Frequency-hopping along with resolution-turning for fast and enhanced reconstruction in ultrasound tomography.

The distorted Born iterative (DBI) method is considered to obtain images with high-contrast and resolution. Besides satisfying the Born approximation condition, the frequency-hopping (FH) technique is necessary to gradually update the sound contrast from the first iteration and progress to the actual sound contrast of the imaged object in subsequent iterations. Inspired by the fact that the higher the frequency, the higher the resolution. Because low-frequency allows for low-resolution object imaging, hence for high-resolution imaging requirements, using low-frequency to possess a high-resolution image from the first iteration will be less efficient. For an effective reconstruction, the object's resolution at low frequencies should be small. And similarly, with high frequencies, the object resolution should be larger. Therefore, in this paper, the FH, and the resolution-turning (RT) technique are proposed to obtain object images with high-contrast and -resolution. The convergence speed in the initial iterations is rapidly achieved by utilizing low frequency in the frequency-turning technique and low image resolution in the resolution-turning technique. It is crucial to ensure accurate object reconstruction for subsequent iterations. The desired spatial resolution is attained by employing high frequency and large image resolution. The resolution-turning distorted Born iterative (RT-DBI) and frequency-hopping distorted Born iterative (FH-DBI) solutions are thoroughly investigated to exploit their best performance. This makes sense because if it is not good to choose the number of iterations for the frequency f1 in FH-DBI and for the resolution of N1 × N1 in RT-DBI, then these solutions give even worse quality than traditional DBI. After that, the RT-FH-DBI integration was investigated in two sub-solutions. We found that the lower frequency f1 used both before and after the RT would get the best performance. Consequently, compared to the traditional DBI approaches, the normalized error and total runtime for the reconstruction process were dramatically decreased, at 83.6% and 18.6%, respectively. Besides fast and quality imaging, the proposed solution RT-FH-DBI is promised to produce high-contrast and high-resolution object images, aiming at object reconstruction at the biological tissue. The development of 3D imaging and experimental verification will be studied further.

Angiopoietin-2 blockade suppresses growth of liver metastases from pancreatic neuroendocrine tumors by promoting T cell recruitment.

Improving the management of metastasis in pancreatic neuroendocrine tumors (PanNETs) is critical, as nearly half of patients with PanNETs present with liver metastases, and this accounts for the majority of patient mortality. We identified angiopoietin-2 (ANGPT2) as one of the most upregulated angiogenic factors in RNA-Seq data from human PanNET liver metastases and found that higher ANGPT2 expression correlated with poor survival rates. Immunohistochemical staining revealed that ANGPT2 was localized to the endothelial cells of blood vessels in PanNET liver metastases. We observed an association between the upregulation of endothelial ANGPT2 and liver metastatic progression in both patients and transgenic mouse models of PanNETs. In human and mouse PanNET liver metastases, ANGPT2 upregulation coincided with poor T cell infiltration, indicative of an immunosuppressive tumor microenvironment. Notably, both pharmacologic inhibition and genetic deletion of ANGPT2 in PanNET mouse models slowed the growth of PanNET liver metastases. Furthermore, pharmacologic inhibition of ANGPT2 promoted T cell infiltration and activation in liver metastases, improving the survival of mice with metastatic PanNETs. These changes were accompanied by reduced plasma leakage and improved vascular integrity in metastases. Together, these findings suggest that ANGPT2 blockade may be an effective strategy for promoting T cell infiltration and immunostimulatory reprogramming to reduce the growth of liver metastases in PanNETs.

Hybrid Multi-Label Classification Model for Medical Applications Based on Adaptive Synthetic Data and Ensemble Learning.

In recent years, both machine learning and computer vision have seen growth in the use of multi-label categorization. SMOTE is now being utilized in existing research for data balance, and SMOTE does not consider that nearby examples may be from different classes when producing synthetic samples. As a result, there can be more class overlap and more noise. To avoid this problem, this work presented an innovative technique called Adaptive Synthetic Data-Based Multi-label Classification (ASDMLC). Adaptive Synthetic (ADASYN) sampling is a sampling strategy for learning from unbalanced data sets. ADASYN weights minority class instances by learning difficulty. For hard-to-learn minority class cases, synthetic data are created. Their numerical variables are normalized with the help of the Min-Max technique to standardize the magnitude of each variable's impact on the outcomes. The values of the attribute in this work are changed to a new range, from 0 to 1, using the normalization approach. To raise the accuracy of multi-label classification, Velocity-Equalized Particle Swarm Optimization (VPSO) is utilized for feature selection. In the proposed approach, to overcome the premature convergence problem, standard PSO has been improved by equalizing the velocity with each dimension of the problem. To expose the inherent label dependencies, the multi-label classification ensemble of Adaptive Neuro-Fuzzy Inference System (ANFIS), Probabilistic Neural Network (PNN), and Clustering-Based Decision tree methods will be processed based on an averaging method. The following criteria, including precision, recall, accuracy, and error rate, are used to assess performance. The suggested model's multi-label classification accuracy is 90.88%, better than previous techniques, which is PCT, HOMER, and ML-Forest is 65.57%, 70.66%, and 82.29%, respectively.

Innovative production of value-added products using agro-industrial wastes via solid-state fermentation.

The prevalence of organic solid waste worldwide has turned into a problem that requires comprehensive treatment on all fronts. The amount of agricultural waste generated by agro-based industries has more than triplet. It not only pollutes the environment but also wastes a lot of beneficial biomass resources. These wastes may be utilized as a different option/source for the manufacturing of many goods, including biogas, biofertilizers, biofuel, mushrooms and tempeh as the primary ingredients in numerous industries. Utilizing agro-industrial wastes as good raw materials may provide cost reduction and lower environmental pollution levels. Agro-industrial wastes are converted into biofuels, enzymes, vitamin supplements, antioxidants, livestock feed, antibiotics, biofertilizers and other compounds via solid-state fermentation (SSF). By definition, SSF is a method used when there is little to no free water available. As a result, it permits the use of solid materials as biotransformation substrates. Through SSF methods, a variety of microorganisms are employed to produce these worthwhile things. SSFs are therefore reviewed and discussed along with their impact on the production of value-added items. This review will provide thorough essential details information on recycling and the use of agricultural waste.

Angiopoietin-2-Dependent Spatial Vascular Destabilization Promotes T-cell Exclusion and Limits Immunotherapy in Melanoma.

T-cell position in the tumor microenvironment determines the probability of target encounter and tumor killing. CD8+ T-cell exclusion from the tumor parenchyma is associated with poor response to immunotherapy, and yet the biology that underpins this distinct pattern remains unclear. Here we show that the vascular destabilizing factor angiopoietin-2 (ANGPT2) causes compromised vascular integrity in the tumor periphery, leading to impaired T-cell infiltration to the tumor core. The spatial regulation of ANGPT2 in whole tumor cross-sections was analyzed in conjunction with T-cell distribution, vascular integrity, and response to immunotherapy in syngeneic murine melanoma models. T-cell exclusion was associated with ANGPT2 upregulation and elevated vascular leakage at the periphery of human and murine melanomas. Both pharmacologic and genetic blockade of ANGPT2 promoted CD8+ T-cell infiltration into the tumor core, exerting antitumor effects. Importantly, the reversal of T-cell exclusion following ANGPT2 blockade not only enhanced response to anti-PD-1 immune checkpoint blockade therapy in immunogenic, therapy-responsive mouse melanomas, but it also rendered nonresponsive tumors susceptible to immunotherapy. Therapeutic response after ANGPT2 blockade, driven by improved CD8+ T-cell infiltration to the tumor core, coincided with spatial TIE2 signaling activation and increased vascular integrity at the tumor periphery where endothelial expression of adhesion molecules was reduced. These data highlight ANGPT2/TIE2 signaling as a key mediator of T-cell exclusion and a promising target to potentiate immune checkpoint blockade efficacy in melanoma. SIGNIFICANCE: ANGPT2 limits the efficacy of immunotherapy by inducing vascular destabilization at the tumor periphery to promote T-cell exclusion.

Performance analysis of biofuel-ethanol blends in diesel engine and its validation with computational fluid dynamics.

The engine tests aimed to produce comparable data for fuel consumption, exhaust emissions, and thermal efficiency. The computational fluid dynamics (CFD) program FLUENT was used to simulate the combustion parameters of a direct injection diesel engine. In-cylinder turbulence is controlled using the RNG k-model. The model's conclusions are validated when the projected p-curve is compared to the observed p-curve. The thermal efficiency of the 50E50B blend (50% ethanol, 50% biofuel) is higher than the other blends as well as diesel. Diesel has lower brake thermal efficiency among the other fuel blends used. The 10E90B mix (10% ethanol, 90% biofuel) has a lower brake-specific fuel consumption (BSFC) than other blends but is slightly higher than diesel. The temperature of the exhaust gas rises for all mixtures as the brake power is increased. CO emissions from 50E50B are lower than diesel at low loads but slightly greater at heavy loads. According to the emission graphs, the 50E50B blend produces less HC than diesel. NOx emission rises with increasing load in the exhaust parameter for all mixes. A 50E50B biofuel-ethanol combination achieves the highest brake thermal efficiency, 33.59%. The BSFC for diesel is 0.254 kg/kW-hr at maximum load, while the BSFC for the 10E90B mix is 0.269 kg/kW-hr, higher than diesel. In comparison to diesel, BSFC has increased by 5.90%.

Composition of Hybrid Deep Learning Model and Feature Optimization for Intrusion Detection System.

Recently, with the massive growth of IoT devices, the attack surfaces have also intensified. Thus, cybersecurity has become a critical component to protect organizational boundaries. In networks, Intrusion Detection Systems (IDSs) are employed to raise critical flags during network management. One aspect is malicious traffic identification, where zero-day attack detection is a critical problem of study. Current approaches are aligned towards deep learning (DL) methods for IDSs, but the success of the DL mechanism depends on the feature learning process, which is an open challenge. Thus, in this paper, the authors propose a technique which combines both CNN, and GRU, where different CNN-GRU combination sequences are presented to optimize the network parameters. In the simulation, the authors used the CICIDS-2017 benchmark dataset and used metrics such as precision, recall, False Positive Rate (FPR), True Positive Rate (TRP), and other aligned metrics. The results suggest a significant improvement, where many network attacks are detected with an accuracy of 98.73%, and an FPR rate of 0.075. We also performed a comparative analysis with other existing techniques, and the obtained results indicate the efficacy of the proposed IDS scheme in real cybersecurity setups.

Best Fit DNA-Based Cryptographic Keys: The Genetic Algorithm Approach.

DNA (Deoxyribonucleic Acid) Cryptography has revolutionized information security by combining rigorous biological and mathematical concepts to encode original information in terms of a DNA sequence. Such schemes are crucially dependent on corresponding DNA-based cryptographic keys. However, owing to the redundancy or observable patterns, some of the keys are rendered weak as they are prone to intrusions. This paper proposes a Genetic Algorithm inspired method to strengthen weak keys obtained from Random DNA-based Key Generators instead of completely discarding them. Fitness functions and the application of genetic operators have been chosen and modified to suit DNA cryptography fundamentals in contrast to fitness functions for traditional cryptographic schemes. The crossover and mutation rates are reducing with each new population as more keys are passing fitness tests and need not be strengthened. Moreover, with the increasing size of the initial key population, the key space is getting highly exhaustive and less prone to Brute Force attacks. The paper demonstrates that out of an initial 25 × 25 population of DNA Keys, 14 keys are rendered weak. Complete results and calculations of how each weak key can be strengthened by generating 4 new populations are illustrated. The analysis of the proposed scheme for different initial populations shows that a maximum of 8 new populations has to be generated to strengthen all 500 weak keys of a 500 × 500 initial population.

IoT-Based Smart Mask Protection against the Waves of COVID-19.

In the year 2020, the word "pandemic" has become quite popular. A pandemic is a disease that spreads over a wide geographical region. The massive outbreak of coronavirus popularly known as COVID-19 has halted normal life worldwide. On 11th March 2020, the World Health Organization (WHO) quoted the COVID-19 outbreak as a "Pandemic". The outbreak pattern differs widely across the globe based on the findings discovered so far; however, fever is a common and easily detectable symptom of COVID-19 and the new COVID strain. After the virus outbreak, thermal scanning is done using infrared thermometers in most public places to detect infected persons. It is time-consuming to track the body temperature of each person. Besides, close contact with infected persons can spread the virus from the infected persons to the individual performing the screening or vice-versa. In this research, we propose a device architecture capable of automatically detecting the coronavirus or new COVID strain from thermal images; the proposed architecture comprises a smart mask equipped with a thermal imaging system, which reduces human interactions. The thermal camera technology is integrated with the smart mask powered by the Internet of Things (IoT) to proactively monitor the screening procedure and obtain data based on real-time findings. Besides, the proposed system is fitted with facial recognition technology; therefore, it can also display personal information. It will automatically measure the temperature of each person who came into close contact with the infected humans or humans in public spaces, such as markets or offices. The new design is very useful in healthcare and could offer a solution to preventing the growth of the coronavirus. The presented work hasa key focus on the integration of advanced algorithms for the predictive analytics of parameters required for in-depth evaluations. The proposed work and the results are pretty effectual and performance cognizant for predictive analytics. The manuscript and associated research work integrate the IoT and Internet of Everything (IoE) based analytics with sensor technologies with real-time data so that the overall predictions will be more accurate and integrated with the health sector. Supplementary Information: The online version contains supplementary material available at 10.1007/s12652-022-04395-7.

Appraisals of the Bangladeshi Medicinal Plant Calotropis gigantea Used by Folk Medicine Practitioners in the Management of COVID-19: A Biochemical and Computational Approach.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first recognized in Wuhan in late 2019 and, since then, had spread globally, eventually culminating in the ongoing pandemic. As there is a lack of targeted therapeutics, there is certain opportunity for the scientific community to develop new drugs or vaccines against COVID-19 and so many synthetic bioactive compounds are undergoing clinical trials. In most of the countries, due to the broad therapeutic spectrum and minimal side effects, medicinal plants have been used widely throughout history as traditional healing remedy. Because of the unavailability of synthetic bioactive antiviral drugs, hence all possible efforts have been focused on the search for new drugs and alternative medicines from different herbal formulations. In recent times, it has been assured that the Mpro, also called 3CLpro, is the SARS-CoV-2 main protease enzyme responsible for viral reproduction and thereby impeding the host's immune response. As such, Mpro represents a highly specified target for drugs capable of inhibitory action against coronavirus disease 2019 (COVID-19). As there continue to be no clear options for the treatment of COVID-19, the identification of potential candidates has become a necessity. The present investigation focuses on the in silico pharmacological activity of Calotropis gigantea, a large shrub, as a potential option for COVID-19 Mpro inhibition and includes an ADME/T profile analysis of that ligand. For this study, with the help of gas chromatography-mass spectrometry analysis of C. gigantea methanolic leaf extract, a total of 30 bioactive compounds were selected. Our analyses unveiled the top four options that might turn out to be prospective anti-SARS-CoV-2 lead molecules; these warrant further exploration as well as possible application in processes of drug development to combat COVID-19.

Muscle-derived interleukin 6 increases exercise capacity by signaling in osteoblasts.

Given the numerous health benefits of exercise, understanding how exercise capacity is regulated is a question of paramount importance. Circulating interleukin 6 (IL-6) levels surge during exercise and IL-6 favors exercise capacity. However, neither the cellular origin of circulating IL-6 during exercise nor the means by which this cytokine enhances exercise capacity has been formally established yet. Here we show through genetic means that the majority of circulating IL-6 detectable during exercise originates from muscle and that to increase exercise capacity, IL-6 must signal in osteoblasts to favor osteoclast differentiation and the release of bioactive osteocalcin in the general circulation. This explains why mice lacking the IL-6 receptor only in osteoblasts exhibit a deficit in exercise capacity of similar severity to the one seen in mice lacking muscle-derived IL-6 (mIL-6), and why this deficit is correctable by osteocalcin but not by IL-6. Furthermore, in agreement with the notion that IL-6 acts through osteocalcin, we demonstrate that mIL-6 promotes nutrient uptake and catabolism into myofibers during exercise in an osteocalcin-dependent manner. Finally, we show that the crosstalk between osteocalcin and IL-6 is conserved between rodents and humans. This study provides evidence that a muscle-bone-muscle endocrine axis is necessary to increase muscle function during exercise in rodents and humans.

The intake of an extract from seeds of Tamarindus indica L. modulates the endocrine function of adult male mice under a high fat diet.

TBP is a natural product from Tamarindus indica L. seeds used as a natural remedy in India. This product is an antioxidant and may have beneficial effects on endocrine and metabolic functions. However, the regulatory mechanisms involved remain to be elucidated. In males, testosterone is synthesized by Leydig cells from the testis. With aging and obesity, testis function declines, leading to decreased testosterone synthesis. The aim of the current research is to determine how TBP improves testosterone production in male mice under a high fat diet leading to hypoandrogenic condition. Using C2C12 myoblast cells, we have found that TBP increased mitochondrial mass and oxygen respiration, as well as the production of the IGF-1 hormone. In addition, treatment of TM3 Leydig cells with TBP resulted in increased testosterone production. In mice under a high fat diet, TBP lowered blood glucose level and corticosterone production and improved total testosterone production after five weeks of treatment. In addition, testicular expressions of genes encoding the mitochondrial transporter of cholesterol (Star) and steroidogenic enzymes (Cyp11a1, Hsd3b1, Cyp17a1 and Hsd17b3) were increased by TBP. Hence, TBP may prevent the detrimental effects of long-term consumption of a high fat diet and may have health benefits on the endocrine function.

Mediation of the Acute Stress Response by the Skeleton.

We hypothesized that bone evolved, in part, to enhance the ability of bony vertebrates to escape danger in the wild. In support of this notion, we show here that a bone-derived signal is necessary to develop an acute stress response (ASR). Indeed, exposure to various types of stressors in mice, rats (rodents), and humans leads to a rapid and selective surge of circulating bioactive osteocalcin because stressors favor the uptake by osteoblasts of glutamate, which prevents inactivation of osteocalcin prior to its secretion. Osteocalcin permits manifestations of the ASR to unfold by signaling in post-synaptic parasympathetic neurons to inhibit their activity, thereby leaving the sympathetic tone unopposed. Like wild-type animals, adrenalectomized rodents and adrenal-insufficient patients can develop an ASR, and genetic studies suggest that this is due to their high circulating osteocalcin levels. We propose that osteocalcin defines a bony-vertebrate-specific endocrine mediation of the ASR.

Role of CCN5 (WNT1 inducible signaling pathway protein 2) in pancreatic islets.

In search of direct targets of insulin-like growth factor (IGF)-1 action, we discovered CCN5 (WNT1 inducible signaling pathway protein 2 [WISP2]) as a novel protein expressed in pancreatic ß-cells. As a member of the "CCN" ( C ysteine-rich angiogenic inducer 61 [Cyr61], C onnective tissue growth factor [CTGF in humans], and N ephroblastoma overexpressed [Nov; in chickens]) family, the expression of CCN5/WISP2 is stimulated by IGF-1 together with Wnt signaling. When overexpressed in insulinoma cells, CCN5 promotes cell proliferation and cell survival against streptozotocin-induced cell death. The cell proliferation effect seems to be caused by AKT phosphorylation and increased cyclin D1 levels. These properties resemble those of CCN2/CTGF, another isoform of the CCN family, although CCN5 is the only one within the family of six proteins that lacks the C-terminal repeat. Treatment of primary mouse islets with recombinant CCN5 protein produced similar effects to those of gene transfection, indicating that either as a matricellular protein or a secreted growth factor, CCN5 stimulates ß-cell proliferation and regeneration in a paracrine fashion. This review also discusses the regulation of CCN5/WISP2 by estrogen and its involvement in angiogenesis and tumorigenesis.

Programmed death-ligand 1 overexpression is a prognostic marker for aggressive papillary thyroid cancer and its variants.

Programmed death-ligand 1(PD-L1) expression on tumor cells is emerging as a potential predictive biomarker in anti-PD-L1 directed cancer immunotherapy. We analyzed PD-L1 expression in papillary thyroid carcinoma (PTC) and its variants and determined its prognostic potential to predict clinical outcome in these patients. This study was conducted at an academic oncology hospital which is a prime referral centre for thyroid diseases. Immunohistochemical subcellular localization (IHC) analyses of PD-L1 protein was retrospectively performed on 251 archived formalin fixed and paraffin embedded (FFPE) surgical tissues (66 benign thyroid nodules and 185 PTCs) using a rabbit monoclonal anti-PD-L1 antibody (E1L3N, Cell Signaling Technology) and detected using VECTASTAIN rapid protocol with diaminobenzidine (DAB) as the chromogen. The clinical-pathological factors and disease outcome over 190 months were assessed; immunohistochemical subcellular localization of PD-L1 was correlated with disease free survival (DFS) using Kaplan Meier survival and Cox multivariate regression analysis. Increased PD-L1 immunostaining was predominantly localized in cytoplasm and occasionally in plasma membrane of tumor cells. Among all combined stages of PTC, patients with increased PD-L1 membrane or cytoplasmic positivity had significantly shorter median DFS (36 months and 49 months respectively) as compared to those with PD-L1 negative tumors (DFS, both 186 months with p < 0.001 and p < 0.01 respectively). Comparison of PD-L1+ and PD-L1- patients with matched staging showed increased cytoplasmic positivity in all four stages of PTC that correlated with a greater risk of recurrence and a poor prognosis, but increased membrane positivity significantly correlated with a greater risk of metastasis or death only in Stage IV patients. In conclusion, PD-L1 positive expression in PTC correlates with a greater risk of recurrence and shortened disease free survival supporting its potential application as a prognostic marker for PTC.

Decreased 11ß-Hydroxysteroid Dehydrogenase 1 Level and Activity in Murine Pancreatic Islets Caused by Insulin-Like Growth Factor I Overexpression.

We have reported a high expression of IGF-I in pancreatic islet ß-cells of transgenic mice under the metallothionein promoter. cDNA microarray analysis of the islets revealed that the expression of 82 genes was significantly altered compared to wild-type mice. Of these, 11ß-hydroxysteroid dehydrogenase 1 (11ß-HSD1), which is responsible for the conversion of inert cortisone (11-dehydrocorticosterone, DHC in rodents) to active cortisol (corticosterone) in the liver and adipose tissues, has not been identified previously as an IGF-I target in pancreatic islets. We characterized the changes in its protein level, enzyme activity and glucose-stimulated insulin secretion. In freshly isolated islets, the level of 11ß-HSD1 protein was significantly lower in MT-IGF mice. Using dual-labeled immunofluorescence, 11ß-HSD1 was observed exclusively in glucagon-producing, islet α-cells but at a lower level in transgenic vs. wild-type animals. MT-IGF islets also exhibited reduced enzymatic activities. Dexamethasone (DEX) and DHC inhibited glucose-stimulated insulin secretion from freshly isolated islets of wild-type mice. In the islets of MT-IGF mice, 48-h pre-incubation of DEX caused a significant decrease in insulin release, while the effect of DHC was largely blunted consistent with diminished 11ß-HSD1 activity. In order to establish the function of intracrine glucocorticoids, we overexpressed 11ß-HSD1 cDNA in MIN6 insulinoma cells, which together with DHC caused apoptosis and a significant decrease in proliferation. Both effects were abolished with the treatment of an 11ß-HSD1 inhibitor. Our results demonstrate an inhibitory effect of IGF-I on 11ß-HSD1 expression and activity within the pancreatic islets, which may mediate part of the IGF-I effects on cell proliferation, survival and insulin secretion.

mReg2 inhibits nuclear entry of apoptosis-inducing factor in mouse insulinoma cells.

We have reported earlier that murine-regenerating gene mReg2 protects MIN6 mouse insulinoma cells from ER stress and caspase-mediated apoptosis. In apoptotic cells, DNA damage is induced by the nuclear translocation of mitochondrial apoptosis-inducing factor (AIF). Here we tested the hypothesis that mReg2 may regulate Scythe and/or hsp70 which influence the nuclear import of AIF. Treatment with thapsigargin (Tg) or doxorubicin induced an increase in nuclear AIF in MIN6 cells carrying the empty transfection vector (MIN6-VC) but not in cells overexpressing mReg2 (MIN6-mReg2). On one hand, nuclear Scythe was higher in the nucleus of MIN6-mReg2 compared with that in MIN6-VC cells. mReg2 did not alter the expression of AIF or Scythe. On the other hand, mReg2 induced the expression of hsp70 which is known to promote cytosolic retention of AIF. We conclude that mReg2 inhibits AIF-mediated apoptosis by promoting the nuclear presence of Scythe and inducing hsp70.

Attenuation of unfolded protein response and apoptosis by mReg2 induced GRP78 in mouse insulinoma cells.

Murine regenerating (mReg) genes have been implicated in preserving islet cell biology. Expanding on our previous work showing that overexpression of mReg2 protects MIN6 insulinoma cells against streptozotocin-induced apoptosis, we now demonstrate that mReg2 induces glucose-regulated peptide 78 (GRP78) expression via the Akt-mTORC1 axis and protects MIN6 cells against ER stress induced by thapsigargin and glucolipotoxicity. Activation of mTORC1 activity results from both mReg2-induced increased mTOR phosphorylation as well as increased expression of Raptor and GßL. Inhibition of Akt and mTORC1 blunted the ability of mReg2 to induce GRP78 and attenuate unfolded protein response (UPR). Knockdown of GRP78 sensitized the cells overexpressing mReg2 to UPR without affecting its ability to activate Akt-mTORC1 signaling. Induced expression of mReg2 may protect insulin producing cells from ER stress in diabetes.

IGF-I stimulates CCN5/WISP2 gene expression in pancreatic ß-cells, which promotes cell proliferation and survival against streptozotocin.

IGF-I is normally produced from hepatocytes and other sources, stimulates protein synthesis, cell survival, and proliferation through receptor-mediated activation of phosphatidylinositol 3-kinase and MAPK, and targets specific molecules within the pancreatic islet cells. The current study was designed to identify novel targets that may mediate its pro-islet actions. Whole-genome cDNA microarray analysis in IGF-I-overexpressing islets identified 82 genes specifically up- or down-regulated. Prominent among them was CCN5/WISP2 whose expression was increased 3- and 2-fold at the mRNA and protein levels. Dual-labeled immunofluorescence revealed that CCN5 expression was low in the ß-cells of wild-type islets but was significantly induced in response to IGF-I overexpression. In vitro treatment of mouse islets with IGF-I increased both CCN5 mRNA and protein levels significantly. To define the role of CCN5 in islet cell biology, we stably overexpressed its cDNA in insulinoma MIN6 cells and detected a 2-fold increase in the proliferation of MIN6-CCN5 compared with that in control cells, which correlated with significant elevations in the levels of cyclin D1 and the phosphorylation of Akt and Erk2. Moreover, MIN6-CCN5 cells were found to be resistant to streptozotocin-induced cell death. Using confocal microscopy and subcellular fractionation, we found that overexpressed CCN5 exhibited cytoplasmic accumulation upon stimulation by high glucose. Our results indicate that CCN5, which is minimally expressed in islet ß-cells, is strongly and directly induced by IGF-I. CCN5 overexpression stimulates the proliferation of insulinoma cells, activates Akt kinase, and inhibits streptozotocin-induced apoptosis, suggesting that increased CCN5 expression contributes to IGF-I-stimulated islet cell growth and/or survival.

Parp1 deficient mice are protected from streptozotocin-induced diabetes but not caerulein-induced pancreatitis, independent of the induction of Reg family genes.

Poly(ADP-ribose) polymerase (Parp) 1 is a key regulator of cell death, its inhibition prevented streptozotocin-induced diabetes and attenuated caerulein-induced acute pancreatitis. Reg family proteins are significantly induced by Parp1 inhibitor, experimental diabetes and/or acute pancreatitis. We propose that Reg proteins are involved in the protection of pancreatic cells by Parp1 inhibition. To test this possibility, Parp1-/- and wild-type mice were injected with streptozotocin to induce diabetes. Separately, acute pancreatitis was induced with repeated injections of caerulein. Upon streptozotocin administration, Parp1-/- mice displayed much decreased hyperglycemia and preserved serum insulin level. The treatment induced similar levels of Reg1, -2, -3α and -3ß genes in the pancreas of both wild-type and Parp1-/- mice, suggesting that the upregulation of Reg family genes during streptozotocin-induced diabetes was independent of Parp1 ablation. In caerulein-induced pancreatitis, unlike being reported, Parp1 knockout caused no relief on the severity of pancreatitis; the upregulation of pancreatic Reg1, -2, -3α and -3ß genes upon caerulein was unaffected by Parp1 deletion. Our results reconfirmed the protective effect of Parp1 gene deletion on islet ß-cells but questioned its effect on the acinar cells. In either case, the significant induction of Reg family genes seemed independent of Parp1-mediated cell death.