D1 and D2 medium spiny neurons in the nucleus accumbens core have distinct and valence-independent roles in learning

At the core of value-based learning is the nucleus accumbens (NAc). D1- and D2-receptor-containing medium spiny neurons (MSNs) in the NAc core are hypothesized to have opposing valence-based roles in behavior. Using optical imaging and manipulation approaches in mice, we show that neither D1 nor D2 MSNs signal valence. D1 MSN responses were evoked by stimuli regardless of valence or contingency. D2 MSNs were evoked by both cues and outcomes, were dynamically changed with learning, and tracked valence-free prediction error at the population and individual neuron level. Finally, D2 MSN responses to cues were necessary for associative learning. Thus, D1 and D2 MSNs work in tandem, rather than in opposition, by signaling specific properties of stimuli to control learning.

Dopamine signaling in the nucleus accumbens core mediates latent inhibition

Studies investigating the neural mechanisms by which associations between cues and predicted outcomes control behavior often use associative learning frameworks to understand the neural control of behavior. These frameworks do not always account for the full range of effects that novelty can have on behavior and future associative learning. Here, in mice, we show that dopamine in the nucleus accumbens core is evoked by novel, neutral stimuli, and the trajectory of this response over time tracked habituation to these stimuli. Habituation to novel cues before associative learning reduced future associative learning, a phenomenon known as latent inhibition. Crucially, trial-by-trial dopamine response patterns tracked this phenomenon. Optogenetic manipulation of dopamine responses to the cue during the habituation period bidirectionally influenced future associative learning. Thus, dopamine signaling in the nucleus accumbens core has a causal role in novelty-based learning in a way that cannot be predicted based on purely associative factors.

Clinical Profiles and Outcomes of COVID-19 in Kidney Transplant Recipients: Experience From a High-Volume Public Sector Transplant Center in India

OBJECTIVES

Data are so far limited on outcomes of kidney transplant recipients with COVID-19 seen at public sector hospitals in developing countries with limited resources.

MATERIALS AND METHODS

We retrospectively investigated a cohort of 157 kidney transplant recipients (75% living and 25% deceased donors) seen at a public sector transplant hospital in India from March to December 2020 who had reverse-transcriptase polymerase chain reaction tests that confirmed COVID-19. Demographic data, immunosuppression regimens, clinical profiles, treatments, and outcomes were analyzed. In our center, maintenance immunosuppression was reduced according to disease severity and case-by-case evaluations. There were also 53 patients with asymptomatic or mild COVID-19 symptoms who received home care to optimize the utilization of scarce resources during travel restrictions.

RESULTS

In our kidney transplant recipient group, median age was 43 years (133 male; 24 female patients); recipients presented at a median of 4 years after transplant. The most common comorbidities included arterial hypertension (73%) and diabetes (24%); presenting symptoms at the time of COVID-19 positivity included cough (49%), fever (58%), and sputum production (32%). Clinical severity ranged from asymptomatic (4%), mild (45%), moderate (31%), and severe (20%) disease. Statistically significant risk factors for mortality included older age, dyspnea, severe disease, obesity, allograft dysfunction prior to COVID-19, acute kidney injury, higher levels of inflammatory markers (C-reactive protein, interleukin 6, procalcitonin), abnormality in chest radiography, and intensive care/ventilator requirements (P < .05). Overall patient mortality was 9.5% (15/157) in hospitalized patients, 21% (15/71) in patients in the intensive care unit, 100% (15/15) in patients who required ventilation, and 0% among those in home treatment.

CONCLUSIONS

The mortality rate in kidney transplant recipients with COVID-19 was higher than in the nonimmunosuppressed general population (1.2%) in India. To our knowledge, this is a largest single-center study of kidney transplant recipients with COVID-19 so far.

Consequences of the first and second COVID-19 wave on kidney transplant recipients at a large Indian transplant centre

Background

There is a scarcity of data comparing the consequences of first and second COVID‐19 waves on kidney transplant recipients (KTRs) in India.

Methods

We conducted a single‐centre retrospective study of 259 KTRs with COVID‐19 to compare first wave (March 15–December 31 2020, n = 157) and second wave (April 1–May 31 2021, n = 102).

Results

KTRs during second wave were younger (43 vs. 40 years; p‐value .04) and also included paediatric patients (0 vs. 5.9%; p‐value .003). Symptoms were milder during the second wave (45 vs. 62.7%; p‐value .007); COVID‐19 positive patients had less frequent cough (32 vs. 13.8%; p‐value .001), fever was less frequent (58 vs. 37%; p‐value .001), and we observed fewer co‐morbidities (11 vs. 20.6%; p‐value .04). The percentages of neutrophils (77 vs. 83%; p‐value .001) and serum ferritin (439 vs. 688; p‐value .0006) were higher during second wave, while lymphocyte counts were reduced (20 vs. 14%; p‐value .0001). Hydroxychloroquine (11 vs. 0%; p‐value .0001) and tocilizumab (7 vs. 0%; p‐value .004) were more frequently prescribed during first wave, while utilization of dexamethasone (6 vs. 27%; p‐value .0001) and remdesivir (47 vs. 65%; p‐value .03) increased during the second wave. Mucormycosis (1.3 vs. 10%; p‐value .01) and ICU admissions (20 vs. 37.2%; p‐value .002) were more frequent during second wave. The 28‐day mortality rate (9.6 vs. 10%; p‐value 1) was not different.

Conclusions

There has been a different clinical spectrum of COVID‐19 amongst KTR with similar mortality between the two waves at a large Indian transplant centre.

A large single centre study from India reporting on the health outcomes of COVID‐19 infected kidney transplant recipients during the two waves of between 2020 and 2021. The rate of intensive care admission was more frequent during the second wave of infection although mortality rates were similar in both waves.

Role of Sialic Acid and Alkaline Dnase in Breast Cancer

Serum levels of sialic acid and alkaline DNase (ADA) were analysed in 495 blood samples collected from 170 breast cancer patients before and during/after anticancer treatment. Fifty-six healthy females were included in the study to define the cutoff values. The markers were analysed by highly sensitive spectrophotometric methods. Statistical evaluation of the data was done using Student's ‘t’ test, paired ‘t’ test and ROC curve analysis. The total sialic acid (TSA), lipid bound sialic acid (LSA) and ADA in sera of untreated breast cancer patients were significantly higher than in controls. ROC curve analysis revealed TSA and LSA to be useful markers for diagnosis of breast cancer. Serum levels of TSA and LSA were significantly decreased in complete responders as compared to their pretreatment values. The pretreatment ADA values showed much individual variation. However, responders showed higher levels of ADA than untreated patients. In nonresponders the values of the biomarkers were comparable with pretreatment levels. The study suggested that TSA and LSA can be helpful in the diagnosis of breast cancer. All three markers can be used for assessment of response to anticancer treatment in breast cancer patients.

Comparison of Prolactin, CA 15–3 and TPA in Breast Carcinomas

Circulating prolactin, CA 15–3 and TPA were assayed pre-therapeutically and sequentially thereafter from 68 breast cancer patients attending the Gujarat Cancer and Research Institute, Ahmedabad — a regional cancer institute in Western India. The three marker values were correlated with the stage, histologic grade and disease status. At least one of the markers was elevated in 82% of patients. CA 15–3 and TPA levels were elevated with the advancement of stage. Prolactin levels were high in poorly differentiated tumors of pre-menopausal patients. The disease status was effectively reflected by the levels of prolactin and CA 15–3. TPA showed high false positivity so was of no use as an indicator of disease status. Recurrence could be predicted early, with a lead time of 3–6 months using prolactin and CA 15–3.

Squamous Cell Carcinoma Antigen and Protein-Bound Sialic Acid in the Management of Head and Neck Cancer

Serum squamous cell carcinoma antigen (SCCAg) and protein-bound sialic acid (PBSA) were measured in 43 head and neck cancer patients and 50 controls. SCCAg and PBSA were correlated with clinical stage, histological grade, presence/absence of keratin and disease course. Patients with advanced cancer (stage III and IV) and grade III tumors had higher PBSA levels but no such difference was observed for SCCAg. Head and neck cancer patients were grouped according to the disease status i.e. a) patients who developed recurrence and b) who responded to the adjuvant therapies. There was an excellent correlation between serial serum PBSA changes and the progression of disease or the response to therapy in patients with advanced head and neck cancer.

Prognostic Significance of DNA Aneuploidy and p21ras Oncoprotein Expression in Colorectal Cancer and Their Role in the Determination of Treatment Modalities

The purpose of the present study was to investigate the prognostic significance of DNA ploidy, S-phase fraction and p21ras oncoprotein expression in patients with colorectal cancer and to correlate these factors with the clinical behavior of the tumors and their response to therapy. Of 79 patients with colorectal cancer 57% (45/79) had early stage disease. Forty-one percent (32/79) had aneuploid tumors while 30% (24/79) of the tumors had a high (>10%) S-phase fraction. p21ras oncoprotein expression was detected in 38% (30/79) of tumors. Patients with aneuploid tumors had a worse prognosis than patients with diploid tumors (p=0.0002). Similarly, patients with high S-phase fraction tumors had a shorter survival than those with low S-phase fraction tumors (p=0.005). No such difference was found between p21ras-positive and p21ras-negative tumor subgroups. In early stage colorectal cancer, aneuploidy was closely correlated with disease outcome (p=0.029). Early stage patients with diploid tumors who received radiotherapy and chemotherapy had a better prognosis than patients with aneuploid tumors. In conclusion, DNA ploidy is a significant and independent prognostic factor in colorectal cancer. Aneuploidy and genetic alteration of the p21ras oncoprotein are important in determining the biological aggressiveness of colorectal cancer. Furthermore, DNA ploidy may identify those subgroups of patients with early stage disease who may benefit from more aggressive treatment.

Telomerase Activity in Breast Cancer in Western India (Gujarat)

The purpose of this study was to examine the association of telomerase activity with clinical and histopathological prognostic variables in primary breast cancer (n=64). Telomerase activity in breast cancer was also compared with that in benign (n=10) and non-malignant tissues (n=8; post-lumpectomy tissues histopathologically defined as containing no residual tumor). The parameter was assessed using the Telomerase PCR ELISA kit. Values above OD 0.120 were considered positive. Estrogen and progesterone receptors (ER and PgR) were assayed by the dextran-coated charcoal method and levels >10 fmol/mg cytosol protein were taken as positive. Telomerase activity was detected in 20% and 50% of the patients with benign lesions and primary breast cancer, respectively, and in 50% of post-lumpectomy breast tissues histopathologically defined as containing no residual tumor. Telomerase activity was present in all stages of breast carcinoma and showed a significant inverse correlation with lymph node status (p=0.006), lymphatic invasion (p=0.035) and necrosis (p=0.033). Moreover, when stage II patients were grouped according to nodal involvement, a trend towards significance was observed (p=0.055). No correlation was observed with ER and PgR. The results of our study suggest that telomerase activity might be associated with the presence of cancer cells. Furthermore, telomerase activation may occur early in breast cancer and may be periodically downregulated during subsequent tumor progression.

Semiquinone glucoside derivative provides protection against γ-radiation by modulation of immune response in murine model

Present study was undertaken to evaluate radioprotective and immunomodulatory activities of a novel semiquinone glucoside derivative (SQGD) isolated from Bacillus sp. INM-1 in C57 BL/6 mice. Whole body survival study was performed to evaluate in vivo radioprotective efficacy of SQGD. To observe effect of SQGD on immunostimulation, Circulatory cytokine (i.e., interleukin-2 (IL-2), IFN-γ, IL-10, granulocyte colony stimulating factor (G-CSF), granulocyte macrophage colony stimulating factor (GM-CSF), and macrophage colony stimulating factor (M-CSF) expression was analyzed in serum of irradiated and SQGD treated mice at different time intervals using ELISA assay. Results of the present investigation indicated that SQGD pre-treatment (-2 h) to lethally irradiated mice provide ∼ 83% whole body survival compared with irradiated mice where no survival was observed at 30(th) post irradiation day. Significant (p < 0.05) induction in IL-2 and IFN-γ expression was observed at all tested time intervals with SQGD pre-treated irradiated mice as compared with irradiated mice alone. However, sharp increase in IL-10 expression was observed in irradiated mice which were found to be subsidized in irradiated mice pre-treated with SQGD. Similarly, significant (p < 0.05%) induction in G-CSF, M-CSF and GM-CSF expression was observed in irradiated mice treated with SQGD as compared with irradiated control mice at tested time intervals. In conclusion, SQGD pre-treatment to irradiated mice enhanced expression of IL-12 and IFN-γ while down-regulated IL-10 expression and thus modulates cytoprotective pro-inflammatory TH1 type immune response in irradiated mice. Further, SQGD pre-treatment to irradiated mice accelerate G-CSF, GM-CSF and M-CSF expression suggesting improved haematopoiesis and enhanced cellular immune response in immuno-compromised irradiated mice that may contribute to in vivo radiation protection.

Semiquinone derivative isolated from Bacillus sp. INM-1 protects cellular antioxidant enzymes from γ-radiation-induced renal toxicity

This study was focused to evaluate protection of indigenous antioxidant system of mice against gamma radiation-induced oxidative stress using a semiquinone (SQGD)-rich fraction isolated from Bacillus sp. INM-1. Male C57bl/6 mice were administered SQGD (50 mg/kgb.w.i.p.) 2 h before irradiation (10 Gy) and modulation in antioxidant enzymes activities was estimated at different time intervals and compared with irradiated mice which were not pretreated by SQGD. Compared to untreated controls, SQGD pretreatment significantly (p < 0.05) accelerates superoxide dismutase, catalase, GSH, and glutathione-S-transferase activities. Similarly, significant (p < 0.05) increase in the expression of superoxide dismutase, catalase, GSH, and glutathione-S-transferase was observed in irradiated mice pretreated by SQGD, compared to only irradiated groups. Total antioxidant status equivalent to trolox was estimated in renal tissue of the mice after SQGD administration. Significant ABTS(+) radical formation was observed in H2O2-treated kidney homogenate, due to oxidative stress in the tissue. However, significant decrease in the levels of ABTS(+) radical was observed in kidney homogenate of the mice pretreated with SQGD. Therefore, it can be concluded that SQGD neutralizes oxidative stress by induction of antioxidant enzymes activities and thus improved total antioxidant status in cellular system and hence contributes to radioprotection.

The neuropsychology of the schizo-obsessive subtype of schizophrenia: a new analysis

BACKGROUND

Interest in the neuro-cognitive profile of patients with schizophrenia and co-morbid obsessive compulsive disorder (schizo-OCD) is rising in response to reports of high co-morbidity rates. Whereas schizophrenia has been associated with global impairment in a wide range of neuro-cognitive domains, OCD is associated with specific deficits featuring impaired performance on tasks of motor and cognitive inhibition involving frontostriatal neuro-circuitry.

METHOD

We compared cognitive function using the CANTAB battery in patients with schizo-OCD (n=12) and a schizophrenia group without OCD symptoms (n=16). The groups were matched for IQ, gender, age, medication, and duration of illness.

RESULTS

The schizo-OCD patients made significantly more errors on a task of attentional set-shifting (ID-ED set-shift task). By contrast, no significant differences emerged on the Stockings of Cambridge task, the Cambridge Gamble Task or the Affective Go/NoGo tasks. No correlation emerged between ID-ED performance and severity of schizophrenia, OCD or depressive symptoms, consistent with neurocognitive impairment holding trait rather than state-marker status. Schizo-obsessives also exhibited a trend toward more motor tics emphasizing a neurological contribution to the disorder.ConclusionOur findings reveal a more severe attentional set-shifting deficit and neurological abnormality that may be fundamental to the neuro-cognitive profile of schizo-OCD. The clinical implications of these impairments merit further exploration in larger studies.

S100A9 is not essential for disease expression in an acute (K/BxN) or chronic (CIA) model of inflammatory arthritis

OBJECTIVE

S100A8 (calgranulin A, MRP8) and S100A9 (calgranulin B, MRP14) are calcium-binding proteins highly expressed by activated myeloid cells and thought to be involved in the pathogenesis of inflammatory diseases. Circulating levels of S100A8/S100A9 are elevated in both human and experimental models of autoimmune disease, including rheumatoid arthritis (RA).

METHODS

Mice deficient in S100A9 (S100A9 - /-) and wild-type controls were immunized using standard techniques for the K/BxN serum transfer or the collagen-induced arthritis (CIA) model.

RESULTS

S100A9 - /- animals, with defective expression of both S100A8 and S100A9 proteins, had similar arthritis and histopathology to that of wild-type controls in both mouse models.

CONCLUSION

S100A8 and S100A9 are not essential for disease expression in either the K/BxN serum transfer or the CIA model of inflammatory arthritis.

The impact of chemokine receptor CX3CR1 deficiency during respiratory infections with Mycobacterium tuberculosis or Francisella tularensis

Recruitment of immune cells to infection sites is a critical component of the host response to pathogens. This process is facilitated partly through interactions of chemokines with cognate receptors. Here, we examine the importance of fractalkine (CX3CL1) receptor, CX3CR1, which regulates function and trafficking of macrophages and dendritic cells, in the host's ability to control respiratory infections with Mycobacterium tuberculosis or Francisella tularensis. Following low-dose aerosol challenge with M. tuberculosis, CX3CR1(-/-) mice were no more susceptible to infection than wild-type C57BL/6 mice as measured by organ burden and survival time. Similarly, following inhalation of F. tularensis, CX3CR1(-/-) mice displayed similar organ burdens to wild-type mice. CX3CR1(-/-) mice had increased recruitment of monocytes and neutrophils in the lung; however, this did not result in increased abundance of infected monocytes or neutrophils. We conclude that CX3CR1-deficiency affects immune-cell recruitment; however, loss of CX3CR1 alone does not render the host more susceptible to M. tuberculosis or F. tularensis.

Serum protein signatures detect early radiographic osteoarthritis

OBJECTIVE

To test the hypothesis that early knee and hand osteoarthritis (OA) development is characterized by detectable changes in serum proteins relevant to inflammation, cell growth, activation, and metabolism several years before OA becomes radiographically evident.

METHODS

Using microarray platforms that simultaneously test 169 proteins relevant to inflammation, cell growth, activation and metabolism, we conducted a case-control study nested within the Baltimore Longitudinal Study of Aging (BLSA). Subjects included 22 incident cases of OA and 66 age-, sex- and body mass index (BMI)-matched controls. Serum samples tested were obtained at the time of radiographic classification as either case or control, and up to 10 years earlier at a time when all participants were free of radiographic OA. Proteins with mean signal intensities fourfold higher than background were compared between cases and controls using multivariate techniques.

RESULTS

Sixteen proteins were different between OA cases compared to controls. Four of these proteins [matrix metalloproteinase (MMP)-7, interleukin (IL)-15, plasminogen activator inhibitor (PAI)-1 and soluble vascular adhesion protein (sVAP)-1] were already different in samples obtained 10 years before radiographic classification and remained different at the time of diagnosis. Six additional proteins were only associated with subsequent OA development and not with established OA.

CONCLUSIONS

Changes in serum proteins implicated in matrix degradation, cell activation, inflammation and bone collagen degradation products accompany early OA development and can precede radiographic detection by several years.

Deficiency of PPARα disturbs the response of lipogenic flux and of lipogenic and cholesterogenic gene expression to dietary cholesterol in mouse white adipose tissue

PPARalpha-deficiency in mice fed a high-carbohydrate, low-cholesterol diet was associated with a decreased weight of epididymal adipose tissue and an increased concentration of adipose tissue cholesterol. Consumption of a high (2% w/w) cholesterol diet resulted in a further increase in the concentration of cholesterol and a further decrease in epididymal fat pad weight in PPARalpha-null mice, but had no effect in the wild-type. These reductions in fat pad weight were associated with an increase in hepatic triacylglycerol content, indicating that both PPARalpha-deficiency and cholesterol altered the distribution of triacylglycerol in the body. Adipose tissue de novo lipogenesis was increased in PPARalpha-null mice and was further enhanced when they were fed a cholesterol-rich diet; no such effect was observed in the wild-type mice. The increased lipogenesis in the chow-fed PPARalpha-null mice was accompanied paradoxically by lower mRNA expression of SREBP-1c and its target genes, acetyl-CoA carboxylase and fatty acid synthase. Consumption of a high-cholesterol diet increased the mRNA expression of these genes in the PPARalpha-deficient mice but not in the wild-type. De novo cholesterol synthesis was not detectable in the adipose tissue of either genotype despite a relatively high expression of the mRNA's encoding SREBP-2 and 3-hydroxy-3-methylglutaryl Coenzyme A reductase. The mRNA expression of these genes and of the LDL-receptor in adipose tissue of the PPARalpha-deficient mice was lower than that of the wild-type and was not downregulated by cholesterol feeding. The results suggest that PPARalpha plays a role in adipose tissue cholesterol and triacylglycerol homeostasis and prevents cholesterol-mediated changes in de novo lipogenesis.

Development and standardization of multiplexed antibody microarrays for use in quantitative proteomics

Background

Quantitative proteomics is an emerging field that encompasses multiplexed measurement of many known proteins in groups of experimental samples in order to identify differences between groups. Antibody arrays are a novel technology that is increasingly being used for quantitative proteomics studies due to highly multiplexed content, scalability, matrix flexibility and economy of sample consumption. Key applications of antibody arrays in quantitative proteomics studies are identification of novel diagnostic assays, biomarker discovery in trials of new drugs, and validation of qualitative proteomics discoveries. These applications require performance benchmarking, standardization and specification.

Results

Six dual-antibody, sandwich immunoassay arrays that measure 170 serum or plasma proteins were developed and experimental procedures refined in more than thirty quantitative proteomics studies. This report provides detailed information and specification for manufacture, qualification, assay automation, performance, assay validation and data processing for antibody arrays in large scale quantitative proteomics studies.

Conclusion

The present report describes development of first generation standards for antibody arrays in quantitative proteomics. Specifically, it describes the requirements of a comprehensive validation program to identify and minimize antibody cross reaction under highly multiplexed conditions; provides the rationale for the application of standardized statistical approaches to manage the data output of highly replicated assays; defines design requirements for controls to normalize sample replicate measurements; emphasizes the importance of stringent quality control testing of reagents and antibody microarrays; recommends the use of real-time monitors to evaluate sensitivity, dynamic range and platform precision; and presents survey procedures to reveal the significance of biomarker findings.

Development of a simple restriction fragment length polymorphism assay for subtyping of coxsackie B viruses

Coxsackie B viruses (genus, Enterovirus; family, Picornaviridae) can cause aseptic meningitis, encephalitis, pleurodynia, myocarditis and are implicated in the pathogenesis of dilated cardiomyopathy. The differentiation of the group B coxsackieviruses into their subtypes has potential clinical and epidemiological implications. In the present study, a simple restriction fragment length polymorphism (RFLP) assay was developed for typing of group B coxsackieviruses into subtypes 1-6. It is a two step process, first, virus isolation and identification by virus neutralization assay, using pools of polyclonal antisera, second, the reverse transcription polymerase chain reaction (RT-PCR) using a single primer pair selected from the conserved 5'-untranslated region (5'-UTR) of enterovirus genome followed by RFLP. A 440 bp product was amplified from the reference strains of each subtype of group B coxsackievirus and 29 clinical isolates (positive for group B coxsackieviruses by neutralization assay). The amplified products were subjected to restriction endonuclease digestion by enzyme BsaJI. The assay was able to distinguish all six serotypes of coxsackie B viruses. The results were comparable to serotyping and showed that due to the relatively conserved nature of 5'-UTR in enterovirus genome, this region can be used for subgeneric molecular identification of enteroviruses.

Molecular characterization of echovirus 11 isolates from India

BACKGROUND & OBJECTIVES

Echovirus 11 (ECV11) is one of the most frequent non-polio enteroviruses isolated from stool samples of children with acute flaccid paralysis in north India. The present work was undertaken to study the sequence variability in the 440 bp of 5'-non-translated region of ECV11 genome using heteroduplex mobility assay (HMA).

METHODS

Twelve ECV11 isolates were studied for sequence variability in the 5'-non-translated region (5'NTR) using the HMA followed by nucleotide sequencing. HMA was used to determine sequence diversity between Indian ECV11 isolates and prototype Gregory strain. HMA results were confirmed by 5'NTR nucleotide sequencing of five Indian ECV11 isolates.

RESULTS

HMA results showed high genomic diversity between the prototype Gregory strain and Indian ECV11 isolates. All isolates were grouped into five different types of heteroduplex mobility patterns with respect to Gregory strain. A 440 bp 5'NTR fragment of five ECV11 isolates representing different heteroduplex patterns, was sequenced. The sequence alignment showed that 5'NTR of Indian isolates was different from prototype Gregory strain and identical to the ECV11 isolates of Finland and Hungary. Phylogenetic analysis including ECV11 isolate sequences from different parts of the world showed that Indian ECV11 isolates represented a different subgroup.

INTERPRETATION & CONCLUSION

The results of the present study suggested that the HMA could be successfully used as a preliminary screening method for sequence variability determination of enterovirus field isolates. The sequence data generated on ECV11 isolates from India will be useful for future studies of endemic genotypes of echovirus.

Alterations in plasma lipid profile patterns in head and neck cancer and oral precancerous conditions

BACKGROUND

The changes in lipid profile have long been associated with cancer because lipids play a key role in maintenance of cell integrity.

AIMS

The present study evaluated alterations in plasma lipid profile in untreated head and neck cancer patients as well as patients with oral precancerous conditions (OPC) and its association with habit of tobacco consumption.

MATERIAL AND METHODS

This hospital-based case control study included 184 head and neck cancer patients, 153 patients with OPC and 52 controls. Plasma lipids including: (i) Total cholesterol, (ii) LDL cholesterol (LDLC), (iii) HDL cholesterol (HDLC) (iv) VLDL cholesterol (VLDLC) and (v) triglycerides were analysed by spectrophotometric kits.

STATISTICAL ANALYSIS USED

Student's t-test was performed to compare mean values of the parameters.

RESULTS

A significant decrease in plasma total cholesterol and HDLC was observed in cancer patients (P=0.008 and P=0.000 respectively) as well as in patients with OPC (P=0.014 and P=0.000, respectively) as compared to the controls. The plasma VLDL and triglycerides levels were significantly lower in cancer patients as compared to the patients with OPC (P=0.04) and controls (P=0.059). The tobacco habituates showed lower plasma lipid levels than the non-habituates. Our data strengthen the evidence of an inverse relationship between plasma lipid levels and head and neck malignancies as well as OPC.

CONCLUSION

The lower levels of plasma cholesterol and other lipid constituents in patients might be due to their increased utilization by neoplastic cells for new membrane biogenesis. The findings strongly warrant an in-depth study of alterations in plasma lipid profile in head neck cancer patients.

Evaluation of serum sialic acid, sialyltransferase and sialoproteins in oral cavity cancer

OBJECTIVE

Altered glycosylation of glycoconjugates is among the important molecular changes that accompany malignant transformation. The aim of our study was to investigate clinical usefulness of circulatory levels of sialic acid, sialoproteins and sialyltransferase for early diagnosis and management of oral cavity cancer (OC) patients.

MATERIALS AND METHODS

Blood samples collected from 210 untreated OC patients, 100 patients with oral precancerous conditions (OPC) and 100 healthy males. OC patients were followed after initiation of anticancer treatment and 394 follow-up samples were also collected. Serum sialic acid levels were measured spectrophotometrically. Sialyltransferase activity was analysed using radioassay. Alpha 2-6 sialoproteins were isolated using lectin affinity chromatography.

RESULTS

Serum levels of free, protein bound and total sialic acid as well as their ratio with total proteins were significantly elevated in untreated OC patients compared with healthy individuals, patients with OPC as well as complete responders (CR). Levels of the markers were comparable between untreated OC patients and non-responders. We observed positive correlation between serum levels of the markers and extent of malignant disease. Serum sialyltransferase activity showed significant elevations in OC patients compared with the controls (P<0.001), patients with OPC (P<0.05) and CR (P<0.05). Higher sialic acid levels in OC patients at the time of diagnosis showed poor survival. The changes in serum proteins with terminal alpha 2-6 sialic acid correlated well with the alterations in the levels of sialic acid forms and sialyltransferase activity.

CONCLUSION

Our results confirmed the elevations in sialic acid and sialyltransferase levels in OC patients and suggested potential utility of these parameters in prognostication and treatment monitoring of this neoplasm. The alterations in these parameters in circulation were in accordance with the changes in alpha 2-6 sialylated proteins.

Treatment with atorvastatin alters the ratio of interleukin-12/interleukin-10 gene expression [corrected]

BACKGROUND

Statins have been shown to have pleiotropic effects extending beyond their ability to lower cholesterol.

MATERIAL AND METHODS

Seventeen patients with heterozygous familial hypercholesterolaemia participated in a single-blind placebo controlled study. The patients underwent three treatment regimens: placebo (4 weeks), atorvastatin 10 mg day(-1) (4 weeks) and atorvastatin 40 mg day(-1) (12 weeks). Following each treatment period, serum lipids and plasma mevalonic acid were measured, mononuclear leukocytes were isolated and total RNA was prepared. The content of mRNA for IL-12p35 and IL-10 was assayed, blinded, by real-time quantitative polymerase chain reactions.

RESULTS

Treatment of the subjects with atorvastatin decreased the abundance of IL-12p35 mRNA in mononuclear cells, but did not alter that of IL-10, so that the ratio of the IL-12p35 to IL-10 mRNA content was significantly reduced (P < 0.0026). The IL-12p35/IL-10 ratio correlated significantly with plasma mevalonic acid concentrations but not with serum LDL concentrations.

CONCLUSIONS

This study provides evidence that atorvastatin exerts an immunomodulatory effect in vivo, characterized by a decrease in the ratio of IL-12 mRNA to IL-10 mRNA in leukocytes. The immunomodulatory effect of statins, in addition to their cholesterol-lowering properties, may contribute to the rapid cardiovascular benefit observed during treatment with statins and reduced the rate of rejection in patients with solid organ transplantation.

Serum glutathione-S-transferase and glutathione reductase activity in head and neck cancer patients

Glutathione, an antioxidant plays an important role in phase-II detoxification of carcinogens. The levels of reduced glutathione are maintained by glutathione-depleting as well as replenishing enzymes such as glutathione-s-transferase (GST) and glutathione reductase (GR), respectively. Pre and post treatment changes in GST and GR activities in head and neck cancer patients were analysed. Serum GST and GR were analysed from untreated head and neck cancer patients (PT) (n=146), controls with habit of tobacco (VHT) (n=25) as well as without (no) habit of tobacco (NHT) (n=25) and patients with oral precancerous conditions (OPC) (n=50). The cancer patients were followed-up after initiation of anticancer therapy. Follow-up blood samples were collected. Serum GST and GR activities were estimated by highly sensitive and specific spectrophotometric methods. Untreated cancer patients showed elevated mean serum GST and GR activities as compared to NHT. Patients with OPC had declined mean GST activity as compared to WHT and untreated cancer patients. Paired t-test revealed that complete responders (CR) showed significantly elevated GST levels and declined GR activities (p < 0.001) as compared to those in PT. No correlation was found between stage of the disease and GST, GR activity. Paired t-test showed significant decreased in GR activity in nonresponders (NR) treated with radiotherapy (p=0.01). The study suggested that analysis of glutathione and glutathione-depleting enzymes can be helpful for treatment monitoring of head and neck cancer patients.

T-Cell recovery in adults and children following umbilical cord blood transplantation

T-cell reconstitution following allogeneic stem cell transplantation may involve thymic education of donor-derived precursors or peripheral expansion of mature T cells transferred in the graft. T cell-receptor excision circles (sjTRECs) are generated within the thymus and identify new thymic emigrants and those that have not divided. We measured quantitative and qualitative immunologic reconstitution and sjTREC levels in adult and pediatric recipients of umbilical cord blood transplants (UCBTs). sjTRECs were detected at normal levels in all children, starting 12 months after transplantation. sjTRECs were not detected until 18 months after transplantation in adults, and then only at a 3-fold lower level than expected for age. We used complementarity-determining region 3 (CDR3) spectratyping to measure changes in T cell-receptor diversity occurring with restoration of thymic function. T-cell repertoires were skewed in adults and children at 12 to 18 months after transplantation but recovered to near-normal diversity at 2 to 3 years post-UCBT. T-cell repertoires appeared more diverse earlier in children (at 1 to 2 years post-UCBT) than in adults (at 3 to 4 years post-UCBT). We conclude that early T-cell recovery after UCBT occurs primarily through peripheral expansion of adoptively transferred donor T cells and results in skewing of the T-cell repertoire. The reappearance of sjTREC-containing cells after UCBT is associated with increasing numbers of phenotypicaly naive T cells, improved mitogen and recall antigen responses, and diversification of the T-cell repertoire. The delay in central T-cell recovery in adults relative to children may be due to differences in thymic function resulting from age-related atrophy, graft-versus-host disease, or the pharmacologic effects of prophylaxis and treatment of graft-versus-host disease.

Role of pretherapeutic biomarkers in predicting postoperative radiotherapy response in patients with advanced squamous cell carcinoma

PURPOSE

To assess the role of biomarker levels in predicting radiotherapy (RT) response in patients with squamous cell carcinoma of buccal mucosa treated with postoperative RT.

MATERIALS AND METHODS

Thirty-one patients with squamous cell carcinoma of buccal mucosa who received postoperative RT were enrolled for the study. Glutathione S-transferase (GST), glutathione reductase (GR), superoxide dismutase (SOD) and catalase activity were analysed from primary tumour and adjacent normal mucosa of the same patients before RT. p53 and p21ras were localized immunohistochemically.

RESULTS

Enzyme activation was predicted by comparing the levels of these enzymes in tumour and adjacent normal mucosa. Deactivation of GST, activation of GR, SOD and catalase were associated with poor response to RT. p53 immunoreactivity was associated with failure to respond to RT.

CONCLUSIONS

These markers may be useful in predicting treatment outcome in patients receiving postoperative RT, although this conclusion requires confirmation in a larger group of patients.

Characterization of the rodent genes for arylacetamide deacetylase, a putative microsomal lipase, and evidence for transcriptional regulation

In the current study, we have determined the cDNA and the genomic sequences of the arylacetamide deacetylase (AADA) gene in mice and rats. The AADA genes in the rat and mouse consist of five exons and have 2.4 kilobases of homologous promoter sequence upstream of the initiating ATG codon. AADA mRNA is expressed in hepatocytes, intestinal mucosal cells (probably enterocytes), the pancreas and also the adrenal gland. In mice, there is a diurnal rhythm in hepatic AADA mRNA concentration, with a maximum 10 h into the light (post-absorptive) phase. This diurnal regulation is attenuated in peroxisome proliferator-activated receptor alpha knockout mice. Intestinal but not hepatic AADA mRNA was increased following oral administration of the fibrate, Wy-14,643. The homology of AADA with hormone-sensitive lipase and the tissue distribution of AADA are consistent with the view that AADA plays a role in promoting the mobilization of lipids from intracellular stores and in the liver for assembling VLDL. This hypothesis is supported by parallel changes in AADA gene expression in animals with insulin-deficient diabetes and following treatment with orotic acid.

Mutational analysis of the fractalkine chemokine domain. Basic amino acid residues differentially contribute to CX3CR1 binding, signaling, and cell adhesion

Fractalkine (FKN/CX3CL1) is a unique member of the chemokine gene family and contains a chemokine domain (CD), a mucin-like stalk, a single transmembrane region, and a short intracellular C terminus. This structural distinction affords FKN the property of mediating capture and firm adhesion of FKN receptor (CX3CR1)-expressing cells under physiological flow conditions. Shed forms of FKN also exist, and these promote chemotaxis of CX3CR1-expressing leukocytes. The goal of the present study was to identify specific residues within the FKN-CD critical for FKN-CX3CR1 interactions. Two residues were identified in the FKN-CD, namely Lys-7 and Arg-47, that are important determinants in mediating an FKN-CX3CR1 interaction. FKN-K7A and FKN-R47A mutants exhibited 30-60-fold decreases in affinity for CX3CR1 and failed to arrest efficiently CX3CR1-expressing cells under physiological flow conditions. However, these mutants had differential effects on chemotaxis of CX3CR1-expressing cells. The FKN-K7A mutant acted as an equipotent partial agonist, whereas the FKN-R47A mutant had marked decreased potency and efficacy in measures of chemotactic activity. These data identify specific structural features of the FKN-CD that are important in interactions with CX3CR1 including steady state binding, signaling, and firm adhesion of CX3CR1-expressing cells.

Determinants of Variable Response to Statin Treatment in Patients With Refractory Familial Hypercholesterolemia

Abstract —Interindividual variability in low density lipoprotein (LDL) cholesterol (LDL-C) response during treatment with statins is well documented but poorly understood. To investigate potential metabolic and genetic determinants of statin responsiveness, 19 patients with refractory heterozygous familial hypercholesterolemia were sequentially treated with placebo, atorvastatin (10 mg/d), bile acid sequestrant, and the 2 combined, each for 4 weeks. Levels of LDL-C, mevalonic acid (MVA), 7-α-OH-4-cholesten-3-one, and leukocyte LDL receptor and hydroxymethylglutaryl coenzyme A reductase mRNA were determined after each treatment period. Atorvastatin (10 mg/d) reduced LDL-C by an overall mean of 32.5%. Above-average responders (ΔLDL-C −39.5%) had higher basal MVA levels (34.4±6.1 μmol/L) than did below-average responders (ΔLDL-C −23.6%, P <0.02; basal MVA 26.3±6.1 μmol/L, P <0.01). Fewer good responders compared with the poor responders had an apolipoprotein E4 allele (3 of 11 versus 6 of 8, respectively; P <0.05). There were no baseline differences between them in 7-α-OH-4-cholesten-3-one, hydroxymethylglutaryl coenzyme A reductase mRNA, or LDL receptor mRNA, but the latter increased in the good responders on combination therapy ( P <0.05). Severe mutations were not more common in poor than in good responders. We conclude that poor responders to statins have a low basal rate of cholesterol synthesis that may be secondary to a genetically determined increase in cholesterol absorption, possibly mediated by apolipoprotein E4. If so, statin responsiveness could be enhanced by reducing dietary cholesterol intake or inhibiting absorption.

Molecular markers are predictors of recurrence and survival in patients with Dukes B and Dukes C colorectal adenocarcinoma

PURPOSE

The goal was to investigate the prognostic value of various molecular markers like CEA, Cyclin D1, Bcl-2, c-Myc, p53, p21ras, Ki-67, CD44, Factor VIII-related antigen, cytokeratin-19, adenoma antigen, and prolactin in patients with Dukes B and Dukes C colorectal adenocarcinoma.

METHODS

These molecular markers were localized immunohistochemically in nonmalignant (n = 36) and malignant (n = 98) diseases of the colorectum. Data were analyzed statistically using the SPSS software program. The patients with colorectal cancer were followed for a period of five years or their death within that period.

RESULTS

The expression of carcinoembryonic antigen, Cyclin D1, Bcl-2, CD44, cytokeratin-19 and prolactin was significantly higher in malignant diseases (P < 0.05), whereas, p21ras was found to be significantly higher in nonmalignant diseases (P = 0.002) as compared with their respective counterparts. Besides Dukes stage, multivariate analysis indicated a significantly reduced relapse-free survival in patients expressing CD44 and cytokeratin-19 (P < 0.005). Similarly, besides Dukes stage, multivariate analysis indicated a significantly poor overall survival in patients expressing CD44, cytokeratin-19 and prolactin (P < 0.01). In patients with Dukes B disease, only cytokeratin-19 and CD44 expression attained statistical significance (P < 0.05), whereas in patients with Dukes C disease, CD44, p21ras- and c-Myc expression attained statistical significance (P < 0.018). Also, a multivariate analysis in relation to treatment given was performed using CD44 and cytokeratin-19.

CONCLUSION

Besides Dukes stage, multivariate analysis of all the studied molecular markers showed that patients expressing CD44 and cytokeratin-19 had a significantly reduced relapse-free and poor overall survival. Moreover, patients expressing both these markers (CD44 and cytokeratin-19) had the lowest significant relative risk for developing recurrence than patients with both markers negative when treated with surgery followed by adjuvant chemotherapy as compared with patients treated with surgery alone. Thus, in patients with colorectal cancer, immunohistochemical localization of CD44 and cytokeratin-19 may be included as a part of routine pathologic evaluation along with conventional prognostic factors.

Chemokines have diverse abilities to form solid phase gradients

Chemokines play critical roles in leukocyte recruitment into sites of inflammation such as rheumatoid arthritis (RA). While chemokines immobilized on endothelium (solid-phase), but not soluble chemokines, direct rolling leukocytes to firmly adhere to endothelium, soluble and solid-phase chemokine gradients may play important roles in leukocyte extravasation into the tissue. In this study, we have sought to determine (1) if chemokines can be immobilized on structures in the extravascular space, (2) the mechanisms by which chemokines may be immobilized, and (3) if different chemokines have similar potentials to form solid-phase gradients. While secreted alkaline phosphatase (SEAP)-tagged chemokines SLC (CCL21), TARC (CCL17), and RANTES (CCL5) bound to mast cells and the extracellular matrix (ECM) in RA synovium under physiologic salt conditions, MCP1 (CCL2), MIP1 alpha (CCL3), MIP1 beta (CCL4), and fractalkine (FKN, CX3CL1) fusion proteins did not detectably bind. Chemokine binding to ECM and mast cells in situ and to immobilized heparin was inhibited by high salt and glycosaminoglycans (GAGs) heparin, heparan sulfate, chondroitin sulfate, and dermatan sulfate, but not by dextran or hyaluronan, indicating that the chemokines bind to highly sulfated GAGs. Chemokine binding to synovial structures correlated strongly with avidity of chemokine binding to heparin (SLC > TARC > RANTES > MIP1 beta > MCP1 > MIP1 alpha > FKN). A RANTES mutant with decreased avidity for heparin was not able to bind to ECM or mast cells. Thus, these data indicate that chemokines can bind to ECM and mast cell granule constituents in situ via interactions with GAGs. Further, only a subset of chemokines were able to bind efficiently to structures in the extravascular space, indicating that chemokines may form different types of gradients based on their GAG binding ability and that chemotactic gradients in tissues may be quite complex.

A study of chromosome aneuploidy in hereditary breast cancer patients and their healthy blood relatives

Chromosomal abnormalities that may predispose a group of individuals to develop certain neoplasms have been reported in lymphocytes. We evaluated cytogenetic abnormalities in 21 histopathologically confirmed primary breast cancer patients (BCPs), 52 healthy blood relatives (HBRs), belonging to 19 hereditary breast cancer families (HBFs) and 25 females as control. Phytohemagglutinin stimulated peripheral blood lymphocyte (PBL) cultures were used to study the chromosomal abnormalities in BCPs and their HBRs. Short term culture of the tumor tissue was also carried out in defined growth medium. Suitable metaphases (11 to 55) from tumors and a minimum of 100 metaphases from PBL were karyotyped for the cytogenetic analysis. Heterogeneous population of cells with random and nonrandom chromosomal abnormalities was noticed in tumors. In control groups 2-5% of metaphases showed numerical abnormalities, whereas this phenomenon was observed in 3-18% of metaphases in HBRs and 3-23% of metaphases in BCPs. In tumor tissue, 47.05% of BCPs showed numerical abnormalities in more than 16 metaphases. In lymphocytes, this event was observed in 33.33% of BCPs and 13.14% of HBRs. In controls 1.28%, in BCPs 52.04% (tumor) and 13.42% (lymphocytes), and in HBRs 9.03% of metaphases were found aneuploid. Statistically it was highly significant (Fisher's exact test, P<0.00001). In lymphocytes of BCPs, chromosomes 1, 6, 8, 9, 15, 17, 18, 20, and X and in HBRs, chromosomes 8, 15, 17, 18, and X were frequently involved. It can be inferred from the findings that the above mentioned chromosomes may have an important role in early stage of breast carcinogenesis in BCFs. Moreover, presence of similar abnormalities in HBR indicates inherited pattern of this genetic error among them.

Self-antigen-presenting cells expressing diabetes-associated autoantigens exist in both thymus and peripheral lymphoid organs

Recent reports indicate that genes with tissue-restricted expression, including those encoding the type 1 diabetes autoantigens insulin, glutamic acid decarboxylase (GAD), and the tyrosine-phosphatase-like protein IA-2 (or ICA512), are transcribed in the thymus. The reported modulation of diabetes susceptibility by genetically determined differences in thymic insulin levels and studies in transgenic mice provide correlative and functional evidence that thymic expression of peripheral proteins is crucial for immunological self-tolerance. However, there are no specific data about the existence, tissue distribution, phenotype, and function of those cells that express insulin and other self-antigens in the human thymus. We find that the human thymus harbors specialized cells synthesizing (pro)insulin, GAD, and IA-2, mainly localized in the medulla, and we demonstrate such cells also in peripheral lymphoid organs (spleen and lymph nodes). Phenotypic analysis qualifies these cells as antigen-presenting cells (APCs), including both dendritic cells and macrophages. These cells often appear surrounded by apoptotic lymphocytes, both in thymus and spleen, and may therefore be involved in the deletion of autoreactive lymphocytes. Our findings demonstrate the existence of, and define the tissue distribution and phenotype of, a novel subset of APCs expressing self-antigens in human lymphoid organs that appear to be involved in the regulation of self-tolerance throughout life.

Disturbances in the normal regulation of SREBP-sensitive genes in PPAR alpha-deficient mice

Peroxisome proliferator-activated receptor alpha (PPAR alpha)-null mice were used to investigate the nature of the relationship between the normal circadian rhythm of hepatic PPAR alpha expression and the expression of the lipogenic and cholesterogenic sterol regulatory element-binding protein (SREBP)-regulated genes, acetyl-CoA carboxylase, fatty acid synthase (FAS), and 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoAR). The expression of FAS and HMG-CoAR varied rhythmically over the diurnal cycle in the normal mice, with patterns that were the opposite of that of PPAR alpha. The diurnal variation of lipogenic and cholesterogenic gene expression was attenuated or abolished in the PPAR alpha-null mice. This resulted in decreased expression compared with normal mice, but only during the dark phase of the cycle, when food intake was high. The diurnal variation in hepatic fatty acid and cholesterol synthesis was also abolished in the PPAR alpha-null animals and the variations in the concentration of plasma triacylglycerol, nonesterified fatty acids, and cholesterol were all attenuated. The failure of HMG-CoAR expression to increase during the feeding period in the PPAR alpha-null mice was associated with a decrease in hepatic nonesterified cholesterol content and an increase in cholesteryl ester compared with normal mice. There was no defect in the downregulation of hepatic HMG-CoAR mRNA in response to dietary cholesterol in the PPAR alpha-null mice. Under these conditions, hepatic PPAR gamma expression increased in both the control and PPAR alpha-deficient mice. The results suggest that PPAR alpha-deficiency disturbs the normal circadian regulation of certain SREBP-sensitive genes in the liver, but does not affect their response to dietary cholesterol. -- Patel, D. D., B. L. Knight, D. Wiggins, S. M. Humphreys, and G. F. Gibbons. Disturbances in the normal regulation of SREBP-sensitive genes in PPAR alpha-deficient mice. J. Lipid Res. 2001. 42: 328--337.

Comparison of thymocyte development and cytokine production in CD7-deficient, CD28-deficient and CD7/CD28 double-deficient mice

CD7 and CD28 are Ig superfamily molecules expressed on thymocytes and mature T cells that share common signaling 0mechanisms and are co-mitogens for T cell activation. CD7-deficient mice are resistant to lipopolysaccharide (LPS)-induced shock syndrome, and have diminished in vivo LPS-triggered IFN-gamma and tumor necrosis factor (TNF)-alpha production. CD28-deficient mice have decreased serum Ig levels, defective IgG isotype switching, decreased T cell IL-2 production and are resistant to Staphylococcus aureus enterotoxin-induced shock. To determine synergistic roles CD7 and CD28 might play in thymocyte development and function, we have generated and characterized CD7/CD28 double-deficient mice. CD7/CD28-deficient mice were healthy, reproduced normally, had normal numbers of thymocyte subsets and had normal thymus histology. Anti-CD3 mAb induced similar levels of apoptosis in CD7-deficient, CD28-deficient and CD7/CD28 double-deficient thymocytes as in control C57BL/6 mice (P = NS). Similarly, thymocyte viability, apoptosis and necrosis following ionomycin or dexamethasone treatment were the same in control, CD7-deficient, CD28-deficient and CD7/CD28-deficient mice. CD28-deficient and CD7/CD28-deficient thymocytes had decreased [3H]thymidine incorporation responses to concanavalin A (Con A) stimulation compared to control mice (P < or = 0.01 and P < or = 0.05 respectively). CD7/CD28 double-deficient mice had significantly reduced numbers of B7-1/B7-2 double-positive cells compared to freshly isolated wild-type, CD7-deficient and CD28-deficient thymocytes. Con A-stimulated CD4/CD8 double-negative (DN) thymocytes from CD7/CD28 double-deficient mice expressed significantly lower levels of CD25 when compared to CD4/CD8 DN thymocytes from wild-type, CD7-deficient and CD28-deficient mice (P < 0.05). Anti-CD3-triggered CD7/CD28-deficient thymocytes also had decreased IFN-gamma and TNF-alpha production compared to C57BL/6 control, CD7-deficient and CD28-deficient mice (P < or = 0.05). Thus, CD7 and CD28 deficiencies combined to produce abnormalities in the absolute number of B7-1/B7-2-expressing cells in the thymus, thymocyte IL-2 receptor expression and CD3-triggered cytokine production.

Ectopic production of prolactin by colorectal adenocarcinoma

PURPOSE

This study assessed the role of prolactin in patients with Dukes B and C colorectal carcinoma.

METHODS

Circulating prolactin and carcinoembryonic antigen were assayed using immunoradiometric assay and radioimmunoassay kits, respectively, in preoperative blood (n = 98) and tumor-draining venous blood (n = 34) samples of colorectal carcinoma patients. Immunohistochemical localization of prolactin (n = 98), carcinoembryonic antigen (n = 98), and prolactin receptors (n = 56) was performed. The expression of prolactin messenger ribonucleic acid (n = 50) and prolactin receptor messenger ribonucleic acid (n = 50) was studied by reverse transcriptase polymerase chain reaction. Further, prolactin amplimer was sequenced.

RESULTS

Preoperative prolactin and carcinoembryonic antigen levels were significantly higher in patients with colorectal carcinoma than in controls (prolactin, P = 0.001; carcinoembryonic antigen, P = 0.0001). Univariate survival analysis showed that Dukes stage, histologic grade, and circulating prolactin were significant prognostic factors for determining overall survival (Dukes stage, P = 0.00001; histologic grade, P = 0.005; prolactin, P = 0.001). In multivariate analysis, besides Dukes stage, circulating prolactin emerged as the most significant independent prognostic factor influencing overall survival. Preoperative prolactin levels showed excellent significant correlation with response to therapy and progression of disease. A significant tenfold higher mean concentration of prolactin was observed in tumor-draining venous blood than in peripheral blood (P = 0.0001). Diffuse cytoplasmic staining for prolactin was seen in 51 percent (50/98) of the colorectal carcinomas. Prolactin messenger ribonucleic acid expression was seen in 88 percent (44/50) of the colorectal carcinomas. Sequence analysis of the 234-bp prolactin amplimer revealed that the sequence was homologous to exon 5 of pituitary prolactin messenger ribonucleic acid.

CONCLUSION

These multiple approaches confirmed that prolactin is produced by colorectal carcinoma cells. Looking at its prognostic value and correlation with disease activity, it may provide new insights into treatment for patients with colorectal carcinoma.

CXCR3 and CCR5 ligands in rheumatoid arthritis synovium

The pathogenesis of rheumatoid arthritis (RA) may be mediated by Th1-type T cells. Since chemokine receptors CXCR3 and CCR5 are preferentially expressed on Th1 cells, we tested the expression and regulation of several chemokines, including those that signal through CXCR3 (interferon-gamma-inducible protein of 10 kDa, IP-10, CXCL10; and monokine induced by interferon-gamma, Mig, CXCL9) and CCR5 (macrophage inflammatory protein (Mip)-1 alpha, CCL3; and Mip-1 beta, CCL4) in RA synovial fluids, synovial tissues, and blood. Synovial fluid (SF) protein levels of IP-10 (32.1 +/- 10.5 ng/ml), Mig (15.0 +/- 6.4 ng/ml), Mip-1 beta (0.7 +/- 0.3 ng/ml), and Mip-1 alpha (0.8 +/- 0.1 ng/ml) were 100-, 50-, 25-, and 2-fold elevated in RASF compared to control SF (P < 0.001, P < 0.001, P < 0. 001, and P < 0.02, respectively). Tissue levels of IP-10, Mig, and Mip-1 beta were significantly higher in RA than in OA (P < 0.01). Serum levels of IP-10 (3.1 +/- 1.2 ng/ml) were higher in patients with seropositive RA compared to controls (1.2 +/- 0.2 ng/ml) (P < 0.02). There was a gradient of IP-10, Mig, Mip-1 alpha, and Mip-1 beta from the blood into the synovial fluid in RA. Infiltrating T cells around high endothelial venules in RA synovium and 90 +/- 3% of SF CD3(+)CD4(+) T cells expressed CXCR3, and 85 +/- 2% of SF CD3(+)CD4(+) T cells expressed CCR5. Chemokines, including IP-10, Mig, Mip-1 alpha, and Mip-1 beta, may participate in the selective recruitment of CCR5(+)CXCR3(+) T cells to the inflamed synovium.

The development of clinical signs of rheumatoid synovial inflammation is associated with increased synthesis of the chemokine CXCL8 (interleukin-8)

Paired synovial tissue samples were obtained from both clinically uninvolved (CU) and clinically involved (CI) knee joints of eight rheumatoid arthritis (RA) patients. In addition, biopsies were taken from five control subjects. We observed the expression of the chemokines CXCL8, CXCL9, CXCL10, CCL2 and CCL4 in CI and CU joints of RA patients. In particular, CXCL8 protein levels were specifically increased in CI joints compared with CU joints, which was confirmed by immunohistochemistry and in situ hybridization.

Chemokine production by G protein-coupled receptor activation in a human mast cell line: roles of extracellular signal-regulated kinase and NFAT

Chemoattractants are thought to be the first mediators generated at sites of bacterial infection. We hypothesized that signaling through G protein-coupled chemoattractant receptors may stimulate cytokine production. To test this hypothesis, a human mast cell line (HMC-1) that normally expresses receptors for complement components C3a and C5a at low levels was stably transfected to express physiologic levels of fMLP receptors. We found that fMLP, but not C3a or C5a, induced macrophage inflammatory protein (MIP)-1ss (CCL4) and monocyte chemoattractant protein-1 (CCL2) mRNA and protein. Although fMLP stimulated both sustained Ca(2+) mobilization and phosphorylation of extracellular signal-regulated kinase (ERK), these responses to C3a or C5a were transient. However, transient expression of C3a receptors in HMC-1 cells rendered the cells responsive to C3a for sustained Ca(2+) mobilization and MIP-1ss production. The fMLP-induced chemokine production was blocked by pertussis toxin, PD98059, and cyclosporin A, which respectively inhibit G(i)alpha activation, mitgen-activated protein kinase kinase-mediated ERK phosphorylation, and calcineurin-mediated activation of NFAT. Furthermore, fMLP, but not C5a, stimulated NFAT activation in HMC-1 cells. These data indicate that chemoattractant receptors induce chemokine production in HMC-1 cells with a selectivity that depends on the level of receptor expression, the length of their signaling time, and the synergistic interaction of multiple signaling pathways, including extracellular signal-regulated kinase phosphorylation, sustained Ca(2+) mobilization and NFAT activation.

A role for fractalkine and its receptor (CX3CR1) in cardiac allograft rejection

The hallmark of acute allograft rejection is infiltration of the inflamed graft by circulating leukocytes. We studied the role of fractalkine (FKN) and its receptor, CX(3)CR1, in allograft rejection. FKN expression was negligible in nonrejecting cardiac isografts but was significantly enhanced in rejecting allografts. At early time points, FKN expression was particularly prominent on vascular tissues and endothelium. As rejection progressed, FKN expression was further increased, with prominent anti-FKN staining seen around vessels and on cardiac myocytes. To determine the capacity of FKN on endothelial cells to promote leukocyte adhesion, we performed adhesion assays with PBMC and monolayers of TNF-alpha-activated murine endothelial cells under low-shear conditions. Treatment with either anti-FKN or anti-CX(3)CR1-blocking Ab significantly inhibited PBMC binding, indicating that a large proportion of leukocyte binding to murine endothelium occurs via the FKN and CX(3)CR1 adhesion receptors. To determine the functional significance of FKN in rejection, we treated cardiac allograft recipients with daily injections of anti-CX(3)CR1 Ab. Treatment with the anti-CX(3)CR1 Ab significantly prolonged allograft survival from 7 +/- 1 to 49 +/- 30 days (p < 0.0008). These studies identify a critical role for FKN in the pathogenesis of acute rejection and suggest that FKN may be a useful therapeutic target in rejection.

The binding site of human adenosine deaminase for CD26/Dipeptidyl peptidase IV: the Arg142Gln mutation impairs binding to cd26 but does not cause immune deficiency

Human, but not murine, adenosine deaminase (ADA) forms a complex with the cell membrane protein CD26/dipeptidyl peptidase IV. CD26-bound ADA has been postulated to regulate extracellular adenosine levels and to modulate the costimulatory function of CD26 on T lymphocytes. Absence of ADA-CD26 binding has been implicated in causing severe combined immunodeficiency due to ADA deficiency. Using human-mouse ADA hybrids and ADA point mutants, we have localized the amino acids critical for CD26 binding to the helical segment 126-143. Arg142 in human ADA and Gln142 in mouse ADA largely determine the capacity to bind CD26. Recombinant human ADA bearing the R142Q mutation had normal catalytic activity per molecule, but markedly impaired binding to a CD26(+) ADA-deficient human T cell line. Reduced CD26 binding was also found with ADA from red cells and T cells of a healthy individual whose only expressed ADA has the R142Q mutation. Conversely, ADA with the E217K active site mutation, the only ADA expressed by a severely immunodeficient patient, showed normal CD26 binding. These findings argue that ADA binding to CD26 is not essential for immune function in humans.

The effect of peroxisome-proliferator-activated receptor-alpha on the activity of the cholesterol 7 alpha-hydroxylase gene

Cholesterol 7 alpha-hydroxylase (Cyp7a1) plays a central role in the regulation of bile acid and cholesterol metabolism, and transcription of the gene is controlled by bile acids and hormones acting through a complex interaction with a number of potential steroid-hormone-binding sites. Transcriptional activity of the human CYP7A1 gene promoter transfected into HepG2 cells was decreased in a concentration-dependent manner by co-transfection with an expression vector for peroxisome-proliferator-activated receptor-alpha (PPAR alpha). This effect was augmented by 9-cis-retinoic acid receptor-alpha (RXR alpha) and activators of PPAR alpha to give a maximum inhibition of approx. 80%. The region responsible for this inhibition contained a site known to bind hepatocyte nuclear factor 4 (HNF4), and mutation of this site greatly decreased the effect. Co-expression of HNF4 increased promoter activity and decreased the effect of PPAR alpha. Gel-mobility-shift assays failed to detect any binding of PPAR alpha/RXR alpha dimers to any regions of the promoter containing potential binding sites. Also the hepatic abundance of Cyp7a1 mRNA in mice in which the PPAR alpha gene was disrupted was the same as in normal mice, both during the dark phase, when the animals were feeding, and during the light phase, when mRNA abundance was greatly increased. Cholesterol feeding produced the same increase in hepatic Cyp7a1 mRNA abundance in PPAR alpha-null animals as in normals. It is concluded that, whereas PPAR alpha can affect CYP7A1 gene transcription in vitro through an indirect action, probably by competing for co-factors, this is unlikely to be a major influence on Cyp7a1 activity under normal physiological conditions.

Prolactin as a local growth promoter in patients with breast cancer: GCRI experience

AIMS

The aim of this study was to evaluate the prognostic value of pre-operative prolactin (PRL) in conjunction with established prognosticators, and the risk of disease relapse in patients with early and advanced breast cancer. To confirm the hypothesis that PRL is produced by breast tumours molecular analysis of PRL, using immunohistochemistry, mRNA by RT-PCR and direct sequencing, was performed. Furthermore, presence of prolactin receptors (PRLR) was evaluated by immunohistochemical localization in these patients.

METHODS

In 111 breast cancer patients, pre-operative PRL was determined by an immunoradiometric assay (IRMA) method. Immunohistochemical localization of PRL (IHL-PRL) and PRLR was performed on formalin-fixed, paraffin-embedded tissue sections. Expression of PRL mRNA was carried out by reverse transcriptase polymerase chain reaction (RT-PCR). RT-PCR PRL amplimer was sequenced and compared with human pituitary PRL amplimer.

RESULTS

Fifty-eight per cent (64/111) of the patients had hyperprolactinaemia (PRL520.0 ng/ml). With increasing tumour size, a higher incidence of hyperprolactinaemia was noted which was statistically significant (r=0.34, P=0.0001). In stage III patients, and in node positive patients, the incidence of hyperprolactinaemia was significantly higher compared to their respective counterparts (stage II vs stage III, r=0.37, P=0.00006; node negative vs node positive, r=0.30, P=0.001). Hyperprolactinaemic patients had a significantly higher risk of developing recurrent/metastatic disease and a higher mortality risk as compared to patients with PRL <20.0 ng/ml. The multivariate survival analysis indicated that apart from disease stage, prognosis of patients with pre-operative hyperprolactinaemia was poorer than that of patients with PRL <20.0 ng/ml. Seventy-eight per cent (87/111) of the tumours showed positive immunoreactivity with PRL antibody indicating that PRL, or a similar molecule, is produced ectopically by breast tumours. PRL mRNA expression using RT-PCR confirmed the de novo synthesis of PRL. PRL mRNA expression was seen in 52% (33/63) of tumours. Sequence analysis of the 234 bp PRL amplimer revealed that the sequence was homologous to the sequence of exon 5 of human pituitary PRL mRNA. Furthermore, PRLR were present in 80% of tumours detected by immunohistochemical localization. A significant positive correlation was noted between IHL-PRL and PRLR (r=0.26, P=0.006).

CONCLUSIONS

This multifaceted study of PRL suggests that breast cancer cells produce PRL and that this ectopically produced PRL may act as a major local growth promoter via autocrine and paracrine mechanisms. It may provide new insights into endocrine treatment of breast cancer.

Retinoid-related orphan receptor gamma (RORgamma) is essential for lymphoid organogenesis and controls apoptosis during thymopoiesis

To identify the physiological functions of the retinoid-related orphan receptor gamma (RORgamma), a member of the nuclear receptor superfamily, mice deficient in RORgamma function were generated by targeted disruption. RORgamma(-/-) mice lack peripheral and mesenteric lymph nodes and Peyer's patches, indicating that RORgamma expression is indispensable for lymph node organogenesis. Although the spleen is enlarged, its architecture is normal. The number of peripheral blood CD3(+) and CD4(+) lymphocytes is reduced 6- and 10-fold, respectively, whereas the number of circulating B cells is normal. The thymus of RORgamma(-/-) mice contains 74.4% +/- 8.9% fewer thymocytes than that of wild-type mice. Flow cytometric analysis showed a decrease in the CD4(+)CD8(+) subpopulation. Terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) staining demonstrated a 4-fold increase in apoptotic cells in the cortex of the thymus of RORgamma(-/-) mice. The latter was supported by the observed increase in annexin V-positive cells. RORgamma(-/-) thymocytes placed in culture exhibit a dramatic increase in the rate of "spontaneous" apoptosis. This increase is largely associated with CD4(+)CD8(+) thymocytes and may, at least in part, be related to the greatly reduced level of expression of the anti-apoptotic gene Bcl-X(L). Flow cytometric analysis demonstrated a 6-fold rise in the percentage of cells in the S phase of the cell cycle among thymocytes from RORgamma(-/-) mice. Our observations indicate that RORgamma is essential for lymphoid organogenesis and plays an important regulatory role in thymopoiesis. Our findings support a model in which RORgamma negatively controls apoptosis in thymocytes.

Expression of the human poliovirus receptor/CD155 gene during development of the central nervous system: implications for the pathogenesis of poliomyelitis

The gene for the human poliovirus receptor (hPVR/CD155) is the founding member of a new family of genes encoding proteins belonging to the immunoglobulin superfamily. To determine whether CD155 is expressed during mammalian development, we have made use of the previously characterized promoter of the CD155 gene and generated mice transgenic for a CD155 promoter-driven beta-galactosidase reporter gene. Expression of the reporter gene in transgenic embryos was observed during midgestation in anterior midline structures of the developing central nervous system and in the neuroretina. During that period, reporter gene expression appeared within the notochord and floor plate along the entire spinal cord reaching into the caudal diencephalon. In addition, transgene expression was observed in axonal projections emanating from retinal ganglion cells forming the optic nerve to reach the future region of the optic chiasm. Analysis of expression of CD155 during human embryonic development confirmed the distribution of reporter gene expression specified by CD155 promoter activity. The anatomical distribution of CD155 promoter activity during embryogenesis matches that of transacting factors previously identified to regulate transcription of the CD155 gene. Expression of CD155 within embryonic structures giving rise to spinal cord anterior horn motor neurons may explain the restrictive host cell tropism of poliovirus for this cellular compartment of the CNS.