Therapeutic compositions and uses of alpha1-antitrypsin: a patent review (2012 – 2015)

Local Alpha1-Antitrypsin Accelerates the Healing of Tympanic Membrane Perforation in Mice

BACKGROUND

Most tympanic membrane (TM) perforations heal spontaneously, but 10%-20% remain chronic and might lead to impaired hearing and recurrent middle ear infections. Alpha1-antitrypsin (AAT) is a circulating tissue-protective protein that is elevated under inflammatory conditions and is currently indicated for genetic AAT deficiency. Recently, AAT has been shown to promote tissue remodeling and inflammatory resolution.

OBJECTIVE

This study aimed to examine the effects of local clinical-grade AAT treatment on tissue repair in a mouse model of acute traumatic TM perforation.

METHODS

Wild-type mice underwent unilateral TM perforation and were either left untreated or treated locally with human AAT (9 × 10-3 mL at 20 mg/mL on days 0, 1, and 2; n = 15/group). The perforations were evaluated macroscopically on a serial basis. Mice were sacrificed on various days post-injury, and TMs were excised for gene analysis by RT-PCR.

RESULTS

There were no adverse reactions in hAAT-treated ears throughout the study period. Compared with untreated animals, TM closure occurred earlier in the treated group (days until full closure, median: 4 and 9, respectively). According to gene expression analysis, VEGF, TGFβ, and collagen-5A1 were induced earlier in AAT-treated mice (day 4-5 compared with day 9). Additionally, IL-10 expression levels were higher and IL-6 levels were lower in treated versus untreated mice.

CONCLUSION

A local tissue environment rich in AAT promotes early tissue repair in a perforated TM model both macroscopically and molecularly. Studies are underway to examine TM functionality and recombinant AAT formulations for micro-dosing in the format of a single local application.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:3802-3806, 2024.

Alpha1-antitrypsin improves survival in murine abdominal sepsis model by decreasing inflammation and sequestration of free heme

Background

Excessive inflammation, hemolysis, and accumulation of labile heme play an essential role in the pathophysiology of multi-organ dysfunction syndrome (MODS) in sepsis. Alpha1-antitrypsin (AAT), an acute phase protein with heme binding capacity, is one of the essential modulators of host responses to inflammation. In this study, we evaluate the putative protective effect of AAT against MODS and mortality in a mouse model of polymicrobial abdominal sepsis.

Methods

Polymicrobial abdominal sepsis was induced in C57BL/6N mice by cecal ligation and puncture (CLP). Immediately after CLP surgery, mice were treated intraperitoneally with three different forms of human AAT-plasma-derived native (nAAT), oxidized nAAT (oxAAT), or recombinant AAT (recAAT)-or were injected with vehicle. Sham-operated mice served as controls. Mouse survival, bacterial load, kidney and liver function, immune cell profiles, cytokines/chemokines, and free (labile) heme levels were assessed. In parallel, in vitro experiments were carried out with resident peritoneal macrophages (MPMΦ) and mouse peritoneal mesothelial cells (MPMC).

Results

All AAT preparations used reduced mortality in septic mice. Treatment with AAT significantly reduced plasma lactate dehydrogenase and s-creatinine levels, vascular leakage, and systemic inflammation. Specifically, AAT reduced intraperitoneal accumulation of free heme, production of cytokines/chemokines, and neutrophil infiltration into the peritoneal cavity compared to septic mice not treated with AAT. In vitro experiments performed using MPMC and primary MPMΦ confirmed that AAT not only significantly decreases lipopolysaccharide (LPS)-induced pro-inflammatory cell activation but also prevents the enhancement of cellular responses to LPS by free heme. In addition, AAT inhibits cell death caused by free heme in vitro.

Conclusion

Data from the septic CLP mouse model suggest that intraperitoneal AAT treatment alone is sufficient to improve sepsis-associated organ dysfunctions, preserve endothelial barrier function, and reduce mortality, likely by preventing hyper-inflammatory responses and by neutralizing free heme.

Accelerated Wound Border Closure Using a Microemulsion Containing Non-Inhibitory Recombinant α1-Antitrypsin

Wound healing requires a non-compromising combination of inflammatory and anti-inflammatory processes. Human α1-antitrypsin (hAAT), a circulating glycoprotein that rises during acute-phase responses and during healthy pregnancies, is tissue-protective and tolerance-inducing; although anti-inflammatory, hAAT enhances revascularization. hAAT blocks tissue-degrading enzymes, including neutrophil elastase; it is, therefore, unclear how wound healing might improve under hAAT-rich conditions. Here, wound healing was examined in the presence of recombinant hAAT (hAAT^WT) and protease-inhibition-lacking hAAT (hAAT^CP). The impact of both hAAT forms was determined by an epithelial cell gap closure assay, and by excisional skin injuries via a microemulsion optimized for open wounds. Neutrophilic infiltration was examined after 8 h. According to results, both hAAT forms accelerated epithelial gap closure and excisional wound closure, particularly at early time points. Unlike dexamethasone-treated wounds, both resulted in closed borders at the 8-h time point. In untreated and hAAT^CP-treated wounds, leukocytic infiltrates were widespread, in hAAT^WT-treated wounds compartmentalized and in dexamethasone-treated wounds, scarce. Both hAAT forms decreased interleukin-1β and increased VEGF gene expression. In conclusion hAAT improves epithelial cell migration and outcomes of in vivo wounds irrespective of protease inhibition. While both forms of hAAT allow neutrophils to infiltrate, only native hAAT created discrete neutrophilic tissue clusters.

Development of anti-inflammatory peptidomimetics based on the structure of human alpha1-antitrypsin

Human α1-antitrypsin (hAAT) has two distinguishing functions: anti-protease activity and regulation of the immune system. In the present study we hypothesized that those two protein functions are mediated by different structural domains on the hAAT surface. Indeed, such biologically active immunoregulatory sites (not associated with canonical anti-protease activity) on the surface of hAAT were identified by in silico methods. Several peptides were derived from those immunoregulatory sites. Four peptides exhibited impressive biological effects in pharmacological concentration ranges. Peptidomimetic (14) was developed, based on the structure of the most druggable and active peptide. The compound exhibited a potent anti-inflammatory activity in vitro and in vivo. Such a compound could be used as a basis for developing novel anti-inflammatory drug candidates and as a research tool for better understanding hAAT functions.

Inhaled Biologicals for the Treatment of Cystic Fibrosis

Background:

Cystic Fibrosis (CF), one of the most frequent genetic diseases, is characterized by the production of viscous mucus in several organs. In the lungs, mucus clogs the airways and traps bacteria, leading to recurrent/resistant infections and lung damage. For cystic fibrosis patients, respiratory failure is still lethal in early adulthood since available treatments display incomplete efficacy.

Objective:

The objective of this review is to extend the current knowledge in the field of available treat-ments for cystic fibrosis. A special focus has been given to inhaled peptide-based drugs.

Methods:

The current review is based on recent and/or relevant literature and patents already available in various scientific databases, which include PubMed, PubMed Central, Patentscope and Science Direct. The information obtained through these diverse databases is compiled, critically interpreted and presented in the current study. An in-depth but not systematic approach to the specific research question has been adopted.

Results:

Recently, peptides have been proposed as possible pharmacologic agents for the treatment of respiratory diseases. Of note, peptides are suitable to be administered by inhalation to maximize efficacy and reduce systemic side effects. Moreover, innovative delivery carriers have been developed for drug administration through inhalation, allowing not only protection against proteolysis, but also a prolonged and controlled release.

Conclusion:

Here, we summarize newly patented peptides that have been developed in the last few years and advanced technologies for inhaled drug delivery to treat cystic fibrosis.

Challenges in diabetology research in India

BACKGROUND

Diabetes emerges out to be a major epidemic in recent years that engulfs both developed and developing countries across the globe. India, a country witnessing rapid socioeconomic progress and urbanization carries a considerable share of the global diabetes burden. There has been an incongruity between disease burden and the technical capacity to make use of existing knowledge or to generate new knowledge to combat diabetes in India.

AIM

This paper examines the role of different actors, organizations & institutions in shaping diabetology research in India using arrays of scientific indicators such as research output (publications and patents), research finance and role of policy-making bodies. This paper also identifies research gaps and challenges pertinent to this sector.

METHODOLOGY

A combination of three methods patent data analysis, publication data analysis and primary survey corroborated with secondary data to obtain desire objectives. We made an in-depth study of the patent and publication data (2000-2016) to know the research output and direction of Indian actors, institutions and organizations in the area of diabetes research.

RESULTS

This paper identifies some key structural barriers and institutional challenges pertinent to diabetology research in India that will help in canvassing and formulating science, technology and policy guidelines for diabetology research in India CONCLUSION: Multilevel intervention requires bridging the gap between knowledge and action hence policy-making should align to balance resources with innovation capabilities.

Point Mutation of a Non-Elastase-Binding Site in Human α1-Antitrypsin Alters Its Anti-Inflammatory Properties

Introduction

Human α1-antitrypsin (hAAT) is a 394-amino acid long anti-inflammatory, neutrophil elastase inhibitor, which binds elastase via a sequence-specific molecular protrusion (reactive center loop, RCL; positions 357-366). hAAT formulations that lack protease inhibition were shown to maintain their anti-inflammatory activities, suggesting that some attributes of the molecule may reside in extra-RCL segments. Here, we compare the protease-inhibitory and anti-inflammatory profiles of an extra-RCL mutation (cys232pro) and two intra-RCL mutations (pro357cys, pro357ala), to naïve [wild-type (WT)] recombinant hAAT, in vitro, and in vivo.

Methods

His-tag recombinant point-mutated hAAT constructs were expressed in HEK-293F cells. Purified proteins were evaluated for elastase inhibition, and their anti-inflammatory activities were assessed using several cell-types: RAW264.7 cells, mouse bone marrow-derived macrophages, and primary peritoneal macrophages. The pharmacokinetics of the recombinant variants and their effect on LPS-induced peritonitis were determined in vivo.

Results

Compared to WT and to RCL-mutated hAAT variants, cys232pro exhibited superior anti-inflammatory activities, as well as a longer circulating half-life, despite all three mutated forms of hAAT lacking anti-elastase activity. TNFα expression and its proteolytic membranal shedding were differently affected by the variants; specifically, cys232pro and pro357cys altered supernatant and serum TNFα dynamics without suppressing transcription or shedding.

Conclusion

Our data suggest that the anti-inflammatory profile of hAAT extends beyond direct RCL regions. Such regions might be relevant for the elaboration of hAAT formulations, as well as hAAT-based drugs, with enhanced anti-inflammatory attributes.

The impact of alpha-1 antitrypsin augmentation therapy on neutrophil-driven respiratory disease in deficient individuals

Alpha-1 antitrypsin (AAT) is the most abundant serine protease inhibitor circulating in the blood. AAT deficiency (AATD) is an autosomal codominant condition affecting an estimated 3.4 million individuals worldwide. The clinical disease associated with AATD can present in a number of ways including COPD, liver disease, panniculitis and antineutrophil cytoplasmic antibody vasculitis. AATD is the only proven genetic risk factor for the development of COPD, and deficient individuals who smoke are disposed to more aggressive disease. Principally, AAT is a serine protease inhibitor; however, over the past number of years, the assessment of AAT as simply an antiprotease has evolved, and it is now recognized that AAT has significant anti-inflammatory properties affecting a wide range of cells, including the circulating neutrophil.

Protean proteases: at the cutting edge of lung diseases

Proteases were traditionally viewed as mere protein-degrading enzymes with a very restricted spectrum of substrates. A major expansion in protease research has uncovered a variety of novel substrates, and it is now evident that proteases are critical pleiotropic actors orchestrating pathophysiological processes. Recent findings evidenced that the net proteolytic activity also relies upon interconnections between different protease and protease inhibitor families in the protease web.In this review, we provide an overview of these novel concepts with a particular focus on pulmonary pathophysiology. We describe the emerging roles of several protease families including cysteine and serine proteases.The complexity of the protease web is exemplified in the light of multidimensional regulation of serine protease activity by matrix metalloproteases through cognate serine protease inhibitor processing. Finally, we will highlight how deregulated protease activity during pulmonary pathogenesis may be exploited for diagnosis/prognosis purposes, and utilised as a therapeutic tool using nanotechnologies.Considering proteases as part of an integrative biology perspective may pave the way for the development of new therapeutic targets to treat pulmonary diseases related to intrinsic protease deregulation.

Exploration of α1-antitrypsin treatment protocol for islet transplantation: dosing plan and route of administration

Lifelong weekly infusions of human α1-antitrypsin (hAAT) are currently administered as augmentation therapy for patients with genetic AAT deficiency (AATD). Several recent clinical trials attempt to extend hAAT therapy to conditions outside AATD, including type 1 diabetes. Because the endpoint for AATD is primarily the reduction of risk for pulmonary emphysema, the present study explores hAAT dose protocols and routes of administration in attempt to optimize hAAT therapy for islet-related injury. Islet-grafted mice were treated with hAAT (Glassia; intraperitoneally or subcutaneously) under an array of clinically relevant dosing plans. Serum hAAT and immunocyte cell membrane association were examined, as well as parameters of islet survival. Results indicate that dividing the commonly prescribed 60 mg/kg i.p. dose to three 20 mg/kg injections is superior in affording islet graft survival; in addition, a short dynamic descending dose protocol (240→120→60→60 mg/kg i.p.) is comparable in outcomes to indefinite 60 mg/kg injections. Although pharmacokinetics after intraperitoneal administration in mice resembles exogenous hAAT treatment in humans, subcutaneous administration better imitated the physiologic progressive rise of hAAT during acute phase responses; nonetheless, only the 60 mg/kg dose depicted an advantage using the subcutaneous route. Taken together, this study provides a platform for extrapolating an islet-relevant clinical protocol from animal models that use hAAT to protect islets. In addition, the study places emphasis on outcome-oriented analyses of drug efficacy, particularly important when considering that hAAT is presently at an era of drug-repurposing toward an extended list of clinical indications outside genetic AATD.