Recent Patents on Biotechnology - Volume 6, Issue 3, 2012

Research over the past two decades has implicated dysfunction of the ryanodine receptor (RyR), a Ca2+ release channel on the sarcoplasmic reticulum (SR) required for excitation-contraction (EC) coupling, in the pathogenesis of cardiac and skeletal myopathies. These discoveries have led to the development of novel drugs, screening tools, and research methods. The patents associated with these advances tell the story of the initial discovery of RyRs as a target for plant alkaloids, to their central role in cardiac and skeletal muscle excitation-contraction coupling, and ongoing clinical trials with a novel class of drugs called RycalsTM that inhibit pathological intracellular Ca2+ leak. Additionally, these patents highlight questions, controversies, and future directions of the RyR field.

Although some myokines exert their actions on other organs in a hormone-like fashion, many of them operate locally on skeletal muscle themselves. Myokines may thereby provide a feedback loop for the muscle to regulate its own growth and regeneration allowing for adaptation to exercise training. The myokine concept provides a conceptual basis and a whole new paradigm for understanding how muscles communicate with other organs within the muscle itself. New biotechnological patents are published based on the identification of new myokines, and these myokines and their receptors will potentially serve as pharmacological targets for treating muscle diseases, metabolic disorders and other diseases associated with muscle disuse.

Hyperthermia is an important approach for the treatment of several diseases. Hyperthermia is also thought to induce hypertrophy of skeletal muscles in vitro and in vivo, and has been used as a therapeutic tool for millennia. In the first part of our work, we revise several relevant patents related to the utilization of hyperthermia for the treatment and diagnostic of human diseases. In the second part, we present exciting new data on the effects of forced and natural overexpression of HSP72, using murine in vitro (muscle cells) and ex vivo (primary skeletal muscles) models. These studies help to demonstrate that hyperthermia effects are orchestrated by tight coupling between gene expression, protein function, and intracellular Ca2+ signaling pathways with a key role for calcium-induced calcium release. We hope that the review of current patents along with previous unknown information on molecular signaling pathways that underlie the hypertrophy response to hyperthermia in skeletal muscles may trigger the curiosity of scientists worldwide to explore new inventions that fully utilize hyperthermia for the treatment of muscle diseases.

Hyperkalemic periodic paralysis (HyperKPP) is a disease characterized by periods of myotonic discharges and paralytic attacks causing weakness, the latter associated with increases in plasma [K+]. The myotonic discharge is due to increased Na+ influx through defective Na+ channels that triggers generation of several action potentials. The subsequent increase in extracellular K+ concentration causes excessive membrane depolarization that inactivates Na+ channels triggering the paralysis. None of the available treatments is fully effective. This paper reviews the capacity of Na+ K+ATPase pumps, KATP and ClC-1 Cl- channels in improving membrane excitability during muscle activity and how using these three membrane components we can study future and more effective treatments for HyperKPP patients. The review of current patents related to HyperKPP reinforces the need of novel approaches for the treatment of this channelopathy.

Jatropha curcas (JC) is a multipurpose perennial plant that belongs to the Euphorbiaceae family and is native to arid and semiarid tropical regions worldwide. It has many attributes and considerable potential for renewable energy, fish and livestock feeding. Despite its rich application as a renewable source and for animal feeding, JC has barely been explored for its medicinal potential. Here we review several patents related to JC that show it has been underused for medicinal purposes. For example, only one invention disclosure to date utilizes JC, combined with three other plants, in a preparation for wound healing. Motivated by support from the Brazilian funding agencies and anecdotal accounts in Brazil of the medicinal value of JC, we performed a series of pilot studies that demonstrate that JC is able to protect skeletal muscle cells in vitro against the deleterious effects of ethanol. We were able to determine that JC's effects are mediated by the up regulation of HSP60, a critical mitochondrial heat shock related protein that is essential for intracellular REDOX regulation. Given the fact that ethanol myopathy accounts for more than 50% of all cases of myopathy worldwide, we hope that our studies will sparkle new interest from the scientific community to explore the medicinal properties of Jatropha curcas, including the development of new patents leading to new drugs and new targets for the treatment of muscle diseases and other human diseases.

Maintenance of the integrity of the plasma membrane is essential for maintenance of cellular function and prevention of cell death. Since the plasma membrane is frequently exposed to a variety of mechanical and chemical insults the cell has evolved active processes to defend against these injuries by resealing disruptions in the plasma membrane. Cell membrane repair is a conserved process observed in nearly every cell type where intracellular vesicles are recruited to sites of membrane disruption where they can fuse with themselves or the plasma membrane to create a repair patch. When disruptions are extensive or there is an underlying pathology that reduces the membrane repair capacity of a cell this defense mechanism may prove insufficient and the cell could die due to breakdown of the plasma membrane. Extensive loss of cells can compromise the integrity and function of tissues and leading to disease. Thus, methods to increase membrane resealing capacity could have broad utility in a number of disease states. Efforts to find reagents that can modulate plasma membrane reseal found that specific tri-block copolymers, such as poloxamer 188 (P188, or Pluronic F68), can increase the structural stability and resealing of the plasma membrane. Here we review several current patents and patent applications that present inventions making use of P188 and other copolymers to treat specific disease states such as muscular dystrophy, heart failure, neurodegenerative disorders and electrical injuries, or to facilitate biomedical applications such as transplantation. There appears to be promise for the application of poloxamers in the treatment of various diseases, however there are potential concerns with toxicity with long term application and bioavailability in some cases.

Magnesium (Mg2+) is used pharmacologically to sedate specific forms of arrhythmias. Administration of pharmacological doses of catecholamine or adrenergic receptor agonists often results in arrhythmias onset. Results from the present study indicate that stimulation of cardiac adrenergic receptors elicits an extrusion of cellular Mg2+ into the extracellular space. This effect occurs in both perfused hearts and isolated cells within 5-6 min following either β- or α1- adrenergic receptor stimulation, and is prevented by specific adrenergic receptors antagonists. Sequential stimulation of the two classes of adrenergic receptor results in a larger mobilization of cellular Mg2+ provided that the two agonists are administered together or within 1-2 min from each other. A longer delay in administering the second stimulus results in the abolishment of Mg2+ extrusion. Hence, these data suggest that the stimulation of β- and α1-adrenergic receptors mobilizes Mg2+ from two distinct cellular pools, and that Mg2+ loss from either pool triggers a Mg2+ redistribution within the cardiac myocyte. At the sarcolemmal level, Mg2+ extrusion occurs through a Na+/Mg2+ exchange mechanism phosphorylated by cAMP. Administration of quinidine, a patent anti-arrhythmic agent, blocks Na+ transport in a non-specific manner and prevents Mg2+ extrusion. Taken together, these data indicate that catecholamine administration induces dynamic changes in total and compartmentalized Mg2+ pools within the cardiac myocytes, and suggest that prevention of Mg2+ extrusion and redistribution may be an integral component of the effectiveness of quinidine and possibly other cardiac antiarrhythmic agents. Confirmation of this possibility by future experimental and clinical studies might result in new patents of these compounds as Mg2+ preserving agents.

Prostaglandin E2 (PGE2), a prostanoid synthesized from arachidonic acid via the cyclooxygenase pathway, is a modulator of physiological responses including inflammation, fever, and muscle regeneration. Several patents have been filed that are related to PGE2, one of them being directly related to skeletal muscles. In this report, we first summarize the key patents describing inventions for the utilization of PGE2 for either diagnostic or therapeutic purposes, including skeletal muscle. In the second part of our work we present new and exciting data that demonstrates that PGE2 accelerates skeletal muscle myogenic differentiation. Our discovery resulted from our recent and novel concept of bone-muscle crosstalk. Bone and muscle are anatomically intimate endocrine organs and we aimed to determine whether this anatomical intimacy also translates into a biochemical communication from bone cells to muscle cells at the in vitro level. The effects of MLOY4 osteocyte-like cell conditioned medium (CM) and three osteocyte-secreted factors, PGE2, sclerostin and monocyte chemotactic protein (MCP-3), on C2C12 myogenic differentiation were evaluated using morphological analyses, a customized 96-gene PCR array, and measurements of intracellular calcium levels. MLO-Y4 CM and PGE2, but not sclerostin and MCP-3, induced acceleration of myogenesis of C2C12 myoblasts that was linked with significant modifications in intracellular calcium homeostasis. This finding should further stimulate the pursuit of new patents to explore the use of PGE2 and the new concept of bone-muscle crosstalk for the development and application of inventions designed to treat muscle diseases characterized by enhanced muscle wasting, such as sarcopenia.

Genome-wide association study (GWAS) has become a commonly adopted approach for revealing the genetic architecture of complex diseases, with respect to uncovering the unknown genetic variants involved in the disease, their variations in the population and the magnitude of their effects. Though a substantial number of disease-susceptibility variants have been identified, the genetic architecture of complex diseases has remained elusive. It is unclear how many genetic variants in the human genome are associated with diseases, and how the genetic variants interact with one another to cause diseases. This challenge is partly due to the pervasive gene-gene interactions that underlie complex human diseases. Whereas a number of statistical methods have been developed for detecting gene-gene interactions, they are designed for various purposes, such as a particular study design, the order of the interactions being examined, and the measurement of disease phenotypes. This paper provides a survey of the currently available statistical methods and patents from the perspective of their application to various types of phenotypic traits. We also discuss the strength of each method as well as the biological interpretation of results.