MicroRNA-409-3p/BTG2 signaling axis improves impaired angiogenesis and wound healing in obese mice

Wound healing is facilitated by neoangiogenesis, a complex process that is essential to tissue repair in response to injury. MicroRNAs are small, noncoding RNAs that can regulate the wound healing process including stimulation of impaired angiogenesis that is associated with type-2 diabetes (T2D). Expression of miR-409-3p was significantly increased in the nonhealing skin wounds of patients with T2D compared to the non-wounded normal skin, and in the skin of a murine model with T2D. In response to high glucose, neutralization of miR-409-3p markedly improved EC growth and migration in human umbilical vein endothelial cells (HUVECs), promoted wound closure and angiogenesis as measured by increased CD31 in human skin organoids, while overexpression attenuated EC angiogenic responses. Bulk mRNA-Seq transcriptomic profiling revealed BTG2 as a target of miR-409-3p, where overexpression of miR-409-3p significantly decreased BTG2 mRNA and protein expression. A 3' untranslated region (3'-UTR) luciferase assay of BTG2 revealed decreased luciferase activity with overexpression of miR-409-3p, while inhibition had opposite effects. Mechanistically, in response to high glucose, miR-409-3p deficiency in ECs resulted in increased mTOR phosphorylation, meanwhile BTG-anti-proliferation factor 2 (BTG2) silencing significantly decreased mTOR phosphorylation. Endothelial-specific and tamoxifen-inducible miR-409-3p knockout mice (MiR-409IndECKO ) with hyperglycemia that underwent dorsal skin wounding showed significant improvement of wound closure, increased blood flow, granulation tissue thickness (GTT), and CD31 that correlated with increased BTG2 expression. Taken together, our results show that miR-409-3p is a critical mediator of impaired angiogenesis in diabetic skin wound healing.

Human red blood cells release microvesicles with distinct sizes and protein composition that alter neutrophil phagocytosis

Extracellular vesicles (EVs) are membrane-bound structures released by cells and tissues into biofluids, involved in cell-cell communication. In humans, circulating red blood cells (RBCs), represent the most common cell-type in the body, generating daily large numbers of microvesicles. In vitro, RBC vesiculation can be mimicked by stimulating RBCs with calcium ionophores, such as ionomycin and A23187. The fate of microvesicles released during in vivo aging of RBCs and their interactions with circulating cells is hitherto unknown. Using SEC plus DEG isolation methods, we have found that human RBCs generate microvesicles with two distinct sizes, densities, and protein composition, identified by flow cytometry, and MRPS, and further validated by immune TEM. Furthermore, proteomic analysis revealed that RBC-derived microvesicles (RBC-MVs) are enriched in proteins with important functions in ion channel regulation, calcium homeostasis, and vesicular transport, such as of sorcin, stomatin, annexin A7, and RAB proteins. Cryo-electron microscopy identified two separate pathways of RBC-MV-neutrophil interaction, direct fusion with the plasma membrane and internalization, respectively. Functionally, RBC-MVs decrease neutrophil ability to phagocytose E. coli but do not affect their survival at 24 hrs. This work brings new insights regarding the complexity of the RBC-MVs biogenesis, as well as their possible role in circulation.

A nanoparticle probe for the imaging of autophagic flux in live mice via magnetic resonance and near-infrared fluorescence

Autophagy-the lysosomal degradation of cytoplasmic components via their sequestration into double-membraned autophagosomes-has not been detected non-invasively. Here we show that the flux of autophagosomes can be measured via magnetic resonance imaging or serial near-infrared fluorescence imaging of intravenously injected iron oxide nanoparticles decorated with cathepsin-cleavable arginine-rich peptides functionalized with the near-infrared fluorochrome Cy5.5 (the peptides facilitate the uptake of the nanoparticles by early autophagosomes, and are then cleaved by cathepsins in lysosomes). In the heart tissue of live mice, the nanoparticles enabled quantitative measurements of changes in autophagic flux, upregulated genetically, by ischaemia-reperfusion injury or via starvation, or inhibited via the administration of a chemotherapeutic or the antibiotic bafilomycin. In mice receiving doxorubicin, pre-starvation improved cardiac function and overall survival, suggesting that bursts of increased autophagic flux may have cardioprotective effects during chemotherapy. Autophagy-detecting nanoparticle probes may facilitate the further understanding of the roles of autophagy in disease.

Role of the Mosaic Cisternal Maturation Machinery in Glycan Synthesis and Oncogenesis

Tumorigenesis is associated with the deregulation of multiple processes, among which the glycosylation of lipids and proteins is one of the most extensively affected. However, in most cases, it remains unclear whether aberrant glycosylation is a cause, a link in the pathogenetic chain, or a mere consequence of tumorigenesis. In other cases, instead, studies have shown that aberrant glycans can promote oncogenesis. To comprehend how aberrant glycans are generated it is necessary to clarify the underlying mechanisms of glycan synthesis at the Golgi apparatus, which are still poorly understood. Important factors that determine the glycosylation potential of the Golgi apparatus are the levels and intra-Golgi localization of the glycosylation enzymes. These factors are regulated by the process of cisternal maturation which transports the cargoes through the Golgi apparatus while retaining the glycosylation enzymes in the organelle. This mechanism has till now been considered a single, house-keeping and constitutive function. Instead, we here propose that it is a mosaic of pathways, each controlling specific set of functionally related glycosylation enzymes. This changes the conception of cisternal maturation from a constitutive to a highly regulated function. In this new light, we discuss potential new groups oncogenes among the cisternal maturation machinery that can contribute to aberrant glycosylation observed in cancer cells. Further, we also discuss the prospects of novel anticancer treatments targeting the intra-Golgi trafficking process, particularly the cisternal maturation mechanism, to control/inhibit the production of pro-tumorigenic glycans.

TRACE-seq: A transgenic system for unbiased and non-invasive transcriptome profiling of living cells

Dynamic profiling of changes in gene expression in response to stressors in specific microenvironments without requiring cellular destruction remains challenging. Current methodologies that seek to interrogate gene expression at a molecular level require sampling of cellular transcriptome and therefore lysis of the cell, preventing serial analysis of cellular transcriptome. To address this area of unmet need, we have recently developed a technology allowing transcriptomic analysis over time without cellular destruction. Our method, TRACE-seq (TRanscriptomic Analysis Captured in Extracellular vesicles using sequencing), is characterized by a cell-type specific transgene expression. It provides data on the transcriptome inside extracellular vesicles that provides an accurate representation of stress-responsive cellular transcriptomic changes. Thus, the transcriptome of cells expressing TRACE can be followed over time without destroying the source cell, which is a powerful tool for many fields of fundamental and translational biology research.

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TRanscriptomic Analysis Captured in Extracellular vesicles using RNA-sequencing

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Excellent correlation of cellular and EV transcriptome using this method

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Accurate profiling of gene expression changes in response to stress signals

Peripheral blood-derived monocytes show neuronal properties and integration in immune-deficient rd1 mouse model upon phenotypic differentiation and induction with retinal growth factors

BACKGROUND

Cell therapy is one of the most promising therapeutic interventions for retinitis pigmentosa. In the current study, we aimed to assess if peripheral blood-derived monocytes which are highly abundant and accessible could be utilized as a potential candidate for phenotypic differentiation into neuron-like cells.

METHODS

The peripheral blood-derived monocytes were reconditioned phenotypically using extrinsic growth factors to induce pluripotency and proliferation. The reconditioned monocytes (RM) were further incubated with a cocktail of growth factors involved in retinal development and growth to induce retinal neuron-like properties. These cells, termed as retinal neuron-like cells (RNLCs) were characterized for their morphological, molecular and functional behaviour in vitro and in vivo.

RESULTS

The monocytes de-differentiated in vitro and acquired pluripotency with the expression of prominent stem cell markers. Treatment of RM with retinal growth factors led to an upregulation of neuronal and retinal lineage markers and downregulation of myeloid markers. These cells show morphological alterations resembling retinal neuron-like cells and expressed photoreceptor (PR) markers. The induced RNLCs also exhibited relative membrane potential change upon light exposure suggesting that they have gained some neuronal characteristics. Further studies showed that RNLCs could also integrate in an immune-deficient retinitis pigmentosa mouse model NOD.SCID-rd1 upon sub-retinal transplantation. The RNLCs engrafted in the inner nuclear layer (INL) and ganglion cell layer (GCL) of the RP afflicted retina. Mice transplanted with RNLCs showed improvement in depth perception, exploratory behaviour and the optokinetic response.

CONCLUSIONS

This proof-of-concept study demonstrates that reconditioned monocytes can be induced to acquire retinal neuron-like properties through differentiation using a defined growth media and can be a potential candidate for cell therapy-based interventions and disease modelling for ocular diseases.

Apoptosis-inducing factor deficient mice fail to develop hepatic steatosis under high fat high fructose diet or bile duct ligation

Apoptosis-inducing factor (AIF) is a mitochondrial flavoprotein involved in redox signalling and programmed cell death. The role of AIF has been well recognized in diabetes and obesity. However, the aspect of AIF deficiency in the development of hepatic steatosis and liver injury is unknown. Therefore, in the current study, Harlequin (Hq mutant) mouse with markedly reduced content of AIF was investigated to explore the role of AIF on the initiation of liver injury. The wild type (WT) developed physiological and pathological features of non-alcoholic fatty liver disease (NAFLD) that were not seen in the Hq mice with AIF deficiency, when fed on high fat high fructose (HFHF) diet. Following bile duct ligation (BDL), the liver associated pathological changes were less conspicuous in Hq mice as compared to WT mice. The expression of AIF protein and apoptosis was markedly lesser as compared to their respective control in Hq mice on HFHF diet. Furthermore, the genes involved in fatty acid metabolism were also altered in the group of treated Hq mice. In conclusion, Hq mice failed to develop diet induced hepatic steatosis, suggestive of a role of AIF mediated pathway in the initiation and progression of liver inflammation. Thus, partial loss of AIF appears to be hepatoprotective. SIGNIFICANCE OF THE STUDY: AIF deficiency has multiple roles in altered pathology processes and cellular metabolism, thereby compromising the cellular homeostasis. Considering the molecular functions of AIF in other organ pathology little is known about its role in diet induced liver injury. Hence, the aim of the current study was to investigate the role of AIF deficiency in liver injury and diseases with focus on NAFLD. The study will help to deliniate the mechanisms of NAFLD using Harliquin Mice.

DFT and MD simulation supplemented experiments for isotopic fractionation of zinc compounds using a macrocyclic crown ether appended polymeric resin

Isotope effect is a quantum mechanical phenomenon and thus poses a challenge for the separation of isotopes of an element of interest, especially for heavy elements. Isotopic fractionation of zinc is also quite difficult and challenging but is necessitated due to various applications of its isotopes ranging from nuclear medicine to nuclear power reactors. Here, we developed the dibenzo-18-crown-6 (DB18C6) ether-functionalized poly(methacrylic acid) (PMA) resin by exploiting the ion and isotope recognition ability of the crown ether using DFT/MD simulations followed by experiments for isotopic fractionation of zinc. The PMADB18C6 adsorbent was prepared and suitably characterized. Both computational and experimental findings demonstrate that the adsorption and isotope separation of zinc with PMADB18C6 are due to the molecular recognition effect of the "O" dipole of the crown ether. Furthermore, both MD simulations and experiments suggest Langmuir type adsorption isotherms. The adsorption of Zn2+ ions on the PMA resin is predicted to be endothermic, whereas it is exothermic on the PMADB18C6 resin, as revealed from the experimentally observed enthalpy change. A small scale fixed bed column study was demonstrated to test the scale-up application. The values of the experimental separation factors: 1.0013 for 66/64 and 1.0027 for 68/64 confirm the computationally predicted results of 1.00088 and 1.0010, respectively, thus establishing the combined strength of the theory and experiments for the identification of efficient fractionating agents for a complex quantum isotope effect which eventually helps in planning further experiments in view of medicinal and technological applications of zinc isotopes.

Generation of a Rat Model of Acute Liver Failure by Combining 70% Partial Hepatectomy and Acetaminophen

Acute liver failure (ALF) is a clinical condition caused by various etiologies resulting in the loss of metabolic, biochemical, synthesizing, and detoxifying functions of the liver. In most irreversible liver damage cases, orthotropic liver transplant (OLT) remains the only available treatment. To study the therapeutic potential of a treatment for ALF, its prior testing in an animal model of ALF is essential. In the current study, an ALF model in rats was developed by combining 70% partial hepatectomy (PHx) and injections of acetaminophen (APAP) that provides a therapeutic window of 48 h. The median and left lateral lobes of the liver were removed to excise 70% of the liver mass and APAP was given 24 h postsurgically for 2 days. Survival in ALF-induced animals was found to be severely decreased. The development of ALF was confirmed by altered serum levels of the enzymes alanine amino transferase (ALT), aspartate amino transferase (AST), alkaline phosphatase (ALP); changes in prothrombin time (PT); and assessment of the international normalized ratio (INR). Study of the gene expression profile by qPCR revealed an increase in expression levels of genes involved in apoptosis, inflammation, and in the progression of liver injury. Diffused degeneration of hepatocytes and infiltration of immune cells was observed by histological evaluation. The reversibility of ALF was confirmed by the restoration of survival and serum levels of ALT, AST, and ALP after intrasplenic transplantation of syngeneic healthy rat hepatocytes. This model presents a reliable alternative to the available ALF animal models to study the pathophysiology of ALF as well as to evaluate the potential of a novel therapy for ALF. The use of two different approaches also makes it possible to study the combined effect of physical and drug-induced liver injury. The reproducibility and feasibility of current procedure is an added benefit of the model.

Efficacy of generic oral directly acting agents in patients with hepatitis C virus infection

Novel direct-acting antivirals (DAAs) are now the standard of care for the management of hepatitis C virus (HCV) infection. Branded DAAs are associated with high sustained virological response at 12 weeks post-completion of therapy (SVR12), but are costly. We aimed to assess the efficacy of generic oral DAAs in a real-life clinical scenario. Consecutive patients with known HCV infection who were treated with generic-oral DAA regimens (May 2015 to January 2017) were included. Demographic details, prior therapy and SVR12 were documented. Four hundred and ninety patients (mean age: 38.9 ± 12.7 years) were treated with generic DAAs in the study time period. Their clinical presentations included chronic hepatitis (CHC) in 339 (69.2%) of cases, compensated cirrhosis in 120 (24.48%) cases and decompensated cirrhosis in 31 (6.32%) cases. Genotype 3 was most common (n = 372, 75.9%) followed by genotype 1 (n = 97, 19.8%). Treatment naïve and treatment-experienced (defined as having previous treatment with peginterferon and ribavirin) were 432 (88.2%) and 58 (11.8%), respectively. Generic DAA treatment regimens included sofosbuvir in combination with ribavirin (n = 175), daclatasvir alone (n = 149), ribavirin and peginterferon (n = 80), ledipasvir alone (n = 43), daclatasvir and ribavirin (n = 37), and ledipasvir and ribavirin (n = 6). Overall SVR12 was 95.9% (470/490) for all treatment regimens. SVR12 for treatment naïve and experienced patients was 97.0% (419/432) and 87.9% (51/58), respectively, P = .005. High SVR12 was observed with various regimens, irrespective of genotype and underlying liver disease status. There were no differences in SVR12 with 12 or 24 weeks therapy. No major adverse event occurred requiring treatment stoppage. Generic oral DAAs are associated with high SVR rates in patients with HCV infection in a real-life clinical scenario.

Occult Hepatitis B virus Infection (OBI) predominated by genotype D among chronic liver disease patients: The first report from Odisha, Eastern India

Detection of Occult hepatitis B infection (OBI) has higher significance for treatment and management. There is no information available about the OBI and its genotype associated with chronic hepatitis patients in Odisha, India. We aimed to determine the association of OBI and its genotype among the chronic hepatitis patients in Odisha. In a hospital based study, 175 serum samples of chronic hepatitis patients were screened for Hepatitis surface antigen (HBsAg). All the HBsAg - negative samples were tested for hepatitis B core antibodies (HBcAb). HBcAb-positive samples were tested further for Hepatitis surface antibodies (HBsAb), hepatitis B virus HBV-DNA and HBV genotyping. Of the 89 HBsAg negative samples, 79 (88.8%) were found positive for HBcAb and these patients were presumed to have OBI. Among the total HBcAb positive samples, 22 (27.8%) were positive and 57 (72.2%) were negative for HBsAb. Detection of HBV- DNA from 45 out of 79 HBcAb positive samples (57.0%) yielded positive results for OBI which was negative for HBsAb. Genotyping of all hepatitis B virus showed that all 45 (100%) were genotype-D. Detection of OBI among chronic hepatitis patients suggests testing for OBI for management and treatment.

Intrasplenic Transplantation of Hepatocytes After Partial Hepatectomy in NOD.SCID Mice

Partial hepatectomy is a versatile and reproducible method to study liver regeneration and the effect of cell based therapeutics in various pathological conditions. Partial hepatectomy also facilitates the increased engraftment and proliferation of transplanted cells by accelerating neovascularization and cell migration towards the liver. Here, we describe a simple protocol for performing 30% hepatectomy and transplantation of cells in the spleen of a non-obese diabetic/severe combined immunodeficient NOD.SCID (NOD.CB17-Prkdc^scid/J) mouse. In this procedure, two small incisions are made. The first incision is to expose and resect the left lobe of the liver, and another small incision is made to expose the spleen for the intrasplenic transplantation of cells. This procedure does not require any specialized surgical skills, and it can be completed in 5-7 minutes with less stress and pain, faster recovery, and better survival. We have demonstrated the transplantation of hepatocytes isolated from a green fluorescent protein (GFP) expressing mouse (Transgenic C57BL/6-Tg (UBC-GFP) 30Scha/J), as well as hepatocyte like cells of human origin (NeoHep) in partially hepatectomized NOD.SCID mice.

A novel immunodeficient NOD.SCID-rd1 mouse model of retinitis pigmentosa to investigate potential therapeutics and pathogenesis of retinal degeneration

Retinitis pigmentosa (RP) is a common retinal degeneration disease caused by mutation in any gene of the photo transduction cascade and results in photoreceptor dystrophy. Over decades, several animal models have been used to address the need for the elucidation of effective therapeutics and factors regulating retinal degeneration to prohibit or renew the damaged retina. However, controversies over the immune privilege of retina during cell transplantation and the role of immune modulation during RP still remain largely uninvestigated because of the lack of suitable animal models. Here, we have developed an immunocompromised mouse model, NOD.SCID-rd1, for retinitis pigmentosa (RP) by crossing CBA/J and NOD SCID mice and selecting homozygous double mutant animals for further breeding. Characterization of the newly developed RP model indicates a similar retinal degeneration pattern as CBA/J, with a decreased apoptosis rate and rhodopsin loss. It also exhibits loss of T cells, B cells and NK cells. The NOD.SCID-rd1 model is extremely useful for allogenic and xenogenic cell-based therapeutics, as indicated by the higher cell integration capacity post transplantation. We dissect the underlying role of the immune system in the progression of RP and the effect of immune deficiency on immune privilege of the eye using comparative qPCR studies of this model and the immune-competent RP model.

Summary: NOD.SCID-rd1 is an immune compromised mouse model of retinitis pigmentosa (RP) to investigate cell-based therapeutics for retinal rescue during RP and to study immunological aspects of its pathogenesis and progression.

Beneficiation of limestone plant rejects for value addition

Investigations were carried out on lime stone rejects (-1mm) generated at a lime stone washing plant in southern India. These rejects contain 12.09% CaO, 2.95% MgO, 10.73% Al2O3, 4.99% Fe2O3, 43.05% SiO2 and 24.92% LOI. Mineralogical studies including SEM-EDAX, XRD, FTIR and TGA were conducted to confirm relative distribution of minerals in the flotation feed and products. These studies revealed that feed sample consists of quartz and calcite as the major minerals with minor amounts of montmorillonite and dolomite whereas flotation concentrate dominantly consists of calcite, and tailings mostly of quartz and montmorillonite. A commercial grade sodium silicate, oleic acid and MIBC were used as depressant, collector and frother respectively in flotation studies. The effects of different operating parameters were evaluated for both conventional and column flotation. Two stage conventional cell flotation results indicate that a cleaner concentrate of 42.50% lime (CaO) content could be obtained at a yield of 15.65%. The lime (CaO) content of the concentrate was further enhanced up to 44.23% at 20.73% yield using single stage column flotation. The column flotation is more efficient in comparison to the conventional cell for treating this sample. A process flowsheet was developed to treat these rejects based on the studies carried out. This process can minimize the waste generation and the concentrate generated during this process can be directly utilized in the Indian cement industries.

Metaplastic carcinoma of the breast with high grade spindle cell component with osteoid formation--a rare case report

Metaplastic carcinoma breast is rare entity with incidence of 0.02% of all breast malignancies. The ranges of age at diagnosis as well as clinical symptoms do not differ from that of conventional invasive ductal breast cancer. We are reporting a rare case diagnosed as metaplastic breast carcinoma on ultrasonography and confirmed histopathologically. The case merits presentation because of its rarity, low frequency of axillary metastasis and difficulty in interpreting the morphological features which correspond with prognosis.

Quantum nature of a nuclear phase transition

At finite temperatures and low densities, nuclei may undergo a phase change similar to a classical liquid-gas phase transition. Temperature is the control parameter while density and pressure are the conjugate variables. In the nucleus the difference between the proton and neutron concentrations acts as an additional order parameter, for which the symmetry potential is the conjugate variable. We present experimental results which reveal the N/Z dependence of the phase transition and discuss possible implications of these observations in terms of the Landau free energy description of critical phenomena.

Structure and microstructure evolution during martensitic transformation in wrought Fe–26Mn–0.14C austenitic steel: an effect of cooling rate

Structure and microstructure evolution under various cooling rates of a wrought austenitic steel, Fe–26Mn–0.14C (composition in mass %), were studied by the Rietveld method of X-ray diffraction pattern fitting, grain boundary characterization by electron back-scattered diffraction (EBSD) and optical microscopy. Cooling rate, density of stacking faults, and austenite grain size and grain boundaries influence the observed γfcc→ ∊hcptransformation and lead to significant anisotropic X-ray line broadening. Depending on the cooling conditions, the grain boundaries are misoriented at both lower and higher angles. In the ∊-martensites, the dominant planar fault is twins (∼10−3). The austenite grains were found to contain low to moderate density of stacking faults (∼10−4–10−3), which act as efficient nucleation sites of the ∊-martensites. Both X-ray and EBSD analyses estimated negligible twins in the austenite. Approximate average dislocation densities have been estimated and correlated with the grain structure.

Bainite and stress-induced martensite in an AISI type 300 steel: an X-ray diffraction study of the microstructure by the Rietveld method

The present study concerns the X-ray characterization of the microstructure of an AISI type 300 stainless steel with composition Fe–17Cr–8Ni–1Mn–0.1C (wt%), undergoing stress-induced martensite and bainite transformations following γ(f.c.c.) → α(b.c.c.) transformation reactions. The methodology applied is a Rietveld whole X-ray profile fitting technique, adopting the recently developed softwareMAUD(Materials Analysis Using Diffraction) which incorporates the Popa model for crystallite size and microstrain [root mean square (r.m.s.) strain] and the preferred orientation of the crystallites. The analysis also considers the lattice-defect-related features of the evolved microstructures, namely stacking-fault probabilities and dislocation-density values. The study revealed a high degree of stress-induced martensitic transformation (∼94%) in the cold-worked (hand-filed powder) state of the material. However, no low-temperature martensitic transformation could be observed in this class of materials at temperatures below the martensite start temperature (Ms). On isothermal aging at 673 K for different periods of time (1, 3 and 6 h), the austenite transforms partially into bainite with continuously varying volume fractions (17, 42 and 44%) and the corresponding microhardness values are 218, 230 and 233 kg mm−2. The size–strain–shape analysis adopting the Popa model reveals anisotropic and almost isotropic values of the crystallite sizes and r.m.s. strains in the austenite and bainite microstructures, respectively. High values of the dislocation density (∼1016 m−2) were observed in the bainite due to the plastic deformation of the austenite induced by the shape change of the growing bainite. The values of all the above defect parameters have been evaluated and compared in order to elucidate the structure–property relationships.

Effect of selenium deficiency on hepatic type I 5-iodothyronine deiodinase activity and hepatic thyroid hormone levels in the rat

Selenium deficiency in rats for a period of up to 6 weeks inhibited both the production of 3,3',5-tri-iodothyronine (T3) from thyroxine (T4) (5'-deiodination) and also the catabolism of T3 to 3,3'-di-iodothyronine (5-deiodination) in liver homogenates. The hepatic stores of T3 were decreased by only 8% in selenium deficiency, despite the T3 production rate from T4 being only 7% of the rate found in selenium-supplemented rats. Hepatic glutathione S-transferase (GST) activity was increased in both hypothyroidism and selenium deficiency, but apparently by different mechanisms, since mRNA expression for this family of enzymes was lowered by hypothyroidism and increased in selenium deficiency. It is concluded that, since both T3 production and catabolism are inhibited by selenium deficiency, there is little change in hepatic T3 stores, and therefore the changes in the activity of certain hepatic enzymes, such as GST, that are found in selenium deficiency are not the result of tissue hypothyroidism.