Search Results (32)

The presence of hemoglobin beta mRNA and protein in the female gonad suggests that hemoglobin beta may be present in the male gonad as well. The frequent occurrence of hemoglobin beta in nonerythroid tissues with hypoxic environments further underscores a potential role for hemoglobin beta in the testis to facilitate the regulation of oxygen availability for the developing germ cells and Sertoli cells since they are separated from the blood supply by multiple tissues. The presence of mRNA and protein were evaluated by qPCR and immunohistochemistry, respectively. The mRNA and protein for hemoglobin were detected in juvenile and postpuberal porcine testes. The most intense immunolabelling for the protein was present in testicular interstitial cells, in contrast to previously reported ovarian labelling in close proximity to the gamete and observed in porcine ovaries in the current study. The observed decrease in mRNA expression of hemoglobin beta with age is probably due to the change in testicular composition (increase in seminiferous tubule compartment) with age. The localization of hemoglobin beta in the testis will contribute to future understanding of its potential function in facilitating oxygen availability to seminiferous tubules or reducing oxidative damage. Full article

Currently, various types of myoglobins and hemoglobins are widely used in the fields of food additives and biocatalytic applications. However, the limited availability of heme constrains the biosynthesis of these high-activity hemoproteins in microbial chassis cells. In this work, a new heme synthetic pathway was reconstructed in the mitochondria by eliminating the spatial barrier during heme synthesis in Saccharomyces cerevisiae, resulting in a significant enhancement in intracellular heme supply. To further enhance the supply of the essential precursor for heme synthesis (5-aminolevulinate, ALA), the special ALA exporter in the mitochondrial membrane (Ort1p) was identified and knocked out. Moreover, the mitochondrial heme exporter (Ygr127wp) was overexpressed to promote the transport of heme to the cytoplasm to participate in the synthesis of various myoglobins and hemoglobins. Based on these strategies in the engineered strain, the binding ratios of heme in porcine myoglobin (52.4 ± 4.9%) and soybean hemoglobin (75.5 ± 2.8%) were, respectively, increased by 2.4-fold and 3.6-fold, and the titers of porcine myoglobin (130.5 ± 2.8 mg·L⁻¹) and soybean hemoglobin (152.8 ± 2.6 mg·L⁻¹), respectively, increased by 31.1% and 42.1%. Furthermore, the engineered strain presents great potential in the efficient synthesis of other heme-binding proteins and enzymes in S. cerevisiae. Full article

Porcine blood is rich in protein and has always been the focus of research. Heme-peptides prepared from porcine hemoglobin are susceptible to oxidative degeneration during preparation and storage, thus affecting their function and stability. This study evaluated the enhancement effects of L-lysine (Lys) on recovery rate, antioxidant activity, stability, and structure. The results indicated that adding 1% Lys during enzymatic hydrolysis significantly increased the recovery rate of ferrous heme and peptide content by 93.88% and 15.30% (p < 0.05), respectively, and maximally enhanced antioxidant activity by 37.85% (p < 0.05). The contents of iron, ferrous ion, and ferrous heme in the heme-peptides were significantly increased by 97.52%, 121. 97%, and 74.45% (p < 0.05), respectively. Additionally, Lys improved the resistance to pH, temperature, metal ions, pepsin, and trypsin. Meanwhile, the effects of Lys resulted in heme-peptides with a smaller particle size, higher zeta potentials, and a smoother micromorphology. Fourier-transform infrared spectroscopy and fluorescence spectroscopy analysis showed that Lys enhanced the conformational stability of the heme-peptides. Molecular docking further suggested that hydrogen bonding was the main driver of the connections between Lys and the heme-peptides. This study provides theoretical guidance for the efficient utilization of heme-peptides in the food industry. Full article

The use of animal by-products to produce bioactive peptides is a promising and sustainable approach in the food and nutrition industry. Meat by-products can be used as a key raw material for the production of high-value-added components, such as bioactive peptides, to ensure sustainability. Porcine livers and hearts classified as category three by-products were selected for the study, together with those intended for human consumption, in which no changes were observed after veterinary post-mortem examination. Hydrolysis was performed at three different times 3 h, 6 h, and 24 h, using pepsin and papain. The influence of different hydrolysis times and enzymes on the degree of hydrolysis (DH) value was determined. The highest value of DH was found in porcine hearts after 24 h following hydrolysis with pepsin enzymes (33.56 ± 0.31). The antiradical activity was assessed by measuring the absorbance of DPPH• and ABTS•+ in hydrolysates obtained from porcine meat by-products. Porcine livers hydrolysates treated with papain for 24 h showed the highest radical scavenging abilities ABTS•+ (97.2 ± 1.79%) and DPPH• (92.07 ± 2.23%). The identification and quantification of peptides from porcine livers and hearts were conducted using SWATH-MS technology. The most abundant peptides that showed a relationship with antioxidant capacity were WGKVNVDEVGGEALGRL, WGKVNVDEVGGEAL, and GLWGKVNVDEVGGEALGRL from beta hemoglobin. Full article

Background/Objectives: Iron-fortified foods reduce the incidence of iron deficiency anemia. However, the nutritional efficacy of heme iron fortificants is unclear. Methods: In this study, we determined the hemoglobin regeneration efficiency (HRE) of a porcine-derived heme iron powder (HIP), treating anemic rats (hemoglobin (Hb) 3–6 g/dL) with 14-day repletion diets fortified with four different concentrations (12, 24, 36, or 48 mg iron/kg diets) of HIP or a control diet (“no added iron”); n = 9–12/group. Results: Our results demonstrate an inverse association between HRE and increasing dietary iron from the HIP. The HRE ratios of diets containing the HIP powder at 12, 24, 36, or 48 mg iron/kg were 0.508, 0.268, 0.273, and 0.223, respectively. Based on the mean final Hb values at 14 d, the HRE ratio of the 12 mg iron/kg diet was significantly higher (p ≤ 0.05) compared to the other HIP diet groups; however, only the HIP provided in the 36 and 48 mg iron/kg diets restored hemoglobin to high enough levels (mean Hb > 6 g/dL) to correct anemia. Conclusions: Our findings show that HIP at each of the concentrations tested increased Hb; moreover, when present at higher concentrations in the diet, the HIP is capable of restoring hemoglobin to resolve iron deficiency anemia. Full article

Research into mosquito-borne illnesses faces hurdles because feeding fresh animal blood to rear female mosquitoes presents logistical, economic, and safety challenges. In this study, a shelf-stable additive (spray-dried porcine blood; SDPB) hypothesized to supply accessible hemoglobin was evaluated within an alternative meal (AM) containing whey powder and PBS for rearing the yellow fever mosquito Aedes aegypti. LC–MS/MS proteomics, microbial assays, and particle reduction techniques confirmed and characterized the functionality of hemoglobin in SDPB, while engorgement, fecundity, egg viability, and meal stability bioassays assessed AM performance. Chemical assays supported hemoglobin as the phagostimulant in SDPB with aggregates partially solubilized in the AM that can be more accessible via particle reduction. Unpaired two-tailed t-tests indicate that the AM stimulates oogenesis (t₁₁ = 13.6, p = 0.003) and is stable under ambient (1+ y; t₁₂ = 0.576, p = 0.575) and aqueous (14 d; t₁₂ = 0.515, p = 0.639) conditions without decreasing fecundity. Egg hatch rates for the ninth generation of AM-reared Ae. aegypti were 50–70+%. With further development, this meal may serve as a platform for mass rearing or studying effects of nutritional additives on mosquito fitness due to its low cost and stability. Future work may examine tuning spray drying parameters and resulting impacts on hemoglobin agglomeration and feeding. Full article

Listeria monocytogenes is a foodborne pathogen that represents a serious concern for ready-to-eat (RTE) meat products due to its persistence in production facilities. Among the different strategies for the control of this pathogen, the use of antimicrobial peptides derived from food by-products, such as slaughterhouse blood proteins, has emerged as a promising biocontrol strategy. This study evaluated for the first time the use of peptic hydrolysates of porcine hemoglobin as a biocontrol strategy of L. monocytogenes in RTE pork cooked ham. Pure porcine hemoglobin (Hb-P) and porcine cruor (P-Cru) were hydrolyzed using pepsin at different temperatures (37 °C for Hb-P and 23 °C for P-Cru) for 3 h. Then, the hydrolysates were characterized in terms of their degree of hydrolysis (DH), peptide population, color, and antimicrobial activity (in vitro and in situ) against three different serotypes of L. monocytogenes. Reducing the hydrolysis temperature of P-Cru by 14 °C resulted in a 2 percentage unit decrease in DH and some differences in the peptide composition. Nevertheless, the antimicrobial activity (in situ) was not significantly impacted, decreasing the viable count of L. monocytogenes by ~1-log and retarding their growth for 21 days at 4 °C. Although the color of the product was visibly altered, leading to more saturated reddish and yellowish tones and reduced brightness, the discoloration of the hydrolysates can be addressed. This biopreservation approach holds promise for other meat products and contributes to the circular economy concept of the meat industry by valorizing slaughterhouse blood and producing new antilisterial compounds. Full article

Background: This study was conducted to confirm the reliability of an in vitro mechanically induced hemolysis test (ISO 10993-4:2017), which is essential for ensuring the safety of blood pumps. Methods: For appropriate anticoagulant selection, porcine blood was prepared in anticoagulant citrate dextrose solution A (ACD-A), heparin, and citrate phosphate dextrose adenine (CPDA-1), respectively, according to the ASTM F1830 standard. Anticoagulant-treated porcine and bovine blood were circulated in a mock circulatory loop (MCL) for 6 h to observe the rate of plasma-free hemoglobin (pfHb) and RBCs with morphological integrity. Results: A morphological loss of red blood cells (RBCs) was observed over time. While there were differences in morphological loss depending on the anticoagulant, no consistent trend could be identified. The pfHb concentration was significantly higher in bovine than in porcine blood. Conversely, the number of RBCs with morphological integrity decreased over time in both, but the ratio of RBCs with morphological integrity was similar across all timepoints. Conclusions: The percentage of RBCs with morphological integrity can be used as a reliable indicator for the interpretation of mechanically induced hemolysis results in different blood types. Furthermore, the reliability of the in vitro mechanically induced hemolysis test (ISO 10993-4:2017) was assessed. Full article

Mammalian hemoglobins (HB) are a kind of heme-binding proteins that play crucial physiological roles in various organisms. The traditional techniques employed for the extraction of HB are expensive and time-consuming, while the yields of mammalian HB in previous reports were quite low. The industrial Pichia pastoris is a highly effective platform for the secretory expression of heterologous proteins. To achieve efficient secretory expression of HB in P. pastoris, multiple strategies were applied, including the selection of a suitable host, the screening of optimal endogenous signal peptides, the knockout of VPS10, VTH1, and PEP5, and the co-expression of Alpha-Hemoglobin Stabilizing Protein (AHSP). In addition, the conditions for producing HB were optimized at shaking-flask level (BMMY medium with 100 mg/L of hemin, 2% methanol, and 24 °C). Based on these conditions, the higher titers of bovine hemoglobin (bHB, 376.9 ± 13.3 mg/L), porcine hemoglobin (pHB, 119.2 ± 7.3 mg/L), and human hemoglobin (hHB, 101.1 ± 6.7 mg/L) were achieved at fermenter level. The engineered P. pastoris strain and comprehensive strategies can also be applied to facilitate the synthesis of other high-value-added hemoproteins or hemoenzymes. Full article

Acquired Hemophilia A (AHA) is a rare autoimmune disorder characterized by the onset of a sudden and unexpected bleeding episode in a patient with no personal or family history of bleeding diathesis, and with a typical laboratory feature, i.e., a prolonged activated partial thromboplastin time that is not otherwise explained. This bleeding disorder is caused by autoantibodies directed against the coagulation factor VIII (FVIII). AHA is idiopathic in 50% of cases and is secondary to well-defined diseases in the remaining 50%. AHA affects elderly patients although it has also been observed in the post-partum period. Bleeding manifestations are heterogeneous, ranging from mild to life-threatening bleeds involving limbs and organs. Severe bleeding with a significant decrease in hemoglobin levels must be promptly and adequately treated in order to avoid a worsening of the hemorrhages and their complications. According to international recommendations, the bypass agents (i.e., activated prothrombin complex concentrate and activated recombinant factor VII) and the replacement therapy with recombinant porcine FVIII are considered as the first-line therapy for bleeding control, due to their proven clinical efficacy. Plasma-derived or recombinant FVIII concentrates could be used as second-line treatments. Emicizumab may represent a valid and interesting therapeutic option for prophylaxis of bleeding recurrences. Full article

Membrane artificial lungs (oxygenators) are used in cardiopulmonary surgery as well as, in some cases, in severe lung disease to support the natural lung by means of ECMO (extracorporeal membrane oxygenation). The oxygen and carbon dioxide transfer rates of any oxygenator are usually assessed by considering several blood gas parameters, such as oxygen saturation, hemoglobin concentration, partial pressure of oxygen and carbon dioxide, bicarbonate concentration, and $pH$. Here, we report a set of semi-empirical equations that calculate such parameters directly from their partial pressures and assess the acid–base balance during ECMO. The implementation of this equation set permits the evaluation of any oxygenator, existing or prototypes in development, as well as the development of clinical decision-making tools for predicting the blood gas state and acid–base balance during surgical interventions and ECMO. The predicted results are then compared with experimental data obtained from in vitro gas exchange investigations with a commercial oxygenator using fresh porcine blood. The high correlation, $R^2>0.95$, between the predicted and the experimental data suggests a possibility of using such empirical equations in the simulation of gas transfer in a cardiopulmonary system with an oxygenator for any venous inlet blood gas data and also for estimating the acid–base balance during such therapy. Full article

The role of the yolk sac (YS) in miscarriage is not yet clear, largely due to ethical reasons that make in vivo studies difficult to conduct. However, 3D cultures could provide a solution to this problem by enabling cells to be arranged in a way that more closely mimics the structure of the YS as it exists in vivo. In this study, three domestic species (porcine, canine, and bovine) were chosen as models to standardize 3D culture techniques for the YS. Two techniques of 3D culture were chosen: the Matrigel^® and Hanging-Drop techniques, and the 2D culture technique was used as a standardized method. The formed structures were initially characterized using scanning electron microscopy (SEM), immunohistochemistry (IHC), and quantitative real-time PCR (RT-qPCR). In general, the 3D culture samples showed better organization of the YS cells compared to 2D cultures. The formed structures from both 3D methods assemble the mesothelial layer of YS tissue. Regarding the IHC assay, all in vitro models were able to express zinc and cholesterol transport markers, although only 3D culture techniques were able to generate structures with different markers pattern, indicating a cell differentiation process when compared to 2D cultures. Regarding mRNA expression, the 3D models had a greater gene expression pattern on the Hemoglobin subunit zeta-like (HBZ) gene related to the YS tissue, although no significant expression was found in Alpha-fetoprotein (AFP), indicating a lack of endodermal differentiation in our 3D model. With the initial technique and characterization established, the next step is to maintain the cultures and characterize the diversity of cell populations, stemness, functions, and genetic stability of each 3D in vitro model. Full article

This article discusses how to monitor the freezing depth during cryotherapy using a fiber optic array sensor. The sensor was used to measure the backscattered and transmitted light from frozen and unfrozen ex vivo porcine tissue and in vivo human skin tissue (finger). The technique exploited the variations in optical diffusion properties of the frozen and unfrozen tissues to determine the extent of freezing. Ex vivo and in vivo measurements yielded comparable results, despite spectral variations attributable to the hemoglobin absorption peak in the human frozen and unfrozen tissues. However, because the spectral fingerprints of the freeze-thaw process in the ex vivo and in vivo experiments were similar, we could extrapolate the maximum depth of freezing. Therefore, this sensor has the potential to be utilized for monitoring cryosurgery in real time. Full article

The adsorption of proteins on surfaces has been studied for a long time, but the relationship between the structural and functional properties of the adsorbed protein and the adsorption mechanism remains unclear. Using hemoglobin adsorbed on silica nanoparticles, we have previously shown that hemoglobin’s affinity towards oxygen increases with adsorption. Nevertheless, it was also shown that there were no significant changes in the quaternary and secondary structures. In order to understand the change in activity, we decided in this work to focus on the active sites of hemoglobin, the heme and its iron. After measuring adsorption isotherms of porcine hemoglobin on Ludox silica nanoparticles, we analyzed the structural modifications of adsorbed hemoglobin by X-ray absorption spectroscopy and circular dichroism spectra in the Soret region. It was found that upon adsorption, there were modifications in the heme pocket environment due to changes in the angles of the heme vinyl functions. These alterations can explain the greater affinity observed. Full article

Background: The early identification of internal hemorrhage in critically ill patients may be difficult. Besides circulatory parameters, hemoglobin and lactate concentration, metabolic acidosis and hyperglycemia serve as laboratory markers for bleeding. In this experiment, we examined pulmonary gas exchange in a porcine model of hemorrhagic shock. Moreover, we sought to investigate if a chronological order of appearance regarding hemoglobin, lactatemia, standard base excess/deficit (SBED) and hyperglycemia exists in early severe hemorrhage. Methods: In this prospective, laboratory study, twelve anesthetized pigs were randomly allocated to exsanguination or a control group. Animals in the exsanguination group (n = 6) endured a 65% blood loss over 20 min. No intravenous fluids were administered. Measurements were taken before, immediately after, and at 60 min after the completed exsanguination. Measurements included pulmonary and systemic hemodynamic variables, hemoglobin concentration, lactate, base excess (SBED), glucose concentration, arterial blood gases, and a multiple inert gas assessment of pulmonary function. Results: At baseline, variables were comparable. Immediately after exsanguination, lactate and blood glucose were increased (p = 0.001). The arterial partial pressure of oxygen was increased at 60 min after exsanguination (p = 0.04) owing to a decrease in intrapulmonary right-to-left shunt and less ventilation-perfusion inequality. SBED was different to the control only at 60 min post bleeding (p < 0.001). Hemoglobin concentration did not change at any time (p = 0.97 and p = 0.14). Conclusions: In experimental shock, markers of blood loss became positive in chronological order: lactate and blood glucose concentrations were raised immediately after blood loss, while changes in SBED lagged behind and became significant one hour later. Pulmonary gas exchange is improved in shock. Full article