Potent suppression of HIV-1 cell attachment by Kudzu root extract

There is a constant need to improve antiretrovirals against HIV since therapy is limited by cost, side effects and the emergence of drug resistance. Kudzu is a climbing vine from which the root extract (Pueraria lobata), rich in isoflavones and saponins, has long been used in traditional Chinese medicine for a variety of purposes, from weight loss to alcoholism prevention. Here we show that Kudzu root extract significantly inhibits HIV-1 entry into cell lines, primary human CD4⁺T lymphocytes and macrophages, without cell-associated toxicity. Specifically, Kudzu inhibits the initial attachment of the viral particle to the cell surface, a mechanism that depends on the envelope glycoprotein gp120 but is independent from the HIV-1 cell receptor CD4 and co-receptors CXCR4/CCR5. This activity seems selective to lentiviruses since Kudzu inhibits HIV-2 and simian immunodeficiency virus, but does not interfere with Hepatitis C, Influenza, Zika Brazil and adenovirus infection. Importantly, depending on the dose, Kudzu can act synergistically or additively with the current antiretroviral cocktails against HIV-1 and can block   viruses resistant to the fusion inhibitor Enfuvirtide. Together our results highlight Kudzu's root extract value as a supplement to current antiretroviral therapy against HIV.

Physical comorbidity in schizophrenia & its correlates

The presence of common physical comorbidities, their demographic and clinical correlates and impact on functioning was assessed in 100 patients with schizophrenia. The patients had a mean age of 35.12±10.7 yr with mean duration of illness of 8.3±0.58 years. Seventy per cent were detected to have a comorbid physical condition. Common conditions included hypertension (21%), diabetes mellitus (15%) and anaemia (12%). Increasing age, being female, being married, longer duration of illness and longer duration of treatment were associated with higher risk of having a comorbid physical illness. Further studies need to be done with a large sample to confirm these findings.

Type-3 von Willebrand disease in India-Clinical spectrum and molecular profile

INTRODUCTION

Type 3 von Willebrand disease (VWD) is the rare and most severe form of VWD which results from a near-complete deficiency of the von Willebrand factor (VWF). This study evaluates in detail the molecular pathology of type-3 VWD in India. One hundred and two patients from 90 families were evaluated.

PATIENTS AND METHODS

Phenotypic data, including bleeding scores (BS), were documented using structured questionnaires. Diagnosis of type 3 VWD was based on undetectable VWF antigen levels in the plasma. Genomic DNA from these patients was screened for mutations in VWF gene. Structural modeling and expression studies were carried out for missense mutations.

RESULTS

Out of 102 patients, mutations could be identified in 91% (n = 93). Fifty-five different gene variants were identified. Thirty-four (61.8%) were novel. Mutations could be identified in both the alleles in 90 patients, while no causative mutation could be identified in 9 patients; twenty-four (23.5%) patients had mutations clustered in the propeptide region of VWF. Interestingly, five mutations accounted for the defects in 37/93 (39.8%) patients. Structural analysis and in vitro studies on missense mutations imply impaired processes associated with secretion of VWF.

CONCLUSION

This study is one of the largest series to define the molecular basis of type-3 VWD.

Combined coagulation factor VIII and factor IX deficiency (CDF8F9) in a patient from Lithuania

Haemophilia A (FVIII deficiency) and haemophilia B (FIX deficiency) are X-linked inherited bleeding disorders. It is a very rare event to identify both haemophilias in the same patient. So far, only two families with such combination are reported in the literature worldwide supported by genetic background. Patients and methods: Evaluation of clinical data, determination of FVIII and FIX levels and genetic analysis of F8 and F9 genes by direct sequencing. Results: We report on a patient having severe haemophilia B (FIX:C <1 IU dl-1) and mild haemophilia A (FVIII:C 18 IU dl-1 ). FIX deficiency was known since childhood, whereas mild haemophilia A was confirmed at the age of 42 due to unexpected bleeding complications after dental extraction despite adequate substitution with plasma derived FIX concentrate. F9 gene analysis showed a point mutation in exon 2 (c.223C>T, p.R75X), whereas F8 gene analysis revealed a point mutation in exon 4 (c.545A>C, p.D182A). The mother of the patient was heterozygous for F8 mutation, but not for F9 mutation suggesting a de novo F9 mutation. Accidentally, further family from Germany with mild Haemophilia A was identified to have the same F8 mutation. F8 Haplo-type analysis revealed that the p.D182A mutation most likely represents a founder mutation with common ancestors of the German and the Lithuanian family. Conclusions: Our results confirm the rare event of Haemophilia A and haemophilia B in the same patient originating from two distinct genetic defects in F8 and F9 genes.

A novel fibrinogen γ chain frameshift deletion (c.637delT) in a patient with hypodysfibrinogenemia associated with thrombosis

Inherited fibrinogen (FG) disorders are rare and result in quantitative or/and qualitative FG deficiency. While the majority of patients with clinically relevant FG deficiencies demonstrate a bleeding phenotype, a subset of patients are at increased risk of thrombosis.

We report a 54-years old man presenting with a thrombophilic phenotype characterized by two episodes of unprovoked venous thrombosis and a deep vein thrombosis several weeks after myocardial infarction. Recently, he developed A. carotis communis thrombosis and died. Coagulation tests were done using standard procedures. FG genes were screened using direct sequencing. Effect on fibrin clot structure was analyzed by scanning electron microscopy (SEM) and FG chain polymerization was analysed using SDS-PAGE.

While thrombophilia testing was negative, we found a decreased concentration of clottable FG (126-148 mg/dl) compared to FG antigen (182-194 mg/dl of normal). The thrombin time was slightly prolonged, while aPTT and reptilase time were within the normal range. A novel deletion in FGG gene (c.637delT) resulting in a frameshift and the premature termination of the γ chain at amino acid position p.228 was identified. SDS-PAGE showed a time-shift in γ-γ and α-α cross linking. SEM showed no statistically significant differences between the patient´s and a healthy control´s fibrin clot structure.

In addition to the reduction of FG concentration expected by the nature of the mutation also a functional defect (hypodysfibrinogenemia) was found. Moreover this mutation seems to increase the risk of thrombosis warranting long term anticoagulation possibly in a combination with antiplatelet drugs.

A prospective study examining the influence of cardiac rehabilitation on the sedentary time of highly sedentary, physically inactive patients

OBJECTIVES

Prolonged sedentary time is recognized as a distinct health risk, and mortality risks are expected to be greatest for individuals with low exercise levels. It is unknown whether participation in exercise-based cardiac rehabilitation (CR) programs influences sedentary behaviour particularly among those patients expected to be at greatest mortality risk. This study examined the influence of CR participation on sedentary behaviour and identified the proportion and characteristics (socio-demographic and clinical) of patients who do not meet exercise recommendations and have prolonged sedentary times.

METHODS

A prospective study was conducted among patients of an exercise-based CR program and assessments performed at baseline and 3 months. Physical activity and sedentary behaviour information were collected by self-report, and convergent validity was examined on an accelerometer-wearing subsample.

RESULTS

Of 468 CR patients approached, 130 participants were recruited with an average sedentary time of 8hours/day. Sedentary behaviour remained consistent at follow-up (relative change= -2.4%, P=0.07) notwithstanding a greater proportion meeting exercise recommendations (relative change= 57.4%). 19.2% of participants were classified to have prolonged sedentary time and not meet exercise recommendations at baseline. No significant differences were found between the characteristics of high-risk individuals and lower risk subgroups. Findings were consistent among the accelerometer-derived subgroup and the overall sample despite poor to moderate convergent validity.

CONCLUSIONS

These results suggest that the exercise-focus of CR may not reduce sedentary behaviours. Future studies are needed to determine whether sedentary behaviour-specific reduction strategies are more effective than traditional exercise-based strategies and lead to meaningful improvements in clinical outcomes.

Surface disordered rutile TiO2–graphene quantum dot hybrids: a new multifunctional material with superior photocatalytic and biofilm eradication properties

Superior photocatalytic degradation by a TG-hybrid towards methylene blue and rhodamine B with enhanced reactive oxygen species for bacterial toxicity.

Acute thyroid swelling in renal transplant recipient

Tuberculosis (TB) of thyroid gland is rare entity even in solid organ transplant recipients who have a high risk of TB. Thyroid TB is easily diagnosed by fine needle aspiration cytology. The majority of cases require only antitubercular drugs for treatment, and surgical intervention is required only in few patients. We here describe a case of thyroid TB presenting as an acute abscess in postrenal transplant recipient with a background of acute rejection treated with steroid and antithymocyte globulin.

Oxidant mediated one-step complete conversion of multi-walled carbon nanotubes to graphene quantum dots and their bioactivity against mammalian and bacterial cells

A simple, low cost, safe, easy to execute, one-step synthesis of uniform, and monodispersed GQDs with selective toxicity towards the bacterial cells rather than the mammalian cells is reported.

A novel missense mutation in the FGB gene (p.Gly302Arg) leading to afibrinogenemia. Predicted structure and function consequences

Afibrinogenemia represents the rarest form of fibrinogen deficiency. Causative missense mutations occur rarely and may improve the understanding of fibrinogen structure and function.

PATIENTS AND METHODS

The propositus was a 26-year-old Argentinian with afibrinogenemia. FGA, FGB and FGG exons and flanking regions were screened by sequencing and the mutant protein was analyzed in silico.

RESULTS

A novel missense mutation in the FGB gene (Bbeta Gly272Arg, p.Gly302Arg) was identified. In silico analysis revealed its location in a highly conserved region, which preserves the core fold of the C-terminal beta-chain and is important for proper secretion. A substitution by a positively charged large Arg residue in this area would most likely disturb the core fold by additional interactions with adjacent residues (p.Asp291, p.Asp297, p.Asp311), or by forming of non-native interactions with other proteins, thereby hindering the action of molecular chaperones. Both alternatives would disturb the regular secretion of the beta-chain.

CONCLUSIONS

The novel missense mutation in the FGB gene causes afibrinogenemia most probably by affecting the secretion of the fibrinogen beta-chain.

Combined coagulation factor VIII and factor IX deficiency (CDF8F9) in a patient from Lithuania

Haemophilia A (FVIII deficiency) and haemophilia B (FIX deficiency) are X-linked inherited bleeding disorders. It is a very rare event to identify both haemophilias in the same patient. So far, only two families with such combination are reported in the literature worldwide supported by genetic background.

PATIENTS AND METHODS

Evaluation of clinical data, determination of FVIII and FIX levels and genetic analysis of F8 and F9 genes by direct sequencing.

RESULTS

We report on a patient having severe haemophilia B (FIX:C <1 IU dl^-1) and mild haemophilia A (FVIII:C 18 IU dl^-1 ). FIX deficiency was known since childhood, whereas mild haemophilia A was confirmed at the age of 42 due to unexpected bleeding complications after dental extraction despite adequate substitution with plasma derived FIX concentrate. F9 gene analysis showed a point mutation in exon 2 (c.223C>T, p.R75X), whereas F8 gene analysis revealed a point mutation in exon 4 (c.545A>C, p.D182A). The mother of the patient was heterozygous for F8 mutation, but not for F9 mutation suggesting a de novo F9 mutation. Accidentally, further family from Germany with mild Haemophilia A was identified to have the same F8 mutation. F8 Haplotype analysis revealed that the p.D182A mutation most likely represents a founder mutation with common ancestors of the German and the Lithuanian family.

CONCLUSIONS

Our results confirm the rare event of Haemophilia A and haemophilia B in the same patient originating from two distinct genetic defects in F8 and F9 genes.

Chemoradiotherapy for squamous cell anal carcinoma: a review of prognostic factors

AIM

Previous literature has sought prognostic factors for the survival of anal cancer patients. The present study aimed to determine prognostic factors for local disease recurrence, distant metastasis and survival for patients treated with radical chemoradiotherapy (CRT) at the Rosemere Cancer Centre, Preston, UK.

METHOD

Patients treated with CRT for nonmetastatic squamous cell anal cancer between September 2000 and January 2013 were studied. Kaplan-Meier and Cox regression analysis assessed the prognostic value of age, sex, tumour size, the proportion of the anal canal circumference involved (ACCI), nodal disease, tumour location and pretreatment haemoglobin.

RESULTS

One hundred and 48 patients with a mean age of 63 years were studied, of whom 15% suffered local disease recurrence and 10% developed distant metastasis. The 5-year overall and cancer-specific survival rates were 84% and 86%, respectively. Predictors of local recurrence were tumour size >5 cm and over two-thirds ACCI (P < 0.01). Predictors of distant metastasis and poor survival were tumour size >5 cm (P < 0.01), node positive disease on imaging (P < 0.05), over two-thirds ACCI (P < 0.01) and a pretreatment haemoglobin level below 130 g/l (P < 0.05). Multivariate analysis found large tumour size to be the most significant factor for local recurrence (P = 0.002) and survival (P = 0.02) whilst over two-thirds ACCI was most predictive of distant metastasis (P < 0.001). Age, gender, palpable lymph nodes and tumour location were not of prognostic value for local disease recurrence, distant metastasis or survival.

CONCLUSION

Tumour size, nodal disease, over two-thirds ACCI and low pretreatment haemoglobin confer poorer prognostic and survival outcomes. Use of intensity-modulated radiation therapy may allow greater radiation doses to be given for locally advanced tumours, thus improving local control and survival and reducing morbidity.

Custom-made silicone hand prosthesis: A case study

Up to now, a cosmetic glove was the most common method for managing transmetacarpal (TMC) and carpometacarpal (CMC) amputations, but it is devoid of markings and body color. At this amputation level, it is very difficult to fit a functional prosthesis because of the short available length, unsightly shape, grafted skin, contracture and lack of functional prosthetic options. A 30-year-old male came to our clinic with amputation at the 1st to 4th carpometacarpal level and a 5th metacarpal that was projected laterally and fused with the carpal bone. The stump had grafted skin, redness, and an unhealed suture line. He complained of pain projected over the metacarpal and suture area. The clinical team members decided to fabricate a custom-made silicone hand prosthesis to accommodate the stump, protect the grafted skin, improve the hand's appearance and provide some passive function. The custom silicone hand prosthesis was fabricated with modified flexible wires to provide passive interphalangeal movement. Basic training, care and maintenance instructions for the prosthesis were given to the patient. The silicone hand prosthesis was able to restore the appearance of the lost digits and provide some passive function. His pain (VAS score) was reduced. Improvement in activities of daily living was found in the DASH questionnaire and Jebsen-Taylor Hand Function test. A silicone glove is a good option for more distal amputations, as it can accommodate any deformity, protect the skin, enhance the appearance and provide functional assistance. This case study provides a simple method to get passively movable fingers after proximal hand amputation.

Accuracy of ultrasound dating formulae in the late second-trimester in pregnancies conceived with in-vitro fertilization

Purpose: To investigate the accuracy of ultrasound dating formulae in the late second trimester of pregnancy.

Material and Methods: A dataset of 136 singleton pregnancies conceived by artificial reproductive techniques was studied to assess the accuracy of ultrasound dating formulae in the late second trimester, and compared with early second trimester. A total of 21 published ultrasound-dating formulae were tested.

Results: For most formulae, late second trimester scans yielded results that were marginally less accurate than the early second trimester. The best performance was obtained with dating formulae based on femur length, either alone or combined with the biparietal diameter. These formulae had mean absolute errors of 3–3.5 days. Combining two or more parameters did not result in any substantial gain in accuracy.

Conclusions: Pregnancy dating by ultrasound in the late second trimester is sufficiently accurate for routine clinical use. Formulae based on femur length appear to be at least as accurate as head measurements.

Composition dependence of charge and magnetic length scales in mixed valence manganite thin films

Mixed-valence manganese oxides present striking properties like the colossal magnetoresistance, metal-insulator transition (MIT) that may result from coexistence of ferromagnetic, metallic and insulating phases. Percolation of such phase coexistence in the vicinity of MIT leads to first-order transition in these manganites. However the length scales over which the electronic and magnetic phases are separated across MIT which appears compelling for bulk systems has been elusive in (La_1−yPr_y)_1−xCa_xMnO₃ films. Here we show the in-plane length scale over which charge and magnetism are correlated in (La_0.4Pr_0.6)_1−xCa_xMnO₃ films with x = 0.33 and 0.375, across the MIT temperature. We combine electrical transport (resistance) measurements, x-ray absorption spectroscopy (XAS), x-ray magnetic circular dichroism (XMCD), and specular/off-specular x-ray resonant magnetic scattering (XRMS) measurements as a function of temperature to elucidate relationships between electronic, magnetic and morphological structure of the thin films. Using off-specular XRMS we obtained the charge-charge and charge-magnetic correlation length of these LPCMO films across the MIT. We observed different charge-magnetic correlation length for two films which increases below the MIT. The different correlation length shown by two films may be responsible for different macroscopic (transport and magnetic) properties.

Identification and functional characterization of a novel F5 mutation (Ala512Val, FVB onn ) associated with activated protein C resistance

Essentials Activated protein C (APC) resistance is a prevalent risk factor for venous thrombosis. A novel missense mutation (Ala512Val - FVBonn ) was characterized in vitro and in silico. FVBonn is a new cause of APC resistance and venous thrombosis. FVBonn expresses additionally enhanced procoagulant activity in the absence of APC.

SUMMARY

Background Activated protein C (APC) resistance is a prevalent risk factor for venous thrombosis. This phenotype is most commonly associated with the factor V Arg506Gln mutation (FV Leiden), which impairs the APC-mediated inactivation of both activated FV (FVa) and activated FVIII (FVIIIa). Objectives Here, we report the identification and characterization of a novel FV mutation (Ala512Val, FVBonn ) in six patients with APC resistance and venous thrombosis or recurrent abortions. Methods FVBonn was expressed in a recombinant system and compared with recombinant wild-type (WT) FV and FV Leiden in several functional assays. Results FVBonn conferred APC resistance to FV-depleted plasma, both in the activated partial thromboplastin time (APTT)-based test (APC sensitivity ratio [APCsr] of 1.98 for FVBonn versus 4.31 for WT FV and 1.59 for FV Leiden) and in the thrombin generation-based test (normalized APCsr of 5.41 for FVBonn versus 1.00 for WT FV and 8.99 for FV Leiden). The APC-mediated inactivation of FVaBonn was slower than that of WT FVa (mainly because of delayed cleavage at Arg506), but was greatly stimulated by protein S. The APC cofactor activity of FVBonn in FVIIIa inactivation was ~ 24% lower than that of WT FV. In line with these findings, an in silico analysis showed that the Ala512Val mutation is located in the same loop as the Arg506 APC cleavage site and might hamper its interaction with APC. Moreover, FVBonn was more procoagulant than WT FV and FV Leiden in the absence of APC, because of an increased activation rate and, possibly, an enhanced interaction with activated FX. Conclusions FVBonn induces hypercoagulability via a combination of increased activation/procoagulant activity, decreased susceptibility to APC-mediated inactivation, and slightly reduced APC cofactor activity.

Clinico-Hematologic Profile of Factor XIII-Deficient Patients

A retrospective analysis of clinico-hematologic parameters of 18 factor XIII-deficient patients was carried out. The hematologic tests included activated partial thromboplastin time (APTT), prothrombin time (PT), and clot solubility. Laboratory diagnosis of FXIII deficiency was made where bleeding time, PT, APTT, and thrombin time were normal and the clot solubility test result with 5M urea was positive. Factor XIII level with family screening was performed using commercially available kits. History of prolonged bleeding from the umbilical stump was present in four (22.2%) patients. The most common site of bleeding was the skin (11 of 18 patients). Three patients were given prophylaxis (FFP in two, factor XIII in one). A high prevalence of recurrent abortion in female pa tients with FXIII deficiency (two of the three patients in this study) was observed.

Clinicohematologic Spectrum in Patientswith Lupus Anticoagulant

A retrospective analysis of clinicohematologic parameters of 25 patients with lupus anticoagulant was carried out. The hematologic tests included dilute Russel viper venom test (dRVVT), kaolin clotting time (KCT), activated partial thromboplastin time, and prothrombin time. The diagnosis of lupus anticoagulants was based on the presence of prolonged KCT/dRVVT, its absence of correction with normal plasma and correction by phospholipids. Specific factor assays and platelet aggregation studies were performed wherever required. Ten patients (40%) had thrombosis, which was venous in 5 (50%) and arterial in 4 (40%). One patient (10%) had both arterial and venous thrombosis and presented with catastrophic antiphospholipid syndrome. Eighteen female patients conceived. Four (22%) of these had recurrent first trimester abortion. Five (20%) patients had bleeding manifestations. One (4%) of these had hypoprothrombinemia and was diagnosed to have hypoprothrombinemia lupus anticoagulant syndrome. However in two of these patients, no cause of bleeding could be identified other than the presence of lupus anticoagulants. It is concluded that patients with lupus anticoagulant have a varied spectrum of hemostatic disorders. Bleeding may sometimes occur in these patients due to associated thrombocytopenia or associated factor inhibitors. Rarely, it may occur due to presence of lupus anticoagulants alone.

Tricky typhus ticks two: A report of two sisters from North India presenting with acute respiratory distress syndrome due to scrub typhus

Scrub typhus is emerging as an important cause of acute febrile illness in Northern India. This is a report of two sisters presenting concurrently with acute respiratory distress syndrome. A diagnosis of scrub typhus was made in both the patients, and they were successfully treated with doxycycline.

A novel missense mutation in the FGB gene (p.Gly302Arg) leading to afibrinogenemia

Afibrinogenemia represents the rarest form of fibrinogen deficiency. Causative missense mutations occur rarely and may improve the understanding of fibrinogen structure and function. Patients and methods: The propositus was a 26-year-old Argentinian with afibrinogenemia. FGA, FGB and FGG exons and flanking regions were screened by sequencing and the mutant protein was analyzed in silico. Results: A novel missense mutation in the FGB gene (Bbeta Gly272Arg, p.Gly302Arg) was identified. In silico analysis revealed its location in a highly conserved region, which preserves the core fold of the C-terminal beta-chain and is important for proper secretion. A substitution by a positively charged large Arg residue in this area would most likely disturb the core fold by additional interactions with adjacent residues (p.Asp291, p.Asp297, p.Asp311), or by forming of non-native interactions with other proteins, thereby hindering the action of molecular chaperones. Both alternatives would disturb the regular secretion of the beta-chain. Conclusions: The novel mis-sense mutation in the FGB gene causes afibrinogenemia most probably by affecting the secretion of the fibrinogen beta-chain.

Batf3 deficiency proves the pivotal role of CD8α+ dendritic cells in protection induced by vaccination with attenuated Plasmodium sporozoites

Increasing evidence indicates that hepatic CD8α⁺ dendritic cells (DCs) are important antigen cross-presenting cells (APC) involved in the priming of protective CD8⁺ T-cell responses induced by live-attenuated Plasmodium sporozoites. Experimental proof for a critical role of CD8α⁺ DCs in protective pre-erythrocytic malaria immunizations has pivotal implications for vaccine development, including improved vectored subunit vaccines. Employing Batf3^-/- mice, which lack functional CD8α⁺ DCs, we demonstrate that deficiency of these particular APCs completely abolishes protection and corresponding signatures of vaccine-induced immunity. We show that in wild-type, but not in Batf3^-/- , mice CD8α⁺ DCs accumulate in the liver after immunization with live irradiation-attenuated P. berghei sporozoites. IFN-γ production by Plasmodium antigen-specific CD8⁺ T cells is dependent on functional Batf3. In addition, our results demonstrate that the dysfunctional cDC-CD8+ T-cell axis correlates with MHC class II upregulation on splenic CD8α^- DCs. Collectively, these findings underscore the essential role of CD8α⁺ DCs in robust protection induced by experimental live-attenuated malaria vaccines.

Expression of microRNA-155 correlates positively with the expression of Toll-like receptor 7 and modulates hepatitis B virus via C/EBP-β in hepatocytes

Effective recognition of viral infection and successive activation of antiviral innate immune responses are vital for host antiviral defence, which largely depends on multiple regulators, including Toll-like receptors (TLRs) and microRNAs. Several early reports suggest that specific TLR-mediated immune responses can control hepatitis B virus (HBV) replication and express differentially with disease outcome. Considering the versatile function of miR-155 in the TLR-mediated innate immune response, we aimed to study the association between miR-155 and TLRs and their subsequent impact on HBV replication using both a HBV-replicating stable cell line (HepG2.2.15) and HBV-infected liver biopsy and serum samples. Our results showed that miR-155 was suppressed during HBV infection and a subsequent positive correlation of miR-155 with TLR7 activation was noted. Further, ectopic expression of miR-155 in vitro reduced HBV load as evidenced from reduced viral DNA, mRNA and subsequently reduced level of secreted viral antigens (HBsAg and HBeAg). Our results further suggested that CCAAT/enhancer-binding protein-β (C/EBP-β), a positive regulator of HBV transcription, was inhibited by miR-155. Taken together, our study established a correlation between miR-155 and TLR7 during HBV infection and also demonstrated in vitro that increased miR-155 level could help to reduce HBV viral load by targeting C/EBP-β.

Interaction of α-crystallin with some small molecules and its effect on its structure and function

BACKGROUND

α-Crystallin acts like a molecular chaperone by interacting with its substrate proteins and thus prevents their aggregation. It also interacts with various kinds of small molecules that affect its structure and function.

SCOPE OF REVIEW

In this article we will present a review of work done with respect to the interaction of ATP, peptide generated from lens crystallin and other proteins and some bivalent metal ions with α-crystallin and discuss the role of these interactions on its structure and function and cataract formation. We will also discuss the interaction of some hydrophobic fluorescence probes and surface active agents with α-crystallin.

MAJOR CONCLUSIONS

Small molecule interaction controls the structure and function of α-crystallin. ATP and Zn+2 stabilize its structure and enhance chaperone function. Therefore the depletion of these small molecules can be detrimental to maintenance of lens transparency. However, the accumulation of small peptides due to protease activity in the lens can also be harmful as the interaction of these peptides with α-crystallin and other crystallin proteins in the lens promotes aggregation and loss of lens transparency. The use of hydrophobic probe has led to a wealth of information regarding the location of substrate binding site and nature of chaperone-substrate interaction. Interaction of surface active agents with α-crystallin has helped us to understand the structural stability and oligomeric dissociation in α-crystallin.

GENERAL SIGNIFICANCE

These interactions are very helpful in understanding the mechanistic details of the structural changes and chaperone function of α-crystallin. This article is part of a Special Issue entitled Crystallin Biochemistry in Health and Disease.