The apolipoprotein C-III (Gln38Lys) variant associated with human hypertriglyceridemia is a gain-of-function mutation.

Recent cell culture and animal studies have suggested that expression of human apo C-III in the liver has a profound impact on the triacylglycerol (TAG)-rich VLDL1 production under lipid-rich conditions. The apoC-III Gln38Lys variant was identified in subjects of Mexican origin with moderate hypertriglyceridemia. We postulated that Gln38Lys (C3QK), being a gain-of-function mutation, promotes hepatic VLDL1 assembly/secretion. To test this hypothesis, we expressed C3QK in McA-RH7777 cells and apoc3-null mice to contrast its effect with WT apoC-III (C3WT). In both model systems, C3QK expression increased the secretion of VLDL1-TAG (by 230%) under lipid-rich conditions. Metabolic labeling experiments with C3QK cells showed an increase in de novo lipogenesis (DNL). Fasting plasma concentration of TAG, cholesterol, cholesteryl ester, and FA were increased in C3QK mice as compared with C3WT mice. Liver of C3QK mice also displayed an increase in DNL and expression of lipogenic genes as compared with that in C3WT mice. These results suggest that C3QK variant is a gain-of-function mutation that can stimulate VLDL1 production, through enhanced DNL.

Microsome-associated lumenal lipid droplets in the regulation of lipoprotein secretion.

PURPOSE OF REVIEW: Liver is the major organ in mammals that possesses the capacity to release triglyceride within VLDL. VLDL assembly requires apolipoprotein (apo) B-100 with the assistance of microsomal triglyceride transfer protein (MTP), which facilitates the mobilization of triglyceride into the microsomal lumen. Recent experimental evidence has suggested that the lumenal triglyceride associated with endoplasmic reticulum (ER)/Golgi may represent an entity serving as precursors for large VLDL1. RECENT FINDINGS: Under lipid-rich conditions, discrete triglyceride-rich lipidic bodies, termed lumenal lipid droplets, are accumulated in association with ER/Golgi microsomes. Formation of the microsome-associated lumenal lipid droplets (MALD) is dependent on the activity of MTP, and the resulting apoB-free lipidic body is associated with a variety of proteins including apolipoproteins that are components of VLDL. Formation and utilization of MALD during the assembly and secretion of VLDL1 have a profound influence on hepatic cell physiology, such as ER stress responses. SUMMARY: This review summarizes current understanding of hepatic triglyceride homeostasis in general, and highlights the functional significance of triglyceride compartmentalization between cytosol and microsomes in particular. Understanding of MALD metabolism may shed new light on the prevention and treatment of liver diseases associated with abnormally elevated intracellular triglycerides.

In-Silico Aided Screening and Characterization Results in Stability Enhanced Novel Roxadustat Co-Crystal.

Roxadustat (RXD) is an approved drug substances for the treatment of renal anemia. It has poor aqueous solubility and photochemical stability. This study employs a comprehensive approach to enhance the stability and physicochemical properties RXD through coformer selection and characterization. The investigation integrates delta pKa analysis, molecular complementary assessment, molecular electrostatic potential surface analysis, and machine learning techniques to predict potential co-crystal formation and binding interactions between drug molecules and coformers. The co-crystal screening which lead to in a novel RXD-nicotinamide co-crystal (RXD-NA). Experimental characterization underscores the physical and chemical stability of the co-crystals. To elucidate the supramolecular synthons and understand the intermolecular interactions in the RXD-NA co-crystal, Hirshfeld surfaces analysis, quantum theory of atoms in molecules (QTAIM) analysis and non-covalent interaction (NCI) analysis were performed. Computational analysis of photo-isomer formation aligns with experimental observations, further enhancing our understanding of RXD-coformer interactions. RXD-NA co-crystal was found photo-chemically stable as compared to free base API drug substance. This integrated methodology provides a systematic framework for informed co-crystal design, holding promise for optimizing RXD formulations based on molecular interactions and stability considerations. Consequently, this study contributes valuable insights to the field of rational drug design and formulation optimization.

Intrahepatic role of exchangeable apolipoproteins in lipoprotein assembly and secretion.

Exchangeable apolipoproteins, composed mainly of amphipathic α-helices, are associated with various plasma lipoproteins and play an important role in the metabolism of those lipoproteins to which they bind. Accumulating experimental evidence suggests that exchangeable apolipoproteins, such as apoE, apoA-IV, and apoC-III, also play a role intracellularly in facilitating lipid recruitment at different stages of very low-density lipoprotein assembly and trafficking through the endoplasmic reticulum-Golgi secretory compartments. Experimental evidence also suggests that apoA-I may become lipidated intracellularly through mechanisms dependent on or independent of ATP-binding cassette transporter A1. Thus, expression of these secretory proteins may exert an impact on hepatic triglyceride and cholesterol homeostasis during their transit from the endoplasmic reticulum through the Golgi apparatus. This review summarizes findings related to the modulation of intracellular assembly of very low-density lipoprotein and high-density lipoprotein by exchangeable apolipoproteins.

Improved recovery and identification of membrane proteins from rat hepatic cells using a centrifugal proteomic reactor.

Despite their importance in many biological processes, membrane proteins are underrepresented in proteomic analysis because of their poor solubility (hydrophobicity) and often low abundance. We describe a novel approach for the identification of plasma membrane proteins and intracellular microsomal proteins that combines membrane fractionation, a centrifugal proteomic reactor for streamlined protein extraction, protein digestion and fractionation by centrifugation, and high performance liquid chromatography-electrospray ionization-tandem MS. The performance of this approach was illustrated for the study of the proteome of ER and Golgi microsomal membranes in rat hepatic cells. The centrifugal proteomic reactor identified 945 plasma membrane proteins and 955 microsomal membrane proteins, of which 63 and 47% were predicted as bona fide membrane proteins, respectively. Among these proteins, >800 proteins were undetectable by the conventional in-gel digestion approach. The majority of the membrane proteins only identified by the centrifugal proteomic reactor were proteins with ≥ 2 transmembrane segments or proteins with high molecular mass (e.g. >150 kDa) and hydrophobicity. The improved proteomic reactor allowed the detection of a group of endocytic and/or signaling receptor proteins on the plasma membrane, as well as apolipoproteins and glycerolipid synthesis enzymes that play a role in the assembly and secretion of apolipoprotein B100-containing very low density lipoproteins. Thus, the centrifugal proteomic reactor offers a new analytical tool for structure and function studies of membrane proteins involved in lipid and lipoprotein metabolism.

Efficacy of Siddha Therapeutics on Mantha Sanni (Autism Spectrum Disorder) Among Pediatric Patients: An Interventional Non-randomized Open-Label Clinical Trial.

BACKGROUND: Autism Spectrum Disorder (ASD) refers to a collection of neurodevelopmental disorders that affect brain development and can lead to various psychological imbalances in caregivers of affected children. Siddha formulations have been shown to have a role beyond the physical body and play a significant role in managing Mantha sannior ASD. The objective of this study was to examine the impacts of Amukkara chooranam and Yegamooli thylam in the pediatric population diagnosed with ASD. METHODS: This was a prospective, interventional, non-randomized, open clinical trial involving 30 patients who met the inclusion and exclusion criteria. Patients received Amukkara chooranam at a dose of 300 mg for ages 3-4 years, 500 mg for ages 5-7 years, and 1 gm for ages 8-12 years, twice a day with honey for 90 days, and Yegamooli thylam was administered using the Thuvalai external manipulation technique once a day for 90 days. Scoring by the Indian Scale for Assessment of Autism (ISAA) was documented at the end of the 0th day, 45th day, and 90th day. RESULTS: The scores were compared at each follow-up, and a statistically significant difference was found at the end of the 90th day of treatment with Amukkara chooranam and Yegamooli thylam (P < 0.05). The statistical analysis included calculating the mean and standard deviation of the clinical assessment, parameters both before and after the treatment were 37.66667 ±13.82485. CONCLUSION: The treatment with Amukkara chooranam and Yegamooli thylam resulted in a clinically significant improvement in clinical assessment parameters in children with ASD.

Prehabilitation for spine surgery: A scoping review.

We aimed to identify and describe the current interventions used in preoperative programs ("prehabilitation") for spine surgery. Knowledge gaps in approaches, feasibility, timing, patient experience, clinical outcomes, and health care costs were explored while describing their potential benefits on physical and psychological outcomes. An electronic search was conducted from January 2004 to February 2022 in Ovid Medline, Embase, EBSCO CINAHL, the Cochrane Database of Systematic Reviews, and PEDro to identify studies in English evaluating adults enrolled in prehabilitation before undergoing elective spine surgeries. Studies were uploaded into DistillerSR for systematic screening after removing duplicates. Four reviewers screened nested references for inclusion based on titles and abstracts, followed by their full-text review. Two reviewers subsequently extracted data and summarized the results. The results were reported using Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines. Studies were rated for quality using National Health and Medical Research Council criteria. Out of 18,879 potential studies, a total of 23 studies (0.12%) met the eligibility criteria and were included in this scoping review. The prehabilitation programs included general education (n = 6, 26%), exercise (n = 6, 26%), cognitive behavioral therapy (n = 3, 13%), pain neuroscience education (n = 3, 13%), health behavior counseling (n = 3, 13%), and mindfulness (n = 2, 9%). Additional studies are needed to identify optimal patient characteristics, intervention dosage, and whether multimodal approaches using a combination of physical and psychological strategies lead to more favorable outcomes. Although studies on prehabilitation for spine surgery are limited, they seem to demonstrate that prehabilitation programs are feasible, reduce medical expenditures, and improve patients' postoperative pain, disability, self-efficacy, psychological behaviors, and satisfaction with surgical outcomes. The available literature suggests there is an opportunity to improve patient experience, clinical outcomes and reduce medical costs with the use of prehabilitation in spine surgery.

Missense mutation in APOC3 within the C-terminal lipid binding domain of human ApoC-III results in impaired assembly and secretion of triacylglycerol-rich very low density lipoproteins: evidence that ApoC-III plays a major role in the formation of lipid precursors within the microsomal lumen.

Hepatic assembly of triacylglycerol (TAG)-rich very low density lipoproteins (VLDL) is achieved through recruitment of bulk TAG (presumably in the form of lipid droplets within the microsomal lumen) into VLDL precursor containing apolipoprotein (apo) B-100. We determined protein/lipid components of lumenal lipid droplets (LLD) in cells expressing recombinant human apoC-III (C3wt) or a mutant form (K58E, C3KE) initially identified in humans that displayed hypotriglyceridemia. Although expression of C3wt markedly stimulated secretion of TAG and apoB-100 as VLDL(1), the K58E mutation (located at the C-terminal lipid binding domain) abolished the effect in transfected McA-RH7777 cells and in apoc3-null mice. Metabolic labeling studies revealed that accumulation of TAG in LLD was decreased (by 50%) in cells expressing C3KE. A Fat Western lipid protein overlay assay showed drastically reduced lipid binding of the mutant protein. Substituting Lys(58) with Arg demonstrated that the positive charge at position 58 is crucial for apoC-III binding to lipid and for promoting TAG secretion. On the other hand, substituting both Lys(58) and Lys(60) with Glu resulted in almost entire elimination of lipid binding and loss of function in promoting TAG secretion. Thus, the lipid binding domain of apoC-III plays a key role in the formation of LLD for hepatic VLDL assembly and secretion.

Antitumor activity of ethanol extract of Gracilaria edulis (Gmelin) Silva on Ehrlich ascites carcinoma-bearing mice.

OBJECTIVE: To evaluate antitumor activity of Gracilaria edulis in Swiss albino mice with Ehrlich ascites carcinoma (EAC). METHODS: Tumors were induced in mice by intraperitoneal injection of EAC cells. Ethanol extract of Gracilaria edulis (EEGE) was administered to the experimental animals in different doses after 24 h of tumor inoculation. The antitumor effect of the EEGE was evaluated by assessing in vitro cytotoxicity, survival time, biochemical parameters and hepatic enzyme levels. RESULTS: EEGE increased the life span of EAC-bearing mice compared with that of the model control mice (P<0.05 or P<0.01). EEGE treatment also converted the changes of biochemical parameters and hepatic enzyme levels in the EAC-bearing mice (P<0.05 or P<0.01). EEGE induced inhibition of tumor formation in EAC-bearing mice compared with that of the model control group (P<0.05 or P<0.01). CONCLUSION: The present study scientifically proved the antitumor activity of marine algae G. edulis and the effect can be correlated with doses.

Secretion of triacylglycerol-poor VLDL particles from McA-RH7777 cells expressing human hepatic lipase.

Hepatic lipase (HL) plays a role in the catabolism of apolipoprotein (apo)B-containing lipoproteins through its lipolytic and ligand-binding properties. We describe a potential intracellular role of HL in the assembly and secretion of VLDL. Transient or stable expression of HL in McA-RH7777 cells resulted in decreased (by 40%) incorporation of [(3)H]glycerol into cell-associated and secreted triacylglycerol (TAG) relative to control cells. However, incorporation of [(35)S]methionine/cysteine into cell and medium apoB-100 was not decreased by HL expression. The decreased (3)H-TAG synthesis/secretion in HL expressing cells was not attributable to decreased expression of genes involved in lipogenesis. Fractionation of medium revealed that the decreased [(3)H]TAG from HL expressing cells was mainly attributable to decreased VLDL. Expression of catalytically-inactive HL (HL(SG)) (Ser-145 at the catalytic site was substituted with Gly) in the cells also resulted in decreased secretion of VLDL-[(3)H]TAG. Examination of lumenal contents of microsomes showed a 40% decrease in [(3)H]TAG associated with lumenal lipid droplets in HL or HL(SG) expressing cells as compared with control. The microsomal membrane-associated [(3)H]TAG was decreased by 50% in HL expressing cells but not in HL(SG) expressing cells. Thus, expression of HL, irrespective of its lipolytic function, impairs formation of VLDL precursor [(3)H]TAG in the form of lumenal lipid droplets. These results suggest that HL expression in McA-RH7777 cells result in secretion of [(3)H]TAG-poor VLDL.

Nonsynonymous mutations within APOB in human familial hypobetalipoproteinemia: evidence for feedback inhibition of lipogenesis and postendoplasmic reticulum degradation of apolipoprotein B.

Five nontruncating missense APOB mutations, namely A31P, G275S, L324M, G912D, and G945S, were identified in heterozygous carriers of familial hypobetalipoproteinemia (FHBL) in the Italian population. To test that the FHBL phenotype was a result of impaired hepatic secretion of mutant apoB proteins, we performed transfection studies using McA-RH7777 cells stably expressing wild type or mutant forms of human apolipoprotein B-48 (apoB-48). All mutant proteins displayed varied impairment in secretion, with G912D the least affected and A31P barely secreted. Although some A31P was degraded by proteasomes, a significant proportion of it (although inappropriately glycosylated) escaped endoplasmic reticulum (ER) quality control and presented in the Golgi compartment. Degradation of the post-ER A31P was achieved by autophagy. Expression of A31P also decreased secretion of endogenous apoB and triglycerides, yet the impaired lipoprotein secretion did not lead to lipid accumulation in the cells or ER stress. Rather, expression of genes involved in lipogenesis was down-regulated, including liver X receptor alpha, sterol regulator element-binding protein 1c, fatty acid synthase, acetyl-CoA carboxylase 1, stearoyl-CoA desaturase 1, and lipin-1. These results suggest that feedback inhibition of hepatic lipogenesis in conjunction with post-ER degradation of misfolded apoB proteins can contribute to reduce fat accumulation in the FHBL liver.

Inter-examinerreliability study of physical examination procedures to assess the cervical spine.

OBJECTIVE: The objective of this study was to establish the level of inter-examiner reliability for six common cervical manual and physical examination procedures used to assess the cervical spine. MATERIALS: Reliability study that used a convenience sample of 51 patients between the ages of 16-70 years presenting with a chief complaint of neck pain. Two physical therapists independently performed the same series of cervical physical examination procedures on each of the participant. The clinicians were blinded to each other's findings and the clinical status of the patient. Kappa coefficients (κ) were calculated for levels of agreement between the clinicians for each procedure. RESULTS: When assessing for asymmetrical motion, excellent levels of reliability (κ range: 0.88-0.96) were observed for the Bilateral Modified Lateral Shear (asymmetry criterion), Bilateral C2 Spinous Kick (asymmetry criterion) and Flexion-Rotation Tests. When pain provocation was used as the indicator of a positive test during palpation of the cervical facet joints, moderate to substantial levels of reliability (κ range: 0.53-0.76) were observed. When patients were instructed not to provide feedback to the clinicians about pain provocation during facet joint palpation and clinicians relied solely on their qualitative assessment of segmental mobility, the level of reliability was lower (κ range: 0.45-0.53). Due to 100 % prevalence of negative findings, Kappa values could not be calculated for the Sharp-Purser test or the Unilateral C2 Spinous Kick Test. CONCLUSIONS: Most physical examination procedures examined in this study demonstrated moderate to excellent levels of inter-examiner reliability. Palpation for segmental mobility without pain provocation demonstrated a lower level of reliability compared to palpation for pain provocation. Correlation with clinical findings is necessary to establish validity and the applicability of these procedures in clinical practice.

Risk factors predisposing to acute stroke in India: a prospective study.

BACKGROUND: Stroke is an important neurological disorder with significant morbidity and mortality. In India, the risk factors for stroke (obesity, diabetes mellitus, alcoholism, hypertension, and sedentary lifestyle) are mounting with economic growth and increasing the disease burden. OBJECTIVE: To assess the severity and risk factors of stroke in India and identify any new predisposing factors. METHODS: A multicentric (six tertiary care hospitals across India) prospective observational study (from September 2016 to July 2017) was conducted on 526 stroke patients, presenting within the first 24 h to examine the risk factors for ischemic and hemorrhagic strokes. Severity was determined using the National Institutes of Health Stroke Scale (NIHSS). RESULTS: Predominantly male (72.3%), 75% of the sample was >50 years old, with a mean body mass index (BMI) of 25.8 ±â€Š4.3 kg/m2 and 14.6% obese patients. Hypertension and diabetes mellitus were the commonest comorbidities, followed by a history of ischemic heart disease and familial history of stroke. 20.5% of patients had mild strokes, 57.4% had moderate, 8.4% experienced moderate-severe strokes, whereas 7.2% had severe strokes. Regarding the admission diagnoses, 56.8% were ischemic, 18.6% were hemorrhagic, 1.1% had a transient ischemic attack, 6.6% suffered recurrent strokes, and 17% were other forms. CONCLUSION: The foremost risk factors for stroke in India, hypertension and diabetes, need to be controlled and treated like other global high-risk populations for stroke prevention. The NIHSS scores highlight the relationship between risk factors and stroke severity.

Expression of apolipoprotein C-III in McA-RH7777 cells enhances VLDL assembly and secretion under lipid-rich conditions.

Apolipoprotein (apo) C-III plays a regulatory role in VLDL lipolysis and clearance. In this study, we determined a potential intracellular role of apoC-III in hepatic VLDL assembly and secretion. Stable expression of recombinant apoC-III in McA-RH7777 cells resulted in increased secretion efficiency of VLDL-associated triacylglycerol (TAG) and apoB-100 in a gene-dosage-dependent manner. The stimulatory effect of apoC-III on TAG secretion was manifested only when cells were cultured under lipid-rich (i.e., media supplemented with exogenous oleate) but not lipid-poor conditions. The stimulated TAG secretion was accompanied by increased secretion of apoB-100 and apoB-48 as VLDL(1). Expression of apoC-III also increased mRNA and activity of microsomal triglyceride transfer protein (MTP). Pulse-chase experiments showed that apoC-III expression promoted VLDL(1) secretion even under conditions where the MTP activity was inhibited immediately after the formation of lipid-poor apoB-100 particles, suggesting an involvement of apoC-III in the second-step VLDL assembly process. Consistent with this notion, the newly synthesized apoC-III was predominantly associated with TAG within the microsomal lumen that resembled lipid precursors of VLDL. Introducing an Ala23-to-Thr mutation into apoC-III, a naturally occurring mutation originally identified in two Mayan Indian subjects with hypotriglyceridemia, abolished the ability of apoC-III to stimulate VLDL secretion from transfected cells. Thus, expression of apoC-III in McA-RH7777 cells enhances hepatic TAG-rich VLDL assembly and secretion under lipid-rich conditions.

Functional analysis of the missense APOC3 mutation Ala23Thr associated with human hypotriglyceridemia.

We have shown that expression of apolipoprotein (apo) C-III promotes VLDL secretion from transfected McA-RH7777 cells under lipid-rich conditions. To determine structural elements within apoC-III that confer to this function, we contrasted wild-type apoC-III with a mutant Ala23Thr originally identified in hypotriglyceridemia subjects. Although synthesis of [(3)H]glycerol-labeled TAG was comparable between cells expressing wild-type apoC-III (C3wt cells) or Ala23Thr mutant (C3AT cells), secretion of [(3)H]TAG from C3AT cells was markedly decreased. The lowered [(3)H]TAG secretion was associated with an inability of C3AT cells to assemble VLDL(1). Moreover, [(3)H]TAG within the microsomal lumen in C3AT cells was 60% higher than that in C3wt cells, yet the activity of microsomal triglyceride-transfer protein in C3AT cells was not elevated. The accumulated [(3)H]TAG in C3AT microsomal lumen was mainly associated with lumenal IDL/LDL-like lipoproteins. Phenotypically, this [(3)H]TAG fractionation profiling resembled what was observed in cells treated with brefeldin A, which at low dose specifically blocked the second-step VLDL(1) maturation. Furthermore, lumenal [(35)S]Ala23Thr protein accumulated in IDL/LDL fractions and was absent in VLDL fractions in C3AT cells. These results suggest that the presence of Ala23Thr protein in lumenal IDL/LDL particles might prevent effective fusion between lipid droplets and VLDL precursors. Thus, the current study reveals an important structural element residing within the N-terminal region of apoC-III that governs the second step VLDL(1) maturation.

γ-Secretase Inhibition Lowers Plasma Triglyceride-Rich Lipoproteins by Stabilizing the LDL Receptor.

Excess plasma triglycerides (TGs) are a key component of obesity-induced metabolic syndrome. We have shown that γ-secretase inhibitor (GSI) treatment improves glucose tolerance due to inhibition of hepatic Notch signaling but found additional Notch-independent reduction of plasma TG-rich lipoproteins (TRLs) in GSI-treated, as well as hepatocyte-specific, γ-secretase knockout (L-Ncst) mice, which suggested a primary effect on hepatocyte TRL uptake. Indeed, we found increased VLDL and LDL particle uptake in L-Ncst hepatocytes and Ncst-deficient hepatoma cells, in part through reduced γ-secretase-mediated low-density lipoprotein receptor (LDLR) cleavage and degradation. To exploit this novel finding, we generated a liver-selective Nicastrin ASO, which recapitulated glucose and lipid improvements of L-Ncst mice, with increased levels of hepatocyte LDLR. Collectively, these results identify the role of hepatic γ-secretase to regulate LDLR and suggest that liver-specific GSIs may simultaneously improve multiple aspects of the metabolic syndrome.

Malignant Cylindroma of Post Aural Region Involving the Temporal Bone.

Dermal eccrine cylindroma is a benign adnexal tumour commonly affecting the neck, scalp and skin of elderly individuals. These are poorly circumscribed dermal or subcutaneous lesions consisting of numerous rounded ovoid or cord shaped dermal island that fit together to form a jigsaw pattern. Malignant transformation is not commonly seen. This case highlights malignant transformation of a dermal eccrine cylindroma in the post aural region extending to involve the underlying mastoid bone.

Neosis: a novel type of cell division in cancer.

Using computerized video time-lapse microscopy, we studied early cellular events during carcinogen-induced transformation of C3H10T1/2 cells. Multinucleate/polyploid giant cells (MN/PGs) formed due to DNA damage are thought to die via mitotic catastrophe. Before they die, some MN/PGs undergo a novel type of cell division, termed neosis, characterized by karyokinesis via nuclear budding followed by asymmetric, intracellular cytokinesis, producing several small mononuclear cells, termed the Raju cells, with extended mitotic life span (MLS). Mitotic derivatives of Raju cells give rise to transformed cell lines, inherit genomic instability, display a phenotype and transcriptome different from the neosis mother cell, and anchorage-independent growth. Neosis of MN/PGs also precedes spontaneous transformation of p53-/- mouse cells. Rodent neotic clones, and primary and metastatic human tumor cells undergo spontaneous or induced secondary/tertiary neosis. Neosis seems to extend the MLS of cells under conditions of genetic duress not favoring mitosis. It precedes tumorigenesis, occurs several times during tumor progression, yielding tumor-initiating Raju cells and introducing tumor cell heterogeneity subject to natural selection during tumor progression. Events during neosis, and its relevance to origin of established cell lines, multistep carcinogenesis, cancer stem cells, and therapeutic advantages of anti-neotic agents (neosicides) are discussed.

Induction of protein kinase C substrates, Myristoylated alanine-rich C kinase substrate (MARCKS) and MARCKS-related protein (MRP), by amyloid beta-protein in mouse BV-2 microglial cells.

Microglial activation by amyloid beta-protein in senile plaques contributes to neurodegeneration in Alzheimer disease. In BV-2 microglial cells, amyloid beta-protein 1-40 (Abeta 1-40) elicited a dose-dependent increase (3-4 fold) of Myristoylated alanine-rich C kinase substrate (MARCKS) and MARCKS-related protein (MRP), two protein kinase C substrates implicated in membrane-cytoskeletal alterations underlying microglial adhesion, migration, secretion, and phagocytosis. Neither MARCKS nor MRP was induced by the amyloid fragment Abeta 25-35, although both Abeta 1-40 and Abeta 25-35 caused extensive aggregation of BV-2 cells. Interferon-gamma synergistically enhanced the induction by Abeta 1-40 of inducible nitric oxide synthase, but not MARCKS or MRP. Our results suggest that MARCKS and MRP may play important roles in microglia activated by amyloid peptides.