baghdad, Iraq, from May 2020 to May 2021. Sixty patients with T2DM were evaluated for fasting plasma glucose (FPG), GH, IGF-1, HbA1c, HOMA-IR, HOMA-B, and anthropometric measures following a comprehensive history and physical examination, focusing on any variables that could influence their metabolic profile. Patients with Type 1 diabetes mellitus, thyroid disease, pituitary disease, chronic kidney disease, hepatic disease, and pregnancy were excluded from the study.

RESULTS

Patients with poorly controlled diabetes (HbA1c > 8) exhibited significantly elevated IGF-1 levels compared to those with HbA1c < 8 (166 vs. 134, P = 0.016). The mean IGF-1 was significantly lower in patients with insulin resistance (IR) compared to those without IR (143 vs. 192, P = 0.001), with a significant negative correlation with Body Mass Index (BMI) and a significant positive correlation with HbA1c and Quantitative Insulin Sensitivity Index (QUICKI). Elevated IGF-1 levels were observed with increasing age, duration of T2DM, higher HbA1c, higher QUICKI, and lower BMI. No significant difference was found in IGF-1 values with regards to HOMA-B, fasting insulin, and waist-hip ratio.

CONCLUSION

Patients with poorly controlled T2DM exhibit higher IGF-1 levels, while those with obesity and high insulin resistance demonstrate lower IGF-1 levels. Further prospective studies are warranted to evaluate the potential of using IGF-1 to reduce insulin resistance and improve metabolic and glycaemic measures in individuals with T2DM and obesity or insulin resistance.

Unraveling the ncRNA landscape that governs colorectal cancer: A roadmap to personalized therapeutics

Colorectal cancer (CRC) being one of the most common malignancies, has a significant death rate, especially when detected at an advanced stage. In most cases, the fundamental aetiology of CRC remains unclear despite the identification of several environmental and intrinsic risk factors. Numerous investigations, particularly in the last ten years, have indicated the involvement of epigenetic variables in this type of cancer. The development, progression, and metastasis of CRC are influenced by long non-coding RNAs (lncRNAs), which are significant players in the epigenetic pathways. LncRNAs are implicated in diverse pathological processes in CRC, such as liver metastasis, epithelial to mesenchymal transition (EMT), inflammation, and chemo-/radioresistance. It has recently been determined that CRC cells and tissues exhibit dysregulation of tens of oncogenic and tumor suppressor lncRNAs. Serum samples from CRC patients exhibit dysregulated expressions of several of these transcripts, offering a non-invasive method of detecting this kind of cancer. In this review, we outlined the typical paradigms of the deregulated lncRNA which exert significant role in the underlying molecular mechanisms of CRC initiation and progression. We comprehensively discuss the role of lncRNAs as innovative targets for CRC prognosis and treatment.

The effect of 60 days of 6° head-down-tilt bed rest on circulating adropin, irisin, retinol binding protein-4 (RBP4) and individual metabolic responses in young, healthy males

Background

Alterations in the circulating concentrations and target-tissue action of organokines underpin the development of insulin resistance in microgravity and gravity deprivation. The purpose of this study was to examine changes in circulating adropin, irisin, retinol binding protein-4 (RBP4), and the metabolic response of healthy young males following 60 days of 6° head-down-tilt (HDT) bed rest, with and without reactive jump training (RJT), to explore links with whole-body and tissue-specific insulin sensitivity. To our knowledge, this is the first time that adropin, irisin, and RBP4 have been studied in HDT bed rest.

Methods

A total of 23 male subjects (29 ± 6 years, 181 ± 6 cm, 77 ± 7 kg) were exposed to 60 days of 6° HDT bed rest and randomized to a control (CTRL, n = 11) or a RJT (JUMP, n = 12) group (48 sessions with ≤4 min total training time per session). Circulating adropin, irisin, and RBP4 were quantified in fasting serum before and after HDT bed rest. A subanalysis was performed a posteriori to investigate individual metabolic responses post-HDT bed rest based on subjects that showed an increase or decrease in whole-body insulin sensitivity (Matsuda index).

Results

There were significant main effects of time, but not group, for decreases in adropin, irisin, Matsuda index, and liver insulin sensitivity following HDT bed rest (p < 0.05), whereas RBP4 did not change. The subanalysis identified that in a subgroup with decreased whole-body insulin sensitivity (n = 17), RBP4 increased significantly, whereas adropin, irisin, and liver insulin sensitivity were all decreased significantly following HDT bed rest. Conversely, in a subgroup with increased whole-body insulin sensitivity (n = 6), liver insulin sensitivity increased significantly after HDT bed rest, whereas adropin, irisin, and RBP4 did not change.

Conclusion

Investigating individual metabolic responses has provided insights into changes in circulating adropin, irisin, RBP4, in relation to insulin sensitivity following HDT bed rest. We conclude that adropin, irisin, and RBP4 are candidate biomarkers for providing insights into whole-body and tissue-specific insulin sensitivity to track changes in physiological responsiveness to a gravity deprivation intervention in a lean male cohort.

A Comprehensive Insight and In Silico Analysis of CircRNAs in Hepatocellular Carcinoma: A Step toward ncRNA-Based Precision Medicine

Circular RNAs (circRNAs) are cardinal players in numerous physiological and pathological processes. CircRNAs play dual roles as tumor suppressors and oncogenes in different oncological contexts, including hepatocellular carcinoma (HCC). Their roles significantly impact the disease at all stages, including initiation, development, progression, invasion, and metastasis, in addition to the response to treatment. In this review, we discuss the biogenesis and regulatory functional roles of circRNAs, as well as circRNA-protein-mRNA ternary complex formation, elucidating the intricate pathways tuned by circRNAs to modulate gene expression and cellular processes through a comprehensive literature search, in silico search, and bioinformatics analysis. With a particular focus on the interplay between circRNAs, epigenetics, and HCC pathology, the article sets the stage for further exploration of circRNAs as novel investigational theranostic agents in the dynamic realm of HCC.

An update on chronic complications of diabetes mellitus: from molecular mechanisms to therapeutic strategies with a focus on metabolic memory

Diabetes mellitus, a chronic metabolic disease, often leads to numerous chronic complications, significantly contributing to global morbidity and mortality rates. High glucose levels trigger epigenetic modifications linked to pathophysiological processes like inflammation, immunity, oxidative stress, mitochondrial dysfunction, senescence and various kinds of cell death. Despite glycemic control, transient hyperglycemia can persistently harm organs, tissues, and cells, a latent effect termed "metabolic memory" that contributes to chronic diabetic complications. Understanding metabolic memory's mechanisms could offer a new approach to mitigating these complications. However, key molecules and networks underlying metabolic memory remain incompletely understood. This review traces the history of metabolic memory research, highlights its key features, discusses recent molecules involved in its mechanisms, and summarizes confirmed and potential therapeutic compounds. Additionally, we outline in vitro and in vivo models of metabolic memory. We hope this work will inform future research on metabolic memory's regulatory mechanisms and facilitate the development of effective therapeutic compounds to prevent diabetic complications.

Human circular RNA hsa_circ_0000231 clinical diagnostic effectiveness as a new tumor marker in gastric cancer

BACKGROUND

Owing to the subtlety of initial symptoms associated with gastric cancer (GC), the majority of patients are diagnosed at later stages. Given the absence of reliable diagnostic markers, it is imperative to identify novel markers that exhibit high sensitivity and specificity. Circular RNA, a non-coding RNA, plays an important role in tumorigenesis and development and is well expressed in body fluids.

AIMS

In this study, we aimed to identify hsa_circ_0000231 as a new biomarker for the diagnosis of GC and to assess its clinical diagnostic value in serum.

METHODS AND RESULTS

The stability and correctness of hsa_circ_0000231 was determined by agarose gel electrophoresis, Rnase R assay and Sanger sequencing. Real-time quantitative polymerase chain reaction (qRT-PCR) was designed to discover the expression level of hsa_circ_0000231 and whether it has dynamic serum monitoring capability. The correlation between hsa_circ_0000231 and clinicopathological parameters was analyzed by collecting clinical and pathological data from GC patients. In addition, diagnostic efficacy was assessed by constructing receiver operating characteristic curves (ROC). Hsa_circ_0000231 exhibits a stable and consistently expressed structure. In GC serum, cells, and tissues, it demonstrates reduced expression levels. Elevated expression levels observed postoperatively suggest its potential for dynamic monitoring. Additionally its expression level correlates with TNM staging and neuro/vascular differentiation. The area under ROC curve (AUC) for hsa_circ_0000231 is 0.781, indicating its superior diagnostic value compared to CEA, CA19-9, and CA72-4. The combination of these four indicators enhances diagnostic accuracy, with an AUC of 0.833.

CONCLUSIONS

The stable expression of hsa_circ_0000231 in the serum of gastric cancer patients holds promise as a novel biomarker for both the diagnosis and dynamic monitoring of GC.

Research Progress on Lipocalin-2 in Diabetic Encephalopathy

Diabetic encephalopathy is a central nervous complication of diabetes mellitus which is characterized by cognitive impairment and structural and neurochemical abnormalities, which is easily neglected. Lipocalin-2 (LCN2) is a 25 kDa transporter in the lipocalin family that can transport small molecules, including fatty acids, iron, steroids, and lipopolysaccharides in the circulation. Recently, LCN2 has been found to be a significant regulator of insulin resistance and glucose homeostasis. Numerous studies have shown that LCN2 is connected to central nervous system abnormalities, including neuroinflammation and neurodegeneration, while the latest researches have found that LCN2 is closely related to the development of diabetic encephalopathy. Nevertheless, its precise role in the pathogenesis of diabetic encephalopathy remains to be determined. In this paper, we review recent evidence on the role of LCN2 in diabetic encephalopathy from multiple perspectives in order to decipher the impact of LCN2 in both the aetiology and treatment of diabetic encephalopathy.

Lipocalin 2 Participates in the Epidermal Differentiation and Inflammatory Processes of Psoriasis

As a multifunctional cytokine, lipocalin 2 is weakly expressed in skin and serum under normal conditions. However, it is over-expressed by neutrophils and keratinocytes in the skin lesions and sera in several skin diseases. Recent studies demonstrated that lipocalin 2 participates in the pathogenesis of psoriasis by exerting versatile effects on skin resident cells and infiltrating immune cells. Lipocalin 2 inhibits the synthesis of keratin, involucrin, and loricrin in keratinocytes, leading to epidermal parakeratosis via the Tcf7l1-lipocalin 2 signaling axis. It also recruits inflammatory cells such as T cells and neutrophils into skin lesions via the IL-23/IL17, p38-MAPK, and ERK-1/2 signaling pathways. Additionally, lipocalin 2 and other cytokines such as IL-17 have the synergetic effects on skin cells. The neutralization of lipocalin 2 or relevant cytokines can alleviate psoriasis, verifying that lipocalin 2 is an effective interfering target for psoriasis. In this review, we summarize the roles of lipocalin 2 in the processes of psoriatic inflammation and the promising therapeutic strategies based on lipocalin 2-related molecules.

Lipocalin-2: a role in hepatic gluconeogenesis via AMP-activated protein kinase (AMPK)

PURPOSE

Evidence is accumulating that lipocalin2 (LCN2) is implicated in insulin resistance and glucose homeostasis, but the underlying possible mechanisms remain unclear. This study is to investigate the possible linkage between LCN2 and AMP-activated protein kinase (AMPK) or forkhead transcription factor O1 (FoxO1), which influences insulin sensitivity and gluconeogenesis in liver.

METHODS

LCN2 knockout (LCN2KO) mice and wild-type littermates were used to evaluate the effect of LCN2 on insulin sensitivity and hepatic gluconeogenesis through pyruvate tolerance test (PTT), glucose tolerance test (ipGTT), insulin tolerance test (ITT), and hyperinsulinemic-euglycemic clamps, respectively. LCN2KO mice and WT mice in vivo, and in vitro HepG2 cells were co-transfected with adenoviral FoxO1-siRNA (Ad-FoxO1-siRNA) or adenovirus expressing constitutively active form of AMPK (Ad-CA-AMPK), or dominant negative adenovirus AMPK (Ad-DN-AMPK), the relative mRNA and protein levels of two key gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6P) were measured.

RESULTS

Improved insulin sensitivity and inhibited gluconeogenesis in the LCN2KO mice were confirmed by pyruvate tolerance tests and hyperinsulinemic-euglycemic clamps. Nuclear FoxO1 and its downstream genes PEECK and G6P were decreased in the livers of the LCN2KO mice, and AMPK activity was stimulated and directly phosphorylated FoxO1. In vitro, AMPK activity was inhibited in HepG2 cells overexpressing LCN2 leading to a decrease in phosphorylated FoxO1 and an increase in nuclear FoxO1.

CONCLUSION

The present study demonstrates that LCN2 regulates insulin sensitivity and glucose metabolism through inhibiting AMPK activity, and regulating FoxO1 and its downstream genes PEPCK/G6P, which regulate hepatic gluconeogenesis.

Paradoxical role of lipocalin-2 in metabolic disorders and neurological complications

Lipocalin-2 (LCN2), also known as 24p3 and neutrophil gelatinase-associated lipocalin (NGAL), is a 25-kDa secreted protein implicated in various metabolic and inflammatory diseases. Early studies suggest the protective function of LCN2 in which it acts as a bacteriostatic agent that competes with bacteria for iron-bound siderophores. However, both detrimental and beneficial roles of LCN2 have recently been documented in metabolic and neuroinflammatory diseases. Metabolic inflammation, as observed in diabetes and obesity, has been closely associated with the upregulation of LCN2 in blood plasma and several tissues in both humans and rodents, suggesting its pro-diabetic and pro-obesogenic role. On the contrary, other studies imply an anti-diabetic and anti-obesogenic role of LCN2 whereby a deficiency in the Lcn2 gene results in the impairment of insulin sensitivity and enhances the high-fat-diet-induced expansion of fat. A similar dual role of LCN2 has also been reported in various animal models for neurological disorders. In the midst of these mixed findings, there is no experimental evidence to explain why LCN2 shows such a contrasting role in the various studies. This debate needs to be resolved (or reconciled) and an integrated view on the topic is desirable. Herein, we attempt to address this issue by reviewing the recent findings on LCN2 in metabolic disorders and assess the potential cellular or molecular mechanisms underlying the dual role of LCN2. We further discuss the possibilities and challenges of targeting LCN2 as a potential therapeutic strategy for metabolic disorders and neurological complications.

Serum level of insulin-like growth factor-I in type 2 diabetic patients: impact of obesity

Background Insulin-like growth factor-I (IGF-I) is homologous to proinsulin and possesses glucose reducing activity. The association between the level of IGF-I and diabetes has been highlighted. However, this association is controversial due to the influence of different factors including obesity. The aim of the study was to evaluate serum level of IGF-I in type 2 diabetic patients compared to control subjects. Materials and methods A cross-sectional study involving 100 participants was conducted. Serum levels of IGF-I were measured using enzyme-linked immunosorbent assay (ELISA) and the fasting plasma glucose (FPG) levels were measured using the glucose oxidase method. Results IGF-I levels in the diabetic patients were significantly lower than in non-diabetic control subjects (105.13 ± 6.34 vs. 159.96 ± 9.62 ng/mL, p < 0.0001). Among the diabetic group, there was no significant difference in IGF-I levels between obese diabetic patients and non-obese diabetic patients, p = 0.18. Similarly, among the non-diabetic group, a non-significant difference was found in IGF-I levels between obese non-diabetic and non-obese non-diabetic subjects, p = 0.156. However, among the obese group, obese diabetic patients had significantly lower IGF-I serum levels compared to obese non-diabetic subjects (112.07 ± 7.97 vs. 147.07 ± 13.05 ng/mL, p = 0.02). Furthermore, among the non-obese group, the non-obese diabetic patients had significantly lower IGF-I serum levels compared to the non-obese non-diabetic subjects (91.66 ± 9.93 vs. 171.86 ± 13.86 ng/mL, p < 0.0001). No significant associations were observed between IGF-I level and any of the age, gender, body mass index (BMI), FPG levels, or the duration of diabetes. Conclusions Type 2 diabetes mellitus is associated with lower levels of IGF-I regardless to the presence or absence of obesity.

IGF and IGFBP as an index for discrimination between vitamin D supplementation responders and nonresponders in overweight Saudi subjects

Vitamin D deficiency is common in the Kingdom of Saudi Arabia (KSA). Therefore, it is significant to recognize which biochemical markers modulate serum 25 hydroxyvitamin D (25(OH)D) in response to vitamin D supplementation in such a population. Our aim was to study the correlation of insulin-like growth factor (IGF) and insulin growth factor binding protein (IGFBP) with serum 25(OH)D in response to vitamin D supplementation in a Saudi population. A total of 199 (89 males/110 females) vitamin D deficient subjects (25(OH)D level <50 nmol/L), aged 40.4 ± 11.4 years, were given vitamin D supplements (50,000 IU/mL every week) for the first 2 months, then twice a month for 2 months, followed by daily 1000 IU in the last 2 months. Fasting blood samples were taken at baseline and 6 months after the final dose of vitamin D. Serum 25(OH)D, IGF-1 and IGF-2, and IGFBPs 2-5 were measured. Vitamin D response was computed for all subjects as the difference in levels of serum 25(OH)D concentration at the end of 6 months compared to baseline. After intervention, serum 25(OH)D concentration significantly increased from 35.6 nmol/L (26.6-43.5) to 61.8 nmol/L (54.8-73.3) in responder subjects (P < .01) and from 35.1 nmol/L (21.2-58.2) to 38.3 nmol/L (25.5-48.3) in nonresponders (P = .13). Subjects with lower baseline serum IGF-II, IGFBP-2, and IGF-1/IGFBP-3 ratio are more sensitive to acute vitamin D status changes. IGF1 and IGF-1/IGFBP-3 ratio significantly increased in all subjects after 6 months (P = .01). Changes in 25(OH)D was significantly associated with changes in IGFBP-2 and IGF-1/IGFBP-3 ratio in responders only. This study proposes that changes in circulating IGF-I and IGFBP-3 are modulated by vitamin D supplementation and can be taken into consideration in investigations involving vitamin D correction. Moreover, increase in serum 25(OH)D and IGF-I/IGFBP-3 molar ratio are more sensitive markers for the response to vitamin D supplementation in Saudi population.

Association of lipocalin-2 level, glycemic status and obesity in type 2 diabetes mellitus

BACKGROUND

Management of type 2 diabetes mellitus aims to maintain a normal glycemic status, which if not, it may lead to acute and/or chronic diabetic complications. Earlier studies found Lipocalin-2 elevated in complications associated with type 2 diabetes mellitus such as ischemic heart disease. These lipocalin-2 changes had been linked to obesity and uncontrolled diabetes. So, it could be useful to understand the effect of glycemic control and obesity on lipocalin-2.

METHODS

This was a case control study. Fifty-seven patients with type 2 diabetes and 30 non-diabetic controls participated after getting a written consent. Weight (kg), height (m) and waist circumference (cm) were measured then the body mass index (kg/m2) was determined. Blood samples were collected after an overnight fasting. HbA1c, lipid profile and serum creatinine were measured using enzymatic methods. Lipocalin-2 was measured using sandwich ELISA.

RESULTS

Lipocalin-2 was found significantly higher in patients with type 2 diabetes (P = 0.001). However, it had no significant correlation with any of the studied variables. Females had elevated BMI compared to males in the patients group (P < 0.001). HbA1c, serum creatinine, LDL and total cholesterol were elevated in patients with diabetes (P < 0.02). HDL was lower in the patients (P = 0.002). Significant elevation in HbA1c was found in male patients (P = 0.028) compared to female patients. Patients were further classified into controlled, uncontrolled diabetics, obese and non-obese. There was a significant elevation in waist circumference in uncontrolled diabetics compared to controlled ones. Lipocalin-2 had no significant changes between controlled and uncontrolled diabetics nor non-obese and obese patients.

CONCLUSION

Patients with type 2 diabetes mellitus have elevated level of serum lipocalin-2. There was no significant association found between lipocalin-2 and glycemic control nor obesity.

Type 3c (pancreatogenic) diabetes mellitus secondary to chronic pancreatitis and pancreatic cancer

Diabetes mellitus is a group of diseases defined by persistent hyperglycaemia. Type 2 diabetes, the most prevalent form, is characterised initially by impaired insulin sensitivity and subsequently by an inadequate compensatory insulin response. Diabetes can also develop as a direct consequence of other diseases, including diseases of the exocrine pancreas. Historically, diabetes due to diseases of the exocrine pancreas was described as pancreatogenic or pancreatogenous diabetes mellitus, but recent literature refers to it as type 3c diabetes. It is important to note that type 3c diabetes is not a single entity; it occurs because of a variety of exocrine pancreatic diseases with varying mechanisms of hyperglycaemia. The most commonly identified causes of type 3c diabetes are chronic pancreatitis, pancreatic ductal adenocarcinoma, haemochromatosis, cystic fibrosis, and previous pancreatic surgery. In this Review, we discuss the epidemiology, pathogenesis, and clinical relevance of type 3c diabetes secondary to chronic pancreatitis and pancreatic ductal adenocarcinoma, and highlight several important knowledge gaps.

The influence of type 2 diabetes on serum GH and IGF-I levels in hospitalized Japanese patients

OBJECTIVE

Although serum insulin like growth factor type 1 (IGF-I) levels are negatively correlated with hemoglobin A1c (HbA1c) in patients with type 1 diabetes, this correlation is controversial in patients with type 2 diabetes mellitus (T2DM) because of the influence of multiple factors including insulin secretion and obesity. The aim of this study was to evaluate the influence of T2DM on serum growth hormone (GH) and IGF-I levels in Japanese patients, who exhibited relatively low BMI compared with white patients in the previous studies.

DESIGN

We retrospectively analysed 315 consecutive Japanese hospitalized patients with T2DM. We analysed factors correlated with changes in serum IGF-I levels and those related to diabetes.

RESULTS

The median HbA1c was 8.7% (7.4-10.2) and the median body mass index (BMI) was 26.2kg/m(2) (23.1-29.7), which was relatively low compared with the previous studies. Overall, no correlations was found between serum GH or IGF-I levels and fasting plasma glucose (FPG) or HbA1c; however, when stratified by FPG and HbA1c levels, serum IGF-I levels were significantly lower in patients with FPG≥200mg/dL than in those with FPG<200mg/dL (p=0.039). In addition, serum IGF-I levels were significantly lower in patients with HbA1c≥12% than in those with HbA1c<12% (p=0.046). Multiple linear regression analysis revealed a positive correlation between fasting C-peptide levels and serum IGF-I levels (p=0.040), whereas no correlations was found for BMI, duration of T2DM, FPG levels, or HbA1c. Moreover, patients with improved HbA1c levels during the follow up period showed a significant increase in serum IGF-I levels.

CONCLUSIONS

Serum IGF-I levels were significantly decreased in Japanese patients with uncontrolled T2DM, and impaired insulin secretion may be a mechanism underlying this effect. When diagnosing acromegaly in patients with uncontrolled diabetes, these factors should be taken into account.

Lipocalin-2 inhibits autophagy and induces insulin resistance in H9c2 cells

Lipocalin-2 (Lcn2; also known as neutrophil gelatinase associated lipocalin, NGAL) levels are increased in obesity and diabetes and associate with insulin resistance. Correlations exist between Lcn2 levels and various forms or stages of heart failure. Insulin resistance and autophagy both play well-established roles in cardiomyopathy. However, little is known about the impact of Lcn2 on insulin signaling in cardiomyocytes. In this study, we treated H9c2 cells with recombinant Lcn2 for 1 h followed by dose- and time-dependent insulin treatment and found that Lcn2 attenuated insulin signaling assessed via phosphorylation of Akt and p70S6K. We used multiple assays to demonstrate that Lcn2 reduced autophagic flux. First, Lcn2 reduced pULK1 S555, increased pULK1 S757 and reduced LC3-II levels determined by Western blotting. We validated the use of DQ-BSA to assess autolysosomal protein degradation and this together with MagicRed cathepsin B assay indicated that Lcn2 reduced lysosomal degradative activity. Furthermore, we generated H9c2 cells stably expressing tandem fluorescent RFP/GFP-LC3 and this approach verified that Lcn2 decreased autophagic flux. We also created an autophagy-deficient H9c2 cell model by overexpressing a dominant-negative Atg5 mutant and found that reduced autophagy levels also induced insulin resistance. Adding rapamycin after Lcn2 could stimulate autophagy and recover insulin sensitivity. In conclusion, our study indicated that acute Lcn2 treatment caused insulin resistance and use of gain and loss of function approaches elucidated a causative link between autophagy inhibition and regulation of insulin sensitivity by Lcn2.

Insulin-like growth factor I, growth hormone, and insulin sensitivity: the effects of a one-year cholecalciferol supplementation in middle-aged overweight and obese subjects

Both altered GH-IGF-I axis and low serum levels of 25-hydroxyvitamin D (25(OH)D) are linked to measures of metabolic syndrome. Our hypothesis was that there is a relation between GH, IGF-I, and 25(OH)D; and that vitamin D supplementation may have an effect on the levels of GH, IGF-I, and IGF-I/IGFBP-3 ratio. 318 overweight and obese subjects completed a one-year randomized intervention with either 40,000 or 20,000 IU cholecalciferol per week or placebo. GH, IGF-I, IGFBP-3 and measures of insulin resistance were evaluated at baseline and at the end of study. There was a significant relation between entities of GH-IGF-I axis and insulin resistance. Subjects with severe obesity had significantly lower serum 25(OH)D and had a significant linear decline in IGF-I/IGFBP-3 ratio with increasing serum 25(OH)D quartiles. Vitamin D status was an independent predictor of GH-IGF-I axis and supplementation with vitamin D decreased IGF-I/IGFBP-3 ratio in subjects without severe obesity. No corresponding effect of vitamin D supplementation on BMI or insulin resistance was observed. Adverse effects of GH-IGF-I axis on glucose metabolism and the development of metabolic syndrome may be in part associated with the changes in vitamin D status.

Pathophysiology and treatment of diabetic retinopathy

In the past years, the management of diabetic retinopathy (DR) relied primarily on a good systemic control of diabetes mellitus, and as soon as the severity of the vascular lesions required further treatment, laser photocoagulation or vitreoretinal surgery was done to the patient. Currently, even if the intensive metabolic control is still mandatory, a variety of different clinical strategies could be offered to the patient. The recent advances in understanding the complex pathophysiology of DR allowed the physician to identify many cell types involved in the pathogenesis of DR and thus to develop new treatment approaches. Vasoactive and proinflammatory molecules, such as vascular endothelial growth factor (VEGF), play a key role in this multifactorial disease. Current properly designed trials, evaluating agents targeting VEGF or other mediators, showed benefits in the management of DR, especially when metabolic control is lacking. Other agents, directing to the processes of vasopermeability and angiogenesis, are under investigations, giving more hope in the future management of this still sight-threatening disease.

Circulating levels of lipocalin-2 and retinol-binding protein-4 are increased in psoriatic patients and correlated with baseline PASI

Psoriasis has been related to metabolic syndrome (MS). Adipocytokines produced by white adipose tissue may be involved in the pathogenesis of psoriasis and its association with MS. Our objectives were to characterize the profile of a number of different inflammatory and atherogenic markers, vitamins, adipokines and cytokines and their potential involvement in MS in patients with moderate-to-severe psoriasis without joint involvement compared to anthropometrically matched controls, and to evaluate correlation with severity of the skin disease and changes after narrow-band UVB (NB-UVB) phototherapy. We designed a prospective cross-sectional study. Baseline waist circumference, body fat composition, lipid, carbohydrate and calcium metabolism profile, inflammation markers, homocysteine and vitamins D, B6, B12 and folic acid, leptin, resistin, omentin, lipocalin-2, adipocyte fatty acid-binding protein, retinol-binding protein-4 (RBP-4), interleukin-6, soluble tumour necrosis factor receptor 1 (sTNFR1) and interleukin-17 of 50 psoriasis patients and 50 gender, age and body mass index-matched controls were recorded, then evaluated after NB-UVB in the patients. The patients had higher baseline serum concentrations of leptin, RBP-4, lipocalin-2 and sTNFR1. Baseline psoriasis area and severity index correlated with serum concentrations of RBP-4 and lipocalin-2 only. Principal components analysis disclosed a component including vitamins B12, B6, folic acid, calcidiol and HDL-cholesterol that was only present in healthy controls and opposed to a cluster of variables which promote MS. This component was absent in the patients. Our results point to lipocalin-2 and RBP-4 as relevant mediators of the trend towards MS in psoriatic patients.